Abstract 11480: Extent of Late Gadolinium Enhancement in Cardiac Magnetic Resonance Predicts Mortality and Morbidity in Hypertrophic Cardiomyopathy With Systolic Dysfunction: Result From Longitudinal Study
Background: A subset of patients with hypertrophic cardiomyopathy (HCM) develop systolic dysfunction so-called end-stage phase. Reduced left ventricular (LV) ejection fraction (EF) reflects poor prognosis. Late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) detecting myocardial fibrosis is associated with major adverse cardiac events (MACE) in HCM with preserved systolic function. Inverse relationship is present between LGE and LVEF in HCM, however, which of LGE or LVEF predicts mortality and morbidity more precisely in HCM with systolic dysfunction remains unresolved.
Methods and Results: We assessed the extent of LGE with a threshold of 6 SD expressed as a percentage of the total LV mass (%LGE) in 50 consecutive HCM patients with systolic dysfunction defined as LVEF < 50 % (average 34 ± 12 %) who underwent CMR (39 males, mean age 58 ± 14 years) and followed them over 1440 ± 547 days. The primary composite endpoint was MACE such as all-cause death, lethal arrhythmia, LV assist device implantation, heart transplantation or stroke due to cardiac emboli and separate secondary endpoint was unplanned heart failure hospitalization (UHFH). LGE was detected in all patients with an extent of 30
± 15 % of LV mass. During the follow up, 17 of 50 patients developed MACE. On the other hand, and 22 of 50 patients had several UHFH. Multivariable analysis revealed %LGE as the only independent predictor of both of primary and secondary endpoints. These risks increased as %LGE increased (hazard ratio [HR]:
1.08 / %, 95 % confidence interval [CI] = 1.01 to 1.16, p = 0.018 and HR: 1.14 / %, 95 % CI = 1.05 to 1.26, p < 0.001, respectively). LVEF was inversely related to %LGE (r = - 0.44; p < 0.01) and was a predictor of both endpoints in univariate analysis, but not an independent predictor in multivariate analysis. The number of recurrent UHFH per patient was more related to %LGE than LVEF (r = 0.60; p < 0.0001 and r =
- 0.36; p < 0.05, respectively).
Conclusion: %LGE is the only independent predictor of MACE and UHFH and reflects mortality and morbidity more precisely than LVEF in HCM with systolic dysfunction. Quantification of LGE is useful for predicting MACE and recurrent UHFH and can contribute to further risk stratification in HCM with systolic dysfunction.
- © 2013 by American Heart Association, Inc.