Inter-Observer Variability Affects Treatment of Ascending Aortic Aneurysms: Real World Evidence from a Prospective Multi-Center Study on Thoracic Aortic Aneurysms

P0178 

Abstract Submission 

Saurabh Gupta (1), Ayse Hafsa (2), Jehangir Appoo (3), Eric Herget (4), Ming Hao Guo (5), Philippe Demers (6), Michael Chu (7), Rony Atoui (8), William Brinkman (9), John Bozinovski (10), Francois Dagenais (11), Nimesh Desai (12), Ismail El-Hamamsy (13), Juan Grau (14), G. Chad Hughes (15), Arminder Jassar (16), Kevin Lachapelle (17), Maral Ouzounian (18), Himanshu Patel (19), Zlatko Pozeg (20), Richard Whitlock (21), Munir Boodhwani (22)

(1) N/A, Canada, (2) University of Ottawa Heart Institute, Ottawa, Ontario, (3) Libin Cardiovascular Institute, University of Calgary, Calgary, AB, (4) University of Calgary, Calgary, NA, (5) University of Ottawa Heart Institute, Ottawa, ON, (6) Montreal Heart Institute, Montreal, QC, (7) University Hospital, London Health Sciences Centre, London, Canada, (8) Northern Ontario School of Medicine, Sudbury, ON, (9) Baylor Scott & White Health, TX, (10) Ohio State University Wexner Medical Center, Columbus, OH, (11) Quebec Heart and Lung Insitute, Quebec, Quebec, (12) University of Pennsylvania, Philadelphia, PA, (13) Mount Sinai Hospital, New York, NY, (14) The Valley Hospital, Ridgewood, NJ, (15) Duke University Medical Center, Durham, NC, (16) Massachusetts General Hospital, Boston, MA, (17) Division of Cardiac Surgery, McGill University Health Centre, Montreal, QC, (18) Toronto General Hospital, Toronto, ON, (19) University of Michigan Hospital, Ann Arbor, MI, (20) New Brunswick Heart Centre, Saint John, New Brunswick, (21) Population Health Research Institute, Hamilton, Canada, (22) N/A, Ottawa, ON

Saurabh Gupta    -  Contact Me
N/A

Ayse Hafsa    -  Contact Me
University of Ottawa Heart Institute

Jehangir Appoo    -  Contact Me
Libin Cardiovascular Institute, University of Calgary

Eric Herget    -  Contact Me
University of Calgary

Ming Hao Guo    -  Contact Me
University of Ottawa Heart Institute

Philippe Demers    -  Contact Me
Montreal Heart Institute

*Michael Chu    -  Contact Me
University Hospital, London Health Sciences Centre

Rony Atoui    -  Contact Me
Northern Ontario School of Medicine

*William Brinkman    -  Contact Me
Baylor Scott & White Health

John Bozinovski    -  Contact Me
Ohio State University Wexner Medical Center

*Francois Dagenais    -  Contact Me
Quebec Heart and Lung Insitute

*Nimesh Desai    -  Contact Me
University of Pennsylvania

*Ismail El-Hamamsy    -  Contact Me
Mount Sinai Hospital

*Juan Grau    -  Contact Me
The Valley Hospital

*G. Chad Hughes    -  Contact Me
Duke University Medical Center

*Arminder Jassar    -  Contact Me
Massachusetts General Hospital

Kevin Lachapelle    -  Contact Me
Division of Cardiac Surgery, McGill University Health Centre

*Maral Ouzounian    -  Contact Me
Toronto General Hospital

*Himanshu Patel    -  Contact Me
University of Michigan Hospital

Zlatko Pozeg    -  Contact Me
New Brunswick Heart Centre

Richard Whitlock    -  Contact Me
Population Health Research Institute

*Munir Boodhwani    -  Contact Me
N/A

Saurabh Gupta    -  Contact Me
N/A

Objective:
There is a lack of prospective evidence around the risk profile of ascending thoracic aortic aneurysms (ATAA). Current societal guidelines rely heavily on maximal aortic diameter to guide intervention. Using data from the largest ever prospective multi-center study of ATAA, we assess the degree of inter-observer variability in assessing maximal aortic diameters as reported by 22 sites (real-world) to core lab data.

Methods:
TITAN: SvS (Treatment In Thoracic Aortic aNeurysm: Surgery versus Surveillance) is a multi-center trial randomizing patients with ATAA between 5.0-5.4 cm to an initial strategy of surgery versus surveillance. A parallel registry enrolls patients who are not randomized. To assess accuracy, aortic measures of site-reported CTs were compared to the core lab reported measurements of the same CTs. Along with comparing maximal aortic diameter, note was also made when measurements deviated by ≥2mm, and how often measurement differences resulted in whether patients were surgical candidates or not.

Results:
CT reports of 458 patients from 22 sites were available (mean age 67.9 +/-9.8; 18.6% female). The mean maximum ATAA diameter reported by sites was higher than core lab (51.05mm +/-5.1 vs 50.48mm +/-7.06; p<0.05). In 97/264 (36.74%) patients, maximal aortic diameters differed by ≥2mm between site-reported vs. core-lab (23 lower; 74 higher). The discrepancy for CT measurements was site-dependent; some site reports had 0 such differences, while others had as many as 44% reports incongruent by ≥2mm. According to core lab measurements, 93/458 (20.3%) patients reviewed did not meet criteria for intervention (92 had aortas under 5cm; 1 was over 5.4cm). In fact, 64/264 (24.2%) patients who met criteria for surgery based on site CT reports, no longer met criteria based on core lab measurements. Two orthogonal measurements for each aortic site, as recommended by imaging guidelines, were not provided in 120/458 (26.2%).

Conclusion:
Based on contemporary data from the largest ever prospective study on ATAA, significant variability exists between site reported aortic diameters on CT scans compared to diameters reported by an imaging core lab. Up to 20% of patients are diagnosed as meeting a surgical threshold before they actually reach it. The significant difference in inter-observer variability superimposed on lack of prospective evidence on risk profile of ascending aortic aneurysms, suggests need for more nuanced reproducible risk profiling of the ascending aorta. When completed, the Titan:SvS trial may provide further evidence on the risk profile of ATAA.

Ascending Aorta