Chagas cardiomyopathy: the potential of diastolic dysfunction and brain natriuretic peptide in the early identification of cardiac damage.
BACKGROUND
Chagas disease remains a major cause of mortality in several countries of Latin America and has become a potential public health problem in non-endemic countries as a result of migration flows. Cardiac involvement represents the main cause of mortality, but its diagnosis is still based on nonspecific criteria with poor sensitivity. Early identification of patients with cardiac involvement is desirable, since early treatment may improve prognosis. This study aimed to assess the role of diastolic dysfunction, abnormal myocardial strain and elevated brain natriuretic peptide (BNP) in the early identification of cardiac involvement in Chagas disease.


RESULTS
Fifty-four patients divided into 3 groups--group 1 (undetermined form: positive serology without ECG or 2D-echocardiographic abnormalities; N = 32), group 2 (typical ECG abnormalities of Chagas disease but normal 2D-echocardiography; N = 14), and group 3 (regional wall motion abnormalities, left ventricular [LV] end-diastolic diameter >55 mm or LV ejection fraction <50% on echocardiography; N = 8)--and 44 control subjects were studied. Patients with significant non-cardiac diseases, other heart diseases and previous treatment with benznidazol were excluded. The median age was 37 (20-58) years; 40% were men. BNP levels, longitudinal and radial myocardial strain and LV diastolic dysfunction increased progressively from group 1 to 3 (p for trend <0.01). Abnormal BNP levels (>37 pg/ml) were noted in 0%, 13%, 29% and 63% in controls and groups 1 to 3, respectively. Half of patients in the undetermined form had impaired relaxation patterns, whereas half of patients with ECG abnormalities suggestive of Chagas cardiomyopathy had normal diastolic function. In group 1, BNP levels were statistically higher in patients with diastolic dysfunction as compared to those with normal diastolic function (27 ± 26 vs. 11 ± 8 pg/ml, p = 0.03).


CONCLUSIONS
In conclusion, the combination of diastolic function and BNP measurement adds important information that could help to better stratify patients with Chagas disease.
Garcia-Alvarez
Ana
A
Thorax Clinic Institute, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain.
Sitges
Marta
M
Pinazo
María-Jesús
MJ
Regueiro-Cueva
Ander
A
Posada
Elizabeth
E
Poyatos
Silvia
S
Ortiz-Pérez
José Tomás
JT
Heras
Magda
M
Azqueta
Manel
M
Gascon
Joaquim
J
Sanz
Ginés
G
D000328:Adult; D015415:Biomarkers; D002598:Chagas Cardiomyopathy / Q000175:diagnosis* / Q000503:physiopathology; D003971:Diastole / Q000502:physiology*; D042241:Early Diagnosis; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D007843:Latin America; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D012680:Sensitivity and Specificity
D015415:Biomarkers; D020097:Natriuretic Peptide, Brain