Cardiopulmonary bypass management and risk of new-onset atrial fibrillation after cardiac surgery

OBJECTIVES Cardiopulmonary bypass (CPB) management may potentially play a role in the development of new-onset atrial fibrillation (AF) after cardiac surgery. The aim of this study was to explore this potential association.METHODS Patients who underwent coronary artery bypass grafting and/or valvular surgery during 2016-2020 were included in an observational single-centre study. Data collected from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry and a local CPB database were merged. Associations between individual CPB variables (CPB and aortic clamp times, arterial and central venous pressure, mixed venous oxygen saturation, blood flow index, bladder temperature and haematocrit) and new-onset AF were analysed using multivariable logistic regression models adjusted for patient characteristics, comorbidities and surgical procedure.RESULTS Out of 1999 patients, 758 (37.9%) developed new-onset AF. Patients with new-onset postoperative AF were older, had a higher incidence of previous stroke, worse renal function and higher EuroSCORE II and CHA2DS2-VASc scores and more often underwent valve surgery. Longer CPB time [adjusted odds ratio 1.05 per 10 min (95% confidence interval 1.01-1.08); P = 0.008] and higher flow index [adjusted odds ratio 1.21 per 0.2 l/m2 (95% confidence interval 1.02-1.42); P = 0.026] were associated with an increased risk for new-onset AF, while the other variables were not. A sensitivity analysis only including patients with isolated coronary artery bypass grafting supported the primary analyses.CONCLUSIONS CPB management following current guideline recommendations appears to have minor or no influence on the risk of developing new-onset AF after cardiac surgery. New-onset postoperative atrial fibrillation (POAF) is a common complication following cardiac surgery.