Among 4,684 adults undergoing isolated coronary artery bypass grafting (CABG) in Florida between 2021 and 2024, postoperative atrial fibrillation (POAF) occurred in 355 patients (7.58%) and independently increased expected length of stay by 30% (IRR 1.30, 95% CI 1.23–1.36) and raised odds of facility rather than home discharge by 33% (OR 1.33). Critically, however, POAF did not independently predict 90-day readmission (OR 1.25, p=.063) or composite complications (OR 1.20, p=.118). Bayesian risk modeling revealed that concurrent chronic heart failure amplified 90-day complication probability from a 27.2% baseline to 42.6%.
This finding meaningfully reframes clinical priorities after cardiac surgery. The prevailing clinical focus on managing the acute arrhythmia itself — rate control, anticoagulation, cardioversion — may be less decisive for downstream outcomes than aggressive optimization of chronic comorbidities, particularly heart failure. The result aligns with growing evidence that surgical complications are often proxies for underlying disease burden rather than independent causal drivers of morbidity. The Bayesian Beta-Binomial modeling approach adds interpretive depth beyond standard regression, surfacing synergistic risk interactions standard analyses can miss. Limitations include the retrospective observational design, a Florida-only cohort limiting generalizability, and residual confounding inherent to administrative data. The 7.58% POAF incidence is notably lower than the 20–40% commonly reported in the literature, raising questions about capture completeness. As a preprint not yet peer-reviewed, these findings warrant cautious interpretation pending independent validation. Still, the call to redirect post-discharge frameworks toward primary care–driven comorbidity management is both practical and clinically actionable.