Nearly half of coronary artery bypass grafting patients had device-detected atrial fibrillation within 1 year while the burden dropped to approximately 0% after 30 days, according to a recent study.
Researchers reported a prospective, multicenter cohort evaluating the incidence and burden of new-onset atrial fibrillation after coronary artery bypass grafting (CABG).
The researchers enrolled adults undergoing first-time isolated CABG for three-vessel or left main disease, receiving at least two bypass grafts, with a preoperative left ventricular ejection fraction of at least 35% and no prior arrhythmias. At skin closure, patients received an insertable cardiac monitor (Reveal LINQ LNQ11, Medtronic) to enable continuous electrocardiographic surveillance beginning in the operating room; outcomes were assessed over 1 year. The primary outcome was cumulative incidence of device-detected, adjudicated atrial fibrillation (AF) (episodes ≥ 2 minutes). Secondary outcomes included AF burden, asymptomatic and undetected episodes versus standard monitoring, and major adverse cardiac and cardiovascular events. The study followed Strengthening the Reporting of Observational Studies in Epidemiology, was conducted at LMU University Hospital (Munich) and Jena University Hospital (Jena), and clinical decisions (including anticoagulation) were left to treating physicians.
From November 2019 through November 2023, 1,217 patients were assessed, 198 were implanted (mean age, 66 years; 173 male, 25 female), and 1,008 were excluded; 192 completed 1 year of monitoring, totaling 193 patient-years.
The 1-year cumulative incidence of new-onset AF was 48% (95% confidence interval, 41%–55%). Median AF burden over 1 year was 0.07% (interquartile range, 0.02%–0.23%), corresponding to 370 minutes. Burden was front-loaded: median 3.65% on days 1 to 7, 0.04% on days 8 to 30, and 0% on days 31 to 365 (368, 13, and 0 minutes, respectively). “The very low AF burden questions the current guideline recommendations that long-term oral anticoagulation should be considered in patients with new-onset AF after CABG,” noted Florian E. M. Herrmann, MD, of the Department of Cardiac Surgery, LMU University Hospital, LMU Munich, Munich, Germany, and colleagues. After discharge, three patients had an AF episode lasting at least 24 hours.
Across the cohort, 2,053 AF episodes constituting 2,522 hours occurred during the monitored time.
Incident AF clustered early: 95% of first episodes occurred within 30 days; among those with incident AF within 30 days, 21% had recurrence later than 30 days. Of 554 recurrent episodes occurring after day 30, the median episode length was 4 minutes; 43% were asymptomatic and only 3% were detected by standard monitoring. Ten patients had 15 episodes lasting at least 24 hours; seven such episodes occurred after discharge and were not detected by standard monitoring.
At 1 year, major adverse cardiac and cardiovascular events rates were similar with and without AF (7.4% vs 6.8%); no strokes occurred in the AF group, whereas two nondisabling strokes occurred in patients without AF during the index hospitalization.
Full disclosures can be found in the published study.
Source: JAMA