The VTACH study is published in this week’s edition of The Lancet. It is the work of Professor Karl-Heinz Kuck, Asklepios Klinik St Georg, Hamburg, Germany, and colleagues. It shows that use of catheter ablation prior to implantable cardioverter-defibrillator (ICD) implantation reduces the risk of ventricular tachycardia recurrence at two years. This is an invasive procedure used to remove a faulty electrical pathway from the heart of people who are prone to developing cardiac arrhythmias. Catheters are advanced towards the heart and radiofrequency energy is applied to destroy the abnormal tissue that is causing the arrhythmia. Ventricular tachycardia (VT) is a rapid heartbeat that originates in the ventricles. Patients with episodes of VT are at high risk of repeat VT, ventricular fibrillation, and death. Use of an implantable cardioverter defibrillator (ICD) reduces mortality compared with drug treatment for VT. Ventricular fibrillation (VF) is when uncoordinated contraction of the ventricle muscles in the heart occurs. This can cause heart attacks and sudden death. An implantable cardioverter-defibrillator (ICD) is a small battery-powered electrical impulse generator which is implanted in patients who are at risk of sudden cardiac death due to ventricular fibrillation. The device is programmed to detect cardiac arrhythmia and correct it by delivering a shock of electricity.
There is a decreased quality of life for patients who receive ICD shocks, especially if five or more shocks per year are delivered. Moreover, there is an increased mortality compared with patients who do not receive shocks. In addition, ICDs do not prevent sudden cardiac death in 3 to 7 percent of patients. Drug treatment (mainly amiodarone in combination with β blockers) can reduce the number of ICD interventions. However, lifetime intake is necessary and it is associated with serious adverse events. The VTACH study was planned to evaluate 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.
A total of sixteen centres in four European countries (Germany, Switzerland, Czech Republic, and Denmark) participated in this randomised controlled trial. Overall, 107 eligible patients aged 18 to 80 years were assessed: 52 were assigned to ablation plus ICD, and 55 to ICD only. Mean follow-up was 22.5 months. Findings showed that time to recurrence of VT or VF was longer in the ablation group (median 19 months) than in the control group (6 months). After two years, estimates for survival free from VT or VF were 47 percent in the ablation group and 29 percent in the control group. This signifies 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. There were no reports of deaths occurring within 30 days after ablation. A total of 15 device-related complications requiring surgical intervention occurred in 13 patients: four in the ablation group and nine in the control group. Nine patients died during the study: five in the ablation group and four in the control group.
The authors write in conclusion: “Prophylactic VT ablation before defibrillator implantation seemed to prolong time to recurrence of VT in patients with stable VT, previous myocardial infarction, and reduced LVEF. Prophylactic catheter ablation should therefore be considered before implantation of a cardioverter defibrillator in such patients.”
In an associated note, Dr William G Stevenson and Dr Usha Tedrow, Cardiovascular Division, Brigham and Women’s Hospital, Boston, MA, USA, remark: “Implantable defibrillators are a life-saving safety-net for patients with sustained ventricular tachycardia late after myocardial infarction. 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. 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 implantable cardioverter defibrillator, provided that the expertise to safely perform the procedure is available.”
“Catheter ablation of stable ventricular tachycardia before defibrillator implantation in patients with coronary heart disease (VTACH): a multicentre randomised controlled trial”
Karl-Heinz Kuck, Anselm Schaumann, Lars Eckardt, Stephan Willems, Rodolfo Ventura, Etienne Delacrétaz, Heinz-Friedrich Pitschner, Josef Kautzner, Burghard Schumacher, Peter S Hansen, for the VTACH study group
Lancet 2010; 375: 31- 40
Written by Stephanie Brunner (B.A.)