Abstract 19479: Fibrosis Area Measured With Endomyocardial Biopsy Specimens Predicts Poor Long-Term Outcome of End-Stage Hypertrophic Cardiomyopathy
Background: Advanced left ventricular (LV) remodeling and decreased LV function infrequently develops in hypertrophic cardiomyopathy (HCM); generally called end-stage HCM. Despite highly poor prognostic feature of end-stage HCM, predictor of long-term outcome has not yet established. According to a recent report, late-gadlinium enhanced magnetic resonance imaging, which might reflect severity of myocardial fibrosis, could predict poor outcome of end-stage HCM. However, direct pathological evidence of myocardial fibrotic change has not been investigated thus far. Therefore, we sought to clarify the relationship between fibrosis area of endomyocardial biopsy sections and long-term outcome in end-stage HCM.
Method: We studied consecutive 41patients of end-stage HCM (10 female, mean 55±14 years) between 2000 and 2014. All patients underwent cardiac catheterization including right ventricular endomyocardial biopsy to rule out secondary cardiomyopathies, sarcoidosis, amyloidosis or other metabolic heart disease. Demographic, laboratory, and echocardiographic data, as well as survival data, were collected from the patients’ medical records. Fibrosis area was semiquantatively measured as the ratio of blue-colored area to the whole myocardial area in biopsy sections.
Results: Fibrosis area of this study population was 6-32% (mean 16±8%). Patients were divided into two groups based on receiver operating characteristic analysis of fibrosis area: severe fibrosis group (Fibrosis area ≥24%) and less severe fibrosis group (Fibrosis area <24%). There were no significant differences in baseline characteristics including age, sex, BMI, creatinine, hemoglobin, and left ventricular ejection fraction (LVEF) between two groups. Despite of comparable LVEF (36±5 vs. 38±7%, p=0.56), survival analysis revealed that patients with severe fibrosis had worse outcome determined by death, LVAS implantation, and appropriate ICD discharge compared to those with less severe fibrosis (log-rank p=0.002).
Conclusions: Severe fibrosis determined by semiquantitative analysis on endomyocardial biopsy is one of the important predictor of poor outcome in patients with end-stage HCM.
Author Disclosures: Y. Nakashima: None. Y. Sugano: None. T. Nagai: None. H. Kanzaki: None. K. Ogo: None. Y. Ikeda: None. H. Ueda: None. S. Yasuda: None. T. Anzai: None.
- © 2016 by American Heart Association, Inc.