Adverse outcomes in patients with atrial fibrillation and a pacemaker: a cohort study

AIMS: Patients with atrial fibrillation (AF) are at a high risk of adverse cardiovascular outcomes. Little is known about the specific population of AF patients with implanted pacemaker (PM) and their prognosis. Therefore, we aimed to compare the risks of adverse outcomes in AF patients with and without PM. METHODS AND RESULTS: Data from two Swiss prospective, multicentre cohort studies (Swiss-AF, Beat-AF) (n = 3675) with yearly follow-ups (FUs) up to 8 years were analysed. The first main outcome was major adverse cardiovascular events (MACE), a composite of stroke or transient ischaemic attack, myocardial infarction, cardiovascular death, and systemic embolism. The second main outcome was hospitalization for heart failure (HF). Secondary outcomes were the individual components of MACE. We performed time-updated Cox regression analyses to investigate the association of PM and outcomes. Median age was 71.4 years, 28.8% female, 445 (12.1%) patients had a PM at baseline, and 238 additional patients (7.4%, 1.05%/year) received a PM over a median FU of 7 years. Patients with a PM had higher incidence rates for MACE and HF (5.97 and 5.08 per 100 patient-years, respectively), compared to patients without a PM (3.37 and 2.61 per 100 patient-years, respectively). After multivariable adjustment, we found no independent association of PM and MACE (aHR [95% CI] 1.12 [0.95-1.33; P = 0.183]) or HF (aHR [95% CI] 1.14 [0.94-1.37; P = 0.180]). We found consistent results for the individual components of MACE. CONCLUSION: Patients with AF and a PM experienced an increased rate of adverse cardiovascular outcomes. However, the PM itself was not independently associated with these outcomes.