Lancet: Ablation prior to defibrillator shock reduces risk of recurrent VT

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Patients with episodes of ventricular tachycardia (VT) are at high risk of repeat VT, ventricular fibrillation and death; and the use of an implantable cardioverter-defibrillator (ICD) reduces mortality compared with drug treatment for VT. The VTACH study, published Dec. 31 in the Lancet, shows that use of catheter ablation prior to ICD implantation reduces the risk of VT recurrence at two years.

Karl-Heinz Kuck, MD, PhD, from Asklepios Klinik St. Georg in Hamburg, Germany, and colleagues noted that patients who receive ICD shocks have a decreased quality of life (especially if five or more shocks per year are delivered) and increased mortality compared with patients who do not receive shocks. Furthermore, they wrote that ICDs do not prevent sudden cardiac death in 30 percent of patients. Drug treatment, especially amiodarone (Pacerone, Upsher-Smith Laboratories and Cordarone, Wyeth-Ayerst Laboratories)  in combination with beta blockers, can reduce the number of ICD interventions, but lifetime intake is necessary and it is associated with serious adverse events.

The VTACH (Ventricular Tachycardia Ablation in Addition to Implantable Defibrillators in Coronary Heart Disease) trial was designed to assess prophylactic VT ablation followed by implantation of a cardioverter defibrillator in patients with previous heart attack, first episode of stable VT and reduced left ventricular function.

The randomized controlled trial took place in 16 centers in four European countries (Germany, Switzerland, Czech Republic and Denmark). The researchers assessed 107 eligible patients between the ages of 18-80. Fifty-two were assigned to ablation plus ICD, and 55 to ICD only. The mean follow-up was 22.5 months.

Kuck and colleagues found that time to recurrence of VT or VF was longer in the ablation group (median 19 months) than in the control group (six months). At two years, estimates for survival free from VT or VF were 47 percent in the ablation group and 29 percent in the control group—meaning that patients given ablation plus ICD were around 40 percent less likely to experience repeat VT or VF than those given ICD only.

Complications related to the ablation procedure occurred in two patients; no deaths occurred within 30 days after ablation, according to the authors. A total of 15 device-related complications requiring surgical intervention occurred in 13 patients (ablation group, four; control group, nine).

They reported that nine patients died during the study (five in the ablation group and four in the control group).

"Prophylactic VT ablation before defibrillator implantation seemed to prolong time to recurrence of VT in patients with stable VT, previous MI and reduced left ventricular ejection fraction,” the authors concluded. “Prophylactic catheter ablation should therefore be considered before implantation of a cardioverter defibrillator in such patients."

In an accompanying commentary, William G. Stevenson, MD, and Usha Tedrow, MD, from the cardiovascular division at Brigham and Women's Hospital in Boston, wrote: "Implantable defibrillators are a life-saving safety-net for patients with sustained ventricular tachycardia late after MI.”

“The VTACH trial suggests that ablation be considered early, in selected patients who are receiving an implantable cardioverter-defibrillator for stable ventricular tachycardia, in whom recurrences of a ventricular tachycardia are likely,” Stevenson and Tedrow wrote. “Evidence of a positive effect on survival, subsequent hospital admissions or quality of life is needed before this strategy can be recommended for routine use.”

“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 ICD, provided that the expertise to safely perform the procedure is available," Stevenson and Tedrow concluded.