Abstract 3015: Clinical Impact of Cardiac Magnetic Resonance on Risk Factor for Fatal Arrhythmia and Sudden Death in Patients with Hypertrophic Cardiomyopathy
Purpus: Sudden and unexpected death has been recognized as the most devastating and often unpredictable complication in the patients with hypertrophic cardiomyopathy (HCM). We hypothesized that the distribution of myocardial fibrosis by MRI is predictive of fetal arrhythmia in patients with HCM.
Methods: Seventy-four patients with HCM were examined with 1.5T MR system. Cine, myocardial perfusion and Delayed-enhanced MRI (DE-MRI) were performed. Percent delayed-enhancement (DE) and ejection fraction (EF) were measured.
Result: DE was found in 56 patients (76%) in patients with HCM. EF in patients with DE (59.7±8.8%) were significantly smaller than those of patients without DE (63.2±16.0%, p<0.0479). We found significant negative correlations between EF and %DE (r=−0.445, p<0.0001). During follow-up of 1256±193 days, 8 patients (11%) occurred ventricular tachycardia and 7 of them had showed DE. Implantable cardioverter defibrillators were implanted in 4 patients. Four patients died of sudden death and 2 patients died of heart failure. All of them had showed DE and 5 of them had showed perfusion defect in myocardial perfusion MRI. A 41-year-old male died of ventricular fibrillation and underwent autopsy, histological examination showed severe myocardial fibrosis at the insertion points of the right ventricle to the interventricular septum(Figure A⇓). MRI had showed DE and perfusion defect at the same point about 5 years ago(Figure B⇓). All patients without DE have been alive.
Conclusion: Myocardial perfusion and DE-MRI are useful methods for the early diagnosis of myocardial fibrosis as a substrate for fatal arrhythmia and may identify high-risk patient with HCM.