Atrial Fibrillation Outcomes After Coronary Artery Bypass Grafting

Strategic Insights -

Researchers from the Institute of Medicine have published new study results on the outcomes of atrial fibrillation (AF) after coronary artery bypass grafting (CABG). The study found that postoperative atrial fibrillation (POAF) occurring early after CABG was associated with a lower risk of adverse outcomes compared to new-onset AF occurring later after CABG. The researchers analyzed individual patient data from the SWEDEHEART registry and other prospective national registries, including data from 35,329 patients who underwent CABG in Sweden between 2007 and 2020.

Key Takeaways:

  • The study found that POAF occurring early after CABG was associated with a lower risk of adverse outcomes, including all-cause mortality, ischemic stroke, any thromboembolism, heart failure hospitalization, and major bleeding, compared to new-onset AF occurring later after CABG.
  • The adjusted incidence rate ratios for all-cause mortality, ischemic stroke, any thromboembolism, heart failure hospitalization, and major bleeding were higher in patients with Late AF, indicating a greater risk of adverse outcomes.
  • The study suggests that POAF and late-new-onset AF after CABG are two different clinical entities of AF that may require different treatment strategies.
  • The researchers analyzed data from 35,329 patients who underwent CABG in Sweden between 2007 and 2020, with 10,609 patients developing POAF and 628 patients developing late-new-onset AF.
  • The study provides evidence that POAF is associated with a lower risk of morbidity and mortality than late-new-onset AF after CABG.

Statistics:

  • 30.0% of patients developed POAF after CABG, while 2.5% developed late-new-onset AF.
  • The crude mortality rate was lower in patients with POAF than in patients with Late AF: 1.88 (95% CI, 1.63-2.17) per 100 patient-years versus 9.08 (95% CI, 6.92-11.82) per 100 patient-years.
  • Adjusted incidence rate ratios for all-cause mortality: 2.91 (95% CI, 2.10-3.95); ischemic stroke: 1.70 (95% CI, 1.15-2.44); any thromboembolism: 1.59 (95% CI, 1.11-2.22); heart failure hospitalization: 1.61 (95% CI, 1.19-2.12); and major bleeding: 1.73 (95% CI, 1.24-2.36) were higher in patients with Late AF.

Sources:

  • Outcomes in Early Postoperative Versus Late New-Onset Atrial Fibrillation After Coronary Artery Bypass Grafting. Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease, 2025, 14(19).
  • Institute of Medicine Researchers Detail Findings in Atrial Fibrillation (Outcomes in Early Postoperative Versus Late New-Onset Atrial Fibrillation After Coronary Artery Bypass Grafting). Cardiovascular Week. October 20, 2025; p 50.