Percutaneous septal ablation after unsuccessful surgical myectomy for patients with hypertrophic obstructive cardiomyopathy.

OBJECTIVE: To evaluate the long-term outcome of percutaneous septal ablation (PTSMA) after a previous myectomy.

BACKGROUND: Myectomy usually results in symptomatic improvement and reduction of dynamic obstruction in hypertrophic obstructive cardiomyopathy patients (HOCM-pts.). However, a few pts. remain with severe symptoms and obstruction, and need additional interventions.

METHODS: We reviewed our database of 450 pts. who underwent PTSMA in our institution, and identified 11 (7 women, 4 men, mean age: 50 +/- 14 years) with residual or recurrent NYHA class symptoms > or =III and significant left ventricular outflow obstruction (LVOTO) despite a previous myectomy 4 +/- 5 years ago. In-hospital and follow-up data covering 6 +/- 4 years, focusing on mortality and morbidity, symptoms, exercise capacity, and echocardiographic measures were collected.

RESULTS: PTSMA was performed by injection of 3.6 +/- 2.9 ml of alcohol. There was no peri-procedural or late death in this cohort. CK peaked at 614 +/- 434 U/l. In addition to two pts. who already had a pacemaker implanted, two more (18%) who both had pre-existing left bundle branch block were pacemaker-dependent after PTSMA. During follow-up, 9 pts. (81%) reported significant and stable improvement. Two pts. (18%) developed progressive class III symptoms until their last follow-up, one of these together with persistent AF and a non-fatal stroke, the other received an ICD for primary prophylaxis and entered our pre-transplant program. Echo-Doppler showed sustained LVOTO elimination without global LV dilatation in all cases.

CONCLUSIONS: PTSMA is an effective non-surgical option for treating symptoms and residual or recurrent LVOTO after a previous surgical myectomy. The high rate of conduction disturbances in this post-surgical cohort translated into a higher rate of pacemaker dependency after PTSMA.