Association between body mass index and three-year outcome of acute myocardial infarction

Body mass index (BMI), as an important risk factor related to metabolic disease. However, in some studies higher BMI was emphasized as a beneficial factor in the clinical course of patients after acute myocardial infarction (AMI) in a concept known as the “BMI paradox.” The purpose of this study was to investigate how clinical outcomes of patients treated for AMI differed according to BMI levels. A total of 10,566 patients in the Korea Acute Myocardial Infarction Registry-National Institutes of Health (KAMIR-NIH) from May 2010 to June 2015 were divided into three BMI groups (group 1: BMI < 22 kg/m², group 2: ≥ 22 and < 26 kg/m², and group 3: ≥ 26 kg/m²). The primary outcome was major adverse cardiac and cerebrovascular event (MACCE) at 3 years of follow-up. At 1 year of follow-up, the incidence of MACCE in group 1 was 10.1% of that in group 3, with a hazard ratio (HR) of 2.27, and 6.5% in group 2, with an HR of 1.415. This tendency continued up to 3 years of follow-up. The study demonstrated that lower incidence of MACCE in the high BMI group of Asians during the 3-year follow-up period compared to the low BMI group. The results implied higher BMI could exert a positive effect on the long-term clinical outcomes of patients with AMI undergoing percutaneous coronary intervention (PCI).