The development of AF over time in patients with permanent pacemakers: objective assessment with pacemaker diagnostics demonstrates distinct patterns of AF.

AIMS: To describe the long-term patterns of atrial fibrillation (AF) in patients with permanent pacemakers.

METHODS AND RESULTS: A total of 2092 pacemaker Holter downloads were analysed in 323 patients with dual chamber permanent pacemakers, describing a cumulative 1031 patient-years of beat-to-beat monitoring. Four subtypes of AF were applied: (i) non-progressive low-burden PAF (NPLB-PAF, n = 120): such patients never have >1% AF burden throughout follow-up; (ii) chronic progressive PAF (CP-PAF, n = 55): AF burden increases but is never 100%; (iii) relapsing-remitting PAF (RR-PAF, n = 78): AF burden has reduced at least once by more than 2% and is never 100%; (iv) persistent AF (PersAF, n = 70): 100% AF burden for at least 28 days. Overall, mean AF burden rose 0.34% per year (P < 0.0001). After accounting for age, heart failure (HF) had a significant interaction with AF burden (P = 0.0022), but HATCH score and CVA/TIA did not. There were no differences in the frequency or duration of monitoring between the four AF subtypes. Atrial fibrillation episode frequency discriminated between subtypes (P = 0.0004). Eighteen of 70 (26%) patients with PersAF had pacemaker documented episodes of sinus rhythm (i.e. reversion to 'paroxysmal AF') after the onset of PersAF.

CONCLUSION: In this cohort, the development of AF over time appears more complex than current definitions suggest. Atrial fibrillation can remain low burden without progression, remit-relapse, or progress as is described in currently accepted definitions. More frequent episodes of AF indicated a favourable subtype. Persistent AF is not inevitable, and can revert to paroxysmal AF.

CLINICAL TRIAL REGISTRATION: NCT02016950, https://clinicaltrials.gov/show/NCT02016950.