Introduction: The study sought to determine the outcomes of patients with metabolic syndrome (MetS) who received an implantable cardioverter defibrillator (ICD) for primary prevention of sudden cardiac death.
Methods: This is a retrospective study of 171 patients with systolic heart failure who underwent ICD placement for primary prevention of sudden cardiac death from 04/2004 to 09/2008. The clinical identification of patients with metabolic syndrome was based on the modified criteria proposed by the National
Cholesterol Education Program-Adult Treatment Panel III. The mean follow-up period was 27.4 months. Outcomes measured were - cardiovascular mortality, re-hospitalization within 6-months of index ICD placement and appropriate ICD discharge. Statistical analyses were performed using X2 test, Fisher's exact test and logistic regression analysis.
Results: Fifty three percent patients were identified as having MetS, and 71% were obese. The average age of patients with MetS was 70 } 8 years and with No-Mets was 71 } 6 years(P>0.05). Ischemic cardiomyopathy was present in 94% patients with MetS and 93% with No-Mets(P>0.05). Both groups had a higher prevalence of male patients (P>0.05). The mean EF was 24.6}6.9% in MetS and 26.3}7.8% in No-MetS (P>0.05). During follow up period, MetS patients were found to have higher cardiovascular mortality that No-MetS (21 % vs 7%, P=0.01). The heart failure related readmission rates at 6-months were 22% vs 9% for MetS vs No-MetS (P=0.04). CVA was higher in MetS patients than in No-MetS (19% vs 13%) but we did not find any significant difference(p>0.05). MetS patients were more likely to get appropriate ICD discharges than No-MetS (18% vs 6%, P=0.01).With multivariate analysis, after adjusting for age and sex, MetS was found to be a significant predictor of cardiovascular mortality (OR 2.44, 95% CI, 1.03- 7.63, P=0.02) and appropriate ICD discharge (OR 3.13, 95% CI, 1.16-8.03, P=0.03).
Conclusions: MetS appears to be a poor prognostic marker in patients who received ICD placement for primary prevention of sudden cardiac death.