Abstract 14267: Comparative Study of Cardiac Magnetic Resonance and Endomyocardial Biopsy to Predict Left Ventricular Reverse Remodeling and Prognosis in Dilated Cardiomyopathy
Purpose: Both endomyocardial biopsy (EMB) and late gadolinium enhancement-cardiovascular magnetic resonance (LGE-CMR) imaging are used to evaluate myocardial fibrosis, however, few reports have directly compared their clinical significance to predict therapeutic responsiveness.
Methods & Results: We enrolled 93 consecutive patients with newly-diagnosed idiopathic dilated cardiomyopathy (IDCM), who underwent LGE-CMR and EMB at baseline. The LGE area, defined by a signal intensity of ≥5 standard deviations above the remote reference myocardium mean, was not significantly correlated with the collagen volume fraction (CVF), which was calculated using the EMB samples from the posterior left ventricular (LV) wall (R2 = 0.182, p = 0.108). Univariate analysis showed that significant predictors of subsequent LV reverse remodeling (LVRR), estimated as a decrease in LV end-systolic volume index over a 1-year period, in response to optimal pharmacotherapy, included the LGE area and heart rate but not CVF (p = 0.287) among the different clinical parameters at baseline. Multivariate analysis indicated that the LGE area was an independent predictor of subsequent LVRR [β = 4.06; 95% confidence interval (CI), 0.77-2.24; P < 0.001]. Moreover, Kaplan-Meier curves showed significantly lower cardiac event-free survival ratesduring the follow-up period (1010 ± 569 days) in the LGE-positive group than in the LGE-negative group at baseline (p < 0.01); however, there was no significant difference in clinical outcomes between the two groups based on the CVF median (5.0%) (p = 0.582; Figure). Cox proportional regression hazard analysis showed that the LGE area was an independent predictor of cardiac events (risk ratio = 1.06; 95% CI, 1.02-1.10; p < 0.01).
Conclusion: The extent of myocardial fibrosis estimated using LGE-CMR imaging, but not EMB, can predict LVRR and prognosis after optimal pharmacotherapy in patients with initial IDCM presentation.
- © 2013 by American Heart Association, Inc.