Pacemaker-Detected Atrial Fibrillation in Patients With Pacemakers: Prevalence, Predictors, and Current Use of Oral Anticoagulation

BACKGROUND: Dual-chamber pacemakers frequently document atrial fibrillation (AF) in patients without symptoms. Pacemaker-detected AF is associated with a 2.5-fold increased risk of stroke, although it is not established whether oral anticoagulation reduces this risk. This study sought to determine the prevalence and predictors of pacemaker-detected AF and to document current oral anticoagulant use. METHODS: A retrospective analysis included all patients from a single academic hospital who had pacemakers capable of documenting AF. Blinded evaluation of all echocardiograms conducted within 6 months of implantation was performed. RESULTS: Of 445 patients, pacemaker-detected AF was present in 246 (55.3%), who were older (74.3 ± 13.7 years vs 71.7 ± 14.4, P = 0.046), more likely to have a history of clinical AF (29.7% vs 19.1%, P = 0.01), and had a larger left atrial volume index (34.4 ± 11.8 mL/m(2) vs 30.0 ± 9.9 mL/m(2), P = 0.019) than the patients without pacemaker-detected AF. Among patients without a clinical history of AF, left atrial volume index was higher among those with pacemaker-detected AF (33.7 ± 11.3 mL/m(2) vs 29.0 ± 10.1 mL/m(2), P = 0.034). Anticoagulants were used in 35.3% of patients with pacemaker-detected AF, compared with 21.6% of patients without (P < 0.05). In patients with pacemaker-detected AF, anticoagulants were used more frequently among patients who also had clinical AF (58.9%) compared with those without (23.7%, P < 0.001). CONCLUSIONS: Pacemaker-detected AF occurs in 50% of pacemaker patients and is treated with anticoagulants in less than 25% of patients who do not have a history of clinical AF. Clinical trials are needed to determine the role of anticoagulation in this population.