Transcoronary ablation of septal hypertrophy does not alter ICD intervention rates in high risk patients with hypertrophic obstructive cardiomyopathy.

INTRODUCTION: Transcoronary ablation of septal hypertrophy (TASH) is safe and effectively reduces the intraventricular gradient in patients with hypertrophic obstructive cardiomyopathy (HOCM). To analyze the potential of anti- and proarrhythmic effects of TASH, we studied the discharge rates of implanted cardioverter defibrillators (ICD) in patients with HOCM who are at a high risk for sudden cardiac death.

METHODS: ICD and TASH were performed in 15 patients. Indications for ICD-implantation were secondary prevention in nine patients after resuscitation from cardiac arrest with documented ventricular fibrillation (n = 7) or sustained ventricular tachycardia (n = 2) and primary prevention in 6 patients with a family history of sudden deaths, nonsustained ventricular tachycardia, and/or syncope. All the patients had severe symptoms due to HOCM (NYHA functional class = 2.9).

RESULTS: During a mean follow-up time of 41 +/- 22.7 months following the TASH procedure, 4 patients had episodes of appropriate discharges (8% per year). The discharge rate in the secondary prevention group was 10% per year and 5% in the group with primary prophylactic implants. Three patients died during follow-up (one each of pulmonary embolism, stroke, and sudden death).

CONCLUSION: In conclusion, on the basis of ICD-discharge rates in HOCM-patients at high risk for sudden death, there is no evidence for an unfavorable arrhythmogenic effect of TASH. The efficacy of ICD treatment for the prevention of sudden cardiac death in HOCM could be confirmed, however, mortality is high in this cohort of hypertrophic cardiomyopathy patients.