Comparison of cold and tepid modified delnido cardioplegia on myocardial protection in open heart surgery patients

Objectives: Cardioplegia is a crucial component of myocardial protection during aortic cross-clamping and cardiopulmonary bypass. It has been reported to provide effective myocardial protection and improved clinical outcomes with enhanced surgical flow in adult cardiac procedures. This study investigates the efficacy and safety of cold-modified Del Nido cardioplegia versus tepid blood cardioplegia in adult cardiac surgery patients using Myotherm, a device mainly used in cardiac surgery to monitor and manage the myocardial temperature during surgery. Methods: After obtaining approval from the ethics committee and establishing entry criteria that included age, type of heart surgery, and absence of cardioplegic contraindications, the researchers defined exclusion criteria-such as previous heart surgery or significant comorbidities. Seventy patients were randomly divided into two groups: Group A received a cold solution at 4°C( n=35), while Group B received a tepid solution at 28°C (n=35).The amount of cardioplegia was 10 to 15 cc/kg and was injected with a pressure of 70 to 90 mm Hg in an anterograde manner. The temperature of cardioplegia was also adjusted with a Myotherm device. The day before the surgery, a written consent form was obtained from the patients, and the patients were informed about the study method. The sampling method is a double-blind clinical trial to achieve minimal bias, ensuring the reliability of the results and reducing influences on it. This study was conducted in Afshar Hospital in Yazd during 2023 and 2024. Results: There were no significant differences between the two groups in terms of the need for an intra-aortic balloon pump (p=1.0), intraoperative and postoperative inotropic support (p=0.26), and postoperative pacemaker (p=0.49). Also, there were no significant differences between the two groups in terms of troponin I level after surgery (p=0.50), left ventricular ejection fraction after discharge (p=0.34), time to return of spontaneous heart rhythm (P=0.25), cross-clamp time (P=0.30), cardiopulmonary bypass time (P=0.07), and length of stay in the ICU (P=0.21). Conclusions: The result showed that both techniques provide similar results. Although the time of cross-clamp and cardiopulmonary bypass was shorter in the group using tepid solution, these differences were not statistically significant. In other words, cold and tepid solutions are equally effective and safe to protect the myocardium, and doctors can use both types of solutions during open heart surgery.