Mortality risk of sotalol and amiodarone for post-CABG atrial fibrillation

BackgroundSotalol and amiodarone are commonly prescribed antiarrhythmics for the treatment of post-operative atrial fibrillation (POAF). Though they are effective in maintaining sinus rhythm in this population, little is known about their association with mortality.ObjectivesTo examine the association between sotalol and amiodarone exposure and total mortality in individuals with new-onset POAF following CABG.MethodsThe computerised health databases of Quebec, Canada were used to identify all patients over 65 who had undergone CABG and were newly diagnosed with POAF (January 1993 to June 2003). A time-matched nested-case-control approach was used to compare current users of sotalol and amiodarone with those not exposed to either medication during the same period. Rate ratios of mortality were estimated using conditional logistic regression.Results4770 eligible patients were identified (930 cases, 4648 matched controls). Sotalol users had fewer comorbidities and used fewer concomitant medications than amiodarone users at baseline. Current users of sotalol were at decreased risk of mortality compared to individuals not exposed to either study drug during the same period (RRadj. 0.56 (0.39, 0.80)) while current users of amiodarone were at increased risk of mortality (RRadj. 1.50 (1.15, 1.94)). However this association was not consistently observed across all sensitivity and subgroup analyses.ConclusionsCurrent use of sotalol was associated with a decreased risk of mortality. Current use of amiodarone was associated with an increased risk of mortality but not for all subgroups. Additional research is required to better understand the safety of sotalol and amiodarone in individuals with POAF.