P134. Impact of GDMT Compliance on Long-Term Outcomes After Isolated Single vs Bilateral Internal Mammary Artery CABG
Presented During: Adult Cardiac Poster Session II
UPMC Presbyterian
PA
United States - Contact Me
Kei Kobayashi, MD, PhD, is a PGY-4 Integrated Cardiothoracic Surgery resident at the University of Pittsburgh Medical Center (UPMC). He has broad interests across cardiac surgery, with particular focus on congenital heart disease and complex perioperative care. His academic work centers on clinically driven, translational research aimed at improving surgical outcomes and patient recovery, with experience spanning both clinical data analysis and mechanistic questions relevant to cardiothoracic surgery. He is currently completing a dedicated research year focused on clinical research in cardiothoracic surgery at UPMC.
Monday, May 4, 2026: 9:00 AM - 4:00 PM
McCormick Place Lakeside Center
Room: Exhibit Hall, Poster Area
Description
Objective: To evaluate how compliance with guideline-directed medical therapy (GDMT) modifies the incremental benefit of bilateral (BIMA) versus single (SIMA) internal mammary artery grafting in isolated coronary artery bypass grafting (CABG).
Methods: Adults ≥18 years who underwent isolated CABG with SIMA or BIMA between 2011-2024 were retrospectively analyzed. Exclusions included prior CABG, emergent CABG or pre-operative mechanical circulatory support, dialysis, and residence >50 miles from the nearest satellite facility. Prescription records were used to determine GDMT compliance, defined as ≥80% days covered per year for all eligible drugs (statin, beta-blocker, antiplatelet/P2Y12). The primary endpoint was time to first major adverse cardiac event (MACE: all-cause mortality, myocardial infarction, or repeat revascularization). Cox regression assessed associations among conduit strategy, GDMT compliance, and their interaction, adjusting for demographics and comorbidities.
Results: A total of 3616 patients were included (SIMA=3076, BIMA=540). Median follow-up was 7.6 years. Cumulative MACE was significantly higher with SIMA than with BIMA, reaching 44.5% versus 32.1% at 10 years (log-rank p<.001). Cumulative mortality at 10 years was 28.6% for SIMA versus 19.1% for BIMA (log-rank p<.001). BIMA independently reduced MACE risk by 28% (adjusted HR 0.72 [0.60-0.86], p<.001), and GDMT compliance (≥80%) was associated with a 12% lower hazard of MACE (adjusted HR 0.88 [0.78-0.99], p=.030), however, there was no significant conduit-GDMT interaction (p=.479). Using the SIMA-compliant group as reference, the SIMA-non-compliant group had a 16% higher MACE risk (HR 1.16 [1.02-1.31], p=.023). The BIMA-compliant and BIMA-non-compliant groups had HRs of 0.78 (0.58-1.05, p=.106) and 0.80 (0.64-1.00, p=.0497), respectively, relative to SIMA-compliant patients. GDMT compliance significantly improved late survival among SIMA patients (non-compliance HR 1.25 [1.06-1.48], p=.009), but not within BIMA, likely from limited power in the smaller BIMA subgroups.
Conclusions: GDMT adherence did not significantly impact late survival within the BIMA cohort. Compliance with GDMT significantly improves long-term outcomes only in SIMA CABG patients. The persistence of BIMA's overall survival benefit alongside the additive protection of GDMT emphasizes that optimal surgical conduit selection and sustained medical compliance are complementary determinants of late CABG outcomes.
Authors
KEI KOBAYASHI (1), Xander Jacquemyn (1), Jianhui Zhu (1), Floyd Thoma (1), Derek Serna-Gallegos (1), David Kaczorowski (1), Johannes Bonatti (1), Francis Ferdinand (1), David West (1), Takuya Ogami (1), Irsa Hasan (1), Ibrahim Sultan (1), Danny Chu (1)
Institutions
(1) University of Pittsburgh Medical Center, Pittsburgh, PA
Methods: Adults ≥18 years who underwent isolated CABG with SIMA or BIMA between 2011-2024 were retrospectively analyzed. Exclusions included prior CABG, emergent CABG or pre-operative mechanical circulatory support, dialysis, and residence >50 miles from the nearest satellite facility. Prescription records were used to determine GDMT compliance, defined as ≥80% days covered per year for all eligible drugs (statin, beta-blocker, antiplatelet/P2Y12). The primary endpoint was time to first major adverse cardiac event (MACE: all-cause mortality, myocardial infarction, or repeat revascularization). Cox regression assessed associations among conduit strategy, GDMT compliance, and their interaction, adjusting for demographics and comorbidities.
Results: A total of 3616 patients were included (SIMA=3076, BIMA=540). Median follow-up was 7.6 years. Cumulative MACE was significantly higher with SIMA than with BIMA, reaching 44.5% versus 32.1% at 10 years (log-rank p<.001). Cumulative mortality at 10 years was 28.6% for SIMA versus 19.1% for BIMA (log-rank p<.001). BIMA independently reduced MACE risk by 28% (adjusted HR 0.72 [0.60-0.86], p<.001), and GDMT compliance (≥80%) was associated with a 12% lower hazard of MACE (adjusted HR 0.88 [0.78-0.99], p=.030), however, there was no significant conduit-GDMT interaction (p=.479). Using the SIMA-compliant group as reference, the SIMA-non-compliant group had a 16% higher MACE risk (HR 1.16 [1.02-1.31], p=.023). The BIMA-compliant and BIMA-non-compliant groups had HRs of 0.78 (0.58-1.05, p=.106) and 0.80 (0.64-1.00, p=.0497), respectively, relative to SIMA-compliant patients. GDMT compliance significantly improved late survival among SIMA patients (non-compliance HR 1.25 [1.06-1.48], p=.009), but not within BIMA, likely from limited power in the smaller BIMA subgroups.
Conclusions: GDMT adherence did not significantly impact late survival within the BIMA cohort. Compliance with GDMT significantly improves long-term outcomes only in SIMA CABG patients. The persistence of BIMA's overall survival benefit alongside the additive protection of GDMT emphasizes that optimal surgical conduit selection and sustained medical compliance are complementary determinants of late CABG outcomes.
Authors
KEI KOBAYASHI (1), Xander Jacquemyn (1), Jianhui Zhu (1), Floyd Thoma (1), Derek Serna-Gallegos (1), David Kaczorowski (1), Johannes Bonatti (1), Francis Ferdinand (1), David West (1), Takuya Ogami (1), Irsa Hasan (1), Ibrahim Sultan (1), Danny Chu (1)
Institutions
(1) University of Pittsburgh Medical Center, Pittsburgh, PA
Presentation Duration
There is no formal presentation for posters. Your poster will be on display on your assigned day from 9:00AM - 4:00PM
View Submission
ADULT CARDIAC
Coronary Artery Disease