P129. Durability of Internal Mammary Artery Grafts in Cardiac Surgery Patients with Prior Mediastinal Radiation
Massachusetts General Hospital
Boston, MA
United States - Contact Me
Dr. Adham Makarem is a postdoctoral research fellow in the Division of Cardiac Surgery at Massachusetts General Hospital (MGH) and Harvard Medical School (HMS). He is also an affiliate research fellow at the Center for Surgery and Public Health at Brigham and Women's Hospital and Harvard T.H. Chan School of Public Health. Born and raised in Ras El-Maten, Lebanon, he received the Mastercard Foundation full-ride scholarship and completed his B.S. in Medical Laboratory Sciences with distinction and his Doctorate of Medicine (MD) from the American University of Beirut (AUB). He then earned two graduate diplomas from the Program for Advanced Injury Research (MENA-PAIR) at Yale University School of Medicine, and from the Scholars in Health Research Program (SHARP), which is a replica of the Harvard T.H. Chan Clinical Effectiveness Program. Afterwards, he became the first MD ever to receive the prestigious Fulbright Scholarship and continued his education by pursuing his MPH at Boston University School of Public Health, obtaining two functional certificates: Health Policy and Law, and Epidemiology and Biostatistics. He then pursued advanced studies in Biostatistics at Harvard University.
Dr. Makarem has a longstanding interest in cardiothoracic surgery and transplantation, with primary research focuses on surgical outcomes, health services research, and transplant policies. He also has significant experience in designing, conducting, and analyzing clinical trials in the surgical field. Dr. Makarem serves as a review editor and peer reviewer for several transplant and cardiothoracic surgery journals. His research has been presented at several national and international scientific meetings and published in reputed peer-reviewed journals.
Description
Methods: We retrospectively identified all patients who underwent isolated CABG at Mass General Brigham with a history of mediastinal radiation. A 1:3 propensity score–matched cohort without prior mediastinal radiation was constructed based on demographics, comorbidities, and operative characteristics. IMA graft patency was assessed among patients who underwent postoperative coronary angiography, and long-term survival was evaluated using Kaplan–Meier analysis.
Results: A total of 141 patients with prior mediastinal radiation were matched to 423 controls, with balanced baseline characteristics (standardized mean differences <0.1 for all covariates). IMA utilization was lower in the mediastinal radiation group compared with controls (93.3% vs 97.6%, p=0.017), most commonly due to prior radiation or previous cardiac surgery. Radial artery and venous conduit use did not differ significantly between groups. Follow-up coronary angiography was performed more frequently among patients with prior radiation (21.4% vs 12.0%,p = 0.006). Among those who underwent angiography, IMA graft patency (<50% stenosis) was lower in the radiation group (63.3% vs 80.0%) but did not reach statistical significance (p = 0.331). Complete occlusion occurred more often in the radiation cohort (26.7% vs 14.0%). Long-term survival was significantly reduced in the radiation group, with mortality rates of 9.2% vs 3.8% at 1 year (p=0.0113) and 25.5% vs 16.6% at 10 years (p=0.0180). Kaplan–Meier analysis demonstrated inferior overall survival among radiation-exposed patients (HR=1.69, 95% CI 1.14–2.49,p=0.0088).
Conclusion: In this dual-center propensity-matched analysis, prior mediastinal radiation was associated with lower IMA utilization, a trend toward reduced graft patency, and worse long-term survival. Although angiographic follow-up was symptom-driven, these findings raise important questions about the long-term durability of IMA grafts. Practitioners might consider alternative conduit strategies in patients with a history of radiation.
Authors
Adham Makarem (1), Emmanuel Odekunle (2), Patrick Udeh (1), Zoe Laddis (1), Carly Liquori (1), Jack Guiry (3), Boateng Kubi (4), Niyi Odewade (5), Jordan Bloom (1), Motahar Hosseini (1), Arminder Jassar (1), Antonia Kreso (6), Nathaniel Langer (7), Serguei Melnitchouk (1), Eriberto Michel (1), Alireza Rabi (1), David D'Alessandro (8), Sary Aranki (9), George Tolis (10), Ashraf Sabe (11), Thoralf Sundt (12), Akinobu Itoh (10), Asishana Osho (1)
Institutions
(1) Massachusetts General Hospital, Boston, MA, (2) N/A, N/A, (3) Massachusetts General Hospital, Charlottesville, VA, (4) Massachusetts General Hospital, Everett, MA, (5) Brigham & Women's Hospital, Brighton, MA, (6) Division of Cardiac Surgery, Massachusetts General Hospital, Boston, MA, (7) Division of Cardiac Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, (8) Harvard University Medical School, Weston, MA, (9) N/A, Boston, MA, (10) Brigham and Women's Hospital, Boston, MA, (11) Brigham and women's hospital, Boston, MA, (12) Harvard University, Boston, MA