Long term exercise capacity in patients with hypertrophic cardiomyopathy treated with percutaneous transluminal septal myocardial ablation

Background: In hypertrophic obstructive cardiomyopathy, percutaneous transluminal septal myocardial ablation (PTSMA) improves functional capacity in the short term. However, long term functional capacity is unknown. Aim: To assess the long term exercise capacity of patients with hypertrophic obstructive cardiomyopathy undergoing PTSMA. Methods: Twenty three patients (56.5% mate, mean age 44.5 +/- 13.6 years) who underwent PTSMA were included. All patients had also undergone a symptom limited cardiopulmonary exercise treadmill test before the procedure, then after 3 months (early follow-up) and after a mean 7.2 +/- 1.0 years (long term follow-up). Results: Before PTSMA, mean maximal pressure gradient in the left outflow tract (LVOTGmax) was 82 +/- 29 mmHg, 17 patients had NYHA functional class >= III and peak oxygen uptake (pVO(2))was 18 4 ml/kg/min. PTSMA led to a reduction in mean LVOTGmax (to 29 +/- 19 mmHg, p < .0001), improvement of heart failure symptoms (NYHA >= III in 1 patient, p < .0001) and an increase of pVO(2) (to 22 +/- 6 ml/kg/min, p = .0002) at short term. LVOTGmax, functional class and pVO(2) did not change significantly during long term follow-up compared to early follow-up. However, there was a continuous improvement in percentage predicted pVO(2) over time. Conclusions: In patients with hypertrophic obstructive cardiomyopathy and symptoms of heart failure, PTSMA leads to stable long term improvement of objectively measured exercise capacity. (C) 2008 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.