Catheter Ablation More Effective Than Traditional Therapy in Atrial Fibrillation

Patients who received radiofrequency catheter ablation compared with traditional drug therapies for atrial fibrillation (AF) had significantly lower hospitalization and mortality rates, according to a new study published in the February issue of the New England Journal of Medicine.

“Atrial fibrillation prevents the heart from filling and pumping properly. When the heart is not synchronized, it hastens heart failure and increases the risk of stroke,” Nassir F. Marrouche, MD, professor in internal medicine and executive director of the Comprehensive Arrhythmia Research and Management Center at University of Utah Health, said in a statement.

Until this study was published, there had been no previous studies conducted that supported one definitive treatment of AF.

“This clinical trial is the first time we can show with hard data that ablation is saving more lives than arrhythmia medications,” said Marrouche. “It also lowers the cost of treating patients by keeping them out of [the] hospital due to lower incidence of worsening heart failure.”

The 8-year CASTLE-AF clinical trial was conducted by Marrouche and colleagues at the University of Utah Health and Klinikum in Coburg, Germany. The trial compared catheter ablation with conventional drug therapies recommended by the American Heart Association and European Heart Society to control heart rate.

The researchers selected 363 patients from North America, Europe, and Australia with heart failure and a history of symptomatic atrial fibrillation for the study. Patients were then characterized by heart function at less than 35% and separated into 2 groups receiving either radiofrequency catheter ablation (n = 179) or conventional drug therapy (n = 184).

The clinical trial had an endpoint of all-cause mortality and worsening of heart failure, resulting in an unplanned overnight hospitalization. Participants in the ablation group experienced lower overall mortality (28%; 51/179) compared with the traditional therapy group (45%; 82/184). In addition, patients within the catheter ablation group experienced lower cardiovascular mortality (13%; 24/179) compared with the traditional therapy group (25%; 46/184).

“The CASTLE-AF clinical trial represents a landmark in the history of cardiovascular medicine because of its potential impact on our patients who are suffering from heart failure,” said James Fang, MD, chief of cardiovascular medicine at the University of Utah Health. "For the first time in a randomized study, the strategy of catheter ablation for atrial fibrillation may be better than the current approach for these patients."

All patients included in the CASTLE-AF trial previously received an implantable cardioverter defibrillator, which allowed for continuous heart rate monitoring. Marrouche believes this is the primary limitation of the study and may have affected death rates in both groups.

References

Marrouche NF, Brachmann J, Andresen D, et al. Catheter ablation for atrial fibrillation with heart failure. N Engl J Med. 2018;351:2373-2383. DOI: 10.1056/NEJMoa041018.