Impact of BMI on Long-Term Outcomes in Patients with ST-Segment Elevation Myocardial Infarction after Primary Percutaneous Coronary Intervention

Abstract

Aim. Obesity paradox remains a point of debate in ST-segment elevation myocardial infarction (STEMI) patients. The aim of this study was to examine the relationship between body mass index (BMI) and clinical outcomes in STEMI patients undergoing primary percutaneous coronary intervention (PPCI). Methods. Outcomes were assessed in 1429 STEMI patients undergoing PPCI between January 2009 and January 2010 in Beijing. Patients were classified into 6 groups according to age (the younger and elderly groups consisting of patients ≤65 and > 65 years old) and baseline BMI (normal weight, BMI < 24 kg/m2; overweight, 24 kg/m2 ≤BMI < 28 kg/m2; obese, BMI ≥ 28 kg/m2). The primary outcome was death, acute myocardial infarction (AMI), or revascularization. Results. On long-term follow-up (mean follow-up of 59 months), 13.9% of patients experienced the adverse event. Multivariate logistic regression analyses showed that low BMI was a significant predictor of the primary outcome only in the younger group. The odds ratio for overweight in comparison with normal weight was 0.741 (95% CI: 0.413–0.979; $p$  = 0.038), the odds radio for obesity in comparison with normal-weight patients was 0.508 (95% CI: 0.344–0.750; $p$  = 0.016) in the younger group. In the elderly group, diabetes, hypertension, triple disease, regular exercise, angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blockers (ARBs) use after discharge, and bleeding complication were associated with primary outcome. Conclusion. The obesity paradox was recognized only in the younger age group in STEMI patients undergoing PPCI.