Predictors of mortality in patients with dilated cardiomyopathy: relevance of chagas disease as an etiological factor

Abstract

Introduction and objectives: Previous studies on the influence of Chagas disease on mortality in patients with heart failure were limited by the heterogeneity of the patient populations. Few data are available on the association between the underlying cause of dilated cardiomyopathy and long-term prognosis. The aims of this study were to identify risk factors for mortality in patients with dilated cardiomyopathy that was either secondary to Chagas disease or idiopathic and to determine the prognostic value of identifying Chagas disease as the underlying etiology of dilated cardiomyopathy.

Methods: We investigated outcomes in 287 patients with heart failure secondary to dilated cardiomyopathy. Patients were divided into two groups according to the underlying etiology: Chagas cardiomyopathy (224 patients) and idiopathic dilated cardiomyopathy (63 patients). The study end-points were death and heart transplantation.

Results: Over a median follow-up period of 39.5 months, 104 patients died and 9 underwent heart transplantation. Under multivariate Cox proportional hazards analysis, New York Heart Association functional class, left ventricular ejection fraction, right ventricular function and left atrial volume remained predictors of an adverse outcome. Chagas etiology was also independently associated with a poor prognosis (hazard ratio=2.48; 95% confidence interval, 1.28-4.78; P=.007) compared with idiopathic disease, after adjustment for other well-established predictive parameters in heart failure.

Conclusions: The identification of Chagas etiology in patients with dilated cardiomyopathy was of prognostic significance. Chagas cardiomyopathy was associated with poorer survival compared with idiopathic disease, irrespective of other clinical and echocardiographic parameters related to a poor prognosis in heart failure.