Determinants and impact of postoperative atrial fibrillation burden during 2.5 years of continuous rhythm monitoring after cardiac surgery: Results from the RACE V prospective cohort study.

Background: Early postoperative atrial fibrillation (POAF) is common after cardiac surgery and is associated with late-POAF recurrences. However, little is known about the burden of POAF and its potential impact on long-term outcomes after cardiac surgery, particularly on the risk for late-POAF recurrences.
Objective: The purpose of this study was to establish the distribution of POAF burden and to determine the association between early-POAF burden and late-POAF recurrences during 2.5 years of continuous rhythm monitoring after cardiac surgery in patients with and without preoperative history of atrial fibrillation (AF).
Methods: Patients undergoing cardiac surgery were prospectively enrolled and postoperatively continuously monitored with an implantable loop recorder for 2.5 years. All patients underwent extensive clinical assessment at baseline. During follow-up, all AF episodes were registered, and AF associated metrics, such as burden, were calculated for different time intervals. Early-POAF was defined as AF within first 90 postoperative days and late-POAF as AF after this interval.
Results: A total of 98 consecutive patients were included. POAF burden during the early postoperative phase was significantly higher compared to the late postoperative phase (P <.001). The longest individual POAF episode was strongly associated with increased POAF burden after adjusting for age, sex, and AF history (standardized Beta: 0.91, P <.001). Also, early-POAF burden was associated with late-POAF (re)occurrence after adjusting for age, sex, AF history (adjusted hazard ratio 1.93, 95% confidence interval 1.42-2.62, P <.001).
Conclusion: POAF burden was significantly associated with the longest individual POAF episode duration. Additionally, greater early-POAF burden was associated with increased late-POAF incidence, highlighting its potential in estimating the risk for long-term POAF recurrences.
Competing Interests: Disclosures Dr Schotten received consultancy fees or honoraria from Università della Svizzera Italiana (USI, Switzerland), Roche Diagnostics (Switzerland), EP Solutions Inc. (Switzerland), Johnson & Johnson Medical Limited (United Kingdom), and Bayer Healthcare (Germany); and is co-founder and shareholder of YourRhythmics BV, a spin-off company of the University Maastricht. Dr Maesen is a consultant for AtriCure and Medtronic. All other authors have no conflicts of interest to disclose.
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