Percutaneous alcohol septal ablation for obstructive hypertrophic cardiomyopathy (HCM) may be safer than previously thought in middle-age and younger adults, a retrospective study found.
“The 5- and 10-year survival following alcohol septal ablation was 95% and 90% in patients age ≤55 years and 93% and 82% in patients age >55 years, which was comparable to their control groups [with non-obstructive cardiomyopathy, and thus not treated with the ablation procedure],” Max Liebregts, MD, of St. Antonius Hospital Nieuwegein in the Netherlands, and colleagues reported online in JACC: Cardiovascular Interventions.
Adverse arrhythmic events showed the same pattern. They occurred at a rate of 0.7% per year in ablation patients ages 55 and below, compared with 1.0% annually for the non-obstructive HCM cohort (P=0.6). The older septal reduction group experienced these events at 1.4% per year versus 0.5% per year in their age-matched non-obstructive HCM controls (P=0.07).
Periprocedural complications occurred at similar rates between younger and older septal reduction patients, with the exception of individuals over 55 years having increased odds of temporary atrioventricular block (43% versus 21%, P=0.001).
“Alcohol septal ablation is similarly effective for reduction of symptoms in young and elderly patients, although younger patients have a lower risk of procedure-related atrioventricular conduction disturbances,” they concluded
What’s more, “growing evidence supports that alcohol septal ablation is not fraught with the high risk that had been suspected and that long-term survival after alcohol septal ablation may be comparable to that of myectomy, potentially opening this treatment modality to a younger population as well as to center that do not have the surgical expertise,” Mackram F. Eleid, MD, and Rick A. Nishimura, MD, both of the Mayo Clinic College of Medicine in Rochester, Minn., wrote in an accompanying editorial.
“Because the improvement in functional status following alcohol septal ablation in young and elderly patients is similarly good, we propose that the indication for alcohol septal ablation can be broadened to younger patients,” Liebregts’ group suggested. “In other words, younger age alone should not be a reason to exclude alcohol septal ablation.”
Performing the procedure in adolescents and children is still not recommended due to limited safety data, the authors noted.
Liebregts’ observational study included 217 consecutive obstructive HCM patients, who were age-matched with a control group of 349 non-obstructive HCM patients, all from two centers in the Netherlands.
American College of Cardiology/American Heart Association guidelines recommend that percutaneous septal reduction therapy be reserved for elderly patients and those with serious comorbidities; they give a class III recommendation for use in younger patients who can otherwise undergo myectomy.
“One of the main concerns about alcohol septal ablation in younger patients is the potential arrhythmogenic effect of the ablation scar in patients who are already at an increased risk of life-threatening arrhythmias. Recent studies have shown, however, that the long-term risk of sudden cardiac death after alcohol septal ablation is low and comparable to patients who undergo myectomy,” they reported.
Though myectomy is also presumed to be the better choice for younger patients due to the lower risk of atrioventricular block requiring permanent pacemaker implantation, “the present and previous studies have shown that atrioventricular conduction disturbances following alcohol septal ablation are mainly seen in elderly patients, with a need for pacemaker implantation in only 5% of the young patients,” the authors added.
They noted that among the limitations of the study are the baseline differences between age groups and the potential bias stemming from performing septal ablations in tertiary referral centers.
Additionally, the present study “did not include a surgical myectomy group for comparison, and thus, conclusions regarding the efficacy of alcohol septal ablation relative to myectomy in this population cannot be drawn from this investigation,” Eleid and Nishimura wrote.
In fact, “age may only be one factor in the integration of all clinical data to arrive at a patient-centered recommendation for therapy,” they argued, citing other variables such as patient preference and degree of septal hypertrophy.
Liebregts, Eleid, and Nishimura reported no relevant conflicts of interest.
JACC: Cardiovascular Interventions
Liebregts M, et al “Long-term outcome of alcohol septal ablation for obstructive hypertrophic cardiomyopathy in the young and the elderly” JACC Cardiovasc Interv 2016; DOI: 10.1016/j.jcin.2015.11.036.
JACC: Cardiovascular Interventions
Eleid MF, et al “Patient selection for alcohol septal ablation: does age matter?” JACC Cardiovasc Interv 2016; DOI: 10.1016/j.jcin.2015.11.036.