Debra L. Beck and Eugene Braunwald, MD
Alcohol septal ablation was introduced as a new treatment option for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM) about 2 decades ago, but there has been persistent concern that the alcohol-induced infarction might have adverse long-term effects and increase the risk of cardiac mortality. Batzner et al studied the long-term survival after echo-guided alcohol septal ablation (percutaneous transluminal septal myocardial ablation [PTSMA]) in symptomatic patients with HOCM.
From May 2000 to June 2017, PTSMA with alcohol injection was performed in 952 patients (mean age, 55.7 years [range, 14.9 years to 85.1 years]; 59.2% men). The majority of patients were in NYHA class III or IV heart failure (73.3%); 40.7% had exercise-induced syncope and 10.3% had a family history positive for sudden cardiac death. Clinical follow-up after 6.0 ± 5.0 years was achieved in all patients.
During the index procedure, an average of 2.1 ± 0.4 cc of alcohol was injected. Maximal creatine kinase rise was 872 U/l. Echo Doppler gradients were reduced to 33.6 mm Hg at rest and 56.5 mm Hg at Valsalva (p<0.0001 vs. baseline for each).
Total heart block developed during alcohol injection in 39.6% of patients, but implantation of a permanent pacemaker was necessary in only 10.5% of patients.
During hospital stay, 1 patient died due to pulmonary embolism at 3 days after ablation and a second died at 33 days from multiorgan failure after pneumonia (in-hospital death, 0.2%). Including the index and subsequent ablations, (done in 17.2% of patients due to a planned staged procedure), procedure-related mortality was 0.17%.
During follow-up, 1.9% of patients underwent surgical myectomy, and 5.10% underwent cardioverter-defibrillator implantation. Seventy patients died, with the causes being noncardiovascular in 50, stroke-related in 6 and cardiac in 14.
Estimated 5-, 10-, and 15-year overall survival was 95.8%, 88.3% and 79.7%, respectively. Estimated 5-, 10-, and 15-year survival free of cardiovascular events (death related to any cardiovascular disease, including stroke) was 98.6%, 96.5%, and 92.3%, which the corresponding rates for estimated survival free of cardiac events (death related to any cardiac disease, including sudden cardiac death) were 98.9%, 97.0%, and 96.5%.
The researchers concluded that PTSMA is a safe procedure associated with ongoing symptomatic improvement and excellent long-term survival.
“These excellent results provide further reassurance that septal ablation does not increase the risk of sudden cardiac death and sets a benchmark for other institutions performing septal ablation, in analogy to the superb results of septal myectomy reported by a select few surgical centers…” wrote editorialist Dr. MA Fifer. The report also “provides support for the emerging consensus that, for most patients, there is equipoise between septal ablation and septal myectomy.”
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