MAGNETIC-RESONANCE-IMAGING IN CHRONIC CHAGAS-DISEASE - CORRELATION WITH ENDOMYOCARDIAL BIOPSY FINDINGS AND GA-67 CARDIAC UPTAKE

Background: We studied the correlation among cardiac magnetic resonanc e imaging (MRI), gallium-67 myocardial uptake, and right ventricular e ndomyocardial biopsy results in chronic Chagas' disease. To our knowle dge, this represents the first attempt to correlate the histological f indings with cardiac MRI and gallium-67 myocardial uptake for noninvas ive diagnosis of inflammatory activity associated with Chagas' disease . Methods: Ten, male patients with cardiomyopathy secondary to Chagas' disease were studied (mean age, 47.7 +/- 7 years; congestive heart fa ilure New York Heart Association [NYHA] functional class II [two patie nts], III [six patients], and IV [two patients]; and mean echocardiogr aphic Left ventricular [LV] ejection fraction [EF] 36 +/- 6%). The pat ients underwent right ventricular endomyocardial biopsy, cardiac MRI, and gallium-67 myocardial uptake testing. The results of this group we re compared with those of a control group of patients with idiopathic dilated cardiomyopathy who were matched in age (mean age, 46 +/- 10 ye ars), LV function. (mean echocardiographic EF, 30 +/- 4%) and NYHA cla ssification tone patient in class II, five patients in class III, and one patient in, class IV). Results: AIL patients with Chagas' disease showed higher signal intensity on MRI after the administration of gado linium. The intensity of the septal signal changed from 0.90 +/- 0.11 to 1.56 +/- 0.19 (P < 0.001). In the control group, there was no diffe rence in signal intensity with gadolinium (mean septal intensity, 0.94 +/- 0.12 before and 0.99 +/- 0.15 after; NS). On biopsy, eight chagas ic patients had evident signs of myocarditis, and two patients had bor derline evidence myocarditis. However, only one patient in the control group had a histological diagnosis of borderline myocarditis. Gallium -67 cardiac uptake was positive for myocardial inflammatory process in seven chagasic patients and borderline in one. On the other hand only one patient in the control group had an. uptake that was positive for inflammation, and one had a borderline result. Conclusions: In conclu sion, the data from this study strongly suggest that myocarditis is fr equently found in Chagas' disease. Cardiac MRI appears to be an, accur ate and alternative method for the diagnosis of inflammatory process a ssociated with Chagas' disease.