Abstract 3283: Usefulness of Cardiac Magnetic Resonance Imaging in the Clinical Risk Stratification in Patients With Hypertrophic Cardiomyopathy
Background: In hypertrophic cardiomyopathy (HCM), interstitial fibrosis is an important histological modification that has been associated with sudden cardiac death (SCD). Delayed contrast enhancement (DCE) cardiac magnetic resonance (CMR) imaging can delineate the presence and extent of myocardial fibrosis in patients with HCM. The purpose of this study was to assess the relationship between the extent of DCE and the risk of SCD in HCM patients.
Methods: Forty-seven consecutive patients (mean age 60±12 [SD] years, 70% males) underwent CMR evaluation and risk assessment. DCE images were obtained, 20 min after injection of 0.2 mmol/kg of Gadolinium. The extent DCE was expressed as percentage of DCE volume by LV volume (%DCE). DCE volume was determined semi-automatically using DCE analysis software (AZE, Japan) and defined as intensity >2 SD above viable myocardium. LV volume was obtained by cine MRI. Risk factors for SCD included non-sustained ventricular tachycardia (NSVT) on Holter monitoring, unexplained prior syncope, and family history of SCD.
Results: DCE was present in all 47 patients. The mean %DCE was 24.6±15.5 % and the mean LV volume was 185.2±94.3 cm3. Amongst the 47 patients, 14 had NSVT, 10 had unexplained prior syncope, and 4 had family history of SCD. The %DCE was significantly higher in patients with NSVT than those without NSVT (33.7±14.2 % vs. 20.8±14.6, P=0.008), and also significantly higher in patients with syncope than those without syncope (33.8±9.3 % vs. 21.3±15.6, P=0.004). The significant positive relation was observed when comparing %DCE and LV volume (r=0.4, P=0.04).
Conclusion: DCE in CMR is a common finding in HCM, where the extent of DCE was significantly associated with the risk of SCD. Thus, CMR imaging can be a useful tool for the risk stratification in patients with HCM.