ORIGINAL PAPER Flecainide for cardioversion in patients at elevated cardiovascular risk and persistent atrial fibrillation: a prospective observational study Fikret Er • Orhan Aslan • Evren Caglayan • Natig Gassanov • Amir M. Nia • Erland Erdmann • Stephan Rosenkranz Received: 28 August 2009 / Accepted: 5 February 2010 / Published online: 24 February 2010 Ó Springer-Verlag 2010 Abstract Background 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 car- diovascular 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. Objectives 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. Methods The effectiveness, safety and influencing factors of flecainide for cardioversion in high-risk patients were prospectively assessed. Results In 43 of 106 patients (40.6%), sinus rhythm could be restored within 192.4 ± 10.7 min by flecainide. The PROCAM-score was 41.5 ± 0.56 in patients with suc- cessful cardioversion compared to 45.7 ± 0.74 in patients without successful cardioversion (P \ 0.001). ACE-inhib- itor 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 car- dioversion 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. Conclusions When monitored properly, flecainide is safe and useful for cardioversion in patients at elevated car- diovascular risk. Keywords Atrial fibrillation Á Flecainide Á Cardioversion Á Procam Introduction Rate and rhythm control are the two therapeutic strategies in patients with atrial fibrillation (AF) [1]. Aiming rhythm control, sinus rhythm (SR) can be achieved by electrical or pharmacological cardioversion. A number of randomized controlled trials demonstrated the efficiency and safety of flecainide in converting AF to SR [2–4]. Despite the evidence supporting the effectiveness of flecainide for the cardioversion of acute AF, patients with coronary artery disease, cardiomyopathy and elevated cardiovascular risk were excluded in these trials. In low- risk populations, a safe conversion rate under oral flecai- nide of up to 92% has been reported [5]. The application of flecainide is not recommended for treatment of patients with recent myocardial infarction and structural heart dis- eases [6]. This limitation is based on several historical trials, in which the long-term prophylactic use of antiar- rhythmic drugs were detrimental in patients with structural heart disease [7–9]. Whether a single dose of flecainide is effective or associated with an intolerable risk in these patients is not known. Compared to electrical cardioversion (EC), the conversion with oral flecainide is more com- fortable for patients, medical staff and furthermore appears to be more economical. In this study, we assessed the F. Er (&) Á O. Aslan Á E. Caglayan Á N. Gassanov Á A. M. Nia Á E. Erdmann Á S. Rosenkranz Department of Internal Medicine III, Heart Center of the University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany e-mail: Fikret.Er@uk-koeln.de 123 Clin Res Cardiol (2010) 99:369–373 DOI 10.1007/s00392-010-0129-7