A Systematic Review and Meta-Analysis of Long-Term Outcomes After Septal Reduction Therapy in Patients With Hypertrophic Cardiomyopathy.

Objectives: The aim of this meta-analysis was to compare long-term outcomes after myectomy and alcohol septal ablation (ASA) in patients with hypertrophic cardiomyopathy (HCM).

Background: Surgical myectomy and ASA are both accepted treatment options for medical therapy-resistant obstructive HCM. Previous meta-analyses only evaluated short-term outcomes.

Methods: A systematic review was conducted for eligible studies with a follow-up of at least 3 years. Primary outcomes were all-cause mortality and (aborted) sudden cardiac death (SCD). Secondary outcomes were periprocedural complications, left ventricular outflow tract gradient, and New York Heart Association functional class after ≥3 months, and reintervention. Pooled estimates were calculated using a random-effects meta-analysis.

Results: Sixteen myectomy cohorts (n = 2,791; mean follow-up, 7.4 years) and 11 ASA cohorts (n = 2,013; mean follow-up, 6.2 years) were included. Long-term mortality was found to be similarly low after ASA (1.5% per year) compared with myectomy (1.4% per year, p = 0.78). The rate of (aborted) SCD, including appropriate implantable cardioverter defibrillator shocks, was 0.4% per year after ASA and 0.5% per year after myectomy (p = 0.47). Permanent pacemaker implantation was performed after ASA in 10% of the patients compared with 4.4% after myectomy (p < 0.001). Reintervention was performed in 7.7% of the patients who underwent ASA compared with 1.6% after myectomy (p = 0.001).

Conclusions: Long-term mortality and (aborted) SCD rates after ASA and myectomy are similarly low. Patients who undergo ASA have more than twice the risk of permanent pacemaker implantation and a 5 times higher risk of the need for additional septal reduction therapy compared with those who undergo myectomy.