Role of Transcoronary Ablation of Septal Hypertrophy in Patients With Hypertrophic Cardiomyopathy, New York Heart Association Functional Class III or IV, and Outflow Obstruction Only Under Provocable Conditions

Abstract

Background — Transcoronary ablation of septal hypertrophy (TASH) for hypertrophic cardiomyopathy seems to be an effective alternative to surgical myectomy. It remains a point of debate whether an outflow obstruction at rest is a necessary criterion for interventional therapy. Methods and Results — TASH was compared in 45 consecutive patients with no resting gradient and a provocable gradient of ≥30 mm Hg (group I) and in 84 consecutive patients with a resting gradient of ≥30 mm Hg (80±33 mm Hg) (group II). At baseline, all patients were in NYHA functional class (FC) III or IV, unresponsive to medical treatment. Patients in group I were older (63±12 versus 55±17 years, P =0.005) and had a lower postextrasystolic gradient (110±44 versus 171±40 mm Hg, P <0.001). The groups were similar with respect to NYHA FC (3.1±0.3 versus 3.1±0.3), basal septal thickness (22±4 versus 23±3 mm), maximal oxygen consumption (13.1±4.6 versus 14.5±5.0 mL/kg per minute), and pulmonary artery mean pressure at workload (42±9 versus 42±10 mm Hg) ( P >0.05). Median follow-up was 7 months after TASH. The 2 groups showed a significant and similar improvement in provocable obstruction (to 24±24 and 56±51 mm Hg, respectively), basal septal thickness (to 12±3 and 12±4 mm, respectively), NYHA FC (to 1.7±0.6 and 1.5±0.6, respectively), maximal oxygen consumption (to 16.0±5.3 and 16.6±6.0 mL/kg per minute, respectively), and pulmonary artery mean pressure at workload (to 36±9 and 34±9 mm Hg, respectively) ( P >0.05). Conclusions — TASH seems to have beneficial clinical and hemodynamic effects in patients with either provocable or resting outflow obstruction.