A study found that undergoing a cardiac ablation procedure first—before taking any antiarrhythmic therapies—may be the better option for people who have developed a dangerous rhythm after surviving a heart attack.
When a heart attack disrupts the cardiac muscle tissue, abnormal electrical pathways can form that can lead to the rapid pulse rate known as ventricular tachycardia. Medications are typically given first, with clinicians turning to ablation when those drugs fail.
But a trial of 416 patients spanning nearly six years—presented at the annual scientific sessions of the American Heart Association, and published in the New England Journal of Medicine—found that catheter ablation as a first-line treatment led to fewer deaths over time, though the trial was not designed to determine the treatments’ exact effects on mortality.
The study, dubbed VANISH2, included patients in three countries who developed recurrent ventricular tachycardia after a heart attack; all had implanted cardioverter defibrillators to shock their heart back into a proper rhythm if needed. Participants in the medication arm received either amiodarone or sotalol.
With a median of 4.3 years of follow-up, people that received ablation first were 25% less likely to die or receive an ICD shock.
In a composite measure for the study’s primary endpoint, 103 patients were affected in the ablation arm, or 50.7%, compared to 129 patients in the drug therapy group, or 60.6%—including 45 deaths among ablation patients and 54 with medications.
“For people who have survived a heart attack and developed VT, our findings show that performing a catheter ablation to directly treat the heart’s abnormal scar tissue causing the arrhythmia, rather than prescribing heart rhythm medications that can affect other organs as well as the heart, provides better overall outcomes,” said the study’s lead author, John Sapp, assistant dean of clinical research at Dalhousie University in Nova Scotia, Canada.
“Although the study was not large enough to show a statistically definitive effect on all of the parameters that are important to patients and physicians, patients treated with ablation also had fewer ICD shocks for VT, fewer ICD treatments, episodes of three or more VT in a single day and fewer VT episodes not detected by their ICD,” Sapp said in a statement.
“In addition, these results cannot be generalized to patients who have heart muscle scarring caused by a disease other than a blocked coronary artery,” he said.
In terms of procedural complications, the ablation arm saw two related deaths, as well as two cases of non-fatal strokes and one cardiac perforation; five patients had vascular injuries, with two developing major bleeding.
Among those receiving antiarrhythmic drugs, one patient died from lung toxicity, while seven developed pulmonary infiltrates or fibrosis. Other organ-related side effects that led to dose adjustments or discontinuation happened in 25 patients.