Primary OPCAB as a strategy for acute coronary syndrome and acute myocardial infarction.

Background: Conventional coronary artery bypass graft (CABG) surgery using cardiopulmonary bypass (CPB) carries higher mortality and morbidity for patients undergoing surgery during acute coronary syndrome (ACS). The aim of this retrospective study was to evaluate potential benefits of avoiding CPB by instead performing off-pump CAB (OPCAB) during surgery on patients in ACS.
Methods: Among 624 patients who underwent OPCAB between January 1999 and June 2001, 143 underwent surgery during ACS (group 1). The ACS patients in group 1 were divided into 2 subgroups: 66 underwent surgery during acute myocardial infarction (AMI group) and 77 during unstable angina classified as class III or IV according to the Braumwald classification (unstable coronary artery disease [CAD] group). Group 2 (the elective CAD group) consisted of 481 patients who underwent isolated elective OPCAB during the same time period.
Results: Overall 30-day mortality was 4.9% (n = 7) for the ACS group and 0.83% (n = 4) for the elective CAD group (P < .0001). Differences between groups were found in use of inotropes, intraaortic balloon pump, and subsequent conversion of OPCAB to CPB (P < .0001, P < .01, and P < .03, respectively), as well as use of blood transfusion (P < .0003). Multivariate logistic regression analysis for 641 patients revealed ACS (P < .015), AMI (P < .019), renal failure (P < .017), and left ventricle aneurysm (P < .028) as independent risk factors for 30-day mortality in ACS reoperation (P = .02), whereas in AMI renal failure (P = .02) appeared to be an independent risk factor.
Conclusions: OPCAB is a valuable treatment strategy in ACS patients; however, it carries significant mortality and morbidity. Careful preselection and timing of intervention are required in order for patients to fully benefit from the OPCAB strategy.