Atrial fibrillation is the most frequent sustained arrhythmia. Atrial fibrillation recurs frequently after restoration of normal sinus rhythm. Antiarrhythmic drugs have been widely used to prevent recurrence, but the effect of these drugs on mortality and other clinical outcomes is unclear.
The aim of this study was to determine, in patients who recovered sinus rhythm after atrial fibrillation, the effect of long-term treatment with antiarrhythmic drugs on death, stroke and embolism, adverse effects, pro-arrhythmia, and recurrence of atrial fibrillation.
Eleven new studies met inclusion criteria, making a total of 56 included studies, comprising 20,771 patients. Compared with controls, class IA drugs Quinidine and Disopyramide ( odds ratio, OR=2.39, number needed to harm [ NNH ] 109 ) and Sotalol ( OR=2.47, NNH=166 ) were associated with increased all-cause mortality.
Other antiarrhythmics did not seem to modify mortality.
Several class IA ( Disopyramide, Quinidine ), IC ( Flecainide, Propafenone ) and III ( Amiodarone, Dofetilide, Dronedarone, Sotalol ) drugs significantly reduced recurrence of atrial fibrillation ( OR 0.19 to 0.70, number needed to treat [ NNT ] 3 to 16 ). Beta-blockers ( Metoprolol ) also reduced significantly atrial fibrillation recurrence ( OR=0.62, NNT=9 ).
All analysed drugs increased withdrawals due to adverse affects and all but Amiodarone, Dronedarone and Propafenone increased pro-arrhythmia.
In conclusion, several class IA, IC and III drugs, as well as class II ( beta-blockers ), are moderately effective in maintaining sinus rhythm after conversion of atrial fibrillation. However, they increase adverse events, including pro-arrhythmia, and some of them ( Disopyramide, Quinidine and Sotalol ) may increase mortality. Possible benefits on clinically relevant outcomes ( stroke, embolism, heart failure ) remain to be established. ( Xagena )
Source: Cochrane Database of Systematic Reviews, 2012