Percutaneous Transluminal Septal Myocardial Ablation in Hypertrophic Obstructive Cardiomyopathy

Abstract

Background —Percutaneous transluminal septal myocardial ablation (PTSMA) has been introduced as an alternative procedure for reducing the left ventricular outflow tract gradient (LVOTG) in hypertrophic obstructive cardiomyopathy. We report on the acute and mid-term results in 91 symptomatic patients with respect to intraprocedural myocardial contrast echocardiography (MCE). Methods and Results —PTSMA was intended for 46 women and 45 men (54.1±15.5 years). In 2 patients, the intervention could not be completed. In the first 30 patients the target vessel was determined by probatory balloon occlusion alone and in the remainder by additional intraprocedural MCE. Resting LVOTG was reduced from 73.8±35.4 to 16.6±18.1 and nostextrasystolic LVOTG from 149.3±42.5 to 61.9±43.0 mm Hg ( P <0.0001 each). In 10 (11%) patients, permanent DDD pacemaker implantation was necessary. Two (2%) patients died, 1 from ventricular fibrillation associated with treatment for chronic obstructive pulmonary disease after 9 days and 1 from fulminant pulmonary embolism after 2 days. After 3 months, mean New York Heart Association class was reduced from 2.8±0.6 to 1.1±1.0 ( P <0.0001). The LVOTG remained reduced to 14.6±25.5 mm Hg at rest and 49.1±48.7 mm Hg ( P <0.0001 each). Four patients underwent successful repeat PTSMA. Determination of the target vessel by MCE was associated with a higher rate of acute (92% vs 70%; P <0.01) and mid-term (94% vs 64%; P <0.01) success. Conclusions —PTSMA is a promising nonsurgical technique for reduction of symptoms and LVOTG in hypertrophic obstructive cardiomyopathy. MCE has been shown to be a useful addition to probatory balloon occlusion for target vessel selection. Prospective, long-term observations of larger populations and a comparison with the established forms of therapy are necessary to determine the definitive significance of PTSMA.

Role of Percutaneous Septal Ablation in Hypertrophic Obstructive Cardiomyopathy

“…1,3 There has been considerable interest over the past few years in a percutaneous method for relieving obstruction and symptoms that has been referred to in the literature by several names and acronyms. [3][4][5][6][7][8][9] This procedure uses conventional interventional methodology currently available for treating atherosclerotic coronary artery disease to create necrosis of the anterior basal septum by introducing absolute alcohol directly into a proximal septal perforator artery, ultimately reducing LV wall thickness, enlarging the outflow tract and reducing mechanical impedance to LV ejection. Therefore, percu-taneous transluminal septal myocardial ablation (PTSMA) may mimic the morphological and hemodynamic effects of surgical myectomy.…”

“…4 Most other PTSMA practitioners utilize myocardial contrast echocardiography to identify the appropriate septal perforator, which involves 2-dimensional echocardiographic monitoring during introduction of 1 to 2 mL of echo or angiographic contrast through the distal lumen of a balloon dilation catheter. 5,6 Contrast echocardiography enhances the effectiveness and safety of PTSMA by avoiding arteries that supply distant regions of myocardium, as well as by limiting the number of arteries intervened, the frequency of complete heart block requiring permanent pacemaker, the amount of alcohol injected (and creatine phosphokinase levels), and fluoroscopy time. After identification of the most appropriate perforator, balloon occlusion is followed by contrast injection through the coronary guide catheter as well as the distal balloon port to document complete cessation of flow between the distal septal artery and LAD.…”

“…The immediate postablation gradient reduction is probably due to alcohol-mediated septal necrosis and stunning, a mechanism distinct from the septal thinning and ventricular remodeling that is associated with progressive gradient reduction on long-term follow-up. [5][6][7][8][9] Clinical Results…”

“…Specifically, there is greater appreciation for identifying the most appropriate septal vessel for intervention (Figure 1 and Figure 2) and using smaller amounts of alcohol (introduced more slowly) creating more limited areas of myocardial necrosis and scarring. 4,6,10 PTSMArelated mortality has been reported at up to 4%, but in experienced centers is currently 1% to 2% (similar to that of surgery). [7][8][9] Conduction abnormalities are relatively common complications of PTSMA, with permanent right bundle branch block and transitory heart block in about 50% and high-grade atrioventricular block requiring permanent pacemakers in 5% to 20%.…”

Usefulness of Selective Myocardial Contrast Echocardiography in Percutaneous Transluminal Septal Myocardial Ablation. A Case Report.

“…4 Knight et al 5 and Seggewiss et al 6 have both reported that PTSMA significantly reduces LVOT obstruction and improves the symptoms in HOCM, but it has also been reported that permanent pacemaker implantation was required in 20% of the patients because of complete atrioventricular block associated with this procedure. Faber et al 7 reported that myocardial contrast echocardiography (MCE) for target vessel selection in PTSMA improved both the acute and chronic results. We describe a case of HOCM treated by PTSMA in which intraprocedural selective MCE was very helpful in identifying the culprit septal branch.…”