The effect of preoperative and postoperative biomolecule levels on mortality and morbidity in patients with end-stage heart failure implanted with a ventricular assist device

The Impact of Preoperative and Postoperative Biomolecular Levels on Mortality and Morbidity in Patients Implanted with Ventricular Assist Devices for End-Stage Heart Failure Objective: Heart failure is a complex clinical syndrome characterized by various symptoms that develop due to structural or functional cardiac abnormalities. Left ventricular assist devices (LVADs) are widely used in the treatment of end-stage heart failure to prolong survival and improve quality of life. However, their use leads to significant hemodynamic and biomolecular changes, including activation of the RAAS, increased inflammatory markers, and endothelial stress. This study aimed to evaluate the temporal changes in pre- and postoperative levels of biomolecules such as renin, aldosterone, procalcitonin, Pro-BNP, and von Willebrand factor (vWF) in patients undergoing LVAD implantation. It also analyzed the associations of these changes with complications such as postoperative pericardial effusion, stroke, and intra-aortic balloon pump (IABP) requirement. The ultimate goal was to enhance the predictability of complications through biomolecular monitoring and promote personalized patient management. Methods: The study included 22 patients who received the HeartMate HVAD system between 2022 and 2024 at Akdeniz University, Department of Cardiovascular Surgery. Written informed consent was obtained from all patients, and the study was approved by the institutional ethics committee on 30.01.2025. Clinical and biochemical data were retrieved from hospital records and patient interviews. Renin, aldosterone, procalcitonin, NT-proBNP, and vWF levels were assessed at three time points: preoperative, postoperative day 1, and postoperative month 1. Additional laboratory tests included complete blood count, CRP, INR, albumin, liver and kidney function tests, and electrolytes. The relationships between biomolecular changes and postoperative complications were analyzed statistically. Results: The study evaluated 22 LVAD-implanted patients. The mean age was 52.23±11.2 years, with 90.9% being male. The etiology was equally distributed between dilated and ischemic cardiomyopathy. Smoking was reported by 81.8% of patients, while diabetes and hypertension were present in 40.9% and 36.4%, respectively. Significant positive correlations were identified between mitral regurgitation and postoperative pro-BNP and renin levels, whereas negative correlations were observed with VWF and aldosterone levels. Similarly, tricuspid regurgitation was found to be weakly negatively correlated with aldosterone and VWF levels. Pulmonary artery pressure was positively associated with elevated levels of procalcitonin, aldosterone, and pro-BNP, particularly in the postoperative period, suggesting a close link between hemodynamic overload and neurohormonal as well as inflammatory responses. The negative correlations observed between TAPSE values and biomarkers indicate that right ventricular dysfunction may be associated with systemic inflammation and endothelial dysfunction. Furthermore, the strong correlation between procalcitonin and pro-BNP levels supports the hypothesis that inflammatory and hemodynamic processes progress along a shared pathophysiological axis. Preoperative mean values included EF: 20.5%, vWF: 201.6±54.49, Pro-BNP: 3123.91±4400.72, Renin: 9.86±6.91, and Aldosterone: 52.82±40.42. Significant increases were observed in Pro-BNP and vWF levels on postoperative day 1 (p=0.001 and p=0.004, respectively), with a sharp rise in procalcitonin levels (p<0.001). By postoperative month 1, procalcitonin levels returned to baseline (p=0.031), vWF decreased to near baseline levels, while Pro-BNP remained elevated. Observed complications included postoperative pericardial effusion (50%), ischemic stroke (36.4%), gastrointestinal bleeding (36.4%), right heart failure (45.5%), ECMO requirement (4.5%), and IABP use (27.3%). Logistic regression showed no significant association between vWF or procalcitonin changes and bleeding revision. A weak correlation was found between vWF and stroke (p=0.089), while no significant associations were observed for other complications. Although vWF levels increased temporarily post-LVAD implantation, they normalized within one month. Conclusion: This thesis demonstrated that certain biomolecular markers undergo significant changes after LVAD implantation and that aldosterone, in particular, may serve as a prognostic marker for complications such as postoperative pericardial effusion, stroke, and IABP requirement. While vWF and procalcitonin reflect inflammatory and endothelial stress responses, their predictive power remains limited. Due to the small sample size and single-center design, larger, multicenter, and long-term studies are needed to validate the clinical applicability of these findings. Key Words: eft Ventricular Assist Device (LVAD), Heart Failure, Biomolecules, Aldosterone, Procalcitonin, von Willebrand Factor, Pro-BNP, Renin, Postoperative Complications, Prognostic Assessment