Del Nido Versus HTK Cardioplegia in Adult Aortic Valve Replacement

The idea of using del Nido cardioplegia in adult cardiac surgery appeared after many reports proving its safety and efficacy in the paediatric population. Therefore many adult centres started to apply it in everyday practice. Despite its growing popularity and application in different types of cardiac surgeries, there is still an insufficient number of prospective randomized trials which compare del Nido cardioplegia with the Bretschneider-HTK formula in the adult population. The described problem will be analyzed at different levels in this prospective, randomised study. Clinical aspects - del Nido and HTK cardioplegia will be compared in terms of intraoperative and postoperative details such as perfusion details and concentration of cardiac enzymes. Echocardiographic changes - The next step will be revealing potential echocardiographic changes in cardiac function in short- and long-term observations after cardiac surgery. Metabolic changes - the metabolic profile of amino acids and nucleotide changes after each cardioplegia solution delivery will be analyzed. Statistical calculations will be performed by a qualified statistician. In the case of binary variables, Fisher's exact test will be used to assess differences between groups. In the case of quantitative variables, the compliance of the distribution with the normal distribution will be tested using the Shapiro-Wilk test. For quantitative variables with a distribution not significantly different from normal, the Student's t-test will be used for comparison between groups. If the distribution differs significantly from the normal distribution, the Mann-Whitney U test (comparisons of two samples) or the Kruskal-Wallis test (comparisons of many samples) will be used. Correlations between variables will be assessed using the Pearson or Spearman method, depending on the distribution of the variables. Repeated-measures ANOVA will be used to assess the variability of biochemical parameters over time. In all analyses, p\<0.05 will be considered as the level of statistical significance. A comparison of the two cardioplegia solutions would allow assessing whether del Nido provides better cardioprotection than HTK.