Transcatheter Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy
To the Editor:
I read with interest the report by Lakkis et al1 on transcatheter alcohol septal ablation for patients with hypertrophic obstructive cardiomyopathy (HOCM). However, 11 (33%) of their 33 patients developed complete heart block and required permanent pacemaker implantation. This high rate, which has not changed significantly from the rate of 40% previously reported by the same authors in 1997 on a smaller series of patients,2 represents an important complication of this novel procedure.
Furthermore, it should be noted that pacing in HOCM itself carried a high complication rate. In 1 series of 83 patients, infection occurred in 10%, electrode displacement in 12%, and death in 1% due to right ventricular perforation.3
Therefore, it is time for a controlled trial to be performed before this experimental procedure becomes an accepted clinical treatment. Or at least, a prospective registry should be set up to assess the frequency of these complications.4 Braunwald5 proposed the National Heart, Lung, and Blood Institute as such an organization.
- Copyright © 1999 by American Heart Association
Lakkis NM, Nagueh SF, Kleiman NS, Killip D, He Z-X, Verani MS, Roberts R, Spencer WH III. Echocardiography-guided ethanol septal reduction for hypertrophic obstructive cardiomyopathy. Circulation. 1998;98:1750–1755.
Kappenberger L, Linde C, Daubert C, McKenna W, Meisel E, Sadoul N, Chojnowska L, Guize L, Gras D, Jeanrenaud X, Rydén L, for the PIC Study Group. Pacing in hypertrophic obstructive cardiomyopathy: a randomized crossover study. Eur Heart J. 1997;18:1249–1256.
Braunwald E. Induced septal infarction: a new therapeutic strategy for hypertrophic obstructive cardiomyopathy. Circulation. 1997;95:1981–1982.
We thank Dr Cheng for his letter. We, too, were concerned about the high incidence of complete heart block early in our series. We have reviewed the last 50 consecutive patients who presented without a pacemaker, and only 3 (6%) required permanent pacing after the procedure. This incidence of complete heart block compares favorably with that of myomectomy surgery. We believe that the lower incidence of complete heart block is due to modifications of our technique, including the use of myocardial contrast echocardiography.
We completely agree that the time has come for a prospective registry to assess the frequency of complications and the efficacy of the procedure on a national basis. We have approached the National Heart, Blood, and Lung Institute for sponsorship.