Timing of coronary artery bypass grafting after acute myocardial infarction may not influence mortality and readmissions

Objective: Coronary artery bypass grafting is often delayed after acute myocardial infarction to avoid an increase in postoperative morbidity and mortality. We hypothesized that the timing of coronary artery bypass grafting after acute myocardial infarction may not be consistently associated with postoperative outcomes. Methods: All patients who underwent isolated coronary artery bypass grafting at the University of Pittsburgh Medical Center from 2011 to 2017 after an acute myocardial infarction were reviewed. A comparative analysis for time from myocardial infarction presentation to coronary artery bypass grafting was performed with primary outcomes including all-cause mortality and readmission. Results: A total of 7048 patients underwent isolated coronary artery bypass grafting. Of these, 2058 patients had acute myocardial infarction with all relevant variables available for analysis. The study population was divided into 2 coronary artery bypass grafting timing cohorts, including less than 24 hours (n = 292) and 24 hours or more (n = 1766). Previous percutaneous coronary intervention, cardiogenic shock, and intra-aortic balloon pump were more prevalent in the less than 24 hours group. Operative mortality was significantly higher in the less than 24 hours cohort (7.19% vs 3.79%; P = .01). Diabetes mellitus, peripheral vascular disease, serum creatinine, age, chronic obstructive pulmonary disease, and immunosuppression were significant predictors (P < .05) of mortality. After risk adjustment with propensity scoring, there was no difference between time cohorts for operative mortality (4.15% vs 4.58%; P = .62). New-onset atrial fibrillation occurred more frequently in the 24 hours or more cohort. There was no difference between groups for the occurrence of major adverse cardiovascular and cerebrovascular event readmissions. Conclusions: After adjusting for baseline patient characteristics, there was no statistically significant difference between timing cohorts for mortality or major adverse cardiovascular and cerebrovascular event readmissions.