Comparative analysis of clinico-metabolic profiles between St Thomas and del Nido cardioplegia solutions: A pilot study.

Introduction: Cardioplegia (CP) is integral to myocardial protection during cardiac surgery. Two standard cardioplegic solutions viz. Del Nido solution (DNS) and St Thomas solution (STS) are widely used in cardiac surgeries. The DNS is a single-dose CP that offers superior myocardial protection in adults, and studies have claimed myocardial injury in STS patients. The elevated circulatory level of citric acid cycle intermediate, succinate is a metabolic hallmark of ischemia. Its rapid oxidation after reperfusion causes ischemia-reperfusion (IR) injury through mitochondrial reactive oxygen species production. Succinate has been identified as an early marker of IR injury through blood plasma/serum-based clinical metabolomics studies. The primary objective of the study was metabolomic profiling of succinate from the coronary sinus and venous blood.

Methods: Two blood samples each were obtained from coronary sinus (CS) & venous reservoir from patients before the application of aortic cross-clamp and after the release of aortic cross-clamp from 22 patients divided into two groups. The blood-serum metabolic profiles were measured by 800 MHz NMR spectrometer and compared using univariate statistical analysis methods. The study also compared the two groups' cardiopulmonary bypass variables and left ventricle functions.

Result: DNS leads to increased serum levels of succinate in the coronary sinus blood after the reperfusion compared to STS. The results of our study are consistent with a previous study that found DNS administration (90 minutes) increases the inflammatory response in the myocardium.

Conclusion: NMR-based serum metabolomics revealed significantly increased circulatory succinate in coronary sinus blood of patients administered with DNS cardioplegia in comparison to STS cardioplegia. URL- https://ctri.nic.in/Clinicaltrials/login.php.