Low body mass index (BMI) is a predictor of adverse events in patients with ST-elevated myocardial infarction (STEMI) in Western countries. Because the average BMI of Asians is significantly lower than that of the Western population, the appropriate cut-off BMI value and its role in long-term mortality are unclear in Asian patients. Between January 2006 and December 2017, 1215 patients who underwent percutaneous coronary intervention (PCI) for acute STEMI and were alive at discharge (mean age, 67.7 years; male, 75.4%) were evaluated. The cut-off BMI value, which could predict all-cause mortality within 10 years, was detected using a survival classification and regression tree (CART) model. The causes of death according to the BMI value were evaluated in each group. Based on the CART model, the patients were divided into three groups (BMI < 18 kg/m²: 54 patients, 18 kg/m² ≤ BMI ≤ 20 kg/m²: 109 patients, and BMI > 20 kg/m²: 1052 patients). The BMI decreased with age; with an increased BMI, patients with dyslipidemia, diabetes mellitus, and smoking habit increased. During the study period (median, 4.9 years), 194 patients (26.8%) died (cardiac death, 59 patients; non-cardiac death, 135 patients). All-cause mortality was more frequent as the BMI decreased (BMI < 18 kg/m²; 72.8%, 18 kg/m² ≤ BMI ≤ 20 kg/m²; 40.5%, and BMI > 20 kg/m²; 22.8%; log-rank p < 0.001). Non-cardiac deaths were more frequent than cardiac deaths in all groups, and the dominance of non-cardiac death was highest in the lowest BMI group. Cut-off BMI values of 18 kg/m² and 20 kg/m² can predict long-term mortality after PCI in Asian STEMI survivors, whose cut-off value is lower than that in the Western populations. The main causes of death in this cohort differed according to the BMI values.

低体重指数 (BMI) 是西方国家 ST 段抬高型心肌梗死 (STEMI) 患者不良事件的预测指标。由于亚洲人的平均 BMI 显着低于西方人群，因此在亚洲患者中，适当的 BMI 临界值及其在长期死亡率中的作用尚不清楚。在 2006 年 1 月至 2017 年 12 月期间，对 1215 名因急性 STEMI 接受经皮冠状动脉介入治疗 (PCI) 并在出院时存活的患者（平均年龄 67.7 岁；男性，75.4%）进行了评估。使用生存分类和回归树 (CART) 模型检测可预测 10 年内全因死亡率的截止 BMI 值。根据BMI值对各组的死因进行评估。基于CART模型，将患者分为三组（BMI <2：54 名患者，18 kg/m ²  ≤ BMI ≤ 20 kg/m ²：109 名患者，并且 BMI > 20 kg/m ^{2 ：} 1052 名患者）。BMI随着年龄的增长而下降；随着体重指数的增加，患有血脂异常、糖尿病和吸烟习惯的患者增加。在研究期间（中位数，4.9 年），194 名患者（26.8%）死亡（心源性死亡，59 名患者；非心源性死亡，135 名患者）。随着 BMI 降低，全因死亡率更高（BMI < 18 kg/m ²；72.8%，18 kg/m ²  ≤ BMI ≤ 20 kg/m ²；40.5%，和 BMI > 20 kg/m ²；22.8 %; 对数秩p < 0.001)。在所有组中，非心源性死亡均高于心源性死亡，并且非心源性死亡在 BMI 最低的组中最高。^{18 kg/m 2}和 20 kg/m ²的 BMI临界值可以预测亚洲 STEMI 幸存者 PCI 后的长期死亡率，其临界值低于西方人群。该队列的主要死因因 BMI 值而异。