Efficacy and Safety of Multidose del Nido Cardioplegia for Optimal Myocardial Protection in Isolated Coronary Artery Bypass Grafting Surgery: A Comparative Retrospective Cohort Study

Background: The perioperative outcomes of del Nido cardioplegia (DNC) as a single-dose solution have been investigated in cardiac surgical procedures. However, the optimal redosing interval for multiple doses of DNC remains an area of ongoing debate. The purpose of this study is to evaluate the safety and efficacy of multidose DNC administered according to our protocol in comparison to intermittent cold blood cardioplegia (BC) in isolated coronary artery bypass grafting (CABG) patients. Methods: A retrospective analysis was conducted on 79 consecutive isolated CABG patients between January 2022 and March 2023. The Patients were divided into two groups: the DNC group (n = 35), and the BC group (n = 44). Perioperative clinical characteristics, cardiac enzyme levels, and postoperative complications were compared between the groups. DNC was applied in a 1:4 (crystalloid:blood) ratio, with an initial dose of 20 mL/kg. Maintenance doses of 10 mL/kg were given every 45 to 50 minutes. A half dose was given if the aortic cross-clamp was expected to last less than 60 minutes. Warm blood was applied before releasing the aortic cross-clamp. Results: Both groups demonstrated comparable mean aortic cross-clamp and cardiopulmonary bypass times. At 24 hours postoperatively, troponin T levels were significantly lower in the DNC group (p ˂ 0.001), while creatine kinase-myocardial band (CK-MB) levels were higher (p ˂ 0.001). The DNC group required lower defibrillation rates than the BC group (p = 0.008). Multivariate logistic regression analysis revealed that the requirement for defibrillation (odds ratio (OR) = 10.9, 95% confidence interval (CI): 2.9–41.8, p < 0.001), cross-clamp time (OR = 1.04, 95% CI: 1.02–1.1, p = 0.002) and body mass index (BMI) (OR = 0.8, 95% CI: 0.7–0.9, p = 0.030) were independent risk factors for low cardiac output syndrome. DNC and left ventricle ejection fraction >40% were associated with a return to sinus rhythm (OR = 3.6, 95% CI: 1.3–10.1, p = 0.013 and OR = 3.1, 95% CI: 1.1–8.7, p = 0.035, respectively). No significant differences were found in terms of postoperative adverse events, and in-hospital mortality. Conclusion: Multidose DNC in CABG patients provides equivalent clinical outcomes and myocardial protection compared to BC. In addition, the findings suggest that the redosing interval strategy employed in the DNC protocol is acceptable.