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

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. TASH was compared in 45 consecutive patients with no resting gradient and a provocable gradient of > or =30 mm Hg (group I) and in 84 consecutive patients with a resting gradient of > or =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). TASH seems to have beneficial clinical and hemodynamic effects in patients with either provocable or resting outflow obstruction.