Abstract 19320: Whole Genome RNA Sequencing Analysis of Modified Delnido versus Whole Blood Cardioplegia in the Human Left Ventricle
Introduction: During cardiac surgery with cardiopulmonary bypass (CPB), delivery of cardioplegia to achieve electromechanical cardiac quiescence is obligatory. Cardioplegia lowers the metabolic rate of the heart muscle thereby preventing cell death during aortic cross-clamping. The modified delNido cardioplegia (mdNc) solution has the advantage of less frequent dosing, however its consequences at a molecular level are unclear.
Hypothesis: We performed whole genome RNA sequencing of human left ventricular (LV) myocardium pre and post cardioplegia.
Methods: We prospectively enrolled 130 patients undergoing aortic valve replacement surgery with (CPB). Patients exclusively received either mdNc (n=37) or whole-blood cardioplegia (n=93). The LV apex was biopsied at baseline, and after a median of 74 min of cold, cardioplegic arrest. We performed gene expression differential analyses for 18,258 genes between the mdNc and whole-blood cardioplegia group using Limma. Clinical and demographic variables were adjusted for in a multiple logistic regression model. P-values were adjusted for multiple testing.
Results: We identified 20 differentially expressed genes (log2 fold change > 2.0, adjusted P <0.05), of which Humanin-like 9 (MTRNR2L9; log2FC=-6.59, P=1.36E-16) and Myosin, Heavy Chain 7, Cardiac Muscle, Beta (MYH7; log2FC=4.3, P=4.3E-04) were the most differentially expressed. MTRNR2L9 plays a role as a neuroprotective and anti-apoptotic factor. Its upregulation in the mdNc group may play a protective role in ischemic injury. Downregulation of MYH7 in the mdNc group, a gene involved in skeletal muscle contraction, possibly demonstrates a decreased contractile state after delNido.
Conclusion: There are significant differences between traditional whole-blood and modified delNido cardioplegia at a molecular level. Decreased contractile and increased anti-apoptotic genes show measurable perturbations of the modified delNido technique.
Author Disclosures: M. Heydarpour: None. J.I. Ejiofor: None. M.S. Gilfeather: None. S.C. Body: None. S.F. Aranki: None. J.D. Muehlschlegel: None.
- © 2016 by American Heart Association, Inc.