Long-Term Outcomes of Coronary Artery Bypass Grafting in Veterans with Ischemic Cardiomyopathy

Abstract

Background: The Surgical Treatment for Ischemic Heart Failure (STICH) trial showed that surgical revascularization in ischemic cardiomyopathy (ICM) patients improves long-term mortality compared with medical treatment alone. This study examines how veterans with ICM undergoing revascularization fare against patients without ICM; it also examines the outcomes in the veteran population. Methods: This is a retrospective review of a single-center database. From 2000 to 2018, 1,461 patients underwent isolated coronary artery bypass grafting (CABG). Two-hundred-one patients with an ejection fraction less than 35% were classified as the ICM cohort. The primary outcome was mortality. Secondary outcomes included postoperative complications. Subgroup analysis was performed within the ICM cohort comparing off-pump CABG (OPCAB) versus on-pump CABG (ONCAB). Results: ICM patients had a higher incidence of myocardial infarction (MI), diabetes, chronic kidney disease (CKD), and preoperative intra-aortic balloon pump (IABP) use. The non-ICM cohort was more functionally independent. OPCAB was performed in 80.1% of ICM and 66.3% of non-ICM cohorts. There was no statistical difference between ICM and non-ICM cohorts in 30-day mortality (OR 1.94[0.79 – 4.75], P = .15). The ICM cohort had an increased 5-year mortality (OR 1.75[1.14 – 2.69], P = .01) and 10-year mortality (OR 1.71[1.09 - 2.67], P = .02). The ICM cohort showed improved, although not statistically significant, short-term mortality with OPCAB compared with ONCAB (3.1% versus 12.5%, OR 0.31[0.05 – 1.82], P = .20). Conclusion: Veterans with ICM undergoing CABG demonstrated similar short-term survival compared with non-ICM veterans. The long-term survival in the ICM cohort still is inferior to patients without ICM. There is a trend toward improved short-term survival in patients with ICM undergoing OPCAB.