Impact of body mass index in the results after primary angioplasty in patients with ST segment elevation acute myocardial infarction.

INTRODUCTION: Obese patients submitted to elective coronary angioplasty have a paradoxical reduction in hospital and long-term mortality. In primary angioplasty setting, the relation with Body Mass Index (BMI) is less studied. OBJECTIVES: To evaluate the impact of obesity in the results after ST-segment elevation acute myocardial infarction treated by primary angioplasty. METHODS: Study of 539 consecutive patients with ST-segment elevation acute myocardial infarction (STEMI) submitted to primary angioplasty. We evaluated in-hospital, 30-day and one-year all-cause mortality according to BMI: 'normal', <25 kg/m(2); 'overweight', 25-29.9 kg/m(2) and 'obese', ≥ 30 kg/m(2). RESULTS: Obese patients were younger, had more hypertension and hyperlipidemia. There were no differences in previous cardiac history and hospital data. In-hospital mortality was 8.0% for patients with normal BMI, 4.4% for overweight patients and 5.9% for obese patients (P=0.296). At 30 days, 9.6%, 5.2% and 6.9% (P=0.212) and at first year, 11.2%, 5.2% and 6.9% (P=0.064), respectively. Overweight was the only group with decreased risk (OR: 0.44, 95% CI: 0.21-0.90, P=0.015), even after adjustment for confounding variables (OR: 0.37, 95% CI: 0.15-0.95, P=0.038). CONCLUSIONS: Overweight patients had a better prognosis after primary angioplasty for STEMI compared with other BMI groups.