Procedure used in cardiomyopathy may be safer in young than previously thought

12th April 2016

A type of treatment used in hypertrophic cardiomyopathy may be safer for younger and middle-aged people than previously thought, says a new study.

In the past young people with the condition and severe obstruction to blood flow out of the heart have usually been given a type of open heart surgery called a myectomy. In this procedure a small piece of thickened heart wall is surgically removed, allowing the blood flow out of the heart to improve.

In older people a procedure called a septal alcohol ablation has been favoured. This involves injecting alcohol into the affected area of the heart via a vein, usually at the top of the leg.  The alcohol then makes the nearby heart muscle cells slowly die, relieving the obstruction.

 

As this procedure does not involve open heart surgery, patient recovery is much quicker.

People with HCM with obstruction can suffer lots of symptoms, especially when they are active but also sometimes at rest.

The study, from Dr Max Liebregts, from the St Antonius Hospital, Nieuwegein in the Netherlands, and colleagues showed that the ablation reduced symptoms similarly in young and elderly patients and younger patients had a lower risk of developing electrical disturbances from the procedure. Long term survival was good and the risk of cardiac arrest was low in both young and elderly patients, and comparable to HCM patients who did not have obstruction.

"The five and ten-year survival following alcohol septal ablation was 95% and 90% in patients aged 55 or less and 93% and 82% in patients age over 55 years, which was comparable to non-obstructive cardiomyopathy," said Dr Liebregts in an article online in JACC: Cardiovascular Interventions.

Serious arrhythmic events showed the same pattern. They occurred at a rate of 0.7% per year in ablation patients aged 55 and below, compared with 1.0% for those with HCM and no obstruction. The older ablation group had these events at 1.4% per year versus 0.5% per year in their age-matched non-obstructive HCM controls .

What's more growing evidence suggested that the ablation is not fraught with the high risk that had been suspected and that long-term survival may be comparable to that of myectomy, potentially opening this treatment modality to a younger population as well as to centres that do not have the surgical expertise," Drs Mackram Eleid and Rick Nishimura, from the Mayo Clinic College of Medicine in Rochester, America, 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 a septal ablation."

But performing the procedure in adolescents and children was still not recommended due to limited safety data, the authors noted.

"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.

Reference: 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.