Long-Term Prognostic Value of Myocardial Fibrosis in Patients With Chagas Cardiomyopathy

Abstract

Background: Myocardial fibrosis (MF) according to cardiac magnetic resonance (CMR) is a frequent finding in Chagas cardiomyopathy and has been associated with risk factors of poor outcome.

Objectives: The goal of this study was to determine the prognostic value of MF in predicting combined hard events or all-cause mortality.

Methods: Patients with Chagas cardiomyopathy who had a previous CMR evaluation were included, and clinical follow-up was retrospectively obtained. The primary outcome was a combination of all-cause mortality, heart transplantation, antitachycardia pacing or appropriate shock from an implantable cardioverter-defibrillator, and aborted sudden cardiac death; the secondary outcome was all-cause mortality.

Results: A total of 130 patients were included; mean age was 53.6 ± 11.5 years, and 53.9% were female. The majority of patients reported no symptoms of heart failure or arrhythmia, but electrocardiographic and echocardiographic abnormalities were common. On CMR, left ventricular dilatation and dysfunction were frequent, and MF was found in 76.1%, with a mean mass of 15.2 ± 16.5 g. Over a median follow-up of 5.05 years, 58 (44.6%) patients reached the combined endpoint, and 45 (34.6%) patients died. MF was associated with the primary outcome as a continuous variable (adjusted hazard ratio: 1.031; 95% CI: 1.013 to 1.049; p = 0.001) and as a categorical variable (MF ≥12.3 g) (adjusted hazard ratio: 2.107; 95% CI: 1.111 to 3.994; p = 0.022), independently from the Rassi risk score. MF expressed as a continuous variable was also associated with all-cause mortality (adjusted hazard ratio: 1.028; 95% CI: 1.005 to 1.051; p = 0.017) independently from the Rassi risk score.

Conclusions: MF is an independent predictor of adverse outcome in Chagas cardiomyopathy. Our data may support the use of CMR in better risk-stratifying this population and possibly guiding therapy.

Keywords: Chagas cardiomyopathy; cardiac magnetic resonance; delayed enhancement; myocardial fibrosis; prognosis.