Abstract 11687: Management of Hypertrophic Obstructive Cardiomyopathy Using Septal Coiling

Abstract

Introduction: Hypertrophic obstructive cardiomyopathy (HOCM) is a genetic disorder associated with dynamic left ventricular outflow tract obstruction (LVOTO). Medical management of HOCM aims at decreasing the outflow tract gradient and improving symptoms. In a subset of patients, septal reduction is necessary to achieve symptomatic relief. Alcohol Septal Ablation (ASA) is an accepted method for septal reduction, though it carries risks of complications including unpredictable ethanol diffusion, complete heart block requiring pacemaker and death. We sought to evaluate septal coil embolization (CE) as another method to achieve hemodynamic improvement in HOCM patients with severe LVOTO. Method: We identified 53 HOCM patients that underwent CE at our institution. Baseline septal thickness and LVOT gradients were measured at rest and with Valsalva during echocardiogram (ECHO) and catheterization. Immediate and 2-6 month follow-up post coiling gradients were measured using both modalities and results were compared to baseline. Septal thickness was compared before and after CE. Paired t-test was used to compare pre and post values. Results: Mean age was 68, range (31-90) years, 60% were females, 5.6% had prior permanent pacemaker (PPM). Invasive mean gradient (MG) at rest was 56.6 mmHg and immediately post CE was 16.5 mmHg with mean difference (MD) of 40 mmHg (95% CI 10.6-22.4) (p<0.01). Invasive MG following PVC was 123 mmHg pre and 34 mmHg post with MD of 79 mmHg (95% CI 65-111) (p<0.01). ECHO MG at rest was 79 mmHg and 35 mmHg on follow up with MD 44 mmHg (95% CI 27-60) (p<0.01). Septal thickness at baseline was 17.4 mm and was 14.6 mm on follow up with average reduction of 2.8 mm (95% CI 1.5-4.1) (p<0.01). Ninety three percent of patients reported class III-IV NYHA symptoms at baseline, compared to 14% on follow up. A total of 4 patients required new PPM placement and 6 patients required recoiling. Conclusion: Our study demonstrated a safe and effective alternative compared to ASA for treatment of severely symptomatic HOCM patients. The use of coils compared to alcohol ablation for septal reduction affords more precise tissue ablation with a concomitant reduction in the need for permanent pacemaker insertion with a similar hemodynamic and symptomatic success rate.