OBJECTIVES: Interest in Del Nido solution is increasing in adult cardiac surgery. This study compared Del Nido with Buckberg cardioplegia in patients undergoing isolated aortic valve replacement. METHODS: A prospective, two-center, randomized trial was conducted from July 2019 to August 2023, with adult patients undergoing first-time isolated aortic valve replacement, and were randomized to receive Buckberg (n = 159) or Del Nido (n = 152) solution. Primary end-point was Creatin Kinase and ultrasensitive Troponin T postoperative peak level. RESULTS: 311 patients were recruited. Total cardioplegia volume was higher in Del Nido group (1000 ml vs 374.5 ml, p <
0.001). No differences were observed in peak Creatine Kinase or Troponin T levels (422 vs 407 U/L, and 282 vs 258 ng/L for Buckberg and Del Nido, respectively), or during postoperative days 1-5. After cross-clamp removal, patients in Del Nido group showed higher rates of spontaneous rhythm (66.7% vs 43.1%, p <
0.001), and less ventricular fibrillation requiring defibrillation (23.6% vs 49.7%, p <
0.001). Peak intraoperative glucose levels (128 mg/dl vs 198 mg/dl, p <
0.001) and insulin administration (18.1% vs 51.0%, p <
0.001) were lower in the Del Nido group. No other differences were found. CONCLUSIONS: No differences between Del Nido and Buckberg solutions were detected. Del Nido presents better intraoperative glycemic control, higher spontaneous rhythm, less ventricular fibrillation requiring defibrillation after cross-clamp removal, and more comfortable surgical workflow due to less re-dose interruptions.