Non-dilated left ventricular cardiomyopathy at the early stages of chronic chagas disease
R Bestetti, A Rodrigues, A Cardinalli-Neto, A P Otaviano, P R Pavarino, M A NakazoneAbstract
Background
Chronic Chagas disease (CChD), an illness caused by a protozoan transmitted to humans by the kissing bug, has become globalized because of immigration. Approximately 60% of patients have positive serological tests only. However, about 13% of these patients exhibit abnormalities on left ventricular catheterization consistent with non-dilated left ventricular cardiomyopathy (NDLVC). Furthermore, many patients present abnormalities exclusively on the 12-lead ECG, also consistent with NDLVC. Although we have previously observed NDLVC in approximately 10% of patients with heart failure with reduced ejection fraction (HFrEF) secondary to CChD, little is known about NDLVC in patients at the early stages of CChD, that is, those without HFrEF.
Purpose
The aim of this study was to determine the prevalence of NDLVC and its prognostic significance in patients at the early stages of CChD without HFrEF.
Methods
All patients with positive serological tests for CChD followed at our cardiomyopathy outpatient clinic between January 2000 and January 2018 were initially considered for the study. NDLVC was diagnosed when the left ventricular end-diastolic diameter was <55 mm, and in the presence of either segmental wall motion abnormalities (SWMA) or a left ventricular ejection fraction <50% on echocardiography. Continuous variables were compared among groups using analysis of variance (ANOVA), and categorical variables using the chi-square test. Kaplan–Meier survival analysis was used to estimate survival probabilities among groups. A p value <0.05 was considered statistically significant.
Results
A total of 338 patients followed at our outpatient clinic were included in the study: 41 patients had positive serological tests only (12%; Group A), 78 had ECG abnormalities only (23%; Group B), and 219 had Chagas dilated cardiomyopathy with HFrEF (65%; Group C). SWMA on echocardiography were observed in 3 patients (0.7%) in Group A, 16 (20%) in Group B, and 78 (36%) in Group C. Age was higher in group A compared with groups B and C; systemic arterial pressure was higher in group B compared with the other groups. All other variables were higher in group C compared with groups A and B. During a median follow-up of 33 (14.4–66.5) months, 143 (2%) patients died. No death was observed in Group A. Survival rates in Group B were 91%, 87%, 82%, and 77% at 12, 24, 36, and 48 months, respectively, whereas corresponding survival rates in Group C were 94%, 87%, 79%, and 72% (p>0.05). (Figure 1). However, when only patients without SWMA were compared, mortality was higher in patients with Chagas dilated cardiomyopathy than in those with ECG abnormalities only (Figure 2).
Conclusions
Collectively, these findings suggest that patients with NDLVC due to CChD have a poor prognosis at the early stages of the disease, even in the absence of left ventricular systolic dysfunction.Figure 1.For image description, please refer to the figure legend and surrounding text.Figure 2For image description, please refer to the figure legend and surrounding text.