Medium term survival following Alcohol Septal Ablation (ASA) for Hypertrophic Obstructive Cardiomyopathy (HOCM)

Abstract

Introduction: ASA is an established treatment for symptomatic HOCM patients Limited survival data is available following ASA. Method(s): Patients referred to Liverpool Heart and Chest Hospital for consideration of ASA from August 1999 to December 2012 were reviewed. All patients had resting or stress LVOT gradient >50mmHg. All patients were trialled on beta-blockers and/or verapamil prior to ASA. Only those taken to the lab with the intention of delivering alcohol were included. Mean follow up period was 4.2 (+/-3.33) years, range 0.13-12.29. 91 patients were identified, mean age 60.8 (+/-14.4) years. 5 could not receive alcohol due to limitations identifying and instrumenting appropriate septal vessels Results: 84 of 86 patients had satisfactory follow up. Mean pre-ASA NYHA was 2.79 (+/-0.47), improving to 1.95 (+/-0.84) after ASA (p<0.0001). 60 (71.4%) patients improved by >1 NYHA category, 22 (26%) reported no change, 2 (2%) deteriorated. 24 patients had pre- and post-ASA CPEX testing with RER >1.1. Peak VO2 increased from 18.9 to 20.1ml/min/kg (p=0.018), exercise time increased from 568 to 615s (p=0.046). 77 of 86 patients had satisfactory echo data for LVOT gradient assessment. Mean pre-ASA peak resting gradient was 82.9 (+/-51.2)mmHg, median 80, range 0-237mmHg. Mean post-ASA peak gradient was 16.8 (+/-34.7)mmHg (p<0.0001) median 6, range 0-240mmHg. 15 patients died. 1, 2, and 5 year survival rates were 96 (n=69), 89 (n=54) and 69% (n=32) respectively. None suffered sudden cardiac death (SCD). 8 suffered cardiovascular death. One inpatient death was reported due to complications of PPM insertion post ASA. Diastolic heart failure was cause of death in 5, 4 of these patients were in clinical heart failure with normal systolic function pre-ASA MI was reported 9 years after ASA in 1. CVA was reported 4 years after ASA in 1 Non-cardiac death was reported in 7. Cancer n=3, pulmonary fibrosis n=2, renal failure n=1, post-operative complication n=1. One episode of sustained VT was observed 2 weeks post-ASA. VT focus was not thought to be of septal origin. Internal rhythm monitoring was available in 35 patients (16 ICD, 19 PPM) over a mean of 3.74 (+/-3.15) years. No appropriate ICD therapy was delivered. NSVT was seen in 9 patients, 7 had 1 episode <15 beats 1 had 4 episodes <15 beats, 1 had 36 episodes <15 beats, multiple episodes of NSVT were noted before ASA. Conclusion(s): No SCD or appropriate ICD discharges were seen during follow up One inpatient death was reported. The mortality observed over follow up was a combination pre-existing diastolic heart failure, one MI, one CVA and non cardiac causes.