The del Nido cardioplegia (DNC) solution has been widely used for myocardial protection in adult cardiac surgery, however, its use remains unclear in cases with long aortic cross-clamp time. Therefore, this study examined postoperative myocardial injury and the use of intraoperative DNC data of patients with cross-clamp time greater than 100 min in the past 4 years to explore a safe and effective infusion strategy for DNC.

Data were collected from 129 patients who underwent cardiac surgery between January 2020 and July 2024 using DNC with aortic occlusion time greater than 100 min. This single-center cross-sectional cohort study aimed to review relationship between the postoperative myocardial injury (myocardial markers) and the use of intraoperative DNC data during extracardiac surgery. Potential confounders included patient demographics (age, sex, weight, height), high-risk factors, preoperative cardiac function and surgical factors. Statistical methods were used to analyze the data using SPSS 27.0.

On average, the patients underwent cardiopulmonary bypass with duration of 193.43 min. Aortic cross-clamp time was 126.19 min, and 2.22 cardioplegia infusions were administered. Most patients (82.9%) received initial infusion and one re-dose, while 17.1% required two or more re-dose. Postoperative myocardial markers were not correlated with patient demographics but were significantly correlated with cardiopulmonary bypass and aortic cross-clamp time. Particularly, time after the second infusion was the best predictor, with a cutoff of 69.5 min by Receiver Operating Characteristic curve. Patients with longer time after the second infusion had higher myocardial markers and required most postoperative vasoactive support.

In adult cardiac surgery with long aortic cross-clamp time, it is recommended to administer a second infusion within 90 min, and avoid exceeding 70 min to give the third infusion. Multiple infusions do not have a significant effect on postoperative myocardial injury.