Practice Update: Cardiology

CONFERENCE COVERAGE 14

ESC 2017: Catheter Ablation Improves Outcomes in Patients With Heart Failure and Atrial Fibrillation – CASTLE-AF Trial Catheter ablation may improve outcomes for patients with left ventricular dysfunction and atrial fibrillation. Patients who received catheter ablation of atrial fibrillation had lower mortality and less hospitalization for worsening heart failure than those receiving conventional drug treatment. T his outcome of Catheter Ablation vs Standard conventional Treatment in patients with LV dysfunction and After screening more than 3000 patients, CASTLE-AF included 397 patients with symptomatic paroxysmal or persistent atrial fibrillation and heart failure with ejection fraction <35%.

Dr. Marrouche and Johannes Brachmann, MD, of the Klinikum Coburg, Germany, jointly conducted a clinical trial to exam- ine the effect of catheter ablation on all-cause mortality and hospitalization rates in patients with atrial fibrillation and left ventricular dysfunction, vs state-of-the art conventional treatment recommended by the American Heart Association and Euro- pean Society of Cardiology. CASTLE-AF is the first randomized clini- cal trial comparing catheter ablation to current first-line antiarrhythmic drug ther- apy for patients with coexisting heart failure (HF) and atrial fibrillation evaluat- ing the primary outcome of mortality and hospitalization for worsening heart failure. mortality seen in the conventional therapy arm would suggest more advanced heart failure. Over the course of this study, the management of heart failure has changed. • How was medical therapy modified over the trial, and were the adjustments in medical therapy similar in both arms? • What were the power estimates for the primary endpoint? Could this be a play of chance? Nevertheless, we should take away that atrial fibrillation ablation in those with heart failure is a consideration, but the target patient population and the exact magnitude of the treatment effect need refinement. This could be a new direction of care.

AF (CASTLE-AF) was reported at the 2017 European Society of Cardiology (ESC) Con- gress, from August 26–30. “The medical community continues to debate the ideal treatment for atrial fibril- lation in patients with left ventricular dysfunction because clinical studies that support one definitive treatment are lack- ing. Common therapies for atrial fibrillation include medication that regulates or slows the heart rate,” said Nassir F. Marrouche, MD, of the Comprehensive Arrhythmia Research and Management (CARMA) Cen- tre, University of Utah Health, Salt Lake City “Catheter ablation versus standard con- ventional treatment in patients with left ventricular dysfunction and atrial fibril- lation: the CASTLE-AF trial,” a study of 397 patients, evaluated the benefit of catheter ablation of atrial fibrillation on hard cardiovascular outcomes in the set- ting of concomitant heart failure. Over 3000 patients from 30 countries were screened for participation. All had an ICD in place with home-monitoring func- tionality. Patients were randomized to ablation versus conventional therapy, either rate or rhythm control. Follow-up was 37.8 months. The primary endpoint was all-cause mortality and heart failure hospitalization. The study was positive, with a 38% (HR, 0.62; 95% CI, 0.43–0.87; P = .007) relative risk reduction in the primary endpoint. The secondary end- point of death alone demonstrated a 47% reduction. These are remarkable results that are applauded but do raise important questions: • Who were these patients? The large number screened versus those enrolled does raise the question of a selection bias. • How was heart failure treated? The COMMENT By Clyde W Yancy MD, MSc, MACC, FAHA, MACP, FHFSA CASTLE-AF

All patients were supplied with an implant- able cardioverter defibrillator with home monitoring capability to enable continuous surveillance of atrial fibrillation. Patients were recruited from more than 30 clinical centers from North America, Europe, and Australia. Patientswere randomized to radiofrequency catheter ablation or conventional drug

Dr Yancy is Chief of Cardiology at Northwestern University, Feinberg School of Medicine, Associate Director of the Bluhm Cardiovascular Institute at Northwestern Memorial

Hospital, Magerstadt Endowed Professor of Medicine Chair, Professor of Medical Social Sciences, Vice-Dean of Diversity & Inclusion, Northwestern University, Feinberg School of Medicine, Chicago, Illinois.

© ESC Congress 2017 – European Society of Cardiology

PRACTICEUPDATE CARDIOLOGY