Risk factors for acute myocardial infarction during the postoperative period of myocardial revascularization

Abstract

Atherosclerotic coronary disease, in its chronic and acute presentation, is 1 of the 3 major causes of morbidity and mortality in the world 1,2 . It is estimated that thousands of people are injured or die due to atherosclerotic coronary disease, in addition to the cost of hospital care with this disease 1 . One treatment of choice for atherosclerotic coronary disease is myocardial revascularization, performed for the first time as an emergency in 1964 by Garret et al 3 , but actually recognized, disseminated, and enhanced with the studies of Favaloro et al 4,5 at the end of the 1960s. We believe that in 2001 about 700 myocardial revascularization surgeries were performed all over the world 6 . Acute myocardial infarction in the postoperative period is one of the possible complications of myocardial revascularization, and its incidence, depending on the criteria adopted to define it, ranges from 4 to 8% [7][8][9][10][11] . Acute myocardial infarction in the postoperative period increases hospital stay and mortality, involving left ventricular function significantly, contributing to a worse medium-and long-term prognosis of these patients 7,8,12,13 . This study was performed with the primary purpose of identifying predictor risk factors for acute myocardial infarction in the postoperative period, and had the secondary purpose of assessing its incidence in the referred hospital and its influence on mortality and increased hospital stay. MethodsFrom June 1995 to September 2000, 89 patients undergoing myocardial revascularization at the Hospital do Coração, Associação do Sanatório Sírio, experienced acute myocardial infarction in the postoperative period. We performed a retrospective case-control study paired according to the interval between the surgeries (± 6 months between myocardial revascularization of case and control groups), to age (± 5 years), sex, number and types of grafts (19.1% vs. 1.1%; p<0.001 and 15.7 days vs. 10.6 days; p<0.05 respectively) than those of the control.Conclusion -Only previous myocardial revascularization was an independent predictor of acute myocardial infarction in the postoperative period, based on multivariate logistic regression analysis.