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Background:
In patients with ventricular tachycardia (VT) and a history of myocardial infarction, intervention with an implantable cardioverter defibrillator (ICD) can prevent sudden cardiac death and thereby reduce total mortality. However, ICD shocks are painful and do not provide complete protection against sudden cardiac death. We assessed the potential benefit of catheter ablation before implantation of a cardioverter defibrillator.
Methods:
The Ventricular Tachycardia Ablation in Coronary Heart Disease (VTACH) study was a prospective, open, randomised controlled trial, undertaken in 16 centres in four European countries. Patients aged 18–80 years were eligible for enrolment if they had stable VT, previous myocardial infarction, and reduced left-ventricular ejection fraction (LVEF; ≤50%). 110 patients were randomly allocated in a 1:1 ratio to receive catheter ablation and an ICD (ablation group, n=54) or ICD alone (control group, n=56). Randomisation was done by computer-generated randomly permuted blocks and stratified by centre and LVEF (≤30% or >30%). Patients were followed up for at least 1 year. The primary endpoint was the time to first recurrence of VT or ventricular fibrillation (VF). Analysis was by intention to treat (ITT). This study is registered with ClinicalTrials.gov, number NCT00919373.
Findings:
107 patients were included in the ITT population (ablation group, n=52; control group, n=55). Two patients (one in each group) withdrew consent immediately after randomisation without any follow-up data and one patient (ablation group) was excluded because of a protocol violaton. Mean follow-up was 22·5 months (SD 9·0). Time to recurrence of VT or VF was longer in the ablation group (median 18·6 months [lower quartile 2·4, upper quartile not determinable]) than in the control group (5·9 months [IQR 0·8–26·7]). At 2 years, estimates for survival free from VT or VF were 47% in the ablation group and 29% in the control group (hazard ratio 0·61; 95% CI 0·37–0·99; p=0·045). Complications related to the ablation procedure occurred in two patients; no deaths occurred within 30 days after ablation. 15 device-related complications requiring surgical intervention occurred in 13 patients (ablation group, four; control group, nine). Nine patients died during the study (ablation group, five; control group, four).
Interpretation:
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.
Figure 2: Kaplan-Meier curves for the primary endpoint. Estimates for survival free from ventricular tachycardia (VT) or ventricular fibrillation (VF). Censored patients are indicated by dots. The p value was calculated by log-rank test. (Reprinted from Kuck K-H, for the VTACH study group. Catheter ablation of stable ventricular tachycardia before defibrillator implantation in patients with coronary heart disease (VTACH): a multicentre randomised controlled trial. Lancet. 2010;375:31-40, with permission from Elsevier.)
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