Flecainide for cardioversion in patients at elevated cardiovascular risk and persistent atrial fibrillation: a prospective observational study

Flecainide is used as a pill-in-the-pocket treatment for pharmacological cardioversion in patients without structural heart disease and atrial fibrillation (AF). In patients with structural heart disease and elevated cardiovascular risk, flecainide is believed to be harmful. Therefore, data about safety and effectiveness of single-dose flecainide for cardioversion in patients at elevated cardiovascular risk are lacking. One-hundred and six consecutive patients with recent onset AF and known structural heart disease and/or elevated PROCAM-score did receive oral flecainide 300 mg for cardioversion. The effectiveness, safety and influencing factors of flecainide for cardioversion in high-risk patients were prospectively assessed. In 43 of 106 patients (40.6%), sinus rhythm could be restored within 192.4 +/- A 10.7 min by flecainide. The PROCAM-score was 41.5 +/- A 0.56 in patients with successful cardioversion compared to 45.7 +/- A 0.74 in patients without successful cardioversion (P < 0.001). ACE-inhibitor co-medication was associated with a significantly lower rate of conversion by flecainide (HR 2.3, 95% CI, 1.12-4.26, P < 0.01). In 58 of 63 patients in whom cardioversion by flecainide was not effective, electrical cardioversion was performed which was successful in 47 patients. Life-threatening arrhythmias did not occur in any patient. The most common side effect was sinus-bradycardia and transient sinus arrest (2-4 s) immediately after conversion. When monitored properly, flecainide is safe and useful for cardioversion in patients at elevated cardiovascular risk.