Avaliação dos preditores de risco cardiovascular identificados no teste ergométrico em pacientes com doenças de chagas

Abstract

Chagas´ disease is a serious public health issue in Latin America. Despite its current control and transmission in the national territory; it still presents outstanding epidemiological importance, due to the contingent of infected individuals with potential for developing serious forms. Risk stratification of the chagasic patient is essential for an adequate therapeutic approach. The Ergometric test is probably the additional complementary proof of more value isolated in the evaluation of the chagasic according to undetermined form, since it allows determining the working condition as well as the functional integrity of the heart, which has important medical-labor implication. Objective: This study aims at investigating the correlation between the Parameters found in the Ergometric Test, Myocardial Scintilography and Cineangiocoronariography with prognosis and mortality in patients with Chagas' disease. Casuistics and Method: The study design was a retrospective longitudinal cohort; it comprised 339 patients followed at the Heart Disease Outpatient Clinic from January 2000 to December 2010 with positive serology for Trypanosoma Cruzi presenting or not structural heart disease. Ergometric test was found in 77 (22.7%) of these patients. For correlation between the variables of the Ergometric Test and the imaging tests as continuous (possibility of calculation of mean and median), the Student's t test was used; the Chi-Square test for the categorical variables (present or absent). Data from Myocardial Scintilography (with alterations, without alterations and not performed) were compared by ANOVA test. The significance level; p < 0.05. All statistical analyses performed by IBM SPSS - Statistical Package for Social Science for Windows. Results: A group of 66 (85.7%) living patients and a group of 11 (14.3%) who died were selected. The ejection fraction obtained by Echocardiography was 55.52 ± 18.2, of which 59.13 ± 16.6 were in the individuals who remained alive and 33.85 ± 10.7 in the patients who died. The basal systolic blood pressure 118.70 ± 15.75 and the basal diastolic blood pressure 77.52 ± 12.57 were within normal range. The values of the double product were higher in the group of living individuals (p = 0.029). At peak effort there was statistical difference for systolic blood pressure; higher in living chagasic individuals 155.68 ± 23.8 than in those who died 135.45 ± 24.23 and (p value = 0.011). However, there was no difference for the diastolic component of blood pressure, being the value (p = 0.969). The presence of myocardial ischemia recorded in the Scintilography examination also showed a significant difference between both groups; more evident in the group of deaths 4 (36.4%) and p value = 0.015. Presence of depressed systolic blood pressure at peak effort was an independent predictor of overall mortality in the population studied (Risk ratio = 0,976; 95% Confidence Range from 0.995 to 0.996 and p = 0.021). Conclusion: Systolic blood pressure depressed at peak exercise is an independent predictor of mortality in Chagas' disease.