ObjectiveTo compare and analyze the effect of myocardial protection between HTK and del Nido cardioplegia solutions in neonates with surgeries for transposition of the great arteries. MethodsThe clinical data of 208 neonates with complete transposition of the great arteries in our institution from 2014 to 2020 were retrospectively analyzed. According to the cardioplegia solutions utilized in the operations, the patients were divided into two groups: a HTK group and a del Nido group. Propensity score matching was conducted to eliminate the biases. The cardiopulmonary bypass time, aortic cross-clamping time, total amount of cardioplegia solutions, transfusion frequency of cardioplegia, ICU stay time, mechanical support time, inotropic score, hospital stay, left ventricular ejection fraction, N-terminal proBNP and troponin I were compared and analyzed between the two groups after matching. ResultsAfter 1:1 propensity score matching, a total of 54 patients were analyzed with 27 patients in each group. In the HTK group, there were 22 males and 5 females with a median age of 7.0 (2.0, 11.0) d. In the del Nido group, there were 23 males and 4 females with a median age of 8.0 (3.0, 11.0) d. A total of 3 children died after the surgery: 2 (7.4%) patients in the HTK group and 1 (3.7%) patient in the del Nido group. There was no significant difference in hospital mortality between the two groups (P=1.000). The total amount of cardioplegia solutions in the HTK group was significantly higher than that of del Nido group (P<0.001). Transfusion frequency of cardioplegia in del Nido group was significantly higher than that of the HTK group (P=0.043). There was no significant difference in the postoperative ICU time, mechanical support time, length of hospital stay, inotropic score, left ventricular ejection fraction, N-terminal B-type natriuretic peptide precursor or troponin I between the two groups (P>0.05). ConclusionFor neonates with surgeries for complete transposition of the great arteries, HTK cardioplegia solutions can provide effective and safe myocardial protection, which is similar to del Nido cardioplegia solutions.