• Posted November 19, 2024

Ablation Best Treatment for Rapid Heartbeat in Heart Attack Survivors

New research suggests that a procedure now regarded as Plan B when patients have episodes of rapid heartbeat after a heart attack should be the go-to treatment.

Ablation is a minimally invasive procedure to treat abnormal electrical short circuits caused by a heart attack. These episodes -- called ventricular tachycardia (VT) -- are the most common cause of sudden cardiac death.

Today, ablation is typically reserved for patients whose VT doesn't improve with medication, but research presented Saturday at an American Heart Association meeting in Chicago and published simultaneously in the New England Journal of Medicine suggests it may be a better first-line option.

"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 lead author Dr. John Sapp, assistant dean of clinical research at Dalhousie University in Halifax, Nova Scotia, Canada. "These results may change how heart attack survivors with ventricular tachycardia are treated."

Heart attacks leave scar tissue, which sometimes contains surviving bits of heart muscle that create abnormal electrical circuits in the heart, he explained.

These abnormal circuits cause a fast rhythm in the lower chambers of the heart. The rapid heartbeat, in turn, prevents the chambers from filling completely between beats, reducing the flow of blood throughout the body.

Some patients are treated with an implantable defibrillator, which delivers a shock to restore a normal rhythm to the heart. While it may be lifesaving, it doesn't prevent VT, and anti-arrhythmia medications may make matters worse or damage other organs, Sapp said. 

When medication fails to help, ablation is already the go-to remedy. It uses radiofrequency energy to destroy the abnormal tissue causing VT, while leaving the rest of the heart undamaged.

"We have previously shown that when a medication is not preventing episodes of BT, ablation has led to better outcomes than increasing the medications," Sapp said in a meeting news release. "Now we know that ablation is a reasonable option for first-line treatment."

For the new study, his team followed 416 patients in three countries. All had repeated VT episodes and had implanted defibrillators. One group was prescribed an anti-arrhythmic medication, the other had ablation. They were followed for a median of 4.3 years, meaning half were monitored for less time, half for more.

Researchers found that patients who received ablation were 25% less likely to die or have a VT episode requiring a defibrillator shock. This included having three or more VT episodes in one day, as well as those that went undetected by the implant and required hospital care.

The study was too small to show a statistically significant effect on every important parameter, Sapp said, but patients treated with ablation had fewer defibrillator shocks for VT, fewer episodes of three or more VT in a single day and fewer VT episodes that the defibrillator missed.

"Currently, cathether ablation is often reserved as a last-resort therapy when anti-arrhythmic medications fail or cannot be tolerated," Sapp said. "Now we know that ablation is a reasonable option for first-line treatment."

He noted that the study did not determine which patients and characteristics would benefit more from one treatment or another. And, he said, results do not apply to patients whose heart scarring is caused by something other than a blocked artery.

"We also note that, despite these treatments, the rate of VT episodes remained relatively high," Sapp added. "We still need more research and innovation to develop better treatments for these patients."

More information

Learn more about cardiac ablation at the Mayo Clinic.

SOURCE: American Heart Association, news release, Nov. 16, 2024