Background: The cardio-renal syndrome and hepatic impairment play a critical role in end-stage heart failure (HF). Levosimendan is an effective inotropic agent used to maintain cardiac output similar to classic cardiotonic like dobutamine/dopamine. This current research aims to investigate the clinical outcomes of levosimendan and dobutamine/dopamine in Chinese heart transplant awaiting patients with severe hepatic or renal impairment. Methods: We performed a retrospective analysis of 568 heart transplant awaiting individuals with severe hepatic or renal impairment who treated with levosimendan or dobutamine/dopamine in our institution between January 2015 and December 2020. Univariate Cox proportional hazard models and Kaplan-Meier survival curves were applied. The primary endpoint was defined as death included inhospital mortality and the mortality at 30 days, 90 days, 180 days and 1 year after heart transplantation. Results: There were no significant differences in mortality rate at 30, 90, 180 days and 1 years after heart transplantation between the levosimendan and non-levosimendan groups, or between subgroups of patients with severe hepatic impairment or renal impairment. The results were consistent before and after propensity score matching. Conclusions: In the population with advanced heart failure awaiting heart transplantation, levosimendan did not increase short- or long-term mortality rates after surgery compared to dobutamine/dopamine, regardless of their hepatic or renal function. Severe hepatic or renal impairment were not necessarily considered a contraindication for levosimendan in these patients.

The ischemia–reperfusion process of a donor heart during heart transplantation leads to severe mitochondrial dysfunction, which may be the main cause of donor heart dysfunction after heart transplantation. Pyruvate carboxylase (PC), an enzyme found in mitochondria, is said to play a role in the control of oxidative stress and the function of mitochondria. This research examined the function of PC and discovered the signaling pathways controlled by PC in myocardial IRI. We induced IRI using a murine heterotopic heart transplantation model in vivo and a hypoxia–reoxygenation cell model in vitro and evaluated inflammatory responses, oxidative stress levels, mitochondrial function, and cardiomyocyte apoptosis. In both in vivo and in vitro settings, we observed a significant decrease in PC expression during myocardial IRI. PC knockdown aggravated IRI by increasing MDA content, LDH activity, TUNEL-positive cells, serum cTnI level, Bax protein expression, and the level of inflammatory cytokines and decreasing SOD activity, GPX activity, and Bcl-2 protein expression. PC overexpression yielded the opposite findings. Additional research indicated that reducing PC levels could block the Wnt/β-catenin pathway and glutamine metabolism by hindering the movement of β-catenin to the nucleus and reducing the activity of complex I and complex II, as well as ATP levels, while elevating the ratios of NADP+/NADPH and GSSG/GSH. Overall, the findings indicated that PC therapy can shield the heart from IRI during heart transplantation by regulating glutamine metabolism through the Wnt/β-catenin pathway.