Abstract 15618: Prognostic Utility of Myocardial Autophagy and Ultrastructural Findings in Early Dilated Cardiomyopathy: Comparison With Cardiac Magnetic Resonance
Introduction: Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) is a useful tool for visualization of myocardial scarring related to the severity of dilated cardiomyopathy (DCM). However, in early stage DCM, the most effective modality has not been investigated thoroughly. Previously, we demonstrated that evaluating endomyocardial biopsy (EMB) specimens by electron microscopy was an effective method for estimating prognosis of patients with early stage DCM.
Hypothesis: We hypothesize that myocardial ultrastructural changes is observed in early stage DCM and may relate to the prognosis.
Methods: EMB from left ventricle and LGE-CMR were performed in consecutive 63 DCM patients (54.9±13.9 years, 79% man), at their initial presentation with decompensated heart failure (HF). Myofilament lysis and autophagosomes in cardiomyocytes were evaluated by electron microscopy. Clinical data were acquired at the time of admission.
Results: During median follow up of 1.60 years, 13 patients (20.6%) were re-admitted due to recurrence of HF. Although LGE was recognized in only 25 of the 63 DCM patients (39.7%), myofilament lysis, which was apparent in degenerated cardiomyocytes of DCM patients, was recognized in 44 (69.8%). In addition to myofilament lysis, autophagosomes, which might improve HF prognosis by preventing the progression of myocardial degeneration in patients with early DCM, was recognized in 26 (41.3%). By the log-rank test, the mean (±SD) 3-year event-free survival rate for patients with/without LGE was 70.6±7.7 vs. 76.7±7.7% (P=0.324), for those with/without myofilament lysis was 66.7±8.2 vs. 92.9±6.9% (P=0.040), and for those with myofilament lysis with/without autophagosomes was 94.3±5.5 vs. 35.5±12.2% (P<0.001).
Conclusions: Comparison with the number of positive LGE, myocardial change such as myofilament lysis determined by electron microscopy was recognized in more DCM patients. The myocardial change related to their prognosis, especially existing of both myofilament lysis and autophagosomes was most powerful predictor for the prognosis in patients with early stage DCM. Evaluation of cardiac biopsy samples by electron microscopy is effective for prediction of recurrent HF in patients with early stage DCM.
- © 2013 by American Heart Association, Inc.