Longer-lasting benefits – more effective treatment for common heart disease

Early treatment with catheter cryoablation can stop the progression of the disease and reduce the possibility of serious health risks.

A national study led by researchers at the University of British Columbia’s Center for Cardiovascular Innovation sheds light on how to treat atrial fibrillation (AF), a common heart rhythm problem associated with an increased risk of stroke and heart failure.

Research that was recently published in The New England Journal of Medicineshows that early intervention using cryoballoon catheter ablation (cryoablation), as opposed to the standard first-step treatment, antiarrhythmic drugs, is more effective in reducing the risk of significant long-term health effects.

“By treating patients with cryoablation early on, we see fewer people progressing to persistent, more life-threatening forms of atrial fibrillation,” says Dr. Jason Andrade, associate professor of medicine at BBC University and director of the Heart Rhythm Service in Vancouver. General Hospital. “In the short term, this can mean fewer arrhythmia recurrences, improved quality of life and fewer hospital visits. In the long term, this can translate into a reduced risk of stroke and other serious heart problems.”

Cryoablation is a minimally invasive procedure that involves inserting a small tube into the heart to kill the problem tissue with low temperatures. Historically, the procedure has only been used as a secondary treatment for individuals who do not respond to antiarrhythmic drugs.

“This study adds to the growing body of evidence that early intervention with cryoablation may be a more effective initial therapy in appropriate patients,” says Dr. Andrade.

Early intervention stops the progression of the disease

More than one million Canadians, or about 3% of the population, are affected by AF.

While the condition begins as an isolated electrical disturbance, each subsequent incidence can cause electrical and structural changes in the heart, leading to longer-lasting events known as persistent AF (episodes lasting more than seven continuous days).

“Atrial fibrillation is like a snowball rolling down a hill. With each episode of atrial fibrillation, there are progressive changes in the heart, and the heart rhythm problem worsens,” explains Dr. Andrade.

New findings from a multisite clinical trial show that cryoablation can stop this snowball effect.

For the trial, a pan-Canadian research team enrolled 303 patients with AF at 18 sites across Canada. Half of the patients were randomly selected to receive antiarrhythmics, while the other half were treated with cryoablation. All patients received an implantable monitoring device that recorded their heart activity during the study period.

After three years, researchers found that patients in the cryoablation group were less likely to progress to persistent AF compared with patients treated with antiarrhythmics. During the follow-up period, patients who underwent cryoablation also had lower hospitalization rates and experienced fewer serious adverse health events resulting in death, functional disability, or prolonged hospitalization.

Addressing the root cause

Because cryoablation targets and destroys the cells that initiate and maintain AF, researchers say it may lead to longer-lasting benefits.

“With cryoablation, we treat the cause of the condition, rather than using drugs to mask the symptoms,” says Dr. Andrade. “If we start with cryoablation, we might be able to fix atrial fibrillation at an early stage.”

The new study builds on previous work in which Dr. Andrade and his team showed that cryoablation is more effective than antiarrhythmics in reducing the short-term recurrence of atrial fibrillation.

Researchers say more effective early interventions would benefit patients as well as the health care system. Currently, costs associated with providing care related to atrial fibrillation are estimated at 2.5 percent of total annual health care expenditures. These costs are expected to rise to four percent over the next two decades.

“Evidence is mounting that it is time to rethink the way we approach the treatment of atrial fibrillation. With effective early intervention, we can keep people healthy, happy and out of the hospital, which would be a huge benefit for patients and their families, but also for our entire healthcare system.”

Reference: “Progression of Atrial Fibrillation After Cryoablation or Drug Therapy” Jason G. Andrade, MD, Marc W. Deyell, MD, Laurent Macle, MD, George A. Wells, Ph.D., Matthew Bennett, MD, Vidal Essebag , MD , Ph.D., Jean Champagne, MD, Jean-Francois Roux, MD, Derek Yung, MD, Allan Skanes, MD, Yaariv Khaykin, MD, Carlos Morillo, MD, Umjeet Jolly, MD, Paul Novak, MD, Evan Lockwood , MD, Guy Amit, MD, Paul Angaran, MD, John Sapp, MD, Stephan Wardell, MD, Sandra Lauck, DR., Julia Cadrin-Tourigny, MD, Simon Kochhäuser, MD, and Atul Verma, MD for the EARLY-AF Investigators , November 7, 2022, New England Journal of Medicine.
DOI: 10.1056/NEJMoa2212540

The study was funded by the Canadian Cardiac Arrhythmia Network, Medtronic and Baylis Medical.