Background: Percutaneous transluminal septal myocardial ablation (PTSMA) has been introduced as an alternative procedure for reducing the left ventricular outflow tract gradient (LVOTG) in hypertrophic obstructive cardiomyopathy. We report on the acute and mid-term results in 91 symptomatic patients with respect to intraprocedural myocardial contrast echocardiography (MCE).
Methods and results: PTSMA was intended for 46 women and 45 men (54.1+/-15.5 years). In 2 patients, the intervention could not be completed. In the first 30 patients the target vessel was determined by probatory balloon occlusion alone and in the remainder by additional intraprocedural MCE. Resting LVOTG was reduced from 73.8+/-35.4 to 16.6+/-18.1 and nostextrasystolic LVOTG from 149.3+/-42.5 to 61. 9+/-43.0 mm Hg (P<0.0001 each). In 10 (11%) patients, permanent DDD pacemaker implantation was necessary. Two (2%) patients died, 1 from ventricular fibrillation associated with treatment for chronic obstructive pulmonary disease after 9 days and 1 from fulminant pulmonary embolism after 2 days. After 3 months, mean New York Heart Association class was reduced from 2.8+/-0.6 to 1.1+/-1.0 (P<0.0001). The LVOTG remained reduced to 14.6+/-25.5 mm Hg at rest and 49. 1+/-48.7 mm Hg (P<0.0001 each). Four patients underwent successful repeat PTSMA. Determination of the target vessel by MCE was associated with a higher rate of acute (92% vs 70%; P<0.01) and mid-term (94% vs 64%; P<0.01) success.
Conclusions: PTSMA is a promising nonsurgical technique for reduction of symptoms and LVOTG in hypertrophic obstructive cardiomyopathy. MCE has been shown to be a useful addition to probatory balloon occlusion for target vessel selection. Prospective, long-term observations of larger populations and a comparison with the established forms of therapy are necessary to determine the definitive significance of PTSMA.