Usefulness of Non-Anteroseptal Region Left Ventricular Hypertrophy Using Cardiac Magnetic Resonance to Predict Repeat Alcohol Septal Ablation for Refractory Obstructive Hypertrophic Cardiomyopathy

We evaluated a cohort of patients treated with alcohol septal ablation (ASA) to identify predictive factors for repeat ASA. We compared 15 patients who underwent repeat ASA procedures (group R) with 69 patients not requiring repeat procedures (group S) in terms of clinical parameters and morphologic cardiac magnetic resonance. Group R showed higher number of hypertrophic segments (thickness ≥15 mm) in the basal left ventricular level (2.8 ± 1.7 vs 1.7 ± 0.8, p = 0.009) than group S. In the multivariate analysis, diuretics use (adjusted odds ratio 5.8, 95% confidential interval [CI] 1.04 to 32.2, p = 0.045) and the number of non-anteroseptal extended hypertrophy segments at the basal level were independent predictors of a repeat ASA procedure (adjusted odds ratio 3.64/segment, 95% CI 1.40 to 9.4, p = 0.008). One repeat ASA among 21 patients without non-anteroseptal hypertrophy and 1 repeat ASA among 29 patients without posteroseptal hypertrophy were observed; however, 7 of the 14 patients with ≥2 segments of non-anteroseptal hypertrophy received repeat ASA. In conclusion, cardiac magnetic resonance-based cross-sectional investigation elucidated non-anteroseptal hypertrophy (≥2 segments) to be a crucial predictor of repeat ASA. ASA is useful for patients with regional hypertrophy in the basal anteroseptal, but not posteroseptal region, and without heart failure requiring diuretics.