Predictors of unfavourable prognosis in chronic Chagas' disease

Abstract

The aim of this study was to detect clinical predictors of left ventricular dysfunction, left ventricular dilatation and apical aneurysm on echocardiography, all known as independent predictors of lethal outcome for patients with chronic Chagas' disease. Seventy-four patients with a positive complement-fixation test for Chagas' disease participated; 44 (59%) had left ventricular dysfunction, 41 (55%) left ventricular dilatation and 15 (20%) apical aneurysm. A stepwise logistic regression analysis showed that systolic blood pressure (P < 0.001) and male sex (P < 0.001) were independent predictors of left ventricular dilatation on echocardiography. A receiver-operating characteristic curve provided a systolic blood pressure of 120 mmHg with a sensitivity of 70% and a specificity of 63% to predict left ventricular dilatation. The combination of male sex and systolic blood pressure of 120 mmHg had a sensitivity of 56% and a specificity of 91% to predict left ventricular dilatation. In a separate stepwise logistic regression analysis, left ventricular systolic dysfunction was independently predicted by systolic blood pressure (P = 0.006) and New York Heart Association functional class (P = 0.01). Receiver-operating curves provided a blood pressure of 120 mmHg with a sensitivity of 72% and a specificity of 59% to predict left ventricular dysfunction, whereas a New York Heart Association functional score of 2 predicted left ventricular systolic dysfunction with a sensitivity of 78% and a specificity of 50%. The combination of New York Heart Association functional class and a systolic blood pressure of 120 mmHg predicted left ventricular dysfunction with a sensitivity of 59% and a specificity of 77%. The apical aneurysm was independently predicted by myocardial necrosis on the resting ECG, but only with a sensitivity of 20%. Hence, echocardiographic markers of cardiac mortality and sudden cardiac death in Chagas' disease can be independently predicted by clinical examination. This may be useful for screening high-risk chagasic patients.