CABANA: Ablation an ‘acceptable treatment strategy’ for AF
BOSTON — In patients with atrial fibrillation, catheter ablation conferred better outcomes compared with drug therapy in on-treatment and per-protocol analyses, but not in an intention-to-treat analysis, according to the results of the CABANA trial.
The difference in analyses was attributed to nearly 30% of patients assigned to drug therapy eventually receiving ablation, and nearly 10% of patients assigned to ablation not undergoing the procedure, Douglas L. Packer, MD, professor of medicine and consultant in the division of heart rhythm services, department of cardiovascular medicine, Mayo Clinic, said during a presentation at the Heart Rhythm Society Annual Scientific Sessions.
New data reported
At a median follow-up of 4 years, for the primary endpoint of death, disabling stroke, serious bleeding or cardiac arrest, the difference between patients assigned ablation and those assigned drug therapy was not significant in the intention-to-treat analysis (HR = 0.86; 95% CI, 0.65-1.15), but favored ablation in both the on-treatment analysis (HR = 0.67; 95% CI, 0.5-0.89) and the per-protocol analysis (HR = 0.73; 95% CI, 0.54-0.99).
“You can’t benefit from a therapy if you don’t get the therapy,” Packer said at a press conference.
In the intention-to-treat analysis, the catheter ablation group had lower risk for all-cause mortality or CV hospitalization (HR = 0.83; 95% CI, 0.74-0.93) and less AF recurrence (HR = 0.53; 95% CI, 0.46-0.61), but similar risk for all-cause mortality (HR = 0.85; 95% CI, 0.6-1.21), disabling stroke (HR = 0.42; 95% CI, 0.11-1.62), serious bleeding (HR = 0.98; 95% CI, 0.62-1.56) and cardiac arrest (HR = 0.62; 95% CI, 0.24-1.61) compared with the drug therapy group, Packer said.
He also noted that the intention-to-treat primary outcome favored catheter ablation in patients aged younger than 65 years (HR = 0.52; 95% CI, 0.27-1), but not in patients aged 65 to 74 years (HR = 0.84; 95% CI, 0.57-1.23) or those aged 75 years or older (HR = 1.46; 95% CI, 0.8-2.67).
In the on-treatment analysis, the primary endpoint, all-cause mortality and death or CV hospitalization favored the ablation group. It was likewise in the per-protocol analysis, and the treatment effect of catheter ablation for the primary outcome was even greater in those aged younger than 65 years, he said.
Adverse event rates were low in both groups.
“Since I got the data, I found that it’s changed my approach with patients,” Packer said at the press conference. “It is much less common for me to say, ‘let’s just go with the drug and see how it goes.’ I would take that approach if I were unsure that the patient’s symptoms were because of the atrial fibrillation.”
The study population comprised 2,204 patients from 110 sites worldwide with any type of AF eligible for ablation and at least two rate control or rhythm control drugs. Patients younger than 65 years could be included if they had at least one risk factor for CVD or cerebrovascular accident.
In the ablation group (median age, 68 years; 37% women), 90.8% of patients had ablation and 19.4% received repeat ablation. In the drug therapy group (median age, 67 years; 37% women), 99.6% were treated with drugs and 87.2% took at least one rhythm control drug, while 27.5% were crossed over to ablation, Packer said.
Further analyses to come
“Ablation is an acceptable treatment strategy for treating AF with low adverse event rates even in higher-risk patients,” Packer concluded.
When the results are published, more information will be available about who benefited most from ablation, and quality-of-life and health care economics analyses will be presented at the European Society of Cardiology Congress in August, he said.
“At the end of the day, we think this is a very meaningful trial,” Packer said at the press conference. – by Erik Swain
Packer DL, et al. LBCT01-05. Presented at: Heart Rhythm Society Annual Scientific Sessions; May 9-12, 2018; Boston.
Disclosure: The study was funded by Biosense Webster, Boston Scientific, Medtronic, the NIH and St. Jude Medical. Packer reports he has financial ties with numerous device companies.