Takashi Fujita1, Tetsuo Konno2, Junichiro Yokawa3, Eiichi Masuta1, Yoji Nagata1, Noboru Fujino1, Akira Funada1, Akihiko Hodatsu1, Masa-aki Kawashiri1, Masakazu Yamagishi4, Kenshi Hayashi1. 1. Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan. 2. Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan; Research and Education Center for Innovative and Preventive Medicine, Kanazawa University, Kanazawa, Japan. 3. Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan; Division of Cardiology, Fukui Prefectural Hospital, Fukui, Japan. 4. Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan; Research and Education Center for Innovative and Preventive Medicine, Kanazawa University, Kanazawa, Japan. Electronic address: myamagi@med.kanazawa-u.ac.jp.
Abstract
BACKGROUND: Occurrence of malignant ventricular tachyarrhythmias such as ventricular tachycardia and fibrillation (VT/VF) in hypertrophic cardiomyopathy (HCM) can be related to the extent of myocardial fibrosis. Although late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) imaging has been used to detect myocardial fibrosis, few data exist regarding relationships between CMR-determined myocardial fibrosis and VT/VF in genotyped HCM populations. OBJECTIVE: We retrospectively investigated whether the extent of LGE can be increased in HCM patients with VT/VF compared to those without VT/VF in the genotyped HCM population. METHODS AND RESULTS: We studied 35 HCM patients harboring sarcomere gene mutations (TNNI3=22, MYBPC3=12, MYH7=1) who underwent both CMR imaging and 24-h ambulatory electrocardiographic monitoring. VT/VF were identified in 6 patients (2 men, mean age 55.0 years). The extent of LGE was significantly increased in patients with VT/VF (n=6) compared with those without VT/VF (n=29) (18.6±14.4% vs. 8.3±11.4%, p=0.04), although the LGE extent was not an independent predictor for the occurrence of VT/VF. Applying a cut-off point ≥3.25%, episodes of VT/VF were identified with a sensitivity of 100%, specificity of 51.7%, positive predictive value of 30%, negative predictive value of 100%, and the area under the curve of 0.767 (95% confidence interval: 0.590-0.944). CONCLUSION: These results demonstrate that myocardial fibrosis determined by CMR imaging may be increased in genotyped HCM patients with episodes of VT/VF. A further prospective study will be needed to clarify the association between the LGE extent and arrhythmic events in HCM patients harboring sarcomere gene mutations.
BACKGROUND: Occurrence of malignant ventricular tachyarrhythmias such as ventricular tachycardia and fibrillation (VT/VF) in hypertrophic cardiomyopathy (HCM) can be related to the extent of myocardial fibrosis. Although late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) imaging has been used to detect myocardial fibrosis, few data exist regarding relationships between CMR-determined myocardial fibrosis and VT/VF in genotyped HCM populations. OBJECTIVE: We retrospectively investigated whether the extent of LGE can be increased in HCM patients with VT/VF compared to those without VT/VF in the genotyped HCM population. METHODS AND RESULTS: We studied 35 HCM patients harboring sarcomere gene mutations (TNNI3=22, MYBPC3=12, MYH7=1) who underwent both CMR imaging and 24-h ambulatory electrocardiographic monitoring. VT/VF were identified in 6 patients (2 men, mean age 55.0 years). The extent of LGE was significantly increased in patients with VT/VF (n=6) compared with those without VT/VF (n=29) (18.6±14.4% vs. 8.3±11.4%, p=0.04), although the LGE extent was not an independent predictor for the occurrence of VT/VF. Applying a cut-off point ≥3.25%, episodes of VT/VF were identified with a sensitivity of 100%, specificity of 51.7%, positive predictive value of 30%, negative predictive value of 100%, and the area under the curve of 0.767 (95% confidence interval: 0.590-0.944). CONCLUSION: These results demonstrate that myocardial fibrosis determined by CMR imaging may be increased in genotyped HCM patients with episodes of VT/VF. A further prospective study will be needed to clarify the association between the LGE extent and arrhythmic events in HCM patients harboring sarcomere gene mutations.