Pacemaker clinic: an opportunity to detect silent atrial fibrillation and improve antithrombotic treatment

The prevalence of atrial fibrillation (AF) in patients with pacemakers is high, and often passes unnoticed. Our aim was to assess the use of antithrombotic treatment in this group of patients.

All patients who came to our institution to have their pacemakers checked during the year 2008 were included in this study. The atrial activity was assessed by slowing down the paced frequency if necessary, and by the analysis of atrial electrograms in atrial-based pacemakers. The appropriateness of the antithrombotic treatment was evaluated by a cardiologist. Out of 585 patients, 216 (36.9%) displayed AF at some point during the 5.5-year monitoring period (1.5-11), although only 58 (9.9%) displayed it at the time of the implant. Of these 216, 58% were men, with an average age of 80 years (76-86 years). The pacemaker was implanted in response to an atrioventricular block (AVB) in 46.3% of the cases, sinoatrial node disorder in 24.1% of the cases, and slow AF in 25.9% of the cases. The CHADS2 score was 0 points in 4.2% (9) of the cases, 1 point in 19% (41) of the cases, and ≥ 2 points in 77% (173) of the cases. Despite this, only 58.3% of the cases received anticoagulant treatment. The existence of arrhythmia at the time of implantation [odds ratio (OR) = 4.25; 95% confidence interval (95% CI), 1.72-10.51; P = 0.002] and the implantation of a pacemaker with atrioventricular synchronization (OR = 13.23; 95% CI, 2.89-60.56; P = 0.001) were associated with the use of anticoagulant treatment in those cases with CHADS2>2.

Atrial fibrillation is common in patients fitted with pacemakers. Despite the high risk of embolism, an underuse of anticoagulant treatment was observed.