May early myocardial involvement detection in chagas disease have a prognosis impact?

Abstract Background Brain natriuretic peptide (BNP) and novel echocardiographic techniques such as speckle-tracking and a comprehensive evaluation of diastolic function can detect early myocardial involvement in patients with Chagas disease. However, there is lack of longitudinal studies that can confirm whether this early myocardial involvement translates into a worse prognosis. Purpose To assess if early myocardial involvement detected by BNP or a comprehensive echocardiographic evaluation was associated with future events in Chagas disease. Methods 182 consecutive individuals from endemic areas who underwent T. cruzi screening where prospectively included from 2007 to 2014. ECG, BNP and a comprehensive echocardiography including diastolic function and longitudinal myocardial strain were performed. Four different groups were defined: healthy controls (N=77); Chagas indeterminate form (positive serology, normal ECG and left ventricle (LV) diameter (<55 mm), LV ejection fraction (>50%) and no segmental abnormalities, N=88); Chagas patients with abnormal ECG but normal LV dimensions and motility (N=7); and Chagas patients with LV diameter>55 mm or LV ejection fraction<50% or segmental abnormalities (N=13). The primary outcome included advanced atrioventricular block, sustained ventricular tachycardia, heart failure, heart transplant or death. Kaplan Meier with Long rank test and Cox regression analysis was used. Results Mean age was 37±9 and 34% were male. Median follow-up was 63 months (range 1 to 137). The primary endpoint occurred in a total of 11 (10%) individuals: 2 (2.4%) in the Indeterminate group; 3 (43%) in the abnormal ECG group; and 6 (46%) in the group with abnormal LV dimension or motility, with no events among controls (long-rank test<0.01, Figure). In the global population, age, BNP, diastolic dysfunction parameters and longitudinal strain at the inferior and lateral walls were significant predictors. In the cohort of Chagas patients with normal standard echocardiography (N=92), ECG abnormalities (HR=49, p=0.001), Em (HR=0.68, p=0.03), deceleration time (HR=0.01, p=0.01), left atrial diameter (HR=1.24, p<0.01) and longitudinal strain at the midventricular lateral wall (HR=0.75, p=0.028) remained significantly associated with outcome. Cumulative survival without events Conclusions Outcome was significantly more frequent in Chagas patients with abnormalities in ECG or standard echocardiography. In early forms of the disease, myocardial involvement detected by BNP or a comprehensive echocardiography was associated with prognosis, and may help to individualize treatment and follow-up.