Invited Commentary

Abstract

Transmural myocardial infarctions are serious events that yield high rates of in-hospital morbidity and mortality. The timing of surgical coronary revascularization after an ST elevation myocardial infarction (STEMI) has traditionally been delayed for at least 3 days, and preferably 7, to allow the infarct to stabilize and for the systemic neurohormonal milieu to subside. Such a delay has not been previously recommended for patients not with a STEMI. Yu and colleagues [1Yu P-J Cassiere H.A. Kohn N. Dellis S.L. Manetta F. Hartman A.R. Myocardial infarction classification on outcomes in nonemergent coronary artery bypass grafting.Ann Thorac Surg. 2015; 100: 1588-1594Google Scholar] conducted an observational prospective cohort study of patients who had experienced myocardial infarction and required CABG to reexamine the delicate issue of timing after STEMI. The researchers are to be commended for a well-designed study that enrolled more than 400 patients and for the excellent outcomes. The rates of morbidity and mortality were very low in both STEMI and non-STEMI patients alike. There was no difference in timing of CABG between the groups, and, importantly, there was no difference in early mortality. Although the groups were somewhat dissimilar in their preoperative comorbidities, the authors used propensity matching to simulate equality between groups. The outcomes in the matched pairs reflected the unmatched analysis and showed no difference in in-hospital outcomes. What, then, is to be learned from this study? It was a relatively small single-center observational study with a conclusion that seems to contradict multiple prior efforts in the area, including two large studies from statewide databases. Those studies consistently demonstrated that mortality for patients with a STEMI who underwent CABG returned to nearly baseline if the delay in CABG was 7 days or longer. What is missing from many of these studies, however, is important clinical data, including territory of infarct and the presence of ongoing or recurrent ischemia, which may affect the surgeon’s decision regarding the timing of CABG. For patients with ongoing ischemia or shock, these patients very likely undergo emergent surgical or percutaneous revascularization, and they are inherently higher risk than those who undergo urgent or semielective revascularization. This selection bias is an important limitation of the current and previous studies. Additionally, recent advances in modern critical care and postoperative management have led to improved outcomes across the spectrum of cardiac operations. This study should serve as a call to reexamine this critical issue with larger national and statewide databases. Until such a reassessment occurs, the optimal timing for CABG after STEMI will remain a topic of debate. Myocardial Infarction Classification on Outcomes in Nonemergent Coronary Artery Bypass GraftingThe Annals of Thoracic SurgeryVol. 100Issue 5PreviewAlthough patients with ST elevation myocardial infarctions (STEMIs) are known to have worse outcomes than patients with non-ST elevation myocardial infarctions (NSTEMIs), such differences are not well described in the subset of patients undergoing coronary artery bypass grafting. The purpose of this study is to compare postoperative outcomes of patients undergoing nonemergent coronary artery bypass grafting within 1 week after an STEMI versus NSTEMI. Full-Text PDF