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

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 > 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).

Conclusions: TASH seems to have beneficial clinical and hemodynamic effects in patients with either provocable or resting outflow obstruction.