Prognostic implications of clinical, electrocardiographic and hemodynamic findings in chronic Chagas' disease

To evaluate the prognostic importance of 19 clinical, electrocardiographic and hemodynamic variables, 556 chronic chagasic patients were submitted to an extensive protocol, including left cineventriculogram and Holter monitoring, and followed for up to 15 years. The protagonist role of the magnitude of the myocardial compromise in the evolution of chagasic patients is underscored by our results, which indicated the independent prognostic value of an ejection fraction below 0.30 ( P < 0.001), a heart rate higher than 89 beats/min ( P < 0.01), grade IV functional capacity ( P < 0.05), end systolic stress > 120 g/cm 2 ( P < 0.05), and end diastolic volume index > 200 ml/m 2 ( P < 0.05). When only patients with an ejection fraction over 0.29 were considered, variables with independent prognostic value were: the cardio-thoracic ratio ( P < 0.01), functional capacity ( P < 0.05) and heart rate ( P < 0.05). Survival analysis demonstrated that the presence of complex (Lown III, IV) ventricular arrhythmias increased mortality significantly ( P < 0.01) only in patients with an ejection fraction over 0.29. Therefore, preservation of myocardial function is the capital measure in the treatment of chronic chagasic patients.