NEW YORK (Reuters Health) – In patients with ventricular tachycardia (VT) and a previous myocardial infarction, prophylactic VT ablation in advance of defibrillator placement appears to postpone recurrence of the arrhythmia, new research shows.

As reported in the January 2nd issue of The Lancet, use of ablation before defibrillator placement prolonged the median time to recurrence of VT or ventricular fibrillation (VF) from 5.9 to 18.6 months.

The lead author, Dr. Karl-Heinz Kuck, from Asklepios Klinic St. Georg, Hamburg, Germany, and colleagues note that defibrillators are not perfect: the shocks are painful and they do not fully protect against sudden cardiac death. Reducing the need for shocks, even appropriate shocks, is crucial for patients’ quality of life, they add.

In the VTACH study, researchers at 16 European centers assessed VT recurrence and other outcomes in 107 patients who were randomized to receive a defibrillator with or without catheter ablation beforehand. Eligibility criteria included stable VT, prior myocardial infarction, and a left ventricular ejection fraction (LVEF) of 50% or less.

The devices were implanted at a median of 3 days after ablation (in the treatment group) or after the electrophysiological study (in controls). The average follow-up period was 22.5 months.

Ablation-treated patients were 39% more likely to be alive without arrhythmias at 2 years than were control subjects: 47% vs. 29%, according to the report.

Whereas ablation more than tripled the median time to recurrence, the rate of recurrences between the treatment and control groups differed only among patients whose LVEF was more than 30%.

Overall, according to the authors, ablation reduced the incidence of appropriate shocks by 43% and the median number of appropriate device interventions per patient per year of follow-up by 93%. Ablation also “seemed to reduce the rate of hospital admissions for cardiac reasons,” they said.

In two patients, the ablation procedure had to be terminated; one had a transient ischemic ST-segment elevation and the other had a transient cerebral ischemic event. Device-related complications occurred in 4 patients in the ablation group and in 9 in the control group.

Five ablation-treated subjects and four controls died during the study. Six of the 9 deaths were from noncardiac causes. No deaths occurred within 30 days of ablation.

In light of these findings, the investigators conclude that “prophylactic catheter ablation should…be considered before implantation of a cardioverter defibrillator in such patients.”

They caution, however, that their study “included a small number of patients in centers with experienced clinicians,” and the authors of an editorial in the same issue of the journal emphasize that point as well.

Dr. William G. Stevenson and Dr. Usha Tedrow, from Brigham and Women’s Hospital, Boston, comment that “we believe that today’s trial is further evidence to support early use of catheter ablation, as an alternative to antiarrhythmic drug therapy, for symptomatic recurrent ventricular tachycardia after implantation of an implantable cardioverter defibrillator, provided that the expertise to safely perform the procedure is available.”

Reference:
Lancet 2010;375:4-6,31-40.