Catheter-based therapy for hypertrophic obstructive cardiomyopathy. First in-hospital outcome analysis of the German TASH Registry.

BACKGROUND

Registry results of the new catheter-based method in the treatment for HOCM are missing so far. In 1997, the Transcoronary Ablation of Septal Hypertrophy Registry (TASH Registry) was established by the German Cardiac Society (GCS) as a multicenter, national registry of patients with HOCM undergoing the new catheter interventional therapy. This is the report of the in-hospital outcome of patients who underwent the procedure during the first two years of data collection in the registry.

METHODS AND RESULTS

Information was based on three standard forms for each patient, with a total of 86 variables. Information was collected on an "intention to treat" basis. The TASH Registry includes the establishment of a data base in the data collecting center. Ten centers participated. Enrollment forms were received for 264 patients out of 279 patients registered up to January 2000. There was a history of medical treatment of 3.6+/-3.9 years. The vast majority of patients (91%) were treated in three centers. The Vasalva maneuver and the exercise Doppler echocardiography were used for noninvasive stress testing. Exercise Doppler echocardiography induced a significantly higher augmentation of the baseline gradient (70.1% vs 133.4%; p<0.01). The echo-contrast guided technique was used for the intervention in 50.8% and the pressure angiography guided technique in 49.2%. On the average 2.8+/-1.3 ml of alcohol were injected. Before the procedure, the gradient measured by catheterization was 60.4+/-38.6 mmHg at baseline and 142.7+/-46.2 mmHg following the extrasystolic beat. At the end of the session it was reduced significantly by 75% and 67%. The peak phosphocreatine kinase activity was 482.5+/-246.4 U/L. Major complications occurred in 15.6% including a mortality rate of 1.2% and a permanent pacemaker implantation rate because of total heart block in 9.6%. There was an early in-hospital improvement of dyspnoe corresponding to a significant decrease of NYHA functional class from 2.8+/-0.7 to 1.8+/-0.6 (p<0.001). Similar hemodynamic and clinical benefit was found in patients with and without resting gradient at baseline.

CONCLUSION

This analysis for the first time gives a comprehensive overview of clinical characteristics, technique, procedural data, in-hospital outcome and complications in a large number of patients with HOCM who were treated by the new catheter-based method and prospectively enrolled in a registry. The results contribute considerably to critical evaluation and validation of the new technique. This analysis supports the catheter-based method to constitute a new therapeutic option for very symptomatic patients, to be effective both in patients with and without intraventricular pressure gradient at rest and to be an alternative to surgical treatment, as has been stated recently.