Practice Update - ESC Congress 2017

Ablation of Atrial Fibrillation Improves Quality of Life More than Drugs – CAPTAF Trial Ablation of atrial fibrillation has been shown to improve quality of life more than drugs, even though the reduction in atrial fibrillation burden did not differ significantly between treatments. This conclusion, based on results of the multicenter, prospective, randomized Catheter Ablation compared with optimized Pharmacological Therapy for Atrial Fibrillation (CAPTAF) trial, was presented at the 2017 European Society of Cardiology (ESC) Congress, from August 26–30.

C arina Blomström-Lundqvist, MD, PhD, of the University of Uppsala, Sweden, explained that previous randomized trials have reported that pulmonary vein isolation is more effective in preventing atrial fibrillation than antiarrhythmic drugs. None of these trials, however, employed continuous cardiac rhythm monitoring, so effects on the burden of atrial fibrillation could not be assessed reliably. Until now, no trial of ablation of atrial fibrillation has employed quality of life as the primary endpoint even though the main indication for ablation of atrial fibrillation is symptom relief. “Instead,” Dr. Blomström- Lundqvist said, “30-s recurrences of atrial fibrillation have been used as the primary endpoint, hardly a relevant measure of successful therapy.” The main purpose of the CAPTAF trial was to compare the treatment effects of ablation of atrial fibrillation and antiarrhythmic drugs using quality of life as the primary endpoint and an implanta- ble cardiac monitor to assess the burden of atrial fibrillation. CAPTAF included 155 patients with symptomatic atrial fibrillation who had failed one drug for either rate or rhythm control. Patients suffered at least one episode of atrial fibrillation documented on electrocardiography in the previous 12 months. At least one symptomatic paroxysmal episode had occurred in the previous 2 months, or at least two symptomatic episodes of persistent atrial fibrilla- tion necessitating cardioversion in the previous 12 months. Patients received an implantable cardiac monitor for a 2-month run-in period, then were randomized to ablation with pulmonary vein isolation or anti- arrhythmic drug therapy with adequate dosages according to guidelines. The primary endpoint was the change in general health, as measured by the Short Form 36-item health survey, from baseline to 12 months. Secondary endpoints included quality of life (by Short Form 36 and EuroQol 5 Dimensions), symptoms, European Heart Rhythm Association Symptom Classification, burden of atrial fibrillation, and safety. “We measured the burden of atrial fibrillation before randomization so we got a good idea of burden at baseline,” Dr. Blomström-Lundqvist said. The main secondary endpoints were morbidity and mortality as composite outcome, cardiovascular

hospitalization, symptoms, heart failure, left atrial and ventricular function and diameters, exercise capacity, health care economics, rhythm, atrial fibrillation burden, successful vs failed treatment, safety, and "cross-overs" over time. “We tried to record silent atrial fibrillation via a patient log book. We got a record for the first year but in the second year, patients were reluctant to record these episodes. We haven’t analyzed these data yet.” After 12 months of follow-up, the primary endpoint of general health score had improved significantly more in the ablation group (mean change 11.0; 95% confidence interval 6.7–15.2) than in the drug group (mean change 3.1; 95% confidence interval –0.9–7.1), P = .0084. Furthermore, all quality-of-life Short Form 36 subscales except for bodily pain and social functioning had improved significantly more in the ablation group than in the drug group. European Heart Rhythm Association symptom score improved significantly more from baseline to 12 months in the ablation group (from mean 3.0 ± 0.7 to 1.6 ± 0.8) than in the drug group (from mean 2.9 ± 0.7 to 2.1 ± 1.1; P = .0079). Reduction of burden in atrial fibrillation (that is, the proportion of time in atrial fibrillation), obtained from the implantable cardiac monitor, was numer- ically larger in the ablation than in the drug group, but change from baseline did not reach statistical significance between treatment groups. The com- plication rate was comparable between treatment groups. Dr. Blomström-Lundqvist concluded, “Quality of life should be the primary endpoint in future tri- als since the main indication for rhythm control is improvement.” She continued, “The lack of a statistically signifi- cant difference between treatment groups in the reduction in burden of atrial fibrillation suggests that other mechanisms may explain the better improvement of quality of life and symptoms achieved with pulmonary vein isolation compared to antiarrhythmic drugs.” She added, “We confirmed that quality of life improved greatly with ablation vs antiarrhythmic drugs. We think it’s because of side effects of anti- arrhythmic drugs, but we have not determined this definitively.”

Dr. Carina Blomström- Lundqvist

PracticeUpdate Editorial Team

© ESC Congress 2017 – European Society of Cardiology

ESC Congress 2017 • PRACTICEUPDATE CONFERENCE SERIES 7