Transcoronary ablation of septal hypertrophy (TASH): a new treatment option for hypertrophic obstructive cardiomyopathy

Abstract

In 1991, our group started to develop a catheter interventional therapy for hypertrophic obstructive cardiomyopathy (HOCM). The new concept was proposed in 1994. It is based on the conventional PTCA technique with the aim of inducing an artificial myocardial infarction by instillation of 96% ethanol into the most proximally situated septal branch of the left anterior descending coronary artery. This leads to a subaortic contraction disorder with subsequent decrease of the intraventricular pressure gradient, shrinkage of the hypertrophied septal bulge and widening of the outflow tract ("therapeutic remodeling"). The subaortic defect is small and well demarcated as assessed by left ventricular angiography, transesophageal echocardiography and 18 F-glucose positron emission tomography. The term transcoronary ablation of septum hypertrophy (TASH) was suggested. Our patient cohort that now comprises 215 therapeutic procedures in 187 patients underwent a large variety of prospective studies (maximum follow-up 4.5 years) including invasive controls at regular intervals, investigation of hemodynamics at rest and at exercise, transesophageal and transthoracic echocardiography, Doppler echocardiography during bicycle exercise, electrophysiologic testing, Holter monitoring and measurement of myocardial metabolism and perfusion, assessment of microembolic events by transcranial Doppler sonography and histological examinations. This article gives an overview and reports our increasing experience in applying TASH. The following post-TASH findings were obtained: significant hemodynamic and clinical improvement at rest and at exercise, decrease of septum thickness, increase of outflow tract area and decrease of induced ventricular tachycardia. There were well-demarcated, histologically atypical subaortic myocardial defects, no microembolic events, abnormal early peak of infarct related enzymes, and no change of baroreflex sensitivity. Pre-/post-TASH evaluations of the patients should be based in particular on clinical symptoms correlated to the intraventricular gradient measured by bicycle exercise Doppler echocardiography and to outflow tract area as assessed by transesophageal echocardiography. Since 1994, as a roughly estimate, worldwide 1000 patients in 20 countries have been treated. According to published articles, abstract presentations and workshops, TASH consistently leads to a pronounced clinical and hemodynamic benefit for patients with HOCM. TASH has become an established technique. At least in centers with a high level of expertise, it is no longer experimental but a routinely performed alternative to surgical treatment for HOCM, i.e., the previous gold standard of therapy. Of course, patient outcome needs further careful clinical and prognostic evaluation. With respect to complications, TASH appears to be superior to surgery (transaortic septal myectomy) for HOCM. Like surgical treatment, TASH is currently indicated in critically ill patients with typical HOCM (subaortic form), who exhibit with drug refractory symp...

Role of Transcoronary Ablation of Septal Hypertrophy in Patients With Hypertrophic Cardiomyopathy, New York Heart Association Functional Class III or IV, and Outflow Obstruction Only Under Provocable Conditions

“…Also, the arrhythmogenic risk of TASH might depend on lesion size and the amount of ethanol injected. 30,32 However, the potential longterm consequences of the myocardial scar produced by septal ablation remain to be determined at a longer follow-up. 13 Our results support the use of similar treatment strategies for patients with provocable outflow obstruction and patients with gradients under basal conditions.…”

Fünf Jahre TASH (Transkoronare Ablation der Septum Hypertrophie), eine Bilanz

“…In der Zwischenzeit fand die Methode, für die wir, ausgehend von Arbeiten zur Alkoholablation von Rhythmusstörungen (5), die Bezeichnung TASH (Transkoronare Ablation der Septum Hypertrophie) vorschlugen, zunehmende Verbreitung. Nach publizierten Arbeiten, Vortragspräsentationen und persönlichen Mitteilungen dürften bis heute in Deutschland etwa 600 Patienten und weltweit insgesamt über 1000 Patienten in etwa 20 Ländern behandelt worden sein (25). In 5 Jahren wurden danach in Deutschland etwa ebensoviele Patienten mittels TASH behandelt wie in 37 Jahren mittels Operation (transaortale septale Myektomie).…”

“…Die bisherigen Publikationen über die katheterinterventionelle Behandlung der HOCM konzentrieren sich bezüglich größerer Erfahrungen auf relativ wenige Zentren (7, 12,15,17,23,25,26,28,31,37).…”

“…Unterschiedlich ist das Auswahlverfahren für den Fall, dass mehrere proximale Septaläste zur Verfügung stehen (Vorgehen nach hämodynamischen Kriterien oder echokardiographischen Kriterien (7, 12,14,20,23,25,37).…”

Transkoronare Ablation der Septumhypertrophie (TASH): Ersetzt sie die Operation (Myektomie)?

“…Die Katheterbehandlung der HOCM mittels TASH stellt eine neue Behandlungsm6glichkeit bei deutlich symptomatischen Patienten mit typischer ttOCM (subaortale Form) dar [3,4,8,14,17,26]. Voraussetzungen sind eine erfolglose, ª etwa sechs Monate durchgefª medikament6se Therapie oder der Schweregrad IV (NYHA).…”