Long-Term AF Burden After CABG low Despite Higher Initial Incidence: JAMA

A new study published in the Journal of American Medical Association showed that even while the incidence of new-onset atrial fibrillation (AF) during coronary artery bypass grafting (CABG) is greater than anticipated, the total AF burden was extremely low, particularly after 30 days.

It is unknown how often new-onset atrial fibrillation is during CABG. However, according to North American recommendations, the patients with new-onset AF following CABG should get 60 days of oral anticoagulation. This is a moderate-strength recommendation (class 2a) based on data from nonrandomized clinical research. Therefore, this study evaluated the AF burden and test the hypothesis that the incidence of new-onset AF during the first year following CABG is greater than stated in the present literature.

198 patients with 3-vessel coronary artery disease or left main disease and no prior history of arrhythmias who were given an insertable cardiac monitor during CABG for long-term continuous electrocardiographic monitoring were included in this study conducted in two academic cardiac surgery centers in Germany.

The patients were monitored for a year after being enrolled between November 2019 and November 2023. After a year of continuous monitoring with implanted cardiac monitors during CABG, atrial fibrillation was discovered. The cumulative incidence of new-onset AF within a year following surgery was the main endpoint. Clinical results and the burden of AF were secondary outcomes.

1008 of the 1217 patients that were evaluated were eliminated. Within the first year following CABG, 95 of the 198 patients (mean age, 66 [SD, 9] years; 173 male [87.4%]; 25 female [12.6%]) experienced new-onset AF (cumulative incidence, 48%; 95% CI, 41%-55%).

During the first year, the median AF load was 370 minutes, or 0.07% (IQR, 0.02%-0.23%). On days 1 through 7, the median AF load was 3.65% (IQR, 0.95%-9.09%); on days 8 through 30, it was 0.04% (IQR, 0%-1.21%); and on days 31 through 365, it was 0% (IQR, 0%-0.0003%), or 368, 13, and 0 minutes, respectively. 3 patients experienced an AF episode lasting more than 24 hours after being discharged.

Overall, the AF burden in these patients was extremely low, particularly after 30 days, despite the fact that the rate of new-onset AF following CABG in this research was greater than previously documented. The existing guidelines, which advocate long-term oral anticoagulation for patients with new-onset AF following CABG, are called into doubt by the extremely low AF burden.

Source:

Herrmann, F. E. M., Jeppsson, A., Kirov, H., Charitos, E. I., Dacian, D., Brömsen, J., Massberg, S., Sadoni, S., Doenst, T., Juchem, G., & Hagl, C. (2025). Long-term continuous monitoring of new-onset atrial fibrillation after coronary artery bypass grafting. JAMA: The Journal of the American Medical Association, 334(20), 1827–1835. https://doi.org/10.1001/jama.2025.14891