Patients who had catheter ablation for atrial fibrillation (Afib) had fewer symptoms, a significant long-term improvement in quality of life and fewer recurrences and hospitalizations than those who received drug therapy alone, according to a government-funded study.
The same study showed that catheter ablation appeared no more effective than drugs in preventing strokes, deaths, and other complications.
The Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial was a randomized trial that compared state-of-the-art drug therapies for Afib to ablation, a procedure in which a doctor inserts a catheter through a patient’s blood vessels to scar or destroy heart tissue causing the irregularities. Funded in part by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health (NIH), the study’s findings were published in two articles in the Journal of the American Medical Association.
From its launch in November 2009 to April 2016, CABANA enrolled more than 2,200 patients at 126 sites in the United States, Canada, Europe, and Asia. About half the patients were randomly assigned to the ablation procedure. The other half was assigned to drug therapy, but could choose to undergo ablation if their symptoms could not be controlled. Approximately 27% of patients in the drug therapy arm ended up also receiving ablation. The median follow-up period for the trial was 48.5 months.
Before beginning the study, 86% of patients in the ablation group and 84% on drug therapy reported Afib symptoms during the previous month. By the end of the study, however, only 25% of patients in the ablation arm reported symptoms compared with 35% of patients treated with drug therapy alone.
Just 12 months after the start of treatment, the quality of life of patients in both groups improved substantially. However, those treated with ablation saw a greater decrease in Afib symptoms such as fatigue and shortness of breath, and these quality-of-life improvements were sustained over the five years of follow-up. Ablation for Afib had previously been shown to improve quality of life over drug therapy, but those early studies had limited sample sizes and short follow-ups of one year or less. The researchers also noted that patients with the most severe quality of life impairments at the time of enrollment in the study showed significantly greater improvement after catheter ablation than patients with initially mild symptoms.
“Since current drug therapies often have limited effectiveness in controlling atrial fibrillation, it is very important to understand whether ablation, an invasive procedure, yields better outcomes,” said Dr. David Goff, director of the Division of Cardiovascular Sciences at NHLBI, in a prepared statement. “As these two papers show, CABANA provided a wealth of information that doctors can use to manage patients better and improve their quality of life.”
The overall rate of deaths and strokes was lower than expected, and about 9% of those assigned to ablation were not able to undergo the procedure. This could have affected the study’s results, according to principal investigator Dr. Douglas Packer, a cardiologist and professor of medicine at Mayo Clinic, in Rochester, Minn.
“Most commonly, we look at clinical trial data by comparing the results according to which group a patient is randomly assigned, but patients and physicians do not always follow the assigned treatment,” Packer explained. “When we examined the data according to the treatment actually received, the ablation group had significantly lower rates of death as well as the combination of death, disabling stroke, serious bleeding, or cardiac arrest compared with patients who only received drug therapy.”
The article titled Effect of Catheter Ablation vs Antiarrhythmic Drug Therapy on Mortality, Stroke, Bleeding, and Cardiac Arrest Among Patients with Atrial Fibrillation, can be found here. The other article, Effect of Catheter Ablation vs Medical Therapy on Quality of Life Among Patients with Atrial Fibrillation: the CABANA Randomized Clinical Trial, can be found here.