Background: It is generally considered that patients with prior myocardial infarction (PMI) have worse outcomes than those without PMI after coronary artery bypass grafting (CABG). However, any difference in outcomes of patients with anterior or inferior PMI undergoing CABG has never been determined.
Methods: We retrospectively reviewed the records of 310 patients with anterior or inferior PMI who underwent isolated CABG between September 2004 and September 2008. Of these, 151 patients had anterior PMI (anterior group), and 159 patients had inferior PMI (inferior group). Preoperative and postoperative variables were compared between the groups. Multivariate logistic regression analysis was used to identify independent predictors of major postoperative complications including death.
Results: Patients of the inferior group were significantly older (68.3 +/- 9.2 vs 65.5 +/- 11.0; p = 0.015) and had more diseased vessels per patient (2.9 +/- 0.3 vs 2.8 +/- 0.5; p = 0.009) than the anterior group. A higher rate of mild or moderate mitral regurgitation was observed in the inferior group (18.2% vs 8.6%; p = 0.0209). The operative mortality was higher in the inferior group (5.0% vs 0%; p = 0.0073). Rates of respiratory failure (6.9% vs 0.7%; p = 0.0199) and requirement for hemodialysis (5.7% vs 0.7%; p = 0.0056) were higher in the inferior group. Multivariate analysis revealed inferior PMI (p = 0.0068) as the only independent predictor of major postoperative complications including death.
Conclusions: The present study indicates that patients with inferior PMI have poorer outcomes after isolated CABG than those with anterior PMI.