Differences in Patient Characteristics in Randomized Arm vs. Parallel Registry of Patients with Ascending Aortic Aneurysms: Insights from a Contemporary Multi-center Prospective Trial
Presented During:
Thursday, April 25, 2024: 5:38PM - 7:00PM
Sheraton Times Square
Posted Room Name:
Central Park
Abstract No:
P0103
Submission Type:
Abstract Submission
Authors:
Sarah Brownlee (1), Munir Boodhwani (2), Jehangir Appoo (3), Ming Hao Guo (2), Adham Makarem (4), Philippe Demers (5), Michael Chu (6), Rony Atoui (7), William Brinkman (8), John Bozinovski (9), Francois Dagenais (10), Nimesh Desai (11), Ismail El-Hamamsy (12), Juan Grau (13), G. Chad Hughes (14), Kevin Lachapelle (15), Maral Ouzounian (16), Himanshu Patel (17), Zlatko Pozeg (18), Richard Whitlock (19), Arminder Jassar (1)
Institutions:
(1) Massachusetts General Hospital, Boston, MA, (2) University of Ottawa Heart Institute, Ottawa, ON, (3) Libin Cardiovascular Institute, University of Calgary, Calgary, AB, (4) Massachusetts General Hospital, BOSTON, MA, (5) Montreal Heart Institute, Montreal, QC, (6) University Hospital, London Health Sciences Centre, London, Canada, (7) Northern Ontario School of Medicine, Sudbury, ON, (8) Baylor Scott & White Health, TX, (9) Ohio State University Wexner Medical Center, Columbus, OH, (10) Quebec Heart and Lung Insitute, Quebec, Quebec, (11) University of Pennsylvania, United States, (12) Mount Sinai Hospital, New York, NY, (13) The Valley Hospital, Ridgewood, NJ, (14) Duke University Medical Center, Durham, NC, (15) Division of Cardiac Surgery, McGill University Health Centre, Montreal, QC, (16) Toronto General Hospital, Toronto, ON, (17) University of Michigan Hospital, Ann Arbor, MI, (18) New Brunswick Heart Centre, Saint John, New Brunswick, (19) Population Health Research Institute, Hamilton, Canada
Submitting Author:
Sarah Brownlee
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Massachusetts General Hospital
Massachusetts General Hospital
Co-Author(s):
*Munir Boodhwani
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University of Ottawa Heart Institute
University of Ottawa Heart Institute
Jehangir Appoo
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Libin Cardiovascular Institute, University of Calgary
Libin Cardiovascular Institute, University of Calgary
Ming Hao Guo
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University of Ottawa Heart Institute
University of Ottawa Heart Institute
Adham Makarem
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Massachusetts General Hospital
Massachusetts General Hospital
Philippe Demers
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Montreal Heart Institute
Montreal Heart Institute
*Michael Chu
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University Hospital, London Health Sciences Centre
University Hospital, London Health Sciences Centre
Rony Atoui
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Northern Ontario School of Medicine
Northern Ontario School of Medicine
*William Brinkman
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Baylor Scott & White Health
Baylor Scott & White Health
John Bozinovski
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Ohio State University Wexner Medical Center
Ohio State University Wexner Medical Center
*Francois Dagenais
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Quebec Heart and Lung Insitute
Quebec Heart and Lung Insitute
*Nimesh Desai
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University of Pennsylvania
University of Pennsylvania
*Ismail El-Hamamsy
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Mount Sinai Hospital
Mount Sinai Hospital
*Juan Grau
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The Valley Hospital
The Valley Hospital
*G. Chad Hughes
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Duke University Medical Center
Duke University Medical Center
Kevin Lachapelle
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Division of Cardiac Surgery, McGill University Health Centre
Division of Cardiac Surgery, McGill University Health Centre
*Maral Ouzounian
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Toronto General Hospital
Toronto General Hospital
*Himanshu Patel
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University of Michigan Hospital
University of Michigan Hospital
Zlatko Pozeg
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New Brunswick Heart Centre
New Brunswick Heart Centre
Richard Whitlock
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Population Health Research Institute
Population Health Research Institute
*Arminder Jassar
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Massachusetts General Hospital
Massachusetts General Hospital
Presenting Author:
*Arminder Jassar
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Massachusetts General Hospital
Massachusetts General Hospital
Abstract:
Objective: Guidelines for intervention on ascending aortic aneurysm repair are based on data from retrospective studies with no evidence from prospective trials. TITAN: SvS (Treatment in Thoracic Aortic aNeurysm: Surgery versus Surveillance) is the largest prospective multi-center study of patients with ascending aortic aneurysms between 5.0-5.4 cm with aim to randomize patients to initial surgery versus surveillance. For patients not randomized, they are enrolled into either an operative registry (surgery as initial treatment), or a surveillance registry (surveillance as initial strategy). We compare patient characteristics for subjects in the randomized and the registry arms of the TITAN:SvS study to understand factors behind patient selection for each strategy.
Methods: Demographic characteristics of 615 patients prospectively enrolled at 22 sites into the TITAN study (9/2018-12/2023) were analyzed and compared between randomized (n=210) and registry arms (operative registry n=147; surveillance registry n= 258). Preoperative characteristics, aortic size, indexed aortic parameters and country and site wise distribution of patients were compared. Categorical variables were compared with chi-square or Fischer's exact test. Continuous variables were compared with one-way ANOVA or Wilcoxon rank-sum test where appropriate.
Results: Patients in the surveillance registry have the most co-morbidities: older, more HTN, dyslipidemia, CAD, Afib, DM, CVA, pHTN and PVD (Table 1). No significant difference was noted in maximal ascending aortic diameter (5.1±0.3, 5.0±0.3, 5.1±0.5cm, p=0.2) or indexed aortic size in the randomized, operative or surveillance registry groups respectively. There was no significant difference in groups in the number of patients above the indexed aortic size, indexed aortic height or indexed aortic area thresholds for intervention suggested in the 2022 ACC/AHA aortic guidelines. Despite similar number of enrolling centers in the USA (n=11) and Canada (n=12), 91% (191/210) of patients in the randomized arm were enrolled in Canada. Of Canadian patients (n=332), 58% were randomized, 9% enrolled in the operative registry, 34% enrolled in the surveillance registry. Of US patients (n=283), 7% were randomized, 42% enrolled in the operative registry, 51% enrolled in the surveillance registry.
Conclusions: Early data from the largest ever prospective multicenter study on ascending aortic aneurysms reveals that patient characteristics rather than ascending aortic size seem to be the main factor driving decision making regarding initial treatment strategy, with younger healthier patients being offered surgery more often. These data suggest that the published outcomes of operative registries cannot be universally applied, as sicker patients may have been excluded. There is a geographic difference in enrollment with Canadian sites contributing heavily to the Randomized arm and US sites contributing heavily to the Registry arms. Reasons for this are likely multifactorial, but may include differences in patient preferences, surgeon perspectives, referral patterns and insurance/healthcare system structures. US vs. Canadian differences in participation has implications both for completion of Titan:SvS and for future randomized trials comparing surgical to conservative therapies. Future trials may consider a strategy of having a parallel registry to an RCT to interpret RCT data alongside contemporary real-world insights.
Methods: Demographic characteristics of 615 patients prospectively enrolled at 22 sites into the TITAN study (9/2018-12/2023) were analyzed and compared between randomized (n=210) and registry arms (operative registry n=147; surveillance registry n= 258). Preoperative characteristics, aortic size, indexed aortic parameters and country and site wise distribution of patients were compared. Categorical variables were compared with chi-square or Fischer's exact test. Continuous variables were compared with one-way ANOVA or Wilcoxon rank-sum test where appropriate.
Results: Patients in the surveillance registry have the most co-morbidities: older, more HTN, dyslipidemia, CAD, Afib, DM, CVA, pHTN and PVD (Table 1). No significant difference was noted in maximal ascending aortic diameter (5.1±0.3, 5.0±0.3, 5.1±0.5cm, p=0.2) or indexed aortic size in the randomized, operative or surveillance registry groups respectively. There was no significant difference in groups in the number of patients above the indexed aortic size, indexed aortic height or indexed aortic area thresholds for intervention suggested in the 2022 ACC/AHA aortic guidelines. Despite similar number of enrolling centers in the USA (n=11) and Canada (n=12), 91% (191/210) of patients in the randomized arm were enrolled in Canada. Of Canadian patients (n=332), 58% were randomized, 9% enrolled in the operative registry, 34% enrolled in the surveillance registry. Of US patients (n=283), 7% were randomized, 42% enrolled in the operative registry, 51% enrolled in the surveillance registry.
Conclusions: Early data from the largest ever prospective multicenter study on ascending aortic aneurysms reveals that patient characteristics rather than ascending aortic size seem to be the main factor driving decision making regarding initial treatment strategy, with younger healthier patients being offered surgery more often. These data suggest that the published outcomes of operative registries cannot be universally applied, as sicker patients may have been excluded. There is a geographic difference in enrollment with Canadian sites contributing heavily to the Randomized arm and US sites contributing heavily to the Registry arms. Reasons for this are likely multifactorial, but may include differences in patient preferences, surgeon perspectives, referral patterns and insurance/healthcare system structures. US vs. Canadian differences in participation has implications both for completion of Titan:SvS and for future randomized trials comparing surgical to conservative therapies. Future trials may consider a strategy of having a parallel registry to an RCT to interpret RCT data alongside contemporary real-world insights.
Aortic Symposium:
Ascending Aorta
Image or Table
