Clinical significance of endomyocardial biopsy in conjunction with cardiac magnetic resonance imaging to predict left ventricular reverse remodeling in idiopathic dilated cardiomyopathy

Endomyocardial biopsy (EMB) and cardiac magnetic resonance (CMR) are useful modalities to study the characteristics of myocardial tissue. However, the prognostic impact of both diagnostic tools to predict subsequent left ventricular reverse remodeling (LVRR) has not been well elucidated. A total of 187 consecutive patients with idiopathic dilated cardiomyopathy (IDCM) who were treated by optimal pharmacotherapy (OPT) and underwent EMB of the LV wall were investigated. The myocardial specimens were semiquantitatively evaluated measuring cardiomyocyte degeneration (CD), interstitial fibrosis (IF), and hypertrophy. In addition, late gadolinium enhancement (LGE)-CMR was performed in 78 (48 %) patients. Seventy-eight (48 %) patients developed LVRR, defined as a ≥10 % increase in LV ejection fraction with a ≥10 % decrease in indexed LV end-diastolic dimension at 12 months after OPT. Multivariate regression analysis revealed that CD (P = 0.003), but not IF (P = 0.320), was an independent predictor of LVRR. In the patients with not only EMB but also CMR, the CD score and LGE area were independent predictors of LVRR (odds ratios/P values 0.268/0.010, 0.855/<0.001, respectively). The patients with mild CD and negative LGE had a better achievement rate of LVRR than those with severe CD and positive LGE (74 vs. 19 %). A combination of CD score on EMB and LGE-CMR is useful to predict subsequent LVRR in IDCM patients.