Associations Between Metabolic Syndrome and Long-Term Mortality in Patients who underwent Percutaneous Coronary Intervention: An Australian Cohort Analysis

Abstract

Metabolic syndrome (MetS) provides significant risk for coronary disease, however long-term prognosis after percutaneous coronary intervention (PCI) has been understudied. We assessed the prevalence and outcomes of patients with MetS from an Australian PCI cohort. We retrospectively examined data from the Melbourne Interventional Group multicenter PCI registry using a modified definition for MetS including ≥3 of the following: hypertension, diabetes mellitus, dyslipidemia, and body mass index ≥30 kg/m2. Thirty-day outcomes and long-term mortality were compared with patients without MetS. Cox regression methods were used to assess the multivariable effect of MetS on long-term mortality. Of 41,146 patients, 12,228 (34%) had MetS. Patients with MetS experienced greater 30-day myocardial infarction (2.2% vs 1.8%, p = 0.013), whereas patients without MetS had a trend for greater 30-day mortality (3.0% vs 3.4%, p = 0.051) and greater in-hospital major bleeding (1.7% vs 2.4%, p <0.001). After a median follow-up of 5.62 years (Q1 2.03, Q3 8.89), patients with MetS experienced greater mortality (24% vs 19%, p <0.001). After adjustment, MetS was not an independent predictor of long-term mortality (hazard ratio 0.95 confidence interval 0.86 to 1.05, p = 0.35). In sensitivity analyses, MetS-Diabetic patients had the highest, and MetS-NonDiabetic obese patients had the lowest long-term mortality. One in 3 patients who underwent all-comer PCI presented with MetS and experienced greater long-term mortality compared with others. However, this association was lost after adjustment for baseline confounders, highlighting that MetS is a marker of risk after PCI. Our findings support the obesity paradox and confirm robust associations between diabetes mellitus and long-term mortality.