Long-term Outcomes After Reoperative Coronary Artery Bypass Grafting

Abstract

Reoperative coronary artery bypass grafting (CABG) surgery has an established increasedoperative risk with worse perioperative morbidity and mortality. However, contemporary propensity-matched outcomes are limited in the existing literature. All patients who underwent CABG from 2011 to 2017 at the University of Pittsburgh Medical Center in Pittsburgh, Pennsylvania were included. Propensity matching yielded risk-adjusted patient populations. Cox regression analysis was performed to identify independent predictors of 30-day, 1-year, and 5-year mortality and readmission. The total population consisted of 7615 patients who underwent CABG; 7265 of these patients had first-time CABG, and 350 patients had reoperative CABG. After propensity score matching, blood product transfusion (45.5% vs 56.4%; P= .002) and delayed sternal closure (0.2% vs 2.5%; P < .001) remained significantly higher for reoperative CABG. There was no difference in 30-day (5.3% vs 7.5%; P= .19) or 1-year (12.1% vs 14.8%; P= .23) mortality for first-time vs reoperative CABG. Five-year mortality was significantly higher for the reoperative cohort (28.5% vs 38.3%; P= .03). There was no difference in 30-day, 1-year, or 5-year hospital readmissions. On Cox multivariable regression analysis, reoperative CABG was not a predictor of mortality or readmission at 30 days, 1 year, or 5 years. After propensity score matching, there was no difference in postoperative mortality or readmission for reoperative CABG up to 1-year. This trend continued for 5-year readmissions; however, 5-year mortality was higher for the reoperative cohort. Risk adjustment did not identify reoperative CABG as a risk factor for long-term mortality.