RESUMEN
BACKGROUND: Right ventricular (RV) involvement is a typical feature of Chagas' disease. In patients with congestive heart failure of other etiologies, RV dysfunction is a strong indicator of poor prognosis. However, the prognostic value of RV dysfunction in patients with Chagas' cardiomyopathy has not been reported. This study sought to investigate the prognostic value of RV dysfunction, apart from other well established risk factors, in patients with Chagas' cardiomyopathy. METHODS: The study enrolled 158 patients (99 men; mean age of 48+/-12 years) from a tertiary center for Chagas' disease. Patients were selected if found to have both the diagnosis of Chagas' disease and cardiomyopathy. All patients underwent a comprehensive Doppler echocardiogram and the global RV function was quantitatively assessed using the RV index of myocardial performance (Tei index). RESULTS: Most of the patients were in NYHA classes I and II (79%). During a mean follow up of 34+/-23 months, 44 patients (28%) died: 24 (55%) patients died of progressive heart failure and 16 (36%) of sudden death. RV Tei index emerged as an independent predictor of survival (hazard ratio 5.75, 95% confidence interval 1.69 to 19.51). Kaplan-Meier survival curves showed a higher cumulative mortality among patients in the highest quartile of RV Tei index, compared with other 3 quartiles (log-rank statistic 21.87, p<0.001). After adjustment for clinical data and LV ejection fraction, RV Tei index in the highest quartile (>0.56) remained a significant predictor of death (hazard ratio 5.29, 95% confidence interval 2.43 to 11.52). CONCLUSIONS: RV function assessed by the Tei index added significant prognostic information, incremental to the NYHA clinical classification and to the standard echocardiographic evaluation of LV systolic function. A simple measure of a Doppler index, which allows analysis of both systolic and diastolic function of the RV, appears to be a useful non-invasive tool for risk stratification in patients with dilated chronic Chagas' cardiomyopathy.