Chagas Cardiomiopathy: The Potential of Diastolic Dysfunction and Brain Natriuretic Peptide in the Early Identification of Cardiac Damage

Introduction

Chagas disease remains a major cause of mortality in several countries ofLatin America and has become a potential public health problem innon-endemic countries as a result of migration flows. Cardiac involvementrepresents the main cause of mortality, but its diagnosis is still based onnonspecific criteria with poor sensitivity. Early identification of patientswith cardiac involvement is desirable, since early treatment may improveprognosis. This study aimed to assess the role of diastolic dysfunction,abnormal myocardial strain and elevated brain natriuretic peptide (BNP) inthe early identification of cardiac involvement in Chagas disease.

Methodology/Principal Findings

Fifty-four patients divided into 3 groups—group 1 (undeterminedform: positive serology without ECG or 2D-echocardiographic abnormalities;N = 32), group 2 (typical ECG abnormalitiesof Chagas disease but normal 2D-echocardiography;N = 14), and group 3 (regional wall motionabnormalities, left ventricular [LV] end-diastolicdiameter >55 mm or LV ejection fraction <50% onechocardiography; N = 8)—and 44control subjects were studied. Patients with significant non-cardiacdiseases, other heart diseases and previous treatment with benznidazol wereexcluded. The median age was 37 (20–58) years; 40% weremen. BNP levels, longitudinal and radial myocardial strain and LV diastolicdysfunction increased progressively from group 1 to 3 (p for trend<0.01). Abnormal BNP levels (>37 pg/ml) were noted in0%, 13%, 29% and 63% in controlsand groups 1 to 3, respectively. Half of patients in the undetermined formhad impaired relaxation patterns, whereas half of patients with ECGabnormalities suggestive of Chagas cardiomyopathy had normal diastolicfunction. In group 1, BNP levels were statistically higher in patients withdiastolic dysfunction as compared to those with normal diastolic function(27±26 vs. 11±8 pg/ml,p = 0.03).

Conclusion/Significance

In conclusion, the combination of diastolic function and BNP measurement addsimportant information that could help to better stratify patients withChagas disease.