Body weight of heart transplant (HTx) recipients affects waitlist days. However, no prior report exists to articulate this in detail. The aim of this study is to analyze the effect of recipients’ weight to HTx. The United Network of Organ Sharing (UNOS) registry was analyzed under the current allocation from 2018 to 2023. The cohort was divided into three even weight groups: low (<77.1 kg), middle (77.1–92.1 kg), and high (>92.1 kg). Candidate/donor demographics, weight distributions, waitlist days in UNOS Status, cumulative incidence of HTx and delisting, post-HTx survival, and cutoff weight for earlier HTx were analyzed. A total of 16,664 HTx recipients were included (5,535: low, 5,537: middle, and 5,592: high). Donors and recipients had a weight distribution mismatch ( p = 0.003). For waitlist days, status 1 was comparable; however, the high group with status ≥2 had approximately twice longer waitlist days than the low group. The high group had a lower incidence of HTx ( p < 0.001) and higher delisting ( p = 0.02) than the low group. One year survival was comparable ( p = 0.28). The weight cutoff for earlier HTx was 80 kg with a 21.6% increased rate of HTx (hazard ratio [HR] = 1.216; 95% confidence interval [CI], 1.171–1.263, p < 0.001). Recipients weighing <80 kg had earlier HTx and a higher incidence of HTx. The effect of pre-HTx weight management requires further study.
Building on validated in vitro and chronic in vivo testing of the Penn State University (PSU) Child Ventricular Assist Device (CVAD), the four-bladed prototype rotor (Rev 0.0) was redesigned using established analytical and computational methods to improve hydraulic efficiency while preserving hemodynamic performance and biocompatibility. Applying turbomachinery principles at the nominal operating condition (3 liters/minute [LPM], 8,000 revolutions/minute [RPM]), a five-bladed design (Rev 1.0) was created with an ideal inflow angle ( β 1 = 41.0°) and outflow angle ( β 2 = 27.4°). In silico simulations of Rev 1.0 across the prototype’s operating range (7,000–9,000 RPM, 1–5 LPM) demonstrated an approximately 40% improvement in hydraulic performance. The Rev 1.0 rotor was then evaluated on a benchtop mock circulatory loop using fresh ovine blood, confirming the in silico gains. The normalized index of hemolysis (NIH), measured at two clinically relevant conditions (1.5 LPM and 3.3 LPM, both at ~80 mm Hg), was 0.052 ± 0.054 and 0.047 ± 0.033 mg/dL, respectively, and high-molecular-weight multimers of von Willebrand factor were preserved within normal to borderline ranges. By achieving target flows and pressures at approximately 1,000 RPM lower speeds, the redesign reduces power requirements and enables longer untethered operation, advancing a fully implantable PSU CVAD toward a critical unmet need in pediatric advanced heart failure.
Immunocompromised patients frequently develop acute respiratory distress syndrome (ARDS) requiring venovenous extracorporeal membrane oxygenation (VV-ECMO), yet evidence on prognostic factors in this population remains limited. This single-center retrospective study evaluated 90 day outcomes and identified predictors of mortality in immunocompromised ARDS patients supported with VV-ECMO. Between September 2009 and December 2021, 112 ARDS patients (49 immunocompromised and 63 immunocompetent) who received VV-ECMO were included. Baseline characteristics and outcomes were compared between groups; multivariate Cox regression analyzed 90 day mortality predictors, with subgroup analyses by immune status. Ninety day mortality was comparable between nonimmunosuppressed and immunosuppressed patients. Pre-ECMO platelet count <75 × 10 9 /L was the sole independent predictor of 90 day mortality, and this association was observed exclusively in immunocompromised patients. Immunocompromised patients with a platelet count ≥75 × 10 9 /L achieved survival comparable to immunocompetent patients, whereas those with a platelet count <75 × 10 9 /L had fewer ventilator-free and ECMO-free days. Immunocompromised status per se was not independently associated with 90 day mortality in VV-ECMO–supported ARDS patients. Pre-ECMO platelet count emerged as a critical risk stratification tool: immunocompromised patients with a platelet count ≥75 × 10 9 /L demonstrated favorable outcomes, whereas those with lower counts were at substantially increased risk.
Heparin locking is used to maintain patency of acute hemodialysis catheters; however, unintended leakage of locking solution into the systemic circulation may increase bleeding risk. Ideally, locking solution would remain confined to the catheter lumen, maintaining patency while minimizing systemic anticoagulation, yet the mechanisms governing heparin retention and dispersion remain inadequately understood. Patient-specific computational fluid dynamics simulations incorporating non-Newtonian blood flow and species transport were performed using a microcomputed tomography-derived model of an acute dual-lumen hemodialysis catheter to evaluate the effects of injection rate, venous blood flow, and lock volume. Injection of the manufacturer-recommended 1.4 ml lock volume over durations of 0.5–5 seconds resulted in 13–16% (900–1100 U) of injected heparin entering the systemic circulation, yielding transient therapeutic systemic heparin concentrations. Rapid injections increased distal penetration of the locking solution and improved heparin retention (from 84% to 87%). Heparin clearance following injection occurred in two phases consisting of rapid early convective washout followed by prolonged slow diffusive clearance. Reducing lock volume substantially decreased systemic heparin exposure while preserving therapeutic intraluminal heparin concentrations. These findings provide mechanistic insight into catheter locking behavior and suggest that optimization of lock volume may reduce unintended systemic anticoagulation while maintaining catheter patency.
Cross-clamp times greater than or equal to 4 hours are critical for donor heart viability. We compared cold storage (CS) and normothermic ex vivo heart perfusion (EVHP) during prolonged preservation using a juvenile porcine model. Twenty-two piglet hearts (~10 kg) were assigned to CS or EVHP for 6 or 8 hours, followed by 2 hours of working-mode (WM) perfusion. Metabolism, cardiac function, and cell damage were compared using two-sample t-tests or Fisher’s exact tests, and temporal changes during perfusion were assessed using linear mixed-effects models and generalized estimating equations. During EVHP, the minimal rate of pressure change decreased, and arterial lactate levels increased after 5–6 hours. Compared to CS, EVHP hearts showed higher left atrial pressure (6 vs. 0 mm Hg, p = 0.011), arterial lactate levels during WM ( p < 0.001), and NFκB-p65 levels ( p = 0.002) at 6 hours, and lower cardiac output (90 vs. 120% of normal, p = 0.026), higher left atrial pressure (7 vs. 3 mm Hg, p = 0.009), higher arterial lactate levels during WM ( p < 0.001), and increased neutrophil infiltration ( p = 0.033) at 8 hours. Ex vivo heart perfusion hearts deteriorated beyond 5–6 hours and showed greater hemodynamic, metabolic, and inflammatory changes at both 6 and 8 hours. Ex vivo heart perfusion enhancements reducing immune response and inflammation are crucial for expanding the donor pool.
