Regional differences in outcomes with ablation versus drug therapy for atrial fibrillation: Results from the CABANA trial.

Abstract

Background

The finding of unexpected variations in treatment benefits by geographic region in international clinical trials raises complex questions about the interpretation and generalizability of trial findings. We observed such geographical variations in outcome and in the effectiveness of atrial fibrillation (AF) ablation versus drug therapy in the Catheter Ablation vs Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial. This paper describes these differences and investigates potential causes.

Methods

The examination of treatment effects by geographic region was a prespecified analysis. CABANA enrolled patients from 10 countries, with 1,285 patients at 85 North American (NA) sites and 919 at 41 non-NA sites. The primary endpoint was a composite of death, disabling stroke, serious bleeding, or cardiac arrest. Death and first atrial fibrillation recurrence were secondary endpoints.

Results

At least 1 primary endpoint event occurred in 157 patients (12.2%) from NA and 33 (3.6%) from non-NA sites over a median 54.9 and 40.5 months of follow-up, respectively (NA/non-NA adjusted hazard ratio (HR) 2.18, 95% confidence interval (CI) 1.48-3.21, P < .001). In NA patients, 78 events occurred in the ablation and 79 in the drug arm, (HR 0.91, 95% CI 0.66, 1.24) while 11 and 22 events occurred in non-NA patients (HR 0.51, 95% CI 0.25,1.05, interaction P = .154). Death occurred in 53 ablation and 51 drug therapy patients in the NA group (HR 0.96, 95% CI 0.65,1.42) and in 5 ablation and 16 drug therapy patients in the non-NA group (HR 0.32, 95% CI 0.12,0.86, interaction P = .044). Adjusting for baseline regional differences or prognostic risk variables did not account for the regional differences in treatment effects. Atrial fibrillation recurrence was reduced by ablation in both regions (NA: HR 0.54, 95% CI 0.46, 0.63; non-NA: HR 0.44, 95% CI 0.30, 0.64, interaction P = .322).

Conclusions

In CABANA, primary outcome events occurred significantly more often in the NA group but assignment to ablation significantly reduced all-cause mortality in the non-NA group only. These differences were not explained by regional variations in procedure effectiveness, safety, or patient characteristics.

Clinical trial registration

ClinicalTrials.gov Identifier: NCT0091150; https://clinicaltrials.gov/study/NCT00911508.

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1016/j.ahj.2024.01.009

Publication Info

Cappato, Riccardo, Daniel B Mark, Adam P Silverstein, Peter A Noseworthy, Gianluca Bonitta, Jeanne E Poole, Jonathan P Piccini, Tristram D Bahnson, et al. (2024). Regional differences in outcomes with ablation versus drug therapy for atrial fibrillation: Results from the CABANA trial. American heart journal, 270. pp. 103–116. 10.1016/j.ahj.2024.01.009 Retrieved from https://hdl.handle.net/10161/31113.

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.

Scholars@Duke

Mark

Daniel Benjamin Mark

Professor of Medicine

Dr. Mark is a clinical cardiologist with the rank of Professor of Medicine (with tenure) as well as Vice Chief for Academic Affairs in the Division of Cardiology, Department of Medicine at Duke University Medical Center. He is also the Director of Outcomes Research at the Duke Clinical Research Institute. He has been on the full-time faculty at Duke since 1985. Prior to that he completed his cardiology fellowship at Duke, his residency and internship at the University of Virginia Hospital, and received his medical degree from Tufts University and his Master’s degree from Harvard. In 1998, he was given the honor of being elected to the American Society for Clinical Investigators and in 2002 he was honored by election to the Association of American Physicians. These organizations are the two most prestigious honor societies in academic medicine. In 2009, Dr. Mark was awarded the American College of Cardiology Distinguished Scientist Award.

Dr. Mark's major research interests include medical economics and quality of life outcomes, outcomes research, and quality of medical care. Currently, Dr. Mark is directing a number of outcomes analyses for ongoing clinical trials including PROMISE (anatomic versus functional testing for coronary artery disease, NIH), CABANA (catheter ablation versus antiarrhythmic drug therapy for atrial fibrillation, NIH), ISCHEMIA (percutaneous coronary intervention versus optimal medical therapy for moderate-severe ischemia), and STICH (CABG +/- ventricular reconstruction versus medical therapy for ischemic heart disease, NIH). He was the principal author of the AHCPR Unstable Angina Guidelines and is a co-author of both the American College of Cardiology Guideline on Exercise Testing and their Coronary Stent Consensus Guideline. He is also the Editor of the American Heart Journal. Dr. Mark has published over 270 peer-reviewed articles, two books, and 80 book chapters. He lectures widely in the US, as well as in Canada, South America, and Europe.

Keywords: cost-effectiveness analysis, disease management, quality of life assessment, resource use.

Piccini

Jonathan Paul Piccini

Professor of Medicine

Jonathan P. Piccini, MD, MHS, FACC, FAHA, FHRS is a clinical cardiac electrophysiologist and Professor of Medicine and Population Health at Duke University Hospital and the Duke Clinical Research Institute. He is the Director of the Cardiac Electrophysiology section at the Duke Heart Center. His focus is on the care of patients with atrial fibrillation and complex arrhythmias, with particular emphasis on catheter ablation, pacing, and lead extraction. His research interests include the development and evaluation of innovative cardiovascular interventions for the treatment of heart rhythm disorders. He serves on the Board of Trustees of the Heart Rhythm Society, is an Associate Editor at JACC: Clinical Electrophysiology, and is an elected member of the American Society for Clinical Investigation. Dr. Piccini has more than 600 publications in the field of heart rhythm medicine and has been the recipient of several teaching and mentorship awards.

Bahnson

Tristram Dan Bahnson

Professor of Medicine

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