Prevalence and Prognostic Impact of Metabolic Syndrome in Asymptomatic (Stage A and B Heart Failure) Patients

Background: Metabolic syndrome (MS) has an increased risk of cardiovascular events. Its relationship with asymptomatic left ventricular dysfunction (LVD) and prognosis has not been completely clarified. Objectives: To determine, in asymptomatic patients (Stage A, B heart failure, HF), whether MS is associated with left ventricular systolic dysfunction (LVSD) and left ventricular diastolic dysfunction and its predictive role for cardiovascular events. Materials and Methods: We included 1920 nonconsecutive patients without symptoms of HF, with at least one cardiovascular risk factor, undergoing echocardiographic evaluation as preventive screening. We subdivided the study population according to the presence (Group 1) or absence (Group 2) of MS. The primary endpoint was a composite of cardiac death, myocardial infarction, coronary artery revascularization, stroke, and acute pulmonary edema. Secondary endpoints were hospitalization for HF and HF progression. Results: Overall prevalence of MS was 13.4% (n = 262, Group 1). In Group 2 (n = 1658), the prevalence of LVSD was 12.2%, while the prevalence of LVSD was 21.8% in Group 1 (relative risk [RR] 2.01; 95% confidence interval 1.4-2.8; P < 0.001). Adjusting for age and gender, MS resulted an independent predictor of LVSD (P < 0.001). After a median follow-up of 22 months, Group 1 patients had a significantly higher incidence of primary events (P < 0.001), including cardiac death (P = 0.04), and secondary events (P < 0.001). Both primary and secondary endpoints were more frequent in patients with LVSD (P < 0.001). In multivariate survival analysis, MS (but not its specific components) and LVSD were independently associated both with primary and secondary events (P <= 0.003). Incremental chi-square analysis showed the presence of combined LVD added to MS, and age raised significantly the predictive value of the model for the primary endpoint (Incremental chi-square = 8.6). Conclusions: In stage A and B HF subjects, the coexistence of MS with functional or structural cardiac abnormalities, detected by echocardiography, showed a significant incremental value in predicting clinical cardiovascular events.