Percutaneous transluminal septal ablation in hypertrophic obstructive cardiomyopathy.

BACKGROUND: Percutaneous transluminal septal myocardial ablation (PTSMA) by alcohol-induced occlusion of septal branches with resulting reduction of LV outflow-tract gradient (LVOTG) is a new treatment option in symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM).
METHODS: In 1996 and 1997 we treated 114 symptomatic patients (56 female; age 53.3 +/- 15.6 years; 5 patients with prior myectomy and 5 with DDD pacer; most in NYHA class III. Five patients underwent re-PTSMA after failed first treatment. In the first 30 patients 1 to 3 septal branches were occluded by injection of 3.4 +/- 1.6 ml absolute alcohol via the central lumen after balloon occlusion of the proximal part of the septal branch. In the remaining patients myocardial contrast echocardiography was available, so that only one branch needed to be occluded.
RESULTS: LVOTG reduction was achieved in 107 (94%) patients: at rest from 73.8 +/- 36.5 to 18.6 +/- 19.7 mmHg (p < 0.00001). Maximal CK rise was 647 +/- 330 U/L. Two (1.8%) patients died during hospital stay. Due to permanent trifascicular block 11 (9.6%) patients required a permanent pacemaker. At 3 months follow-up in 87 patients we observed no cardiac complications, a further LVOTG reduction in 61 % patients, an ongoing symptomatic improvement (NYHA I or II; p < 0.0001 vs. pre PTSMA), and significant reduction of the left posterior wall thickness.
CONCLUSIONS: PTSMA of HOCM results in significant reduction of LVOTG. Careful monitoring during hospital stay is necessary because of the potential risks of the induced therapeutic infarction. Mid-term follow-up showed ongoing symptomatic improvement without cardiac complications. Remodeling after circumscribed septal infarction results in further LVOTG reduction in over 50% of the patients.