Impact of metabolic syndrome on various aspects of microcirculation and major adverse cardiac events in patients with ST-segment elevation myocardial infarction

Background: Microvascular impairment is associated with a poor prognosis even after successful percutaneous coronary intervention (PCI) in acute myocardial infarction. The aim of the present study was to examine the impact of metabolic syndrome (MetS) on various aspects of microvascular function and clinical outcomes. Methods and Results: In 216 consecutive patients with ST-segment elevation myocardial infarction (STEMI) after successful primary PCI, data were collected and analyzed on epicardial coronary flow, ST-segment resolution (STR) on electrocardiography, maximum serum creatine kinase levels, and the incidence of major adverse cardiac events (MACE). The prevalence of MetS was 40.7% (88 patients). Corrected Thrombolysis In Myocardial Infarction frame count was significantly higher in the MetS group than in the non-MetS group (28.1±9.4 vs. 24.7±7.9, P=0.04). STR ≥50% was observed in 51.1% and 69.5%, respectively (P=0.01). Patients with MetS also had higher maximum creatine kinase levels (3,470±2,320 IU/L vs. 2,664±1,850 IU/L, P=0.01). On logistic regression analysis after adjustment for confounders, MetS was an independent negative predictor of complete STR (odds ratio, 0.49; 95% confidence interval [CI]: 0.25-0.95, P=0.03). On Cox multivariate analysis, MetS was an independent predictor for MACE (hazard ratio, 4.85; 95% CI: 1.28-18.3, P=0.02). Conclusions: MetS may damage microcirculation after direct PCI in patients with STEMI and lead to poor prognosis.