Antiarrhythmic use from 1991 to 2007: Insights from the Canadian Registry of Atrial Fibrillation (CARAF I and II)

BackgroundThe pharmacologic management of atrial fibrillation (AF), the most common sustained cardiac arrhythmia, has been traditionally dichotomized into control of ventricular rate or re-establishment and maintenance of sinus rhythm.ObjectiveThe purpose of this study was to evaluate the use of rate-controlling drugs and antiarrhythmic drugs (AAD) in the Canadian Registry of Atrial Fibrillation (CARAF) over a 16-year period from 1991 through 2007.Methods1,400 patients with new-onset paroxysmal AF who were enrolled in CARAF were included in this analysis. We assessed trends in ventricular rate-controlling medication use (digoxin, beta-blockers, and calcium channel blockers) and AAD (class IA, IC, and III antiarrhythmic agents) at baseline and follow-up visits as well as by calendar year.ResultsAAD use increased initially from 1991 to 1994 (peak use 42.5%) before steadily declining. Sotalol use decreased (27% to 6%), whereas amiodarone use increased (1.6% to 17.9%). Rate-controlling medication use decreased from 1991 to 1995 (54.1% to 34.1%) due to declining digoxin use (62.9% to 16.3%). After 1999, there was a continued increase in rate-controlling medication use (peak use 52.5% in 2007) due to increased beta-blocker use (17% to 45.7%). Calcium channel blockers use changed little over the duration of the study.ConclusionThe management of AF has undergone significant shifts since 1990, reflecting the influence of drug development, prevailing belief systems, the impact of large clinical trials, and evidence-based recommendations. Monitoring of pharmacotherapy trends will provide insight into the real-world application of evidence-based guidelines as well as allow the opportunity to identify deficiencies and improve patient care.