Browsing by Author "Rokop, Zachary P."

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    Hepatic Ischemia/Reperfusion Injury After Liver Transplantation Is Not Associated with Early Impairment of Left Ventricular Ejection Fraction
    (International Scientific Information, 2022-12-13) Rokop, Zachary P.; Frick, Kyle; Zenisek, Joseph; Kroepfl, Elizabeth; Mihaylov, Plamen; Patidar, Kavish R.; Nephew, Lauren; Mangus, Richard S.; Kubal, Chandrashekhar; Surgery, School of Medicine
    Background: Early myocardial dysfunction is a known complication following liver transplant. Although hepatic ischemia/reperfusion injury (hIRI) has been shown to cause myocardial injury in rat and porcine models, the clinical association between hIRI and early myocardial dysfunction in humans has not yet been established. We sought to define this relationship through cardiac evaluation via transthoracic echocardiography (TTE) on postoperative day (POD) 1 in adult liver transplant recipients. Material/Methods: TTE was performed on POD1 in all liver transplant patients transplanted between January 2020 and April 2021. Hepatic IRI was stratified by serum AST levels on POD1 (none: <200; mild: 200–2000; moderate: 2000–5000; severe: >5000). All patients had pre-transplant TTE as part of the transplant evaluation. Results: A total of 173 patients underwent liver transplant (LT) between 2020 and 2021 and had a TTE on POD 1 (median time to echo: 1 day). hIRI was present in 142 (82%) patients (69% mild, 8.6% moderate, 4% severe). Paired analysis between pre-LT and post-LT left ventricular ejection fraction (LVEF) of the entire study population demonstrated no significant decrease following LT (mean difference: −1.376%, P=0.08). There were no significant differences in post-LT LVEF when patients were stratified by severity of hIRI. Three patients (1.7%) had significant post-transplant impairment of LVEF (<35%). None of these patients had significant hIRI. Conclusions: hIRI after liver transplantation is not associated with immediate reduction in LVEF. The pathophysiology of post-LT cardiomyopathy may be driven by extra-hepatic triggers.
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    The rate of muscle wasting in liver transplant recipients on waiting list: post-transplant outcomes and associated serum metabolite patterns
    (AME, 2024) Rokop, Zachary P.; O’Connell, Thomas M.; Munsch, Taylor; Nephew, Lauren; Orman, Eric; Mihaylov, Plamen; Mangus, Richard S.; Kubal, Chandrashekhar; Surgery, School of Medicine
    Background: Sarcopenia at the time of liver transplantation (LT) is an established risk factor for mortality following LT. However, most studies in this context have defined sarcopenia by one-time, static measurements. The aims of this study were (I) to determine the impact of the rate of muscle loss in waitlisted LT recipients on post-LT outcomes and (II) to identify patterns of serum metabolites associated with patients with more progressive sarcopenia. Methods: Patients undergoing liver transplant from 2008 to 2018 who received more than one computed tomography (CT) scans within 12 months prior to liver transplant were included (n=61). The psoas muscle index (PMI) was calculated using Slice-O-Matic software and corrected for patient height (m2). Patients were classified into two groups based the rate of reduction in PMI-high wasting [HW; change in PMI (ΔPMI) ≤-1%/month] and low wasting (LW; ΔPMI >-1%/month). Pre-transplant serum metabolic profiles were collected using nuclear magnetic resonance (NMR) spectroscopy. Living kidney donor sera was used as healthy controls. Results: Median ΔPMI was -2.0%/month in HW and -0.15%/month in LW patients (P<0.001). Post-transplant 1-year mortality was significantly higher in HW patients. There were no significant differences in metabolite concentrations between HW and LW patients. However, perturbations in taurine, sarcosine, betaine and the aromatic amino acids (AAAs), were observed in patients with liver disease as compared to healthy controls. Liver disease was also associated with a decrease in lipoprotein profiles, especially high-density lipoprotein (HDL) particles. Conclusions: In patients undergoing LT, the rate of progression of sarcopenia is a strong prognostic indicator of post-LT death. Serum metabolite profiles were not characteristically unique to HW patients, and most closely resemble derangements associated with chronic liver disease.