Impact of obesity on the outcome of Chinese patients with ST-segment myocardial infarction undergoing urgent percutaneous coronary intervention

Objective The aim of the present study was to analyse the impact of obesity on the outcomes of Chinese patients with ST-segment myocardial infarction (STEMI) undergoing urgent percutaneous coronary intervention (PCI). Methods and results A total of 421 patients with STEMI having urgent PCI and who were admitted to the 20 hospitals in the LiaoNing region during the period of 2009 until 2010, were enrolled. The patients were stratified according to body mass index (BMI) as normal weight (18.5 kg/m(2)<= BMI<24.0 kg/m(2), n = 149), overweight (24.0 kg/m(2) <= BMI <28.0 kg/m(2), n = 196), or obese (BMI >= 28.0 kg/m(2), n =76). At follow-up, the main adverse cardiac cerebrovasular events (MACCE, including cardiac death, non-fatal myocardial infarction, revascularization, and stroke) and readmission for cardiovascular events were assessed. The median duration of the follow-up was 367.34 +/- 109.00 days. Obesity was found to be associated with younger age (P < 0.001),a higher prevalence of male gender (P < 0.001), hypertension and hyperlipidaemia (both P = 0.001), and higher levels of low-density lipoprotein (P = 0.01), cholesterol (P = 0.001), and triglycerides (P < 0.001). The PCI characteristics and treatments were similar across the BMI categories. At follow-up, it was found that MACCE/readmission for cardiovascular events-free survival rate was not significantly different among the three groups. Further, after adjustment of confounders, obesity was determined as an independent risk factor for cardiac death (P = 0.04) and non-fatal myocardial infarction (P = 0.04). Conclusions At follow-up, after urgent PCI, obese patients with STEMI have similar MACCE/readmission for cardiovascular events as their normal weight and overweight counterparts. Further, obesity was independently associated with a higher incidence of cardiac death and non-fatal myocardial infarction. However, the "obesity paradox" was not observed in the outcomes.