Absence of protective effect of renin-angiotensin system inhibitors on atrial fibrillation development: Insights from the Canadian Trial of Atrial Fibrillation (CTAF)

Abstract

Antiarrhythmic agents have modest efficacy in preventing atrial fibrillation (AF) recurrence. Although retrospective analyses have suggested a preventive effect of inhibitors of the renin-angiotensin system (RAS) on AF development in patients with congestive heart failure or hypertension, the value of these agents has not been evaluated in patients with AF but without a high prevalence of hypertension or heart failure. A retrospective analysis of the Canadian Trial of Atrial Fibrillation (CTAF) was conducted. CTAF demonstrated the superiority of amiodarone (A) over sotalol or propafenone (SP) in maintaining sinus rhythm in patients with AF. Of the 403 patients randomly assigned in CTAF, 11.7% of the A group and 12.7% of the SP group were receiving a RAS inhibitor at baseline. By multivariate analysis (including all the risk factors known to be associated with AF available in the database), the use of RAS blockers in addition to antiarrhythmic agents was not associated with additional benefit against AF development. There was a recurrence of AF in 59 patients (38.3%) and 14 patients (29.8%) of groups A and A-RAS, respectively, while 93 patients (61.6%) and 32 patients (62.8%) of the SP and SP-RAS groups, respectively, experienced recurrent AF. Blocking the RAS did not provide additional benefit against AF recurrence in CTAF patients treated with an antiarrhythmic drug. These results underscore the need for randomized clinical trials to clearly define the role of RAS inhibitors in treating AF.