Efficacy and safety of cavutilide in patients with various forms of atrial fibrillation and atrial flutter in real-world practice: results of the Russian national registry

Aim . To collect data on the use of Refralon (cavutilide) in real-world practice, to evaluate the efficacy and safety of pharmacological cardioversion (PCV) with Refralon in patients with various forms of atrial fibrillation and atrial flutter (AF/AFL), and to study the impact of cardiovascular comorbidities and prior pulmonary vein catheter ablation on the outcomes of Refralon PCV. Material and methods . This retrospective multicenter study of patients with various forms of AF/AFL undergoing PCV with Refralon. Efficacy endpoints included the restoration of sinus rhythm at 6 and 24 hours after Refralon administration for paroxysmal and persistent AF/AFL, and its maintenance at 24 hours. Safety endpoints included the incidence of mortality, acute cardiovascular events, polymorphic ventricular tachycardia, QT interval >500 ms, and heart rate <50 bpm. Results. The study included 1142 patients with various forms of AF/AFL, aged 63,5 [56; 70] years, from 22 hospitals. The efficacy of Refralon at doses up to 30 µg/kg was 742/836 (88,76%) for persistent AF/AFL and 281/301 (93,36%) for paroxysmal AF/AFL. Recurrence of AF/AFL within 24 hours occurred in 31 (3,03%) patients. No cardiovascular events or deaths were reported. Polymorphic ventricular tachycardia was recorded in 0,44% of patients (0,18% with subsequent ventricular fibrillation, which was terminated by electrical cardioversion), QT interval >500 ms in 14,72%, and bradyarrhythmias in 5,43%. No associations were found between efficacy and safety outcomes and the nature of concomitant cardiovascular pathology, except for a decrease in the rate of sinus rhythm restoration in paroxysmal AF/AFL with left ventricular hypertrophy compared to patients without it (87,9% vs 96,3%; difference in proportions -8,4 percentage points; 95% confidence interval: -18,7; -1,7). Conclusion . In real-world practice, Refralon safely terminates AF/AFL of varying duration in the vast majority of patients. A history of cardiovascular disease and pulmonary vein catheter ablation does not affect the outcomes of cardioversion.