Ventricular late gadolinium enhancement by cardiac MRI as a predictor of atrial fibrillation in hypertrophic cardiomyopathy.

BACKGROUND: Atrial fibrillation (AF) increases stroke and mortality in patients with hypertrophic cardiomyopathy (HCM). Cardiac MRI (CMR) is increasingly used to detect late gadolinium enhancement (LGE) as a reliable indicator of left ventricular fibrosis, a potential predisposing factor of AF. Our research explored the correlation between left ventricular LGE and AF prevalence in HCM. METHODS: This retrospective study involved 351 HCM patients who underwent CMR. LGE percentages (0%, 1-5%, 6-14%, ≥15%) on CMR were compared with AF prevalence in HCM patients. Demographic, comorbidity, and imaging data were analyzed using appropriate univariate and multivariate analyses assessing for significant differences in AF prevalence. The predetermined significance level was p < 0.05. RESULTS: CMR demonstrated increased LGE in those with AF (p = 0.004). Increased LGE correlated with increased AF rates: 27.6% (0% LGE), 38.5% (1-5% LGE), 44.4% (6-14% LGE), and 54.7% (≥15% LGE) (p = 0.101, p = 0.043, p = 0.002, respectively, vs. 0% LGE). Adjusted for age, differences persisted and were most evident for LGE >15% (p = 0.001). Multivariate analysis, factoring age, gender, BMI, RVSP, and LVEF, supported LGE (odds ratio of 1.20, p = 0.036) and LAVI (odds ratio 1.05, 1.02-1.07, p < 0.001) as predictive markers for AF prevalence. CONCLUSIONS: Our study suggests a correlation between ventricular LGE and AF in patients with HCM. LGE exceeding 15% was associated with a significant increase in AF prevalence. These patients may require more frequent AF monitoring.

Importance of newer cardiac magnetic resonance-based risk markers for sudden death prevention in hypertrophic cardiomyopathy: An international multicenter study.

BACKGROUND: The sudden death (SD) risk stratification algorithm in hypertrophic cardiomyopathy (HCM) has evolved, underscored recently by novel cardiac magnetic resonance (CMR)-based risk markers (left ventricular apical aneurysm, extensive late gadolinium enhancement, and end-stage disease with systolic dysfunction) incorporated into the 2020 American Heart Association (AHA)/American College of Cardiology (ACC) HCM guidelines. OBJECTIVE: The purpose of this study was to assess the specific impact of newer, predominantly CMR-based risk markers in a large multicenter HCM population that underwent primary prevention implantable cardioverter-defibrillator (ICD) implants. METHODS: Longitudinal study of 1149 consecutive HCM patients from 6 North American and European HCM centers prospectively judged to be at high SD risk based on ≥1 AHA/ACC individual risk markers and prophylactically implanted with an ICD was performed. European Society of Cardiology (ESC) risk score was retrospectively analyzed with respect to the known clinical outcome. RESULTS: Of 1149 patients with an ICD, 162 (14%) experienced device therapy terminating ventricular tachycardia/ventricular fibrillation 4.6 ± 4.2 years after implant. CMR-based markers solely or in combination led to ICD implantation in 49 of the 162 patients (30%) experiencing device therapy. Particularly low ESC scores (<4%/5 years) would have excluded an ESC ICD recommendation for 67 patients who nevertheless experienced appropriate ICD therapy, including 26 with the CMR-based risk markers not part of the ESC formula. CONCLUSION: Identification and incorporation of novel guideline-supported CMR-based risk markers enhance selection of HCM patients for SD prevention with ICDs. Absence of CMR-based markers from the ESC risk score accounts, in part, for it not identifying many HCM patients with SD events. These data support inclusion of CMR as a routine part of HCM patient evaluation and risk stratification.