The impact of volume substitution on post‐operative atrial fibrillation

BACKGROUND: Post‐operative atrial fibrillation (POAF) represents a common complication after cardiac valve or coronary artery bypass surgery. While strain of atrial tissue is known to induce atrial fibrillating impulses, less attention has been paid to potentially strain‐promoting values during the peri‐ and post‐operative period. This study aimed to determine the association of peri‐ and post‐operative volume substitution with markers of cardiac strain and subsequently the impact on POAF development and promotion. RESULTS: A total of 123 (45.4%) individuals were found to develop POAF. Fluid balance within the first 24 hours after surgery was significantly higher in patients developing POAF as compared to non‐POAF individuals (+1129.6 mL [POAF] vs +544.9 mL [non‐POAF], P = .044). Post‐operative fluid balance showed a direct and significant correlation with post‐operative N‐terminal pro‐brain natriuretic peptide (NT‐ProBNP) values (r = .287; P = .002). Of note, the amount of substituted volume significantly proved to be a strong and independent predictor for POAF with an adjusted odds ratio per one litre of 1.44 (95% CI: 1.09‐1.31; P = .009). In addition, we observed that low pre‐operative haemoglobin levels at admission were associated with a higher need of intraoperative transfusions and volume‐demand. CONCLUSION: Substitution of larger transfusion volumes presents a strong and independent predictor for the development of POAF. Via the observed distinct association with NT‐proBNP values, it can reasonably be assumed that post‐operative atrial fibrillating impulses are triggered via increased global cardiac strain. Optimized pre‐operative management of pre‐existing anaemia should be considered prior surgical intervention in terms of a personalized patient care.