Traditional vs. modified Ringer lactate-based del Nido cardioplegia impacts on clinical outcomes in patients undergoing coronary artery bypass grafting: results from a clinical trial

Introduction: myocardial protection with cardioplegia solution is one of the precautions during coronary bypass grafting surgery (CABG) with cardiopulmonary bypass (CPB) to reduce myocardial damage and ischemia/reperfusion injuries. Unfortunately, the major component of the del Nido cardioplegia solution, Plasma-Lyte A, is unreachable in Iran due to high cost. Therefore, we have utilized lactate Ringer's solution as the base solution for our modified del Nido solution (LR DN). Study design and methods: the present clinical trial was performed on 18-75 year old patients (EF>35%) undergoing CABG with CPB in Imam Hossein hospital Tehran-Iran in 2021. Patients were randomly allocated to LR DN (modified del Nido cardioplegia) and PL DN (standard del Nido cardioplegia solution) groups. Serum level of cardiac troponin I (cTnI) at baseline, declamp, ICU admission, and 24 hours after admission, the type and dosage of inotrope agents, EF, rate of arrhythmia after clamp removal and lactate level were measured and compared between groups. Results: 109 patients were recruited. There were no statistically significant differences between the PL DN cardioplegia and LR DN groups for cardiopulmonary bypass times, cardiac enzymes, transfusion requirements, and arterial blood gases. However, postoperative serum levels of cTnI among patients in the LR DN group was significantly higher than patients of the PL DN group after ICU admission and 24 hours postoperatively. Also, more patients needed epinephrine administration in the operating room in the LR DN group (29.8% vs. 11.5%; p: 0.019 vs. PL DN group). Conclusion: we concluded that standard del Nido cardioplegia solution offers better myocardial protection compared with Ringer's lactate-based del Nido cardioplegia in adult patients undergoing CABG with CPB. We recommend using standard del Nido cardioplegia with a base of Plasma-Lyte A for patients presenting for CABG surgery.