Mini-Orals: Translational Research, Innovation, Predictive Modeling
Activity: Mitral Conclave 2023
Stanford University
Stanford, CA
United States - Contact Me
Joseph Woo, M.D. serves as the Norman E. Shumway Professor and Chair of the Department of Cardiothoracic Surgery at Stanford University and holds a courtesy appointment in the Department of Bioengineering. He received his undergraduate degree from the Massachusetts Institute of Technology and his M.D. from the University of Pennsylvania where he also conducted his postgraduate surgical training in general surgery and cardiothoracic surgery as well as a postdoctoral research fellowship developing novel molecular strategies for attenuating myocardial ischemic injury. Dr. Woo has an active clinical practice of 300 pump cases/year focusing on complex cardiac valve repair, aortic surgery, cardiopulmonary transplantation, and minimally-invasive surgery, and has advanced these fields by developing several innovative operations. Dr. Woo currently runs an NIH R01-funded basic science research lab studying stem cells, angiogenesis, tissue engineering, and valvular biomechanics and has held continuous NIH funding since 2004. He has also served as PI for several clinical device trials as well as translational scientific clinical trials entailing administration of stem cells during coronary artery bypass grafting and LVAD implantation. He has co-authored over 300 peer-reviewed publications.
Nationally, Dr. Woo serves on the Board of Directors of the American Association for Thoracic Surgery and as Associate Editor for the Journal of Thoracic and Cardiovascular Surgery.
JOHNS HOPKINS
North Bethesda, MD
United States - Contact Me
Niv Ad, MD
A cardiac surgeon at White Oak Medical center in Maryland and an adjunct professor of Surgery at the Johns Hopkins University. Dr. Ad is the past president of The International Society for Minimally Invasive Cardiothoracic and Vascular Surgery (ISMICS) the Editor in Chief of INNOVATIONS.
Dr. Ad’s research is focused on Atrial Fibrillation, patients’ outcome and minimally invasive valve surgery and techniques. He led numerous clinical trials and is very well published in the field.
Beaumont Royal Oak Medical Center
Royal Oak, MI
United States - Contact Me
Rakesh M. Suri, MD, DPhil. leads the mitral valve repair and robotic cardiac programs at William Beaumont University Hospital, Corewell Health East. He focuses on pre-emptive care of patients with asymptomatic mitral valve prolapse, including robotic, surgical and transcatheter valve therapies.
In his prior role, he served as the first President of International Operations at the Cleveland Clinic leading international strategy and global business development efforts. From 2017-2021, Dr. Suri led Cleveland Clinic Abu Dhabi as President and Chief Executive Officer and served as Executive Team member of the Cleveland Clinic Enterprise. He oversaw the hospital’s strategy and effective operations as the first-ever U.S. multispecialty hospital to be replicated outside of North America. He led the team towards financial sustainability, improving revenue and decreasing costs while delivering outcomes that led to the hospital being ranked amongst Newsweek top 150 hospitals globally.
Prior to the Cleveland Clinic, Dr. Suri was a consultant in the Division of Cardiovascular Surgery, Professor of Surgery and Chair of the Enterprise Robotic Practice at Mayo Clinic. His academic pursuits include contributions to more than 340 peer-reviewed journal articles and book chapters, more than 15 patents and several FDA multicenter trials. He was the Director of the Cardiovascular Fellowship Program at Mayo Clinic and past President of the Heart Valve Society.
Dr. Suri earned his undergraduate degree at Queen’s University in Kingston, Ontario, Canada, medical degree with honors from the University of Toronto and a doctorate at Magdalen College, Oxford, UK, as a Rhodes Scholar. He completed thoracic surgical residency at Mayo Clinic College of Medicine and is board-certified in both General Surgery and Cardiothoracic Surgery.
Friday, May 5, 2023: 7:00 AM - 8:30 AM
New York Hilton Midtown
Posted Room Name: Petit Trianon
Presentations
MO56. Upregulation of Left Atrial SLN and CTGF Gene Expression in Porcine Models of Mitral Regurgitation
Total Time: 5 Minutes
Objective: Sarcolipin (SLN) is a regulator of the atrial sarcoplasmic reticulum Ca2+-ATPase, and Connective Tissue Growth Factor (CTGF) is a promoter of myocardial remodeling. Their expression in the diseased left atrium (LA) remains unclearly defined. The aim of this study was to evaluate their involvement in LA remodeling in porcine models of mitral regurgitation (MR).
Methods: Eighteen Yorkshire pigs (all female, 37.6±5.4 kg) were enrolled in this study. MR was induced in 13 Yorkshire pigs using catheter-based procedures. Six pigs underwent simultaneous occlusions of the left circumflex artery and the diagonal branch, which resulted in ischemic MR (IMR group) due to bulging of the left ventricular (LV) lateral wall. The other seven pigs underwent chordal severing to induce leaflet prolapse simulating degenerative MR (DMR group). Three months after model creation, animals were sacrificed and the expression of SLN and CTGF in LA was assessed with quantitative PCR. Five normal pigs underwent the same assessment (Sham group).
Results: Echocardiography showed that LV end-diastolic and end-systolic volume indexes, maximum and minimum LA volume indexes were significantly larger in the IMR group than the other two groups. LV ejection fraction, longitudinal and circumferential strain, LA emptying function and reservoir strain were significantly impaired in the IMR group than the other two groups. LA SLN and CTGF expressions were both significantly upregulated in the IMR group compared to the Sham group, and had significant correlation with LA reservoir strain and LV end-diastolic volume index, respectively (Figure). The DMR group showed the same trends in echocardiographic and gene expression data as the IMR group, while there was no statistical significance compared to the Sham group.
Conclusions: Ischemic MR resulted in an exaggerated LA remodeling with significant upregulation of SLN and CTGF in the LA. These genes might serve as possible therapeutic targets for LA remodeling.
Methods: Eighteen Yorkshire pigs (all female, 37.6±5.4 kg) were enrolled in this study. MR was induced in 13 Yorkshire pigs using catheter-based procedures. Six pigs underwent simultaneous occlusions of the left circumflex artery and the diagonal branch, which resulted in ischemic MR (IMR group) due to bulging of the left ventricular (LV) lateral wall. The other seven pigs underwent chordal severing to induce leaflet prolapse simulating degenerative MR (DMR group). Three months after model creation, animals were sacrificed and the expression of SLN and CTGF in LA was assessed with quantitative PCR. Five normal pigs underwent the same assessment (Sham group).
Results: Echocardiography showed that LV end-diastolic and end-systolic volume indexes, maximum and minimum LA volume indexes were significantly larger in the IMR group than the other two groups. LV ejection fraction, longitudinal and circumferential strain, LA emptying function and reservoir strain were significantly impaired in the IMR group than the other two groups. LA SLN and CTGF expressions were both significantly upregulated in the IMR group compared to the Sham group, and had significant correlation with LA reservoir strain and LV end-diastolic volume index, respectively (Figure). The DMR group showed the same trends in echocardiographic and gene expression data as the IMR group, while there was no statistical significance compared to the Sham group.
Conclusions: Ischemic MR resulted in an exaggerated LA remodeling with significant upregulation of SLN and CTGF in the LA. These genes might serve as possible therapeutic targets for LA remodeling.
View Submission
Abstract Presenter
Tomoki Sakata, Thomas Jefferson University Hospital - Contact Me Philadelphia, PAUnited States
MO57. Development and Validation of an Ex-Vivo Porcine Model of Functional Tricuspid Regurgitation
Total Time: 5 Minutes
Objective: Tricuspid annuloplasty is effective for the majority of patients with functional tricuspid regurgitation (FTR), but carries a risk of conduction abnormalities requiring permanent pacemaker, and is ineffective for a subset of patients with severe or torrential regurgitation. We are developing novel repair methods for FTR, and our objective was to create and validate an ex-vivo model to test these approaches.
Methods: In explanted porcine hearts, the right atrium was excised to visualize the tricuspid valve (TV). The pulmonary artery and aorta were clamped and cannulated, the coronary arteries ligated, and the right and left ventricles statically pressurized with air to 30 mmHg and 120 mmHg, respectively. FTR was induced by increasing right ventricular pressure to 80 mmHg for three hours, which resulted in progressive tricuspid annular enlargement, right ventricular dilation, papillary muscle displacement, and central tricuspid malcoaptation. A structured light scanner was used to image the 3D topography of the TV in both the native and FTR state, and images were exported into scan-to-CAD software which allowed for high-resolution 3D computational reconstruction. Relevant geometric measurements were sampled including annular circumference and area, major and minor axis diameter, and tenting height, angle, and area. Geometric measurements from the ex-vivo model were compared to clinical transthoracic echocardiographic (TTE) measurements using two-sample t-tests.
Results: Six porcine hearts were included. Measurements of the native valve were comparable to published TTE data (Table 1), with the exception of minor axis diameter, which was shorter in the ex-vivo model (2.9 vs 3.9 cm, p=0.010), and tenting angle, which was larger in the ex-vivo model (31° vs 22°, p=0.002). Induction of FTR in the ex-vivo model resulted in annular enlargement (FTR vs. native: circumference 13.7 vs.11.6 cm, p<0.001; area 14.7 vs.10.8 cm2, p<0.001) and leaflet tethering (tenting area 1.5 vs. 0.7 cm2, p<0.001). Geometric parameters in the FTR model were similar to published TTE data in the majority of cases, including annular circumference and area, major axis diameter, tenting height, tenting area, and effective regurgitant orifice area (EROA).
Conclusions: This ex-vivo pneumatically-pressurized porcine model closely models the geometry of both the native and regurgitant tricuspid valve complex in humans, and holds promise for testing novel FTR repair strategies.
Methods: In explanted porcine hearts, the right atrium was excised to visualize the tricuspid valve (TV). The pulmonary artery and aorta were clamped and cannulated, the coronary arteries ligated, and the right and left ventricles statically pressurized with air to 30 mmHg and 120 mmHg, respectively. FTR was induced by increasing right ventricular pressure to 80 mmHg for three hours, which resulted in progressive tricuspid annular enlargement, right ventricular dilation, papillary muscle displacement, and central tricuspid malcoaptation. A structured light scanner was used to image the 3D topography of the TV in both the native and FTR state, and images were exported into scan-to-CAD software which allowed for high-resolution 3D computational reconstruction. Relevant geometric measurements were sampled including annular circumference and area, major and minor axis diameter, and tenting height, angle, and area. Geometric measurements from the ex-vivo model were compared to clinical transthoracic echocardiographic (TTE) measurements using two-sample t-tests.
Results: Six porcine hearts were included. Measurements of the native valve were comparable to published TTE data (Table 1), with the exception of minor axis diameter, which was shorter in the ex-vivo model (2.9 vs 3.9 cm, p=0.010), and tenting angle, which was larger in the ex-vivo model (31° vs 22°, p=0.002). Induction of FTR in the ex-vivo model resulted in annular enlargement (FTR vs. native: circumference 13.7 vs.11.6 cm, p<0.001; area 14.7 vs.10.8 cm2, p<0.001) and leaflet tethering (tenting area 1.5 vs. 0.7 cm2, p<0.001). Geometric parameters in the FTR model were similar to published TTE data in the majority of cases, including annular circumference and area, major axis diameter, tenting height, tenting area, and effective regurgitant orifice area (EROA).
Conclusions: This ex-vivo pneumatically-pressurized porcine model closely models the geometry of both the native and regurgitant tricuspid valve complex in humans, and holds promise for testing novel FTR repair strategies.
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- MO057 - Development and Validation of an Ex-Vivo Porcine Model of Functional Tricuspid Regurgitation
Abstract Presenter
Emily Larson, The Johns Hopkins University School of Medicine - Contact Me Baltimore, MDUnited States
MO58. Linear Combination Of Mitral Valve And Machine Learning To Predict Mitral Annuloplasty Band Size in Endoscopic Mitral Valve Surgery
Total Time: 5 Minutes
Background: Endoscopic mitral valve surgery is becoming standard of care. However it has steep learning curve and annular sizing is difficult with conventional sizers.
Methods: A retrospective analysis was performed on 104 patients who underwent mitral repair at one institution from July 2015 to September 2022. 93 of them had CT scans suitable for mitral valvular apparatus measurements (intertrigonal distance, anterior leaflet max length, etc). A machine learning pipeline was created in order to predict annuloplasty band size (from 26 to 38 mm). Mitral measurements were done in MPR modality.
Results: A final model (best model among the trained) was able to predict the annular size with 72% accuracy. A linear combination (PCA fo two components) of intertrigonal distance and anterior leaflet lengths was the main linear combination in the model
Conclusions: Linear combination of mitral valve measurements can predict annular size in clinical setting. Its value is highly valuable for young and inexperienced groups.
Methods: A retrospective analysis was performed on 104 patients who underwent mitral repair at one institution from July 2015 to September 2022. 93 of them had CT scans suitable for mitral valvular apparatus measurements (intertrigonal distance, anterior leaflet max length, etc). A machine learning pipeline was created in order to predict annuloplasty band size (from 26 to 38 mm). Mitral measurements were done in MPR modality.
Results: A final model (best model among the trained) was able to predict the annular size with 72% accuracy. A linear combination (PCA fo two components) of intertrigonal distance and anterior leaflet lengths was the main linear combination in the model
Conclusions: Linear combination of mitral valve measurements can predict annular size in clinical setting. Its value is highly valuable for young and inexperienced groups.
View Submission
Abstract Presenter
Rafik Margaryan, Fondazione Toscana Gabriele Monasterio - Contact Me Massa, Massa and CarraraItaly
MO59. Democratizing Mitral Valve Repair Through the use of a Novel Annuloplasty Ring
Total Time: 5 Minutes
Objectives
Despite the well-documented benefits of mitral valve repair in the setting of degenerative disease, up to 50% of patients treated in the general cardiac surgical community undergo replacement techniques, compared with repair rates of 95-100% in the hands of experienced surgeons. Innovation in annuloplasty ring design carries the potential to expand the benefits of mitral repair to communities in which mitral expertise or case volumes are limited. The objective of this study was to assess the efficacy of a simplified mitral valve repair ring prior to conducting animal studies.
Methods
A novel mitral annuloplasty ring was designed in which microporous, monofilament sutures were attached to a semirigid complete annuloplasty ring with a polyester double-velour cuff in a crosshatch pattern with 2.5 mm spacing. A LifeTec Cardiac BioSimulator platform (Resolution Medical, Fridley, MN) was used in which severe regurgitation was introduced through transection of the chordae attached to the P2 segment of the mitral valve in six porcine hearts. Pressure monitoring of the left atrium and aorta, epicardial echocardiographic assessment, and videographic monitoring of the atrial and ventricular side of the mitral valve confirmed the degree of regurgitation.
Results
In all six porcine hearts, competency of the valve was confirmed following repair both via echocardiographic and videographic assessment. (Figure) Mean left atrial pressures (mmHg) increased from 24±1.6 at baseline to 36±4.1 (P=0.0003) following chordal transection, correcting to 29±4.6 (P=0.02) following repair. Mean aortic pressures (mmHg) decreased from 62±4.0 at baseline to 53±4.0 (P=0.002) following chordal transection, correcting to 60±10.4 (P=0.1) following repair. Mean cardiac output (L/min) decreased from 4.8±0.2 at baseline to 4.1±0.2 (P=0.002) following chordal transection, correcting to 4.7±0.5 (P=0.04) following repair.
Conclusions
Preservation of the coaptation plane through a crosshatch suture grid mounted to an annuloplasty ring restored mitral valve competency with no evidence of clinically significant residual regurgitation in a high-fidelity biosimulator. This novel design carries the potential for greater simplification in mitral valve repair techniques. These findings support the utility of chronic animal studies to establish freedom from thrombosis, hemolysis, and new onset mitral stenosis.
Despite the well-documented benefits of mitral valve repair in the setting of degenerative disease, up to 50% of patients treated in the general cardiac surgical community undergo replacement techniques, compared with repair rates of 95-100% in the hands of experienced surgeons. Innovation in annuloplasty ring design carries the potential to expand the benefits of mitral repair to communities in which mitral expertise or case volumes are limited. The objective of this study was to assess the efficacy of a simplified mitral valve repair ring prior to conducting animal studies.
Methods
A novel mitral annuloplasty ring was designed in which microporous, monofilament sutures were attached to a semirigid complete annuloplasty ring with a polyester double-velour cuff in a crosshatch pattern with 2.5 mm spacing. A LifeTec Cardiac BioSimulator platform (Resolution Medical, Fridley, MN) was used in which severe regurgitation was introduced through transection of the chordae attached to the P2 segment of the mitral valve in six porcine hearts. Pressure monitoring of the left atrium and aorta, epicardial echocardiographic assessment, and videographic monitoring of the atrial and ventricular side of the mitral valve confirmed the degree of regurgitation.
Results
In all six porcine hearts, competency of the valve was confirmed following repair both via echocardiographic and videographic assessment. (Figure) Mean left atrial pressures (mmHg) increased from 24±1.6 at baseline to 36±4.1 (P=0.0003) following chordal transection, correcting to 29±4.6 (P=0.02) following repair. Mean aortic pressures (mmHg) decreased from 62±4.0 at baseline to 53±4.0 (P=0.002) following chordal transection, correcting to 60±10.4 (P=0.1) following repair. Mean cardiac output (L/min) decreased from 4.8±0.2 at baseline to 4.1±0.2 (P=0.002) following chordal transection, correcting to 4.7±0.5 (P=0.04) following repair.
Conclusions
Preservation of the coaptation plane through a crosshatch suture grid mounted to an annuloplasty ring restored mitral valve competency with no evidence of clinically significant residual regurgitation in a high-fidelity biosimulator. This novel design carries the potential for greater simplification in mitral valve repair techniques. These findings support the utility of chronic animal studies to establish freedom from thrombosis, hemolysis, and new onset mitral stenosis.
View Submission
MO60. A Novel Technique for Measuring Mitral Valve Coaptation Height Using Fiberscope Technology: A Developing Approach for Intraoperative Evaluation of Mitral Valve Repair
Total Time: 5 Minutes
Objective: MV repair is the standard treatment for MR. Restoring adequate coaptation height is a key principle of MV repair. Quantitative assessment of MV coaptation remains challenging, with no reliable method available for intraoperative use prior to discontinuing CPB. This study aimed to evaluate the utility of fiberscope (FS) technology to assess MV coaptation height for intraoperative use.
Methods: Ex vivo testing was performed on 3 adult porcine hearts. The LA was resected, leaving ~3mm of atrium above the MV annulus. The LV was pressurized through the aorta to 26.8±1mmHg. A 4mm endoscope was inserted into the LV apex, centered under the MV orifice, and secured by purse-strings. A FS system, consisting of a Milliscope II camera and 0.7mm diameter x 15cm long 90° semi-rigid scope, with 1.2mm focal length (Zibra Corp, Westport, MA), was mounted above the MV annulus in a 3D-printed fixture that enabled orthogonal placement of the device and attachment of calipers for real-time measurements. Two locations on each MV A2 and P2 segments were selected by LV endoscopic evaluation of the MV leaflets and chordae attachments. Three measurements at each location, from the top of coaptation to the leaflet edge, were recorded using the FS. In blinded fashion, the FS was used to identify the leaflet edge. Accuracy was verified using the endoscope. A control (metal rod of similar thickness) was used for comparison, with leaflet length recorded when the control was seen in the LV with the apical endoscope. The FS vs control methods were compared.
Results: Coaptation measurements were similar for the control and FS methods across all hearts at the A2 and P2 locations (A2 11.5±1.1mm control vs 11.3±0.8mm FS; P2 11.5±1.5mm control vs 11.7±2.1mm FS). Both methods had similar variability across the three measurements taken at each leaflet segment location (control SD 0.09-0.95mm and FS SD 0.03-0.90mm). One outlier was excluded from analysis (n=11/12). The difference between measurement methods was less than 1.1mm with a median absolute difference of 0.46 (0.20-0.88)mm. Percent error between measurement methods was less than 8% with a median absolute percent error of 4.03 (1.68-7.57)%.
Conclusions: Utilization of a miniaturized FS enabled precise and accurate quantification of MV coaptation. This novel technique is promising for evaluating post-repair valve competence and coaptation height. Further study and validation in vivo are necessary prior to intraoperative use.
Methods: Ex vivo testing was performed on 3 adult porcine hearts. The LA was resected, leaving ~3mm of atrium above the MV annulus. The LV was pressurized through the aorta to 26.8±1mmHg. A 4mm endoscope was inserted into the LV apex, centered under the MV orifice, and secured by purse-strings. A FS system, consisting of a Milliscope II camera and 0.7mm diameter x 15cm long 90° semi-rigid scope, with 1.2mm focal length (Zibra Corp, Westport, MA), was mounted above the MV annulus in a 3D-printed fixture that enabled orthogonal placement of the device and attachment of calipers for real-time measurements. Two locations on each MV A2 and P2 segments were selected by LV endoscopic evaluation of the MV leaflets and chordae attachments. Three measurements at each location, from the top of coaptation to the leaflet edge, were recorded using the FS. In blinded fashion, the FS was used to identify the leaflet edge. Accuracy was verified using the endoscope. A control (metal rod of similar thickness) was used for comparison, with leaflet length recorded when the control was seen in the LV with the apical endoscope. The FS vs control methods were compared.
Results: Coaptation measurements were similar for the control and FS methods across all hearts at the A2 and P2 locations (A2 11.5±1.1mm control vs 11.3±0.8mm FS; P2 11.5±1.5mm control vs 11.7±2.1mm FS). Both methods had similar variability across the three measurements taken at each leaflet segment location (control SD 0.09-0.95mm and FS SD 0.03-0.90mm). One outlier was excluded from analysis (n=11/12). The difference between measurement methods was less than 1.1mm with a median absolute difference of 0.46 (0.20-0.88)mm. Percent error between measurement methods was less than 8% with a median absolute percent error of 4.03 (1.68-7.57)%.
Conclusions: Utilization of a miniaturized FS enabled precise and accurate quantification of MV coaptation. This novel technique is promising for evaluating post-repair valve competence and coaptation height. Further study and validation in vivo are necessary prior to intraoperative use.
View Submission
MO61. Interpapillary Muscle Distance Predicts Recurrent Mitral Regurgitation Independently from End-Diastolic Left Ventricle Diameter. 5-Years Echocardiographic Results from the PMA Trial
Total Time: 5 Minutes
Objective: Recurrent ischemic mitral regurgitation (IMR) is caused by displacement of papillary muscles due to progressive increase of the left ventricle end-diastolic diameter (LVEDD). We aimed at demonstrate that, if interpapillary muscle distance (IPD) is surgically stabilized, the increase of LVEDD is not associated to recurrent IMR.
Methods: Ninety-six patient with severe IMR were randomized 1:1 for reduction annuloplasty (RA) vs RA + papillary muscle approximation (PMA). At 5 years follow-up, we evaluated: [1] the association of echocardiographic predictors to recurrent IMR (i.e., moderate-severe MR ± reoperation); [2] the correlation of PMA with an improvement of echocardiographic parameters during the study period (i.e., their Δ between preoperative and 5-year measurements); [3] the quantification of how many standard deviations (SD) PMA reduced adverse outcomes.
Results: IPD was the only independent predictor of recurrent moderate to severe MR (OR 10.55, 95% CI 0.61 | 1.33), when adjusted for α and β angles, tenting area, and LVEDD. PMA correlated to an amelioration of α (ρ -0.85) and β (ρ -0.87) angles, pulmonary systolic arterial pressure (ρ -0.44), recurrent MR (ρ -0.32), tenting area (ρ -0.76), left ventricular ejection fraction (ρ +0.56) and end-systolic diameter (ρ -0.67) (p <0.01 for all). PMA reduced the recurrence of MR of 1.91 SD (95% CI -2.28|-1.54), re-hospitalization for heart failure of 2.61 SD (95% CI -2.99|-2.22), reoperation of 2.64 SD (95% CI -3.04|-2.60) cardiac mortality of 2.9 SD (95% CI -3.30|-2.49), and overall mortality of 3.34 SD (95% CI –3.78|-2.90). The results are further detailed in the Figure.
Conclusions: At 5-years follow-up, recurrent IMR is independently predicted by IPD and not by LVEDD. If IPD is surgically stabilized, progressive LVEDD enlargement does not associate with recurrent IMR.
Methods: Ninety-six patient with severe IMR were randomized 1:1 for reduction annuloplasty (RA) vs RA + papillary muscle approximation (PMA). At 5 years follow-up, we evaluated: [1] the association of echocardiographic predictors to recurrent IMR (i.e., moderate-severe MR ± reoperation); [2] the correlation of PMA with an improvement of echocardiographic parameters during the study period (i.e., their Δ between preoperative and 5-year measurements); [3] the quantification of how many standard deviations (SD) PMA reduced adverse outcomes.
Results: IPD was the only independent predictor of recurrent moderate to severe MR (OR 10.55, 95% CI 0.61 | 1.33), when adjusted for α and β angles, tenting area, and LVEDD. PMA correlated to an amelioration of α (ρ -0.85) and β (ρ -0.87) angles, pulmonary systolic arterial pressure (ρ -0.44), recurrent MR (ρ -0.32), tenting area (ρ -0.76), left ventricular ejection fraction (ρ +0.56) and end-systolic diameter (ρ -0.67) (p <0.01 for all). PMA reduced the recurrence of MR of 1.91 SD (95% CI -2.28|-1.54), re-hospitalization for heart failure of 2.61 SD (95% CI -2.99|-2.22), reoperation of 2.64 SD (95% CI -3.04|-2.60) cardiac mortality of 2.9 SD (95% CI -3.30|-2.49), and overall mortality of 3.34 SD (95% CI –3.78|-2.90). The results are further detailed in the Figure.
Conclusions: At 5-years follow-up, recurrent IMR is independently predicted by IPD and not by LVEDD. If IPD is surgically stabilized, progressive LVEDD enlargement does not associate with recurrent IMR.
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Abstract Presenter
Ivancarmine Gambardella, Weill Cornell Medical Center - Contact Me New York, NYUnited States
MO62. Holographic Imaging/Mixed Reality in Degenerative Mitral Disease: a New Tool for a Better Understanding and Planning Operations in Complex Multi-scallops Prolapse?
Total Time: 5 Minutes
Objective: Mitral valve repair is the operation of choice in degenerative disease but the actual repair rate is about 70% of cases only. The main reason is the difficulty in understanding the exact anatomy in prolapse involving multi scallops as in Barlow. Transesophageal echo (TOE) depend on sonographer and surgeon's experiences and images limited on a 2D screen. The aim of this study was to evaluate the feasibility of an Holographic Imaging/Mixed Reality (HIMR) reconstruction from CT scan and if this technology may give a better perception of the real complex mitral anatomy and the surrounding structures.
Methods: Preliminarily we evaluated the feasibility of assessing the pre-operative MV anatomy of patients using HIMR technology starting from a 256 slices CT scan. Patients undergoing MV surgery with multi-segment prolapse underwent a dynamic ECG-gated contrast enhanced CT scan. Acquired clinical images were used as an input for a new created software building a 3D patient-specific holographic reconstructions in 34 cases. Than 10 cardiac surgeons from our staff were asked to compare the HIMR imaging with the corresponding 3D intraoperative TOE by a questionnaire.
Results: The dynamic HIMR was successful reconstructed in 94% of the cases from complex degenerative mitral valve CT scan. In a subjective non quantitive evaluation all the surgeons (n 10) have confirmed a better visualization of the prolapsing scallops in HIMR mode with higher anatomical spatial definition in systole and diastole. From an objective point of view all surgeons could explored the surrounding structure : the subvalvular apparatus ( papillary muscles), the LV outflow tract and Cx artery in a real 3D mode, from different planes and perspectives ( not possible with TOE).
Conclusion: This software provided an intuitive way to fully appreciate the complex MV morphology and dynamics. Objective advantages of HIMR compared to TOE is the enhanced visualization of the valve and surrounding structures in a real 3D mode. Surgeons have the possibility to navigate into the true anatomy through a direct interaction by dynamic holograms providing a real perception of depth and spatial relationships. HIMR has the disadvantage not to be a real time technology but it is a promising new tool for surgeons and cardiologists in undertstanding and planning repair on complex mitral valve cases. Further studies are necessary to prove the real clinical advantage of this new exciting technology.
Methods: Preliminarily we evaluated the feasibility of assessing the pre-operative MV anatomy of patients using HIMR technology starting from a 256 slices CT scan. Patients undergoing MV surgery with multi-segment prolapse underwent a dynamic ECG-gated contrast enhanced CT scan. Acquired clinical images were used as an input for a new created software building a 3D patient-specific holographic reconstructions in 34 cases. Than 10 cardiac surgeons from our staff were asked to compare the HIMR imaging with the corresponding 3D intraoperative TOE by a questionnaire.
Results: The dynamic HIMR was successful reconstructed in 94% of the cases from complex degenerative mitral valve CT scan. In a subjective non quantitive evaluation all the surgeons (n 10) have confirmed a better visualization of the prolapsing scallops in HIMR mode with higher anatomical spatial definition in systole and diastole. From an objective point of view all surgeons could explored the surrounding structure : the subvalvular apparatus ( papillary muscles), the LV outflow tract and Cx artery in a real 3D mode, from different planes and perspectives ( not possible with TOE).
Conclusion: This software provided an intuitive way to fully appreciate the complex MV morphology and dynamics. Objective advantages of HIMR compared to TOE is the enhanced visualization of the valve and surrounding structures in a real 3D mode. Surgeons have the possibility to navigate into the true anatomy through a direct interaction by dynamic holograms providing a real perception of depth and spatial relationships. HIMR has the disadvantage not to be a real time technology but it is a promising new tool for surgeons and cardiologists in undertstanding and planning repair on complex mitral valve cases. Further studies are necessary to prove the real clinical advantage of this new exciting technology.
View Submission
Abstract Presenter
marco diena, Cardioteam Foundation San Gaudenzio Clinic - Contact Me NovaraItaly
MO63. Predictive Geometric Analysis of Mitral Valve for Recurrence of Mitral Regurgitation after Mitral Annuloplasty in Patients with Atrial Functional Mitral Regurgitation
Total Time: 5 Minutes
Objective: Recent studies reveal precise recognition and increased prevalence of atrial functional mitral regurgitation (AFMR). However, the mechanism of AFMR is not fully addressed, and appropriate surgical intervention is still unknown. We herein reviewed patients with AFMR underwent mitral annuloplasty (MAP) in our institution and investigated preoperative geometric characters of the mitral valve in terms of recurrence of MR after surgery.
Method: We retrospectively reviewed 20 patients with AFMR underwent mitral valve surgery from 2010 to 2022 (median age: 75±7 years, male: 30%). Mean follow-up period was 3.2±2.3years. Preoperative three-dimensional transesophageal echocardiogram (3D TEE) was available in all patients and geometric analysis of the mitral valve was performed by software of the Philips Q-Lab.
Result: All patients survived during the follow-up period. MAP was performed in all patients, anterior mitral leaflet chordal reconstruction using artificial chordae in 2 patients, and patch augmentation of mitral posterior leaflet in 1 patient. Freedom rate from recurrent of MR was 79% and 57% at 1year and 3 years, respectively. Recurrent MR occurred in 6 patients and the causes were recurrent of functional MR in 4 patients and detachment of MAP ring in 2 patients. Preoperative 3D TEE examination revealed that patients with recurrent MR had longer circumstance of mitral annulus and larger area of posterior mitral leaflet (PML) than patients without recurrent MR (circumstance of mitral annulus; 137±11 vs. 124±12 mm, p = 0.02, PML area; 797±231 vs. 552±144 mm2 p = 0.01). Especially, lateral side of PML in patients with recurrent MR was longer than those in patients without recurrent MR (P1; 15±5 vs.10±3 mm, p＜0.01, P2; 14±4 vs.11±4 mm, p =0.23, P3; 10±3 vs.8±3 mm, p =0.13).
Conclusion: AFMR patients with longer circumstance of mitral annulus, larger PML area, and asymmetric PML remodeling tended to recur MR after MAP. Those factors in the mitral valve could indicated progressed remodeling and advanced disease stage of AFMR, and MAP only might not be sufficient for those patients.
Method: We retrospectively reviewed 20 patients with AFMR underwent mitral valve surgery from 2010 to 2022 (median age: 75±7 years, male: 30%). Mean follow-up period was 3.2±2.3years. Preoperative three-dimensional transesophageal echocardiogram (3D TEE) was available in all patients and geometric analysis of the mitral valve was performed by software of the Philips Q-Lab.
Result: All patients survived during the follow-up period. MAP was performed in all patients, anterior mitral leaflet chordal reconstruction using artificial chordae in 2 patients, and patch augmentation of mitral posterior leaflet in 1 patient. Freedom rate from recurrent of MR was 79% and 57% at 1year and 3 years, respectively. Recurrent MR occurred in 6 patients and the causes were recurrent of functional MR in 4 patients and detachment of MAP ring in 2 patients. Preoperative 3D TEE examination revealed that patients with recurrent MR had longer circumstance of mitral annulus and larger area of posterior mitral leaflet (PML) than patients without recurrent MR (circumstance of mitral annulus; 137±11 vs. 124±12 mm, p = 0.02, PML area; 797±231 vs. 552±144 mm2 p = 0.01). Especially, lateral side of PML in patients with recurrent MR was longer than those in patients without recurrent MR (P1; 15±5 vs.10±3 mm, p＜0.01, P2; 14±4 vs.11±4 mm, p =0.23, P3; 10±3 vs.8±3 mm, p =0.13).
Conclusion: AFMR patients with longer circumstance of mitral annulus, larger PML area, and asymmetric PML remodeling tended to recur MR after MAP. Those factors in the mitral valve could indicated progressed remodeling and advanced disease stage of AFMR, and MAP only might not be sufficient for those patients.
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MO64. Evaluation of Rheumatic Mitral Valve Repair by Computed Tomography Imaging: Insight into the Interaction between Valve Configuration and Hemodynamic in Mitral Stenosis
Total Time: 5 Minutes
Objective: Altered Valve configuration is closely related to disturbed hemodynamic in rheumatic mitral stenosis. Mitral valve repair has been shown to restore the valve function with improved transvalvular hemodynamics. We tried to explore the relationship between postoperative functional improvement and valve morphology changes with CT imaging.
Method:A total of 32 consecutive patients (age 47.0±9.6 years, 24 female) who underwent valve repair for rheumatic mitral stenosis from 2020 to 2022 were enrolled. An ECG-gated CT were performed both pre- and post-operatively for 2-dimensional measurements of valve geometry at diastole and systole. In addition to regurgitation degree, coaptation height, tenting depth and anterior leaflet length/short annulus axis ratio were assessed for mitral closure. For mitral opening, leaflet mobility, effective orifice area (EOA) and heart rate indexed transmitral gradient were analyzed with validation of echocardiography. Additionally, tapering index was calculated to evaluate the 3-dimensional(3D) configuration in mitral stenosis and its correlation with transmitral gradient was further studied before and after valve repair.
Results:After valve repair, CT image analysis demonstrated increase in coaptation height (5.8±2.1mm vs. 8.0±2.1mm, P<0.01), tenting depth (5.0±1.8mm vs. 7.6±1.9mm, P<0.01) and the augmented anterior leaflet length/short annulus axis ratio (0.95±0.10 vs. 1.17±1.26, P<0.01) at systole. Post repair group showed reduced mitral regurgitation (1.5±1.1 vs. 1.1±0.6, P<0.05). At systole, both increasing anterior and posterior leaflet to annulus distance (16.3±3mm vs. 21.5±3.7mm, 11.4±3.3mm vs. 14.4±2.9mm, both P<0.01) were associate with improved leaflet mobility which subsequently lead to an enlarged CT-derived EOA (1.4±0.5cm2 vs. 2.6±0.4 cm2, P<0.01) and lower heart rate indexed transmitral gradient (8.5±3.9mmHg vs. 2.8±1.1mmHg, P<0.01). Tapering index showed strong correlation with transmitral gradient (r=0.52, P=0.001). The postoperative reduced tapering index (0.9±0.2 vs. 0.5±0.8, P<0.01) corresponded to the structural transformation of stenotic mitral valve from pre-repair flat plate shape to post-repair tubular shape.
Conclusion: Improved valve configuration after valve repair for rheumatic mitral stenosis is directly associated with better transmitral hemodynamic. CT-derived 3D parameter might be a useful adjunct to provide insight into the relations between valve structure, pressure, and flows.
Method:A total of 32 consecutive patients (age 47.0±9.6 years, 24 female) who underwent valve repair for rheumatic mitral stenosis from 2020 to 2022 were enrolled. An ECG-gated CT were performed both pre- and post-operatively for 2-dimensional measurements of valve geometry at diastole and systole. In addition to regurgitation degree, coaptation height, tenting depth and anterior leaflet length/short annulus axis ratio were assessed for mitral closure. For mitral opening, leaflet mobility, effective orifice area (EOA) and heart rate indexed transmitral gradient were analyzed with validation of echocardiography. Additionally, tapering index was calculated to evaluate the 3-dimensional(3D) configuration in mitral stenosis and its correlation with transmitral gradient was further studied before and after valve repair.
Results:After valve repair, CT image analysis demonstrated increase in coaptation height (5.8±2.1mm vs. 8.0±2.1mm, P<0.01), tenting depth (5.0±1.8mm vs. 7.6±1.9mm, P<0.01) and the augmented anterior leaflet length/short annulus axis ratio (0.95±0.10 vs. 1.17±1.26, P<0.01) at systole. Post repair group showed reduced mitral regurgitation (1.5±1.1 vs. 1.1±0.6, P<0.05). At systole, both increasing anterior and posterior leaflet to annulus distance (16.3±3mm vs. 21.5±3.7mm, 11.4±3.3mm vs. 14.4±2.9mm, both P<0.01) were associate with improved leaflet mobility which subsequently lead to an enlarged CT-derived EOA (1.4±0.5cm2 vs. 2.6±0.4 cm2, P<0.01) and lower heart rate indexed transmitral gradient (8.5±3.9mmHg vs. 2.8±1.1mmHg, P<0.01). Tapering index showed strong correlation with transmitral gradient (r=0.52, P=0.001). The postoperative reduced tapering index (0.9±0.2 vs. 0.5±0.8, P<0.01) corresponded to the structural transformation of stenotic mitral valve from pre-repair flat plate shape to post-repair tubular shape.
Conclusion: Improved valve configuration after valve repair for rheumatic mitral stenosis is directly associated with better transmitral hemodynamic. CT-derived 3D parameter might be a useful adjunct to provide insight into the relations between valve structure, pressure, and flows.
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Abstract Presenter
Tianyang Yang, Shanghai Chest Hospital Affiliated to Shanghai Jiaotong University - Contact Me Shanghai, ShanghaiChina
MO65. Application of Stentless Mitral Valve Design to Repair in Infective Endocarditis
Total Time: 5 Minutes
Objective: Mitral valve repair (MVr) in patients with active infective endocarditis (IE) can be challenging. MVr is more preferable in patients who had better avoid warfarin use because of preoperative characteristics or comorbidities. We developed repair technique for active IE using an original stentless mitral valve "NORMO" design. We present our repair technique.
Methods: There were 22 patients of active IE among 343 undergoing MV surgery between April 2019 and December 2022 at our institution. MVr was performed in 9 (40.9%), and MV replacement (MVR) in 13 (59.1%). Mean age was 46.4 years in MVr and 60.6 years in MVR. In patients undergoing MVr, we applied the "NORMO" design to 6 (66.7%) that infection was widely spread over both clear zone and rough zone of several scallops. Figure 1 presents 3 typical cases of repair. We applied a concept of stentless MV, "NORMO" valve, invented by Hitoshi Kasegawa. It is characterized by the design that a single pericardial sheet can be formed three-dimensionally to create a folded structure at the commissure. Infected scallops of leaflet and chordae were resected completely and reconstructed using autologous pericardium in 5, and A3 scallop of anterior leaflet in 1. In 4 cases, pericardial sheet or native anterior leaflet. Prosthetic ring annuloplasty was added in 5 cases except case 5 with entire circumference of severe mitral annular calcification.
Results：In MV repair cases, hospital mortality was 88.9%. 1 patient using "NORMO" design died because of liver cirrhosis on postoperative day 30. Postoperative echocardiography revealed excellent performance of the valve with residual mitral regurgitation (MR) of less than mild. At 3 years, rates of survival and freedom from reoperation were 88.8% and 87.5%, respectively. 1 patient using "NORMO" design required redo MVR for recurrent MR due to rupture of GORE-TEX neo-chordae at 8 months after surgery.
Conclusions："NORMO" design was useful to achieve MV repair for patients of active IE with extensive infection involving several scallops.
Methods: There were 22 patients of active IE among 343 undergoing MV surgery between April 2019 and December 2022 at our institution. MVr was performed in 9 (40.9%), and MV replacement (MVR) in 13 (59.1%). Mean age was 46.4 years in MVr and 60.6 years in MVR. In patients undergoing MVr, we applied the "NORMO" design to 6 (66.7%) that infection was widely spread over both clear zone and rough zone of several scallops. Figure 1 presents 3 typical cases of repair. We applied a concept of stentless MV, "NORMO" valve, invented by Hitoshi Kasegawa. It is characterized by the design that a single pericardial sheet can be formed three-dimensionally to create a folded structure at the commissure. Infected scallops of leaflet and chordae were resected completely and reconstructed using autologous pericardium in 5, and A3 scallop of anterior leaflet in 1. In 4 cases, pericardial sheet or native anterior leaflet. Prosthetic ring annuloplasty was added in 5 cases except case 5 with entire circumference of severe mitral annular calcification.
Results：In MV repair cases, hospital mortality was 88.9%. 1 patient using "NORMO" design died because of liver cirrhosis on postoperative day 30. Postoperative echocardiography revealed excellent performance of the valve with residual mitral regurgitation (MR) of less than mild. At 3 years, rates of survival and freedom from reoperation were 88.8% and 87.5%, respectively. 1 patient using "NORMO" design required redo MVR for recurrent MR due to rupture of GORE-TEX neo-chordae at 8 months after surgery.
Conclusions："NORMO" design was useful to achieve MV repair for patients of active IE with extensive infection involving several scallops.
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MO66. The Impact of Preoperative Left Ventricular Systolic Dysfunction on Reverse Remodelling Following Mitral Repair: Insights from CAMRA CardioLink-2 Randomized Trial
Total Time: 5 Minutes
Objective: The ideal time to undergo mitral repair surgery for degenerative mitral regurgitation is before patients develop systolic dysfunction defined as LVEF ≤60% or LVESD ≥40 mm. We studied the impact of systolic dysfunction on the LV reverse remodeling in the sub-analysis of The Canadian Mitral Research Alliance CardioLink-2 study, a randomized trial comparing leaflet resection versus preservation techniques for posterior leaflet prolapse.
Methods: A total of 74 patients were included in the analysis and divided into 2 groups, those with or without preoperative systolic dysfunction. We compared changes in echocardiography up to 12 months postoperatively.
Results: Systolic dysfunction was identified in 35 participants. Patient characteristics were not significantly different except for higher prevalence of atrial fibrillation in those with systolic dysfunction (17 (49%), vs. 6 (15%), p=0.003). At baseline, those with systolic dysfunction had significantly larger mean LV geometry (57.4mm, 39.9mm, 194.3ml, and 81.0ml vs. 52.2mm, 32.0mm, 162.2ml, and 58.6ml in LVEDD, LVESD, LVEDV, and LVESV, respectively). This association was unchanged before discharge and at 12 months (50.4mm, 35.5mm, 140.8ml, and 63.7ml vs. 46.4mm, 32.5mm, 120.3ml, and 51.4ml, respectively at 12 months); however, those with systolic dysfunction had better (-1.8mm vs +2.1mm, p<0.001 in mean LVESD change) or equivalent (-4.9mm and -38.8ml vs -2.9mm and -31.2ml, p=0.061 and 0.37 in mean LVEDD and LVEDV change) reverse remodeling in acute phase (before discharge vs baseline). In mid-term phase (12 months vs before discharge), those with systolic dysfunction had significant reverse remodeling which was equivalent to those without systolic dysfunction (-2.4mm, -2.8mm and -13.2ml vs -2.9mm, -1.7mm and -12.0ml, p=0.71, p=0.43 and 0.83 in mean LVEDD, LVESD and LVESV change). Those with systolic dysfunction had lower LVEF at baseline (57.7% vs 64.1%, p<0.001), before discharge (48.1% vs 53.5%, p=0.013) and at 12 months (55.1% vs 57.6%, p=0.045) but had significant recovery in mid-term phase which was equivalent to those without systolic dysfunction (4.1% vs 4.5%, p=0.84).
Conclusions: Those with preoperative systolic dysfunction had greater LV dimensions and volumes and lower LVEF postoperatively than those without systolic dysfunction; however, both the groups had similar reverse remodeling both in acute and mid-term phase. Further study is warranted to investigate long-term trends.
Methods: A total of 74 patients were included in the analysis and divided into 2 groups, those with or without preoperative systolic dysfunction. We compared changes in echocardiography up to 12 months postoperatively.
Results: Systolic dysfunction was identified in 35 participants. Patient characteristics were not significantly different except for higher prevalence of atrial fibrillation in those with systolic dysfunction (17 (49%), vs. 6 (15%), p=0.003). At baseline, those with systolic dysfunction had significantly larger mean LV geometry (57.4mm, 39.9mm, 194.3ml, and 81.0ml vs. 52.2mm, 32.0mm, 162.2ml, and 58.6ml in LVEDD, LVESD, LVEDV, and LVESV, respectively). This association was unchanged before discharge and at 12 months (50.4mm, 35.5mm, 140.8ml, and 63.7ml vs. 46.4mm, 32.5mm, 120.3ml, and 51.4ml, respectively at 12 months); however, those with systolic dysfunction had better (-1.8mm vs +2.1mm, p<0.001 in mean LVESD change) or equivalent (-4.9mm and -38.8ml vs -2.9mm and -31.2ml, p=0.061 and 0.37 in mean LVEDD and LVEDV change) reverse remodeling in acute phase (before discharge vs baseline). In mid-term phase (12 months vs before discharge), those with systolic dysfunction had significant reverse remodeling which was equivalent to those without systolic dysfunction (-2.4mm, -2.8mm and -13.2ml vs -2.9mm, -1.7mm and -12.0ml, p=0.71, p=0.43 and 0.83 in mean LVEDD, LVESD and LVESV change). Those with systolic dysfunction had lower LVEF at baseline (57.7% vs 64.1%, p<0.001), before discharge (48.1% vs 53.5%, p=0.013) and at 12 months (55.1% vs 57.6%, p=0.045) but had significant recovery in mid-term phase which was equivalent to those without systolic dysfunction (4.1% vs 4.5%, p=0.84).
Conclusions: Those with preoperative systolic dysfunction had greater LV dimensions and volumes and lower LVEF postoperatively than those without systolic dysfunction; however, both the groups had similar reverse remodeling both in acute and mid-term phase. Further study is warranted to investigate long-term trends.
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MO67. Mini Mitral Simulation Simplified
Total Time: 5 Minutes
Objective: The purpose of this video is to illustrate the basic construction and use of a low cost, low fidelity simulator to be built by the trainee for in-home preparation in minimally invasive mitral valve repair surgery. To achieve technical proficiency, trainees must demonstrate competence with long shafted instruments before performing valve repair. The primary goal is to simulate every stitch that will be placed.
Case video summary: A simulator is constructed using a standard tissue box and three foam sheets at the box base. A drawn template is created to serve as a basis for placement of six suture types: pericardial retraction stitches, antegrade cardioplegia u-stitch, left ventricular vent u-stitch, annulus stitch, neochords, and left atriotomy closure. Practicing with long shafted instruments, the trainee can perfect needle angle, improve efficiency, and minimize errors. Simulation time from start to finish, and number of technical errors should be recorded for each iteration to set goals and achieve deliberate practice.
Conclusion: Using an inexpensive and low fidelity model, every suture step of a minimally invasive mitral valve repair can be replicated. The goal is to allow frequent practice and flatten the learning curve. Unlike all existing models, this setup allows practice of every suture step, critical in the trainee's ability to progress through the entire operation.
Case video summary: A simulator is constructed using a standard tissue box and three foam sheets at the box base. A drawn template is created to serve as a basis for placement of six suture types: pericardial retraction stitches, antegrade cardioplegia u-stitch, left ventricular vent u-stitch, annulus stitch, neochords, and left atriotomy closure. Practicing with long shafted instruments, the trainee can perfect needle angle, improve efficiency, and minimize errors. Simulation time from start to finish, and number of technical errors should be recorded for each iteration to set goals and achieve deliberate practice.
Conclusion: Using an inexpensive and low fidelity model, every suture step of a minimally invasive mitral valve repair can be replicated. The goal is to allow frequent practice and flatten the learning curve. Unlike all existing models, this setup allows practice of every suture step, critical in the trainee's ability to progress through the entire operation.
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Case Video Presenter
Jennifer Perri, UCSF Medical Center - Contact Me San Francisco, CAUnited States
MO68. A Nomogram to Predict the Improvement of Moderate Ischemic Mitral Regurgitation after Coronary Artery Bypass Grafting
Total Time: 5 Minutes
OBJECTIVE: To develop a nomogram to predict improvement in moderate ischemic mitral regurgitation (IMR) after coronary artery bypass grafting (CABG).
METHODS: Data were retrospectively collected from 112 patients with prior myocardial infarction and moderate IMR undergoing CABG. Patients were divided into two groups based on IMR degree 1 year after CABG as follows: Improved Group with no or mild IMR (n = 54) and Failure Group with moderate or severe IMR (n = 58). To determine the predictors of postoperative IMR improvement, preoperative clinical and echocardiographic data were compared, and a nomogram was formulated based on all independent predictors. Discriminative ability, calibration, and clinical usefulness of the prediction model were assessed.
RESULTS: Independent predictors of IMR improvement after CABG constructing the nomogram included duration between infarction and operation, posterior-inferior regional volume ratio to left ventricular (LV) volume, LV dyssynchrony index Tmsv_16_dif, P3 leaflet tethering angle, and annular Non-planar angle. The nomogram exhibited well-fitted calibration curves and excellent discriminative ability. The area under receiver operating characteristic curve was 0.974. Patients with a score > 236 demonstrated a high probability of IMR improvement (sensitivity, 90.7%; specificity, 93.1%). Patients in the Improved Group demonstrated significantly greater actuarial survival rates than those in the Failure Group.
CONCLUSIONS: The nomogram combining 5 preoperative clinical and echocardiographic predictors provides an accurate preoperative estimation of moderate IMR improvement after surgery, with excellent discriminative ability. Based on this nomogram, patients with a higher score predict a higher probability of IMR improvement.
METHODS: Data were retrospectively collected from 112 patients with prior myocardial infarction and moderate IMR undergoing CABG. Patients were divided into two groups based on IMR degree 1 year after CABG as follows: Improved Group with no or mild IMR (n = 54) and Failure Group with moderate or severe IMR (n = 58). To determine the predictors of postoperative IMR improvement, preoperative clinical and echocardiographic data were compared, and a nomogram was formulated based on all independent predictors. Discriminative ability, calibration, and clinical usefulness of the prediction model were assessed.
RESULTS: Independent predictors of IMR improvement after CABG constructing the nomogram included duration between infarction and operation, posterior-inferior regional volume ratio to left ventricular (LV) volume, LV dyssynchrony index Tmsv_16_dif, P3 leaflet tethering angle, and annular Non-planar angle. The nomogram exhibited well-fitted calibration curves and excellent discriminative ability. The area under receiver operating characteristic curve was 0.974. Patients with a score > 236 demonstrated a high probability of IMR improvement (sensitivity, 90.7%; specificity, 93.1%). Patients in the Improved Group demonstrated significantly greater actuarial survival rates than those in the Failure Group.
CONCLUSIONS: The nomogram combining 5 preoperative clinical and echocardiographic predictors provides an accurate preoperative estimation of moderate IMR improvement after surgery, with excellent discriminative ability. Based on this nomogram, patients with a higher score predict a higher probability of IMR improvement.
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Abstract Presenter
Xiaotian Sun, Huashan Hospital Fudan University - Contact Me Shanghai, ShanghaiChina
MO69. Non-Invasive Mitral Tissue Characterization Using Truevue Transillumination: An Imaging-Histology Correlation Study
Total Time: 5 Minutes
Objective:
The feasibility of surgical repair of mitral regurgitation depends on the adequacy of valve tissue quality, and preoperative imaging should ideally predict valve tissue alterations to identify challenging cases. This has traditionally been done using 2D and 3D echocardiography.Here, we evaluate mitral valve tissue characterization by real-time TrueVue transillumination (TV) TEE, a new photorealistic rendering method, and its correlation with histopathology.
Methods:
TV TEE was performed in 15 patients with mitral valve disease requiring surgery; excised valve specimens were examined by a pathologist with proper staining.TV uses a virtual light source to illuminate a specific structure; we backlit mitral leaflets by positioning the light at the maximum depth provided by the technique; then, from the left atrium, we observed the light-tissue interaction which was different depending on the texture of the leaflets. Specifically, a fibrosclerotic degeneration is seen as a section of reduced penetration of the light, a fibroelastic deficiency can be observed as a section of hypertransparent tissue, while myxomatous degeneration is appreciated as areas of fibrotic tissue, scarcely crossed by light, surrounded by more transparent portions in a patchy pattern.Tissue composition was thus graded qualitatively, both at pathology and at TV, in a blinded fashion: 1 to fibrosclerotic degeneration, 2 to fibroelastic deficiency, and 3 to myxomatous degeneration. Anterior mitral leaflets were excised in toto and each portion (medial, central and lateral) scored separately; posterior leaflets were partially resected and scored individually. Cohen's kappa was used to detect the agreement between the two methods.
Results:
39 regions were included in the present analysis (13 anterior leaflets and 2 fragments of posteriors leaflets). A good correspondence was observed between TV tissue characterization and histological findings (Table 1), with a better concordance for fibrosclerotic degeneration (agreement 93%, p<0.001), but still high and significant concordance also for fibroelastic deficiency (agreement 87%, p<0.001) and myxomatous degeneration (agreement 87%, p<0.001).
Conclusions:
In our preliminary study, TV echocardiography demonstrated good prediction of mitral valve tissue characteristics confirmed by pathology. Larger studies will have to confirm the role of this new method in predicting feasibility and success of mitral repair.
The feasibility of surgical repair of mitral regurgitation depends on the adequacy of valve tissue quality, and preoperative imaging should ideally predict valve tissue alterations to identify challenging cases. This has traditionally been done using 2D and 3D echocardiography.Here, we evaluate mitral valve tissue characterization by real-time TrueVue transillumination (TV) TEE, a new photorealistic rendering method, and its correlation with histopathology.
Methods:
TV TEE was performed in 15 patients with mitral valve disease requiring surgery; excised valve specimens were examined by a pathologist with proper staining.TV uses a virtual light source to illuminate a specific structure; we backlit mitral leaflets by positioning the light at the maximum depth provided by the technique; then, from the left atrium, we observed the light-tissue interaction which was different depending on the texture of the leaflets. Specifically, a fibrosclerotic degeneration is seen as a section of reduced penetration of the light, a fibroelastic deficiency can be observed as a section of hypertransparent tissue, while myxomatous degeneration is appreciated as areas of fibrotic tissue, scarcely crossed by light, surrounded by more transparent portions in a patchy pattern.Tissue composition was thus graded qualitatively, both at pathology and at TV, in a blinded fashion: 1 to fibrosclerotic degeneration, 2 to fibroelastic deficiency, and 3 to myxomatous degeneration. Anterior mitral leaflets were excised in toto and each portion (medial, central and lateral) scored separately; posterior leaflets were partially resected and scored individually. Cohen's kappa was used to detect the agreement between the two methods.
Results:
39 regions were included in the present analysis (13 anterior leaflets and 2 fragments of posteriors leaflets). A good correspondence was observed between TV tissue characterization and histological findings (Table 1), with a better concordance for fibrosclerotic degeneration (agreement 93%, p<0.001), but still high and significant concordance also for fibroelastic deficiency (agreement 87%, p<0.001) and myxomatous degeneration (agreement 87%, p<0.001).
Conclusions:
In our preliminary study, TV echocardiography demonstrated good prediction of mitral valve tissue characteristics confirmed by pathology. Larger studies will have to confirm the role of this new method in predicting feasibility and success of mitral repair.
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MO70. Finite Computed Tomographic Analysis of the Morphometrics and Dynamics of the Right Atrio-ventricular Junction in Secondary Functional Tricuspid Regurgitation
Total Time: 5 Minutes
Objective
Secondary functional tricuspid regurgitation (FTR) management remains controversial mainly due to the lack of knowledge in its pathogenesis and the difficulties to measure the actual dimensions of tricuspid annulus (TA) with current imaging methods. Using a new developed method based on cardiac CT-scan acquisition to finely analyze the right atrioventricular junction (RAVJ), we sought to explore modifications of TA morphometry and dynamics in secondary FTR.
Methods
In addition to echocardiographic data, cardiac CT-scans were obtained from 21 patients with severe myxoid mitral regurgitation (MR group) and 21 patients with ischemic or idiopathic dilated cardiomyopathy (DCMP group), all in sinus rhythm. Using an in-house software, 3D semi-automated delineation of 18 points around TA perimeter were defined. Modifications of diameters, 2D/3D areas and perimeters were analyzed through time. Right ventricle (RV) and right atrium (RV) were also delineated to analyze the entire RAVJ dynamics and determine their dimensions. These 2 groups were compared to 30 healthy subjects, considering the presence of a significant FTR in each group of patients.
Results
Maximum TA 3D area was 7.0±1.2cm²/m² in healthy subjects at mid-to-late diastole and was smaller than in patients of the MR group (9.8±2.1cm²/m², p<0.001) or of the DCMP group (9.2±3.0 cm²/m², p<0.001) (Figure). Moreover, in the MR group, but not in the DCMP group, subjects with FTR<2+, had greater TA diameters than healthy patients (maximum septo-lateral diameter, 23.6±3.6mm/m² versus 21.4±2.7mm/m², p=0.035). Conversely, TA shape was more circular and more planar only in the DCMP group with FTR≥2+ compared to all others. In multivariate analysis, both RA area (p<0.001) and RV volume (p=0.002) were independently related to TA dilatation (r=0.845). RV ejection fraction was strongly associated with both RV concentric strain (r=0.66, p<0.001) and with TA apical longitudinal excursion (r=0.64, p<0.001).
Conclusion
Based on multi-phase CT image analyses, TA area was directly related to RV and RA dimensions and these could be used for assessing TA dilatation. Patients with severe mitral myxomatous disease and non-dysfunctional tricuspid valve had yet increased TA diameters which questioned the current cut-off recommendation for concomitant tricuspid annuloplasty in this specific population.
Secondary functional tricuspid regurgitation (FTR) management remains controversial mainly due to the lack of knowledge in its pathogenesis and the difficulties to measure the actual dimensions of tricuspid annulus (TA) with current imaging methods. Using a new developed method based on cardiac CT-scan acquisition to finely analyze the right atrioventricular junction (RAVJ), we sought to explore modifications of TA morphometry and dynamics in secondary FTR.
Methods
In addition to echocardiographic data, cardiac CT-scans were obtained from 21 patients with severe myxoid mitral regurgitation (MR group) and 21 patients with ischemic or idiopathic dilated cardiomyopathy (DCMP group), all in sinus rhythm. Using an in-house software, 3D semi-automated delineation of 18 points around TA perimeter were defined. Modifications of diameters, 2D/3D areas and perimeters were analyzed through time. Right ventricle (RV) and right atrium (RV) were also delineated to analyze the entire RAVJ dynamics and determine their dimensions. These 2 groups were compared to 30 healthy subjects, considering the presence of a significant FTR in each group of patients.
Results
Maximum TA 3D area was 7.0±1.2cm²/m² in healthy subjects at mid-to-late diastole and was smaller than in patients of the MR group (9.8±2.1cm²/m², p<0.001) or of the DCMP group (9.2±3.0 cm²/m², p<0.001) (Figure). Moreover, in the MR group, but not in the DCMP group, subjects with FTR<2+, had greater TA diameters than healthy patients (maximum septo-lateral diameter, 23.6±3.6mm/m² versus 21.4±2.7mm/m², p=0.035). Conversely, TA shape was more circular and more planar only in the DCMP group with FTR≥2+ compared to all others. In multivariate analysis, both RA area (p<0.001) and RV volume (p=0.002) were independently related to TA dilatation (r=0.845). RV ejection fraction was strongly associated with both RV concentric strain (r=0.66, p<0.001) and with TA apical longitudinal excursion (r=0.64, p<0.001).
Conclusion
Based on multi-phase CT image analyses, TA area was directly related to RV and RA dimensions and these could be used for assessing TA dilatation. Patients with severe mitral myxomatous disease and non-dysfunctional tricuspid valve had yet increased TA diameters which questioned the current cut-off recommendation for concomitant tricuspid annuloplasty in this specific population.
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MO71. Neochordoplasty vs. Chordal Transposition for Anterior Leaflet Prolapse: Can Patient-specific Computational Biomechanics Predict Post-repair Mitral Valve Function?
Total Time: 5 Minutes
OBJECTIVE: Mitral valve (MV) repair for anterior leaflet prolapse is relatively more challenging to repair and requires further skilled surgical techniques and experiences. It is difficult to predict and compare the extent of restored MV function for two different repair techniques for a particular case. We have developed a novel 3D echocardiography-based computational tool to perform patient-specific MV repair simulations. In this study, we investigated, visualized, and compared the pre- and post-repair biomechanical characteristics of MV function following virtual neochordoplasty and chordal transposition for anterior leaflet prolapse.
METHODS: A patient-specific MV model having severe mitral regurgitation (MR) due to ruptured A2 chordae was created using 3D echocardiographic data (Fig. 1A). Standard surgical protocols of neochordoplasty and chordal transposition were rigorously designed to perform virtual MV repair simulations (Fig. 1B). Following each repair procedure, virtual ring annuloplasty was conducted to restore a normal size and shape for the annulus. Computational dynamic simulations over the full cardiac cycle were performed to determine the physiologic and biomechanical characteristics of the pre- and post-repair MV function.
RESULTS: Virtual neochordoplasty and chordal transposition successfully demonstrated patient-specific MV repair simulations (Fig. 1C-1D). The pre-repair MV revealed large leaflet malcoaptation and excessive stress distribution in the anterior leaflet where the chordae were ruptured. Virtual neochordoplasty clearly demonstrated markedly reduced prolapse and sufficiently restored leaflet coaptation with relatively uniform stress distribution across both leaflets. While virtual chordal transposition showed sufficiently recovered leaflet coaptation with reduced stresses in the posterior leaflet, the post-repair MV model exhibited concentrated leaflet stresses near the aortomitral junction.
CONCLUSIONS: We have developed a novel computational simulation strategy to evaluate and predict MV function before and after neochordoplasty and chordal transposition in a patient with anterior chordal rupture and severe MR. Both virtual neochordoplasty and chordal transposition techniques decreased anterior leaflet prolapse, restored leaflet coaptation, and lessened stress concentration. This virtual MV repair strategy has the potential for improved pre-surgical planning to predict and optimize post-repair MV function.
METHODS: A patient-specific MV model having severe mitral regurgitation (MR) due to ruptured A2 chordae was created using 3D echocardiographic data (Fig. 1A). Standard surgical protocols of neochordoplasty and chordal transposition were rigorously designed to perform virtual MV repair simulations (Fig. 1B). Following each repair procedure, virtual ring annuloplasty was conducted to restore a normal size and shape for the annulus. Computational dynamic simulations over the full cardiac cycle were performed to determine the physiologic and biomechanical characteristics of the pre- and post-repair MV function.
RESULTS: Virtual neochordoplasty and chordal transposition successfully demonstrated patient-specific MV repair simulations (Fig. 1C-1D). The pre-repair MV revealed large leaflet malcoaptation and excessive stress distribution in the anterior leaflet where the chordae were ruptured. Virtual neochordoplasty clearly demonstrated markedly reduced prolapse and sufficiently restored leaflet coaptation with relatively uniform stress distribution across both leaflets. While virtual chordal transposition showed sufficiently recovered leaflet coaptation with reduced stresses in the posterior leaflet, the post-repair MV model exhibited concentrated leaflet stresses near the aortomitral junction.
CONCLUSIONS: We have developed a novel computational simulation strategy to evaluate and predict MV function before and after neochordoplasty and chordal transposition in a patient with anterior chordal rupture and severe MR. Both virtual neochordoplasty and chordal transposition techniques decreased anterior leaflet prolapse, restored leaflet coaptation, and lessened stress concentration. This virtual MV repair strategy has the potential for improved pre-surgical planning to predict and optimize post-repair MV function.
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MO72. Early Historical Innovations in Mitral Valve Surgery Beginning at the Johns Hopkins Hospital
Total Time: 5 Minutes
Objective: In 1896, Ludwig Rehn conducted the first cardiac surgery. Elliott Cutler performed the first successful mitral valve (MV) commissurotomy in 1923. The advancement of cardiac surgery in the 27 years between these two landmarks is not well known. The objective of this study was to investigate the development of mitral valve surgery (MVS) originating at the Johns Hopkins Hospital (JHH).
Methods: We conducted an analysis of the Chesney Medical Archives and early editions of the JHH Bulletin. A detailed literature search of MVS was made in the Lancet, Boston Medical and Surgical Journal, and Surgery, Gynecology & Obstetrics through 1920.
Results: In 1905, William Halsted recruited Harvey Cushing in 1905 to lead the Johns Hopkins Hunterian Laboratory, where he worked with residents to establish surgical treatments of MV disease. William MacCallum developed the first cardiac valvulotome and a novel dog model of mitral insufficiency via the first successful attempts to produce valvular lesions via direct exposure of the heart, in 1906. In the same year, Gladys Henry determined the preferred surgical approach to the anterior surface of the heart and achieved improved access to the posterior surface by sternotomy or left thoracotomy. She reported 25 canine experiments with a 44% survival rate. MacCallum showed a trans-apical left ventricular approach was preferable to the trans-auricular approach for accessing the MV due to decreased bleeding. Bertram Bernheim invented a needle for annular ligation, inserted via left thoracotomy, to develop the first animal model of mitral stenosis, conducting a trial of 30 animals, 33% recovering, all with mitral stenosis. He noted progressive annular constriction induced bradycardia, now linked to ischemia induced AV nodal block, a possible complication of MV annuloplasty repair. 14 years before Cutler's commissurotomy, Bernheim and MacCallum confirmed their approach for opening stenotic MVs, stating that "this is a point in favor of the future possible operation on man." After moving to the Peter Bent Brigham Hospital in 1915, Cushing trained Elliott Cutler, who performed the first successful valvulotomy, using the approach developed in the Hunterian Lab.
Conclusions: In the early years of JHH, individuals developed novel animal models, cardiac surgical tools, and surgical techniques that significantly contributed to the development of MVS, laying the groundwork for future advances in surgical therapy for MV disease.
Methods: We conducted an analysis of the Chesney Medical Archives and early editions of the JHH Bulletin. A detailed literature search of MVS was made in the Lancet, Boston Medical and Surgical Journal, and Surgery, Gynecology & Obstetrics through 1920.
Results: In 1905, William Halsted recruited Harvey Cushing in 1905 to lead the Johns Hopkins Hunterian Laboratory, where he worked with residents to establish surgical treatments of MV disease. William MacCallum developed the first cardiac valvulotome and a novel dog model of mitral insufficiency via the first successful attempts to produce valvular lesions via direct exposure of the heart, in 1906. In the same year, Gladys Henry determined the preferred surgical approach to the anterior surface of the heart and achieved improved access to the posterior surface by sternotomy or left thoracotomy. She reported 25 canine experiments with a 44% survival rate. MacCallum showed a trans-apical left ventricular approach was preferable to the trans-auricular approach for accessing the MV due to decreased bleeding. Bertram Bernheim invented a needle for annular ligation, inserted via left thoracotomy, to develop the first animal model of mitral stenosis, conducting a trial of 30 animals, 33% recovering, all with mitral stenosis. He noted progressive annular constriction induced bradycardia, now linked to ischemia induced AV nodal block, a possible complication of MV annuloplasty repair. 14 years before Cutler's commissurotomy, Bernheim and MacCallum confirmed their approach for opening stenotic MVs, stating that "this is a point in favor of the future possible operation on man." After moving to the Peter Bent Brigham Hospital in 1915, Cushing trained Elliott Cutler, who performed the first successful valvulotomy, using the approach developed in the Hunterian Lab.
Conclusions: In the early years of JHH, individuals developed novel animal models, cardiac surgical tools, and surgical techniques that significantly contributed to the development of MVS, laying the groundwork for future advances in surgical therapy for MV disease.
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- MO072 - Early historical innovations in Mitral Valve Surgery beginning at the Johns Hopkins Hospital
Abstract Presenter
Emily Rodriguez, The Johns Hopkins School of Medicine - Contact Me Baltimore, MDUnited States