Abstract 18935: Left Ventricular Remodeling Following Alcohol Septal Ablation in Patients with Hypertrophic Cardiomyopathy: Assessment by Cardiac Magnetic Resonance Imaging

Abstract

Background: Treatment of HOCM using percutaneous alcohol septal ablation (ASA) reduces left ventricular outflow tract (LVOT) gradient and symptoms. The question of whether reduced LVOT gradient translates into lower LV wall stress is still unanswered. We propose that that ASA results in decreased LVOT gradient, leading to favorable LV remodeling related to lower circumferential wall strain (CWS). This reduction in wall strain will decrease LV mass to a greater extent than the amount of myocardium involved in the infarct alone.

Methods: Forty-two HOCM patients who underwent ASA between 2002-10 and had cardiac magnetic resonance (CMR) tagged imaging were included. LVOT gradients were assessed both by catheterization and echocardiography. CWS was assessed on CMR images using specialized software (HARP, Diagnosoft). LV mass and infarct size were independently determined using two separate software packages (ARGUS and Diagnosoft). Doppler echocardiography was used to evaluate both resting and peak LVOT gradients. Statistical T-test was performed for data analysis.

Results: After ASA, peak LVOT gradients decreased significantly from 112.5±24.2 to 65.3±45.4 mm Hg, p <0.0001. Shown in the figure is the significant reduction in mean LV circumferential strain in these patients with a mean and maximum follow-up of 8 and 24 months, respectively. There was a significant decrease in LV Mass (225.5±79.5 to 205.1±78.7 g, p<0.0001). The mean LV mass post-ASA corrected for infarct size was 212.5±95 g. The mean decrease in LV mass was significantly greater than the mean infarct size (21.2±24 g vs. 13.0±10.3 g, p=0.02).

Conclusion: ASA reduced LVOT gradient and resulted in reduced CWS by CMR, which resulted in favorable LV remodeling, as demonstrated by a decrease in LV mass greater than the infarct size alone.