Associations between Metabolic Syndrome and Long-term Mortality in PCI patients: An Australian Cohort Analysis

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 multicentre PCI registry using a modified definition for MetS including ≥3 of the following: hypertension, diabetes, dyslipidemia and body mass index ≥30kg/m2. Thirty-day outcomes and long-term mortality were compared to patients without MetS. Cox regression methods were used to assess the multivariable effect of MetS on long-term mortality. Out of 41,146 patients, 12,228 (34%) had MetS. Patients with MetS experienced greater 30-day myocardial infarction (MI) (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 (HR 0.95, CI 0.86-1.05, 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 three patients undergoing all-comer PCI presented with MetS and experienced greater long-term mortality compared to 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 and long-term mortality.