Abstract 14695: Diagnostic Values of Myocardial Biopsy for Predicting Fibrotic Involvement of the Whole Hypertrophic Cardiomyopathy Heart in the Era of Cardiac Magnetic Resonance Imaging
Background: Myocardial scaring has been associated with severe manifestations of hypertrophic cardiomyopathy (HCM), such as end-stage heart failure and sudden cardiac death. Myocardial late gadolinium enhancement (LGE) by cardiac magnetic resonance (CMR) noninvasivelly determines fibrotic scaring in the whole HCM heart. However, histological examination of endomyocardial biopsies remains clinically used to directly assess fibrosis in HCM.
Objective: We aimed at investigating whether histological examination of fibrosis in endomyocardial biopsy tissues provides diagnostic values beyond that given by LGE in HCM patients in the era of CMR.
Methods and Results: We studied 20 consecutive patients with HCM who completed both endomyocardial biopsy and CMR. Examination of endomyocardial biopsy tissues revealed that at least one of the histological hallmarks of HCM such as myocyte disarray, myocyte hypertrophy and fibrosis were observed in 15 (75%) of 20 patients. Histological evidence of fibrosis was observed only in 8 (40%) of 20 patients whereas CMR demonstrated LGE in 14 (70%) of 20 patients (p <0.05). The sensitivity, specificity, positive predictive value and negative predictive value (NPV) of histological evidence of fibrosis for predicting LGE in the whole HCM heart were 50%, 83%, 88% and 42%, respectively.
Conclusions: These findings suggest that the diagnostic values of histological evidence of fibrosis in endomyocardial biopsy tissues are associated with the low sensitivity and NPV for predicting fibrotic scarring demonstrated by LGE in HCM patients. Although histological examination offers a direct assessment of fibrosis in myocardial samples, fibrotic involvement of the whole HCM heart may not be determined.
- © 2011 by American Heart Association, Inc.