Abstract 3903: Clinical Impact of Late Gadolinium Enhancement on Mortality and Incidence of Fatal Arrhythmia in Patients With Hypertrophic Cardiomyopathy
Purpus: Late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) imaging is clinically useful method for the detection of myocardial fibrosis, which are suggested to be arrhythmogenic substrate in hyertrophic cardiomyopathy (HCM). The aim of the study was to clarify the relationship between myocardial fibrosis and the long-term clinical outcome in patients with HCM.
Methods: Seventy-five patients with HCM were examined with 1.5T MR system from 2001 to 2006. Cine, myocardial perfusion and LGE-MRI were performed. Percent perfusion defect (PD) and % LGE were measured. We evaluated predictors of sudden cardiac death and cardiac events. Measured risk factors for sudden cardiac death included cardiac arrest, sustained ventricular tachycardia, family history of sudden death, unexplained syncope, massive left ventricular hypertrophy, nonsustained ventricular tachycardia, % PD and % LGE.
Result: PD and LGE were found in 33 patients (44%) and 54 patients (72%) in patients with HCM respectively. We observed myocardial perfusion pattern in HCM patients and classified three groups as follows: Group 1 (33/75) showed PD (+) and LGE (+), Group 2 (54/75) showed PD (−) and LGE (+), Group 3 (21/75) showed PD (−) and DE (−). During follow-up of 1614±627 days, Group 1 had more severe cardiac events than group 2 and 3 did (Group 1/Group 2/Group 3; sudden cardiac death 3/2/0, heart failure 4/2/2, fatal arrhythmia 6/1/0). Kaplan-Meier analysis showed that survival curves for all-cause death and cardiac event were significantly better in group 3 than in group 1. Cumulative rates of survival for all-cause death were 100% in group 3 and 78.6% in group 1 (log-rank test, p=0.0386), cardiac event were 84.7% in group 3 and 32.7% in group 1 (log-rank test, p=0.0464). Cox regression multivariate analysis showed that prior nonsustained ventricular tachycardia and % LGE was associated with sudden cardiac death and fatal arrhythmia (HR, 7.7 [95% CI, 2.1–28.4]; p=0.002 and HR, 1.049 [95% CI, 1.016 –1.083]; p=0.003, respectively).
Conclusion: LGE is clinically useful methods for the detection of myocardial fibrosis and predicting the long-term clinical outcome in patients with HCM.