Myocardial Revascularization on the Beating Heart After Recent Onset of Acute Myocardial Infarction

Abstract

Objective: Coronary artery bypass grafting (CABG) after the recent onset of acute myocardial infarction (AMI) is associated with high morbidity and mortality. Myocardial revascularization without cardiopulmonary bypass (CPB) has been proposed as an alternative technique to treat these patients in an attempt to decrease the operative risks.

Methods: From January 1995 to June 1999, 518 patients underwent CABG after the recent onset of AMI (1-20 days): 421 patients were revascularized on-CPB and 97 patients off-CPB. Preoperative risk factors (redo operations, congestive heart failure, stroke, extensive calcification of the aorta, and dialysis) were significantly higher in the off-CPB group (p-value < 0.05). Preoperative use of intra-aortic balloon pump (IABP) (off-CPB 5.2% versus on-CPB 2.4%, p-value = NS) and emergent operations (off-CPB 5.2% versus on-CPB 2.6%, p-value = NS) were similar in both groups. Mean number of grafts per patient was 3.46 in the on-CPB group versus 1.82 in the off-CPB group (p-value < 0.005).

Results: Actual mortality was 2.9% in the on-CPB group versus 6.2% in the off-CPB group (p-value = NS). Morbidity was comparable in the two groups. Multivariate analysis showed that advanced age, preoperative hemodynamic instability, and left ventricular hypertrophy were independent risk factors for death. Global ischemic time and preoperative hypertension were independently related to postoperative AMI. At univariate and multivariate analysis, CPB was not related to mortality or major postoperative complications.

Conclusion: Multivariate analysis demonstrates that CABG can be performed safely with or without CPB in patients with recent AMI. CPB is not independently related to mortality or major adverse outcomes.