Early treatment with cryocatheter ablation can stop the progression of a 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 linked to an increased risk of stroke and heart failure.
The research, which was recently published in The New England Journal of Medicinedemonstrates that early intervention using cryoballoon catheter ablation (cryoablation), as opposed to the standard first step of 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 more life-threatening, persistent forms of atrial fibrillation,” says Jason Andrade, MD, associate professor of medicine at UBC and director of Heart Rhythm Services at Vancouver. General Hospital. “In the short term, this can mean fewer arrhythmia recurrences, better quality of life, and fewer hospital visits. In the long run, this can translate into a lower risk of stroke and other serious heart problems.”
Cryoablation is a minimally invasive procedure that involves guiding a small tube into the heart to kill problematic tissue in cold temperatures. Historically, the procedure has only been used as a secondary treatment for people who do not respond after taking 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 disease progression
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 occurrence can cause electrical and structural changes in the heart, leading to longer-term events known as persistent AF (episodes lasting more than seven continuous days).
“Atrial fibrillation is like a snowball rolling downhill. With each episode of atrial fibrillation there are progressive changes in the heart and the heart rhythm problem worsens”, explains Dr. Andrade.
The new findings, derived from a multi-site clinical trial, show that cryoablation can halt this snowball effect.
For the trial, the pan-Canadian research team enrolled 303 AF patients at 18 sites in Canada. Half of the patients were randomly selected to receive antiarrhythmic drugs, while the other half were treated with cryoablation. All patients received an implantable monitoring device that recorded their heart activity throughout the study period.
After three years, the researchers found that patients in the cryoablation group were less likely to progress to persistent AF compared with patients treated with antiarrhythmic drugs. During the follow-up period, cryoablation patients also had lower rates of hospitalization and experienced fewer serious adverse health events resulting in death, functional disability, or prolonged hospitalization.
Address the root cause
Because cryoablation targets and destroys the cells that initiate and perpetuate AF, the researchers say it may have more lasting benefits.
“With cryoablation, we are treating the cause of the condition, rather than using drugs to cover up the symptoms,” says Dr. Andrade. “If we start with cryoablation, we may be able to correct atrial fibrillation early in its course.”
The new study builds on a previous article in which Dr. Andrade and his team showed that cryoablation was more effective than antiarrhythmic drugs in reducing short-term recurrence of atrial fibrillation.
The researchers say the most effective early interventions would benefit both patients and the health care system. Currently, the costs associated with the provision of care associated with atrial fibrillation are estimated to be 2.5 percent of annual overall health care expenses. Those costs are expected to rise to four percent over the next two decades.
“More and more evidence shows that it is time to rethink how 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 tremendous benefit to patients and their families, and also to our entire healthcare system.”
Reference: “Progression of Atrial Fibrillation After Cryoablation or Drug Therapy” by 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, Ph.D., Julia Cadrin-Tourigny, MD, Simon Kochhäuser, MD, and Atul Verma, MD for EARLY-AF researchers, November 7, 2022, New England Journal of Medicine.
The study was funded by the Canadian Cardiac Arrhythmia Network, Medtronic and Baylis Medical.