Effectiveness of antazoline versus amiodarone, flecainide and propafenone in restoring sinus rhythm at the Emergency Department

Purpose Little is known about the effectiveness of pharmacological cardioversion (PCV) with antazoline in comparison to flecainide. The aim of this study was to compare the effectiveness of antazoline in restoring sinus rhythm (SR) versus amiodarone, flecainide and propafenone in a group of emergency department (ED) patients. Materials/methods This was a single-centre retrospective analysis of patient records from an ED in a large hospital in Poland. We analysed a total of 1878 patient records, divided based on the anti-arrhythmic drug (AAD) administered during PCV: antazoline (n=1080), antazoline + β-blocker (n=479), amiodarone (n=129), flecainide (n=102), propafenone (n=88). Of the patients, 63.5% were female (median 65 years, [19-100]). Results The percentage of successful PCV was significantly higher in the antazoline group (84.3%) than in the antazoline + β-blocker (75.8%, p=0.0001), propafenone (75.6%, p=0.0364) and amiodarone (68.8%, p<0.0001) groups. Post-hoc analysis revealed that patients who received PCV with antazoline, antazoline + β-blocker, flecainide and propafenone had significantly shorter time to SR than those who received amiodarone (p<0.0001). Univariate regression analysis revealed that patients who underwent PCV with antazoline were almost twice as likely to return to SR compared to the other groups (p<0.0001, OR 1.81, 95% CI 1.44-2.27). Conclusions This is the first study comparing the effectiveness of antazoline in PCV versus flecainide in addition to the previously studied amiodarone and propafenone. Our results indicate that antazoline is more effective in restoring SR than amiodarone, flecainide and propafenone. In addition, antazoline restored SR significantly faster than amiodarone or propafenone.