Renal sympathetic denervation reduced arrhythmic episodes in a small cohort of patients with implantable cardioverter defibrillators, according to recent findings.

Researchers aimed to evaluate 6-month outcomes in 10 patients treated for refractory ventricular arrhythmias. Six patients had underlying Chagas’ disease, two had nonischemic dilated cardiomyopathy and two had cardiomyopathy.

The researchers used ICD interrogation to obtain data on the number of ventricular tachycardia/ventricular fibrillation episodes and antitachycardia pacing/shocks that occurred within the previous 6 months. They also assessed patients for incidence of these outcomes at 1 and 6 months after treatment.

In the 6-month duration before procedure, the median number of ventricular tachycardia/ventricular fibrillation episodes was 28.5 (range, 1-106), which was reduced to a median of one episode (range, 0-17) at 1 month and zero episodes (range, 0-9) at 6 months. Also in the 6 months before the procedure, the median number of antitachycardia pacing episodes was 20.5 (range 0-52), which decreased to zero episodes (range, 0-7) at 1 months and zero episodes (range, 0-7) at 6 months.

For shock in the 6 months before denervation, the median was eight episodes (range, 0-88). This decreased to zero episodes with a range of 0 to 3 at both 1 and 6 months.

The researchers observed two instances of ventricular tachycardia within a week of denervation. One of these patients needed a shock, but no more episodes were reported through follow-up.

Two patients failed to respond to renal sympathetic denervation. One of those patients had ischemic cardiomyopathy and persistent idioventricular rhythm, and the second patient underwent incomplete denervation to treat multiple renal arteries. At the 2-month mark, one of those patients still was free of arrhythmia. That patient was treated for ventricular tachycardia using external shock.

The researchers reported no major complications related to the procedure. There were three fatalities in the follow-up period, none of which were associated with ventricular arrhythmias.

“Our findings illustrate the relevance of sympathetic activation in patients with [ventricular arrhythmias] and suggest a potential role for catheter-based [renal sympathetic denervation] in reducing arrhythmic burden,” the researchers concluded. – by Rob Volansky

Disclosure: Some of the researchers report receiving consultant fees and research grants from Bristol-Myers Squibb; research grants from GlaxoSmithKline; consultant fees from Bayer, Boehringer Ingelheim and Pfizer.

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