Catheter ablation improved quality of life, but not major adverse cardiac events, versus medical therapy in afib

Catheter ablation was more effective than drug therapy improving quality of life in patients with atrial fibrillation but did not significantly reduce major adverse cardiac events, two reports from one trial found.

The Catheter Ablation vs. Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial, which was funded by the National Heart, Lung, and Blood Institute and industry partners, compared catheter ablation and drug therapy in 2,204 symptomatic patients with afib who were either older than age 65 years or were 65 years of age or younger with at least one risk factor for stroke. Patients from 126 centers in 10 countries enrolled in the study from November 2009 to April 2016, with follow-up ending December 2017. Pulmonary vein isolation (with additional ablation procedures at the discretion of investigators) was done in the 1,108 patients randomized to ablation. Standard rhythm and/or rate-control drugs were prescribed to the other 1,096 patients.

The researchers measured quality-of-life endpoints at 12 months using two scores: the Atrial Fibrillation Effect on Quality of Life (AFEQT) summary score (range, 0 to 100, where 0 indicates complete disability and 100 indicates no disability, with 5 points defined as a patient-level clinically important difference) and the Mayo AF-Specific Symptom Inventory (MAFSI) frequency score (range, 0-40, where 0 indicates no symptoms and 40 indicates the most severe symptoms, with −1.6 points defined as a patient-level clinically important difference) and severity score (range, 0-30, where 0 indicates no symptoms and 30 indicates the most severe symptoms, with −1.3 points defined as a patient-level clinically important difference). The study results were published March 15 by JAMA.

At 12 months, the mean AFEQT summary score was better in the catheter ablation group than in the drug therapy group (86.4 points vs. 80.9 points; adjusted difference, 5.3 points [95% CI, 3.7 to 6.9 points]; P<0.001), as were the mean MAFSI frequency (6.4 points vs. 8.1 points; adjusted difference, −1.7 points [95% CI, −2.3 to −1.2 points]; P<0.001) and severity (5.0 points vs. 6.5 points; adjusted difference, −1.5 points [95% CI, −2.0 to −1.1 points]; P<0.001) scores.

The researchers wrote that among patients with symptomatic atrial fibrillation, catheter ablation led to clinically important and significant improvements in quality of life at 12 months compared with medical therapy. These findings can help guide decisions regarding management of atrial fibrillation, the researchers said.

In a second analysis of the same patient cohort, also published by JAMA on March 15, catheter ablation compared with medical therapy did not significantly reduce the primary composite end point of death, disabling stroke, serious bleeding, or cardiac arrest. In an intention-to-treat analysis over a median follow-up of 48.5 months, the primary end point occurred in 89 patients in the ablation group (8.0%) and 101 patients (9.2%) of the drug therapy group (hazard ratio [HR], 0.86; 95% CI, 0.65 to 1.15; P=0.30).

On the study's secondary end points of all-cause mortality, total mortality or cardiovascular hospitalization, and afib recurrence, rates in the ablation group versus the drug therapy group were 5.2% and 6.1% for all-cause mortality (hazard ratio [HR], 0.85; 95% CI, 0.60 to 1.21; P=0.38), 51.7% and 58.1% for death or cardiovascular hospitalization (HR, 0.83; 95% CI, 0.74 to 0.93; P=0.001), and 49.9% and 69.5% for afib recurrence (HR, 0.52; 95% CI, 0.45 to 0.60; P<0.001), respectively.

The researchers noted that the estimated treatment effect of catheter ablation was affected by lower-than-expected event rates and treatment crossovers, which should be considered in interpreting the results of the trial.

An editorial accompanying both papers noted that shared decision making between cardiologists and patients are critical to determining treatment and that the current results provide additional data to help inform this process. “This approach may be well positioned to occur in comprehensive [atrial fibrillation] management centers that offer the full range of anticoagulation options, antiarrhythmic drug therapy, and percutaneous and surgical procedures, coupled with lifestyle modification, such as weight loss, that may further augment the success of ablation, medical therapies, or both,” the editorialists wrote. “Thus, the CABANA trial provides essential information to optimize the care of patients with AF in a very patient-centric way.”