Ablation Bests Drugs for Ventricular Tachycardia After Heart Attack

CHICAGO — For patients with ventricular tachycardia (VT) and ischemic cardiomyopathy, going right to catheter ablation improved outcomes compared with trying antiarrhythmic drugs first, the VANISH2 trial showed.

Death or serious arrhythmic events occurred 25% less often over a median 4.3 years after catheter ablation compared with an initial strategy of antiarrhythmics (HR 0.75, 95% CI 0.58-0.97, P=0.03), John Sapp, MD, of Dalhousie University in Nova Scotia, reported at the American Heart Association (AHA) Scientific Sessions.

The rate of this primary endpoint — a composite of all-cause death during follow-up or VT storm, appropriate implantable cardioverter defibrillator (ICD) shock, or sustained VT treated by medical intervention more than 14 days after randomization — was 50.7% with catheter ablation versus 60.6% with drug therapy.

The difference was driven by 25% fewer ICD shocks and 74% fewer treated cases of sustained VT in the ablation group. While death from any cause was reduced by 16% as well, the trial wasn’t powered for that comparison or any others for the individual components.

The paper, published simultaneously in the New England Journal of Medicine, suggested the need for a shift in what is common practice and in line with guidelines — to try drug therapy first and then ablation if it fails.

“For a long time we have struggled with identifying the best treatment strategy for our patients with heart failure cardiomyopathy,” said press conference moderator Sana Al-Khatib, MD, MHS, of Duke University Medical Center in Durham, North Carolina. “I’ve always questioned that, like, why can’t we intervene earlier so that we can actually really have an impact on things before the disease progresses? And I think VANISH2 really provides us with interesting data to support that practice.”

Andrea Russo, MD, of Cooper Medical School of Rowan University in Camden, New Jersey, and a past president of the Heart Rhythm Society, agreed: “This may change the way we practice.”

While quality of life findings were not presented for the trial, “I think we could assume that reducing the number of shocks would improve quality of life,” Russo noted.

While ICD shocks can terminate VT — the most common cause of sudden death — they are “a very negative experience for patients … and patients who have shocks have worse outcomes than those who don’t,” Sapp noted.

His group’s prior VANISH trial showed that when antiarrhythmic drugs are not working, it’s better to go to ablation than getting more aggressive with medical therapy. The next question was what should be first-line.

VANISH2 included 416 patients at 22 centers in Canada, the U.S., and France who had a previous myocardial infarction and, within the preceding 6 months while not being treated with antiarrhythmic drugs, experienced ventricular tachycardia storm, an appropriate ICD shock or antitachycardia pacing, or sustained ventricular tachycardia terminated by emergency treatment. The participants were randomly assigned to open-label treatment with the antiarrhythmic drugs sotalol or amiodarone (with randomization stratified by severity that would lead to selection of one over the other) or to undergo catheter ablation within 14 days. All the patients had an ICD.

After a median of 4.3 years of follow-up, the rates of the primary endpoint components between the catheter ablation and drug therapy groups were:

• Death in 22.2% vs 25.4% (HR 0.84, 95% CI 0.56-1.24)
• Appropriate ICD shock after 14 days in 29.6% vs 38.0% (HR 0.75, 95% CI 0.53-1.04)
• Ventricular tachycardia storm (after 14 days) in 21.7% vs 23.5% (HR 0.95, 95% CI 0.63-1.42)
• Treatment of sustained VT below the detection limit of the ICD (after 14 days) in 4.4% vs 16.4% (HR 0.26, 95% CI 0.13-0.55)

Sapp pointed to the high event rates in these patients despite treatment, underscoring the need for using the most effective option early.

Serious nonfatal adverse event rates were similar between groups. Events attributed to ablation within 30 days were: death 1%, major bleeding 1%, stroke 1.5%, perforation 0.5%, and decompensated heart failure 2%. Adverse effects attributed to drug treatment were: death 0.5%, lung complications 3.3%, overactive thyroid 3.3%, liver abnormalities 2.4%, and neurologic problems 2.4%.

One limitation was that more than 95% of the cohort enrolled was male, and it’s not always possible to extrapolate to populations not well represented, Russo noted.

She also called for more information on the study cohort like crossover between drugs and ablation and what the ablation protocol was (such as whether substrate modification was used). Another question she raised was whether typically high-volume, expert centers participating could hamper generalization of the findings.

“Presumably somebody who’s in a smaller community and maybe their option is a lower-volume center, they might want to think a little bit differently about their options,” Russo told MedPage Today.