Association between preoperative uric acid concentration and the occurrence of atrial fibrillation following cardiac surgery: An observational prospective study

Objectives: Uric acid (UA) concentration is associated with an increased risk of atrial fibrillation, but few studies have investigated this association after cardiac surgery. This study investigated the statistical association between postoperative atrial fibrillation (POAF) and preoperative UA concentration according to the type of cardiac surgery.

Methods: Consecutive patients undergoing cardiac surgery at a tertiary center from January to May 2019 were eligible. Patients were separated into two groups according to POAF occurrence. Subgroup analyses were performed in patients undergoing coronary artery bypass grafting (CABG) or valve surgery. Binary logistic regression models were used to assess independent factors of POAF. Principal component analyses (PCA) were performed to investigate whether CABG or valve surgeries were associated with different biological profiles for POAF.

Results: The study included 221 patients, of whom 76 presented at least one POAF episode. The UA concentration was higher in the POAF group compared with the POAF-free group (352 μmol/l [295-420] vs. 321 μmol/l [249-380], p=0.004). This association persisted in multivariable analysis (for 10 μmol, OR= 1.04 [1.34-8,7]; p=0.014) and in patients undergoing isolated CABG. In patients undergoing valve surgery, despite a high incidence of POAF, no association was found. PCA identified different blood biological profiles for POAF after CABG versus valve surgery.

Conclusions: The preoperative UA concentration was independently associated with the occurrence of POAF after CABG but not after valve surgery. PCA results suggests that different biological profiles contribute to POAF occurrence according to the type of cardiac surgery, thus suggesting different strategies for prevention/intervention.