Abstract 16703: Extended Non-anteroseptal Region Left Ventricular Hypertrophy Predicts Repeat Alcohol Septal Ablation for Refractory Hypertrophic Obstructive Cardiomyopathy: Morphological Investigation Using Cardiac Magnetic Resonance

Abstract

Introduction: A residual gradient and repeat septal reduction therapy are more likely to occur with alcohol seplta ablation (ASA) than with surgical myectomy. We evaluated a cohort of patients treated with ASA to identify predictive factors of repeat ASA. Methods: Of 157 patients who underwent ASA, 19 (Group R) who underwent repeat ASA procedures remained after excluding those with planned staged ablation and isolated mid-ventricular obstruction. The median time interval between both procedures was 2.1 years. We compared Group R with patients not requiring repeat procedures (n = 105, Group S) in terms of clinical characteristics, ASA procedures, and morphological cardiac magnetic resonance (CMR), which was used to diagnose regional hypertrophy (thickness ≥ 15 mm) for each left ventricular myocardial segment. Results: Compared with group S, group R had a higher peak creatine phosphokinase value at the first ASA (1250 ± 522 vs. 1028 ± 520 IU/L, p = 0.046) and number of hypertrophic segments in the basal left ventricular level (segments 0-6, 2.8 ± 1.7 vs. 1.7 ± 0.8, p = 0.009). In multivariate analysis, diuretics use [adjusted odds ratio, 9.3 (95%CI: 1.6-56.2)] and the number of extended hypertrophy segments (except the anteroseptal region at the basal left ventricular level) were independent predictors of a repeat ASA procedure (adjusted odds ratio, 6.8 (95%CI: 1.5-32.1)/segment, p = 0.010). The repeat ASA rate was only 5% (1/21) among patients without non-anteroseptal hypertrophy, and 3% (1/29) among those without posteroseptal hypertrophy; however, patients with ≥2 segments of non-anteroseptal hypertrophy had an extremely high rate (50%, 7/14). Conclusions: CMR morphological analysis elucidated the characteristics of regional hypertrophic patterns in patients who underwent repeat ASA and found non-anteroseptal extended hypertrophy (≥ 2 segments) to be a crucial predictor of repeat ASA.