For patients with ischemic heart disease and VT, equipped with a defibrillator, antiarrhythmics are preferred as first line. The results of VANISH2, presented at AHA2024 and published in the NEJM, could however lead to a modification of this strategy.
Automatic defibrillators implantable (ICD) improve the survival of patients with myocardial scar after myocardial infarction (MI) and ventricular tachycardia (VT) by delivering anti-tachycardia pacing or electric shock. However, they do not prevent the occurrence of VT.
About a third of people fitted with an ICD will experience episodes of VT and receive an electric shock within three years of implantation. Among patients with an ICD, those with recurrent VT have an impaired quality of life, more hospitalizations for heart failure and a lower survival rate than others. Patients experiencing episodes of sustained VT (electrical storms) are at particularly high risk of death from any cause.
Antiarrhythmic treatment or catheter ablation?
In case of recurrent VT, the use of antiarrhythmic drugs or catheter ablation is justified. These treatments vary in effectiveness, as do the risks that accompany them. Comparative studies to guide clinical decisions are limited.
Two medications are commonly used to reduce the risk of VT. Sotalol is less effective than amiodarone, but has fewer long-term side effects. It is often preferred in patients who do not have severe ventricular dysfunction, renal failure, or electrical storm. Amiodarone carries a higher risk of extracardiac toxicity than sotalol, but has greater efficacy, and is preferred for patients with more severe ventricular dysfunction or electrical storm.
Catheter ablation has also been shown to reduce the risk of VT. However, it is associated with a risk of procedural complications, which is why it is generally only considered in cases of failure of drug treatment.
The VANISH2 trial
The VANISH trial (Ventricular Tachycardia Antiarrhythmics / Ablation in Ischemic Heart Disease) showed that ablation, combined with continuation of baseline antiarrhythmics, in patients with VT and ischemic cardiomyopathy was associated with a lower risk of a composite endpoint including death, appropriate ICD shock, sustained VT, compared to escalation of antiarrhythmic drugs.
The international VANISH2 study was conducted to compare catheter ablation to systematic antiarrhythmic therapy as first-line treatment in patients with an ICD, ischemic cardiomyopathy and VT without a history of non -response to antiarrhythmic treatment.
In total, 416 patients having had an MI, carrying an ICD, and presenting a clinically significant VT (defined as: an electrical storm, the delivery of a shock by an ICD or an anti-tachycardia stimulation, a VT sustained interrupted by emergency treatment), were randomly assigned, in a 1:1 ratio, to receive antiarrhythmic therapy (sotalol or amiodarone) or to receive ablation with catheter within 14 days of randomization.
The primary endpoint was a composite of: death from any cause during follow-up; occurrence more than 14 days after randomization, VT, shock by appropriate ICD, sustained VT reduced by drug treatment.
First-line catheter ablation is effective
During a median follow-up of 4.3 years, a primary event occurred in 103 of 203 patients (50.7%) in the catheter ablation group. versus 129 of 213 participants (60.6%) received drug treatment (hazard ratio, 0.75; 95% CI, 0.58 to 0.97; p = 0,03).
In the catheter ablation group, adverse events occurring within 30 days of surgery included death in 2 patients (1.0%) and nonfatal adverse events in 23 others (11.3%). Among patients who received drug therapy, adverse events attributed to antiarrhythmic therapy included death due to pulmonary toxic effects in 1 patient (0.5%) and non-fatal adverse events in 46 others (21.6%).
This test has several limitations
In this study, an initial catheter ablation strategy is associated with a lower risk of death from any cause in ischemic cardiomyopathy patients with VT who have an ICD.
Certain limitations should be noted. Future changes in ablation technology or the development of new antiarrhythmic drugs could influence the interpretation of these results. In this trial, ICDs were consistently programmed according to evidence-based recommendations.
Future studies may identify additional programming parameters to reduce the incidence of VT below the ICD detection limit without increasing the risk of administering inappropriate therapies. Finally, while the follow-up period of this trial was relatively long, the adverse effects of amiodarone increase over time, and longer follow-up may be necessary.
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