Abstract 14945: Clinical and CMR Predictors of Myocardial Fibrosis in Hypertrophic Cardiomyopathy: Role of LV Wall Thickness
Background: Current risk stratification of patients with hypertrophic cardiomyopathy (HCM) relies upon the identification of risk markers which indirectly reflect disease severity. Individually however, these markers have poor positive predictive valve. There is growing recognition that fibrosis as assessed by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) may more accurately reflect the state of the underlying substrate. Its presence has been promulgated as a novel risk factor for adverse cardiac events and is potentially of independent prognostic significance. We sought to determine the clinical and CMR predictors of LGE in a large cohort of patients with HCM.
Methods: We enrolled 695 consecutive patients with HCM referred for CMR (486 male, age 55.6±14.6 years). Their diagnosis was made using current clinical guidelines. All patients underwent a standard volumes and LGE-CMR study with full myocardial coverage. Established clinical and CMR predictors were evaluated with binary logistic regression analysis.
Results: LV ejection fraction and wall thickness were the only significant predictors of LGE status. However, the combination of these factors did not significantly improve the ability to predict LGE over wall thickness alone (Harrell's c-statistic [±SE] 0.796±0.018 versus 0.776±0.019 respectively, Figure 1). Receiver operator characteristic analysis revealed a wall thickness of ≥18 mm as the optimum predictor of the presence of LGE with a sensitivity of 67.1%, specificity of 77.5%, positive predictive value of 86.7%, and negative predictive value of 51.8%.
Conclusions: LV wall thickness is a strong predictor of the presence of LGE. Future models assessing the significance of the presence of LGE must adequately control for the strong association between fibrosis and maximum wall thickness. Further work is required to delineate the temporal relationship between the amount of LGE and wall thickness.
- © 2011 by American Heart Association, Inc.