Looking back on 15 years of ultrasound-guided alcohol septal ablation for hypertrophic obstructive cardiomyopathy.

Background

Septal reduction remains an important target of current therapeutic modalities in hypertrophic obstructive cardiomyopathy (HOCM). Surgical septal myectomy has long been considered the gold standard in pharmacotherapy-refractory severely symptomatic patients with marked left ventricular outflow tract (LVOT) obstruction. In recent years, percutaneous alcohol septal ablation (ASA) has matured into the preferred strategy for patients with favourable anatomy and no other coexisting surgically amenable disease.

Methods

We discuss 26 HOCM patients with persistent dyspnoea, angina or syncope despite optimal medical treatment. Baseline septal wall thickness was 20 ± 3 mm, with peak resting/provoked LVOT gradients of 53 ± 35/112 ± 40 mmHg. Guided by echocardiography, alcohol injection could be restricted to the first septal coronary artery in 85% of patients, provoking basal septal infarction with average troponin rise of 3.0 ng/ml.

Results

Eighty-six per cent of patients experienced sustained clinical improvement, associated with a reduction of septal wall thickness to 15 ± 3 mm and resting LVOT gradient to 21 ± 15 mmHg. One of the two non-responders underwent additional septal myectomy 11 years after ASA. Notable adverse events during the follow-up of 7.2 ± 4.7 years included: persistent conduction disturbances (65%) necessitating early postprocedural permanent pacemaker implantation (15%); atrial fibrillation (32%); ventricular tachycardia (4%) and aortic stenosis (14%). Six patients died, of which only 1 cardiac death.

Conclusions

Our case series underscores the efficacy of ASA at relieving LVOT obstruction and improving symptoms in properly selected HOCM patients, with acceptably low procedural and long term mortality and morbidity.