Long-term follow-up of patients with Chagas cardiomyopathy living in a non-endemic area: moving towards identification of early markers of disease progression
Authors: Fernandez Valledor A , Jorda P , Pajuelo C , Hernandez J , Culotta V , Pinazo M.J , Posada E , Aldasoro E , Gascon J , Sitges M , Garcia Alvarez A 
Published: November 2020

Abstract

Background
The number of patients with Chagas disease residing in Europe has increased significantly due to migration flows. Globally, Chagas cardiomyopathy has worse prognosis than other types of dilated cardiomyopathies and about 30% of patients develop cardiac involvement after a variable latency period (10–30 years). However, there is lack of data regarding the evolution of patients with Chagas disease living in a non-endemic area and potential early predictors of disease progression.
OBJETIVE
To describe the natural course of Chagas disease, the incidence rate of transformation into cardiac form and to assess if early predictors of myocardial involvement translate into a worse long-term prognosis in our non-endemic cohort.

Methods
Clinical and echocardiographic follow-up was performed in 202 individuals from endemic areas of Chagas disease. At baseline, electrocardiogram, 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) dimensions and LV ejection fraction (&gt;50%) and no segmental abnormalities, N=92); Chagas patients with abnormal ECG but normal LV dimensions and motility (N=15); and Chagas patients with LV diameter&gt;55 mm or LV ejection fraction&lt;50% or segmental abnormalities (N=18). The primary clinical outcome included advanced atrioventricular block, sustained ventricular tachycardia, heart failure, heart transplant, death or progression of cardiac disease defined as LV systolic dysfunction or new segmental abnormalities. 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 69 months (range 1 to 147). The primary endpoint occurred in a total of 17 (8.4%) individuals: 5 (5.4%) in the Indeterminate group; 3 (20%) in the abnormal ECG group; and 9 (50%) in the group with abnormal LV dimension or motility, with no events among controls (long-rank test&lt;0.01, Figure 2). Six patients evolved from the indeterminate phase to cardiac involvement (2 with isolated ECG changes and 4 with abnormal echocardiography without previous changes in ECG (Figure 1). On echocardiography, there were no differences regarding changes in LV dimensions or LV ejection fraction between Chagas patients with normal baseline echo and controls, but a significantly reduction of Em was observed (−1.6±3.0 vs. 0.2±1.0) in the former. Excluding patients with abnormal echo at baseline, BNP (HR=1.03, p=0.001), Em (HR=0.78, p=0.05) and left atrial diameter (1.23, p=0.01) were predictors of the combined event.

Conclusions
Conversion from the indeterminate to Chagas cardiomyopathy in our cohort was approximately 1.1%/year, but it may happen directly with contractility disturbances. BNP and comprehensive echocardiography may help to early detect disease progression.
Figure 1. Distribution of patients and KM curves

Funding Acknowledgement
Type of funding source: None