Influence of obesity and metabolic syndrome on clinical outcomes of ST-segment elevation myocardial infarction in men undergoing primary percutaneous coronary intervention.

BACKGROUND: The correlation between obesity and metabolic syndrome (MetS) and its impact on cardiovascular disease remains unclear. This study aims to investigate the impact of metabolic status and obesity on clinical outcomes of male patients with ST-segment elevation myocardial infarction (STEMI).

METHODS: Data from the Korea Acute Myocardial Infarction Registry-National Institutes of Health registry were used to evaluate the impact of obesity and MetS on patients undergoing primary percutaneous coronary intervention (PPCI) from November 2005 to November 2015. Patients were grouped according to the presence or absence of obesity and MetS ('obese-/MetS-', 'obese-/MetS+', 'obese+/MetS-', or 'obese+/MetS+', respectively). All-cause death and major adverse cardiac events (MACE) were recorded during 12 months of follow-up.

RESULTS: A total of 14,357 patients were included. Multivariate analysis showed that the presence of MetS was an independent risk factor for all-cause death (HR 2.08, 95% CI 1.30-3.31, p=0.002) and cardiovascular death (HR 2.44, 95% CI 1.33-4.46, p=0.004) at 12 months among normal weight patients. The protective effect of obesity was observed, compared with the obese-/MetS+ group, in terms of all-cause death (HR 0.50, 95% CI 0.31-0.81, p=0.005) and cardiovascular death (HR 0.52, 95% CI 0.28-0.96, p=0.038; vs. total obese individuals), but it might have disappeared compared with the obese-/MetS- group. The rate of MACE did not differ significantly according to category by obesity and MetS.

CONCLUSIONS: The obesity paradox has not been observed between obese and normal weight patients without MetS. Risk stratification on the basis of the presence or absence of MetS is not a clinically useful indicator of outcome in obese male patients with STEMI after PPCI.