Outcome of patients with hypertrophic obstructive cardiomyopathy after percutaneous transluminal septal myocardial ablation and septal myectomy surgery11Supported, in part, by grant NCC9-60 from the National Aeronautics and Space Administration, Houston, Texas, Grant #9951522V from the America Heart Association Ohio Local Chapter, Columbus, Ohio and Grant #R01 HL56688-01A1 from the National Institutes of Health, Bethesda, Maryland.22Presented, in part, at the 49th Annual Scientific Sessions of American College of Cardiology, March 2000, Anaheim, California.

AbstractObjectivesThis study was conducted to evaluate follow-up results in patients with hypertrophic obstructive cardiomyopathy (HOCM) who underwent either percutaneous transluminal septal myocardial ablation (PTSMA) or septal myectomy.BackgroundControversy exists with regard to these two forms of treatment for patients with HOCM.MethodsOf 51 patients with HOCM treated, 25 were treated by PTSMA and 26 patients via myectomy. Two-dimensional echocardiograms were performed before both procedures, immediately afterwards and at a three-month follow-up. The New York Heart Association (NYHA) functional class was obtained before the procedures and at follow-up.ResultsInterventricular septal thickness was significantly reduced at follow-up in both groups (2.3 ± 0.4 cm vs. 1.9 ± 0.4 cm for septal ablation and 2.4 ± 0.6 cm vs. 1.7 ± 0.2 cm for myectomy, both p < 0.001). Estimated by continuous-wave Doppler, the resting pressure gradient (PG) across the left ventricular outflow tract (LVOT) significantly decreased immediately after the procedures in both groups (64 ± 39 mm Hg vs. 28 ± 29 mm Hg for PTSMA, 62 ± 43 mm Hg vs. 7 ± 7 mm Hg for myectomy, both p < 0.0001). At three-month follow-up, the resting PG remained lower in the PTSMA and myectomy groups (24 ± 19 mm Hg and 11 ± 6 mm Hg, respectively, vs. those before procedures, both p < 0.0001). The NYHA functional class was also significantly improved in both groups (3.5 ± 0.5 vs. 1.9 ± 0.7 for PTSMA, 3.3 ± 0.5 vs. 1.5 ± 0.7 for myectomy, both p < 0.0001).ConclusionsBoth myectomy and PTSMA reduce LVOT obstruction and significantly improve NYHA functional class in patients with HOCM. However, there are benefits and drawbacks for each therapeutic method that must be counterbalanced when deciding on treatment for LVOT obstruction