Predictors of unfavourable prognosis in chronic Chagas' disease

The aim of this study was to detect clinical predictors of left ventricular dysfunction, left ventricular dilatation and apical aneurysm on echocardio graphy, all known as independent predictors of lethal outcome for patients with chronic Chagas' disease. Seventy-four patients with a positive complem ent fixation test for Chagas' disease participated; 44 (59%) had left ventr icular dysfunction, 41 (55%) left ventricular dilatation and 15 (20%) apica l aneurysm. A stepwise logistic regression analysis showed that systolic bl ood pressure (P < 0.001) and male sex (P < 0.001) were independent predicto rs 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 di latation. The combination of male sex and systolic blood pressure of 120 mm Hg had a sensitivity of 56% and a specificity of 91% to predict left ventri cular dilatation. In a separate stepwise logistic regression analysis, left ventricular systolic dysfunction was independently predicted by systolic b lood 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 ventricu lar 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 fun ctional class and a systolic blood pressure of 120 mmHg predicted left vent ricular dysfunction with a sensitivity of 5$% and a specificity of 77%. The apical aneurysm was independently predicted by myocardial necrosis on the resting EGG, but only with a sensitivity of 20%. Hence, echocardiographic m arkers 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.