Abstract 17555: The Diagnostic and Prognostic Value of Myocardial Fibrosis in Nonischemic Dilated Cardiomyopathy: A Study by Endomyocardial Biopsy and Cardiac Magnetic Resonance
Purpose: Non-ischemic dilated cardiomyopathy (DCM) is characterized by fibrotic changes beyond myocite vacualization and nuclear abnormalities. While the diagnostic value of endomyocardial fibrosis (EMB) for DCM is well established, its prognostic role remain to be elucidated. Cardiac magnetic resonance (CMR) detects fibrosis as late gadolinium enhancement (LGE).
Methods: We prospectively evaluated consecutive pts referred for unexplained left ventricular dilatation/dysfunction with subacute-chronic heart failure onset (≥ 1 month) who underwent to a CMR and EMB (coronary artery disease was excluded by angiography). Composite end point included cardiac death/transplantation, ventricular arrhythmias, hospitalization for heart failure.
Results: The patients eventually enrolled were 62. At histology 33/62 pts (53%) showed replacement-type fibrosis and 39/63 (63%) LGE on CMR. Of the 33 with positive EMB, 23 pts (69.7%) showed LGE. Out of 29/62 pts (47%) without fibrosis on EMB, LGE was present in 16/29 (55%). On follow-up (52±37 months), 25/62 pts (40%) reached the composite end-point. Kaplan-Meier survival estimates for composite end-point did not show differences between pts with or without fibrosis on EMB (p=0.3) (Figure 1A), whereas LGE reached statistically significance (p=0.002) (Figure 1B). Adding the CMR information in negative EBM subjects, LGE stratified the population at risk for major cardiac events (Figure 1C).
Conclusions: Compared to EMB, CMR is superior in detecting replacement type fibrosis mostly due to the epicardial location of scar in DCM, which is not caught by EMB due to its endocardial approach. Fibrosis alone on EMB seems to be unable to stratify patients for major clinical events. A better survival is demonstrated in DCM pts with fibrosis identified by either techniques.
- © 2013 by American Heart Association, Inc.