Echocardiography-Guided Ethanol Septal Reduction for Hypertrophic Obstructive Cardiomyopathy

Abstract

Background —Left ventricular outflow tract (LVOT) obstruction is frequently responsible for symptoms in hypertrophic obstructive cardiomyopathy (HOCM). Medical therapy is often not sufficient to control these symptoms, and surgical myotomy-myomectomy is required. Methods and Results —We enrolled 33 symptomatic patients with HOCM and obstruction (≥40 mm Hg gradient at rest or ≥60 mm Hg dobutamine-provoked). By contrast echocardiography, the bulging septum was localized and infarcted by injection of 2 to 5 mL of absolute ethanol into the septal artery(ies) supplying the hypertrophied area. Baseline echocardiograms with Doppler, myocardial perfusion tomograms, and treadmill exercise or pharmacological testing were compared with those at 6 weeks and 6 months. The mean rise in creatine kinase was 1964±796 U. All patients experienced symptomatic relief; NYHA class decreased from 3.0±0.5 to 0.9±0.6 ( P <0.001). Exercise time increased from 286±193 to 421±181 seconds ( P =0.03). The resting and dobutamine-provoked gradient decreased from 49±33 and 96±34 mm Hg to 9±19 ( P <0.001) and 24±31 mm Hg ( P <0.001), respectively. Echocardiograms repeated at 6 weeks after the procedure showed a 28% reduction in septal thickness and 17% reduction in left ventricular mass. Myocardial perfusion imaging showed a “septal amputation pattern,” with scarring in the upper and middle septal areas. Complete heart block developed in 11 patients, who then required permanent pacemaker implantation. Conclusions —Echocardiography-guided ethanol septal reduction in patients with HOCM is a safe, minimally invasive procedure that provides symptomatic relief with improved hemodynamic and left ventricular parameters.