Impact of body mass index and waist-to-hip ratio on clinical outcomes in patients with ST-segment elevation acute myocardial infarction (from the Korean Acute Myocardial Infarction Registry)

Abstract

The relation between body mass index (BMI) and waist-to-hip ratio (WHR) to clinical outcomes in patients with ST-segment elevation acute myocardial infarction (MI) has not been well described. As part of the Korean Acute MI Registry, we enrolled 3,734 eligible patients who were diagnosed with ST-segment elevation acute MI. The study population was categorized by BMI (into 4 groups according to the World Health Organization classification for the Asian population) and WHR (into 2 sets of 4 groups, 1 set for men and another for women, based on the INTERHEART study). Baseline characteristics and clinical outcomes were analyzed and compared among the BMI and WHR categories. Mean follow-up duration was 199 +/- 37 days. In the BMI category, underweight versus obese patients were older, were more likely to present with heart failure, and underwent guideline-based treatments less frequently. In the WHR category, the reverse trends were apparent for the latter factors except treatment-use frequencies. The highest mortality rate was observed in patients with the lowest BMI and the highest WHR. In an adjusted model, the highest WHR (hazard ratio 5.57, 95% confidence interval 1.53 to 12.29, p = 0.009) and the underweight (hazard ratio 2.88, 95% confidence interval 1.17 to 6.08, p = 0.021) categories within the 2 anthropometric indexes remained as mortality risk factors. In conclusion, the relation between obesity and prognosis after ST-segment elevation acute MI appears complex and should be further assessed in larger population-based cohort studies to determine the associations apparent in this study.