• Time to recurrent Atrial fibrillation
  

• Recurrence of AF at one year
  

Background: Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with significant morbidity, necessitating treatment.

Radiofrequency ablation for atrial fibrillation/flutter has evolved significantly and is the closest we have come to a ‘cure’ for these dysrhythmias.

Recurrence of atrial fibrillation in those who have undergone radiofrequency ablation as treatment for either atrial flutter (AFl) or AF is up to 40% at one year. There is significant evidence from animal studies that atrial fibrillation may have an inflammatory cause and blockade of angiotension II may be beneficial in its prevention. Recent evidence from clinical trials demonstrate that blockade of angiotensin II in humans leads to reduction of AF.

There is no clinical trial evidence to date of the use of angiotensin II blockade in patients post radiofrequency ablation for AF or AFl to prevent recurrent AF.

Objective: We propose to determine if angiotensin receptor blockers (ARBs) prevent recurrence of atrial fibrillation (AF) in patients who have undergone ablation for AF or AFl at one year.

Hypothesis: ARBs reduce symptomatic recurrence of atrial fibrillation post radiofrequency ablation for paroxysmal atrial fibrillation and atrial flutter.

Research Plan:

Study Design. This will be a randomized, double blind, placebo controlled trial in patients who are post catheter ablation for atrial fibrillation or atrial flutter. Randomization to either an angiotensin-receptor blocker or placebo will occur within 24 hours after the ablation procedure.

Study Population. Patients will be included if they have undergone a catheter ablation procedure for atrial fibrillation or atrial flutter. Those who have undergone a procedure for atrial flutter must also have a history of prior atrial fibrillation, hypertension, left ventricular ejection fraction </= 40% or age >/= 50 years.

Followup. Patients will be followed at 3 monthly intervals for a minimum duration of one year.

Outcome Measures. The primary outcome will be time to symptomatic recurrence of atrial fibrillation. The secondary outcome will be overall burden of atrial fibrillation at one year. The third outcome measure will be quality of life pre and post ablation. Other outcome measures include: recurrent ablation therapy, recurrent atrial tachycardia or atrial flutter, thromboembolic events, changes in biomarkers (CRP, IL-6, ANP, BNP and apelin) from baseline, to 3 months and 6 months.

Statistical Analysis. Kaplan-Meier analysis of the primary outcome will be performed. A Cox proportional hazards model will be constructed to assess the effect of variables chosen a priori on the primary outcome.