The role of Del Nido Cardioplegia in reducing postoperative atrial fibrillation after cardiac surgery in patients with impaired cardiac function

Background: Postoperative atrial fibrillation (POAF) occurs in 20% to 40% of patients who underwent cardiac surgery and can compromise the postoperative course, especially in those with reduced left ventricular ejection fraction. The most common causes are related to surgical trauma and the high variations in volemic and electrolyte balance in the postoperative period. Objectives: As cardioplegic solutions can significantly impact both these factors, the study aimed to assess the role of Del Nido (DN) cardioplegia on the onset of POAF. Methods: A retrospective single-center analysis was carried out on 93 patients undergoing coronary artery bypass graft surgery where cardioplegia was used. The patients were divided into two groups according to the cardioplegic solution (Cold Blood vs Del Nido), and perioperative outcomes were compared. Results: POAF occurred in 21.5% of patients; the patients treated with cold blood cardioplegia (CBC) showed a 3-times higher rate of POAF compared to the DN group (OR: 3.44; 95% CI: 1.1 to 10.5; p = 0.029). The CBC group showed higher serum potassium levels both after the cross-clamp removal (p<0.001), at the ICU admission (p = 0.007), and during the first 3 postoperative days (p = 0.009). The defibrillation rate at cross-clamp removal (p = 0.003), the dose of postoperative epinephrine (p<0.001), and the peak of serum troponin (p = 0.01), were lower in the DN Group. Conclusion: DN cardioplegia showed significantly reduced POAF rates after cardiac surgery by acting on the electrolyte balance, myocardial protection and on the need for postoperative inotropic support.