Adverse Outcomes in Patients with Atrial Fibrillation and a Pacemaker: A Cohort Study.

Background And 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 Data from two Swiss prospective, multicenter cohort studies (Swiss-AF, Beat-AF) (n=3675) with yearly follow-ups up to 8 years were analyzed. The first main outcome was major adverse cardiovascular events (MACE), a composite of stroke or transient ischemic 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.Results 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.