First-Line Catheter Ablation for Post-MI VT Suppression: Insights from VANISH2

 Clinicians often use antiarrhythmic drugs as the first-line therapy for ventricular tachycardia (VT) in patients with ischemic cardiomyopathy. However, data from the randomized VANISH2 trial suggest catheter ablation may offer better outcomes when used first.

For patients with VT after myocardial infarction (MI), recurrent VT can lead to poor quality of life and reduced survival. Implantable cardioverter-defibrillators (ICDs) effectively treat VT episodes but deliver painful shocks. Suppression of VT via catheter ablation or antiarrhythmic drugs is a preferred alternative.

The VANISH trial previously showed that ablation is superior when antiarrhythmic drugs fail. In VANISH2, researchers aimed to determine the benefits of starting with catheter ablation instead of drugs.

The trial enrolled 416 patients with prior MI, an ICD, and significant VT across 22 centers in three countries. Participants were randomized to either catheter ablation within 14 days or antiarrhythmic drug therapy with sotalol or amiodarone. Follow-up lasted a median of 4.3 years.

Results showed a reduced risk of the composite endpoint of death or serious arrhythmia outcomes in the ablation group (50.7% vs 60.6%). This was largely due to fewer cases of sustained VT below the ICD detection limit after 14 days (4.4% vs 16.4%).

Subgroup analysis revealed an advantage of ablation for patients eligible for sotalol but not for those who could take amiodarone. Sotalol, while less effective, has a better side effect profile, making it unsuitable for the sickest heart failure patients.

Adverse events differed between groups. The ablation group experienced two deaths (1.0%) and 11.3% nonfatal events, including stroke, cardiac perforation, and vascular injury. The drug group reported one drug-related death (0.5%) and 21.6% nonfatal events, including pulmonary fibrosis and organ-specific toxicities.

The study faced challenges with low female representation. Researchers attribute this to women experiencing heart attacks and VT development later in life, potentially explaining their lower prevalence in the trial.

Experts emphasize the importance of balancing risks and benefits when managing VT post-MI. While ICDs save lives, they can worsen heart failure and increase mortality. Antiarrhythmic drugs have toxicities, positioning catheter ablation as a promising option.

Take-Home Key Points:

1. Catheter ablation as a first-line therapy may improve outcomes for post-MI VT compared to antiarrhythmic drugs.
2. The primary benefit lies in reducing sustained VT episodes and ICD shocks.
3. Ablation appears most advantageous for patients eligible for sotalol rather than amiodarone.
4. Both treatment options carry unique risks, with fewer adverse events reported in the ablation group.
5. Further research is needed to address gender disparities in trial populations and outcomes.