Sodium-glucose co-transporter-2 inhibitors for hospitalised patients with COVID-19: a prospective meta-analysis of randomised trials.

BACKGROUND: Sodium-glucose co-transporter-2 (SGLT2) inhibitors have been proposed as a potential treatment for adults hospitalised with COVID-19, due to their potential anti-inflammatory and endothelial protective effects. Published evidence from randomised control trials (RCTs) does not provide evidence of benefit. We aimed to estimate the effect of oral administration of SGLT2 inhibitors compared with usual care or placebo in adults hospitalised with COVID-19. METHODS: Eligible RCTs that estimated the effect of oral administration of SGLT2 inhibitors compared with usual care or placebo on 28-day all-cause mortality (primary outcome) were included in this prospective meta-analysis. The primary safety outcome was ketoacidosis by 28 days. Trials were identified through systematic searches of ClinicalTrials.gov, EudraCT, and the WHO ISRCTN registry between Nov 1, 2022 and Jan 31, 2023. The search terms were "random*" AND "COVID" AND each SGLT2i, not restricted by trial status or language. Individual searches were then combined. Prespecified summary outcome data, overall and within subgroups of interest, were provided by each trial. The primary analyses were inverse variance weighted meta-analysis of odds ratios (ORs). Risk of bias was assessed using the Cochrane Risk of Bias tool. This study was registered with PROSPERO, CRD42023406442. FINDINGS: Three eligible trials randomly assigned 6096 participants (3025 to the SGLT2 inhibitor group and 3071 to the usual care or placebo group). 2381 (39%) patients were women and 1547 (25%) had type 2 diabetes at randomisation. By 28 days, there were 351 deaths in the SGLT2 inhibitor group and 382 deaths in the usual care or placebo group (summary OR 0·93 [95% CI 0·79-1·08]; p=0·33, I2 for inconsistency across trials 0%). The risk of bias was assessed as being low. Ketoacidosis was observed in seven participants in the SGLT2 inhibitor group and two patients in the usual care or placebo group. INTERPRETATION: Although administration of SGLT2 inhibitor was safe, we found no clear evidence that adding SGLT2 inhibitor therapy improved outcomes in patients hospitalised with COVID-19 compared with usual care or placebo. These data do not support the use of SGLT2 inhibitors as standard treatment in adults hospitalised for COVID-19. FUNDING: None.

A surface-functionalized whole blood-based dielectric microsensor for assessment of clot firmness in a fibrinolytic environment.

Accurate assessment of fibrin clot stability can predict bleeding risk in coagulopathic conditions such as thrombocytopenia and hypofibrinogenemia. Hyperfibrinolysis - a clinical phenotype characterized by an accelerated breakdown of the fibrin clot - makes such assessments challenging by obfuscating the effect of hemostatic components including platelets or fibrinogen on clot stability. In this work, we present a biofunctionalized, microfluidic, label-free, electronic biosensor to elicit unique, specific, and differential responses from the multifactorial processes of blood coagulation and fibrinolysis ex vivo. The microsensor tracks the temporal variation in the normalized real part of the dielectric permittivity of whole blood (<10 µL) at 1 MHz as the sample coagulates within a three-dimensional, parallel-plate, capacitive sensing area. Surface biofunctionalization of the microsensor's electrodes with physisorption of tissue factor (TF) and aprotinin permits real-time assessment of the coagulation and fibrinolytic outcomes. We show that surface coating with TF and manual addition of TF result in a similar degree of acceleration of coagulation kinetics in human whole blood samples. We also show that surface coating with aprotinin and manual addition of aprotinin yield similar results in inhibiting tissue plasminogen activator (tPA)-induced upregulated fibrinolysis in human whole blood samples. Validated through a clinically relevant, complementary assay - rotational thromboelastometry for clot viscoelasticity - we finally establish that a microsensor dual-coated with both TF and aprotinin detects the hemostatic rescue in the tPA-induced hyperfibrinolytic profile of whole blood and the hemostatic dysfunction due to concurrent platelet depletion in the blood sample, thus featuring enhanced ability in evaluating complex, combinatorial coagulopathies.

TEMPORARY REMOVAL: Alterations in visible light exposure modulate platelet function and regulate thrombus formation.

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Effect of sodium-glucose co-transporter-2 inhibitors on survival free of organ support in patients hospitalised for COVID-19 (ACTIV-4a): a pragmatic, multicentre, open-label, randomised, controlled, platform trial.

BACKGROUND: Patients hospitalised for COVID-19 are at risk for multiorgan failure and death. Sodium-glucose co-transporter-2 (SGLT2) inhibitors provide cardiovascular and kidney protection in patients with cardiometabolic conditions and could provide organ protection during COVID-19. We aimed to investigate whether SGLT2 inhibitors can reduce the need for organ support in patients hospitalised for COVID-19. METHODS: This pragmatic, multicentre, open-label, randomised, controlled, platform trial was conducted across 63 sites in the USA, Spain, Brazil, Italy, and Mexico. Patients aged at least 18 years hospitalised for COVID-19 (moderate or severe illness) were randomly assigned (1:1), via an interactive voice system or web-response system, to receive locally available SGLT2 inhibitor (administered orally, once daily) plus standard-of-care or standard-of-care for 30 days. The primary outcome was organ support-free days evaluated through 21 days, assessed using intention-to-treat approach. This trial is registered on ClinicalTrials.gov, NCT04505774. FINDINGS: The first patient was randomly assigned to the SGLT2 inhibitor domain on Dec 3, 2021. On March 31, 2023, at the recommendation of the data and safety monitoring board, enrolment in the SGLT2 inhibitor domain for both moderately and severely ill hospitalised patients was stopped prematurely for futility due to a low likelihood of finding a treatment benefit. The final randomised population consisted of 575 patients (mean age 72 years [SD 13], 242 (42%) female and 154 (27%) Hispanic; 504 in the moderate illness group and 71 in the severe illness group). 573 patients had a known 21-day outcome; 215 (75%) of 285 patients in the SGLT2 inhibitor plus standard-of-care group did not require respiratory or cardiovascular organ support versus 231 (80%) of 288 patients in the standard-of-care group. The adjusted odds ratio (OR) for an SGLT2 inhibitor effect on organ support-free days was 0·74 (95% Credible Interval [CrI] 0·48-1·13; where OR higher than 1 indicated treatment benefit, yielding a posterior probability of futility P(OR <1·2) of 99% and a posterior probability of inferiority P(OR<1·0) of 91%). There were 37 deaths (13%) in the SGLT2 inhibitor plus standard-of-care group and 42 deaths (15%) in the standard-of-care group at 90 days (hazard ratio 0·91 [95% CrI 0·58-1·43], probability of hazard ratio <1 of 66%). No safety concerns were observed with SGLT2 inhibitors, including no cases of ketoacidosis. INTERPRETATION: SGLT2 inhibitors did not significantly increase days free of organ support or reduce mortality in patients hospitalised with COVID-19. SGLT2 inhibitors were well tolerated with no observed safety concerns. Overall, these findings do not support the use of SGLT2 inhibitors as standard care in patients hospitalised with COVID-19. FUNDING: National Institutes of Health.

Trauma patients have reduced ex vivo flow-dependent platelet hemostatic capacity in a microfluidic model of vessel injury.

Trauma is the leading cause of death in individuals up to 45 years of age. Alterations in platelet function are a critical component of trauma-induced coagulopathy (TIC), yet these changes and the potential resulting dysfunction is incompletely understood. The lack of clinical assays available to explore platelet function in this patient population has hindered detailed understanding of the role of platelets in TIC. The objective of this study was to assess trauma patient ex vivo flow-dependent platelet hemostatic capacity in a microfluidic model. We hypothesized that trauma patients would have flow-regime dependent alterations in platelet function. Blood was collected from trauma patients with level I activations (N = 34) within 60 min of hospital arrival, as well as healthy volunteer controls (N = 10). Samples were perfused through a microfluidic model of injury at venous and arterial shear rates, and a subset of experiments were performed after incubation with fluorescent anti-CD41 to quantify platelets. Complete blood counts were performed as well as plasma-based assays to quantify coagulation times, fibrinogen, and von Willebrand factor (VWF). Exploratory correlation analyses were employed to identify relationships with microfluidic hemostatic parameters. Trauma patients had increased microfluidic bleeding times compared to healthy controls. While trauma patient samples were able to deposit a substantial amount of clot in the model injury site, the platelet contribution to microfluidic hemostasis was attenuated. Trauma patients had largely normal hematology and plasma-based coagulation times, yet had elevated D-Dimer and VWF. Venous microfluidic bleeding time negatively correlated with VWF, D-Dimer, and mean platelet volume (MPV), while arterial microfluidic bleeding time positively correlated with oxygenation. Arterial clot growth rate negatively correlated with red cell count, and positively with mean corpuscular volume (MCV). We observed changes in clot composition in trauma patient samples reflected by significantly diminished platelet contribution, which resulted in reduced hemostatic function in a microfluidic model of vessel injury. We observed a reduction in platelet clot contribution under both venous and arterial flow ex vivo in trauma patient samples. While our population was heterogenous and had relatively mild injury severity, microfluidic hemostatic parameters correlated with different patient-specific data depending on the flow setting, indicating potentially differential mechanistic pathways contributing to platelet hemostatic capacity in the context of TIC. These data were generated with the goal of identifying key features of platelet dysfunction in bleeding trauma patients under conditions of flow and to determine if these features correlate with clinically available metrics, thus providing preliminary surrogate markers of physiological platelet dysfunction to be further studied across larger cohorts. Future studies will continue to explore those relationships and further define mechanisms of TIC and their relationship with patient outcomes.

Association between timing of operative interventions and mortality in emergency general surgery.

Background: Emergency general surgery (EGS) often demands timely interventions, yet data for triage and timing are limited. This study explores the relationship between hospital arrival-to-operation time and mortality in EGS patients. Study design: We performed a retrospective cohort study using an EGS registry at four hospitals, enrolling adults who underwent operative intervention for a primary American Association for the Surgery of Trauma-defined EGS diagnosis between 2021 and 2023. We excluded patients undergoing surgery more than 72 hours after admission as non-urgent and defined our exposure of interest as the time from the initial vital sign capture to the skin incision timestamp. We assessed the association between operative timing quintiles and in-hospital mortality using a mixed-effect hierarchical multivariable model, adjusting for patient demographics, comorbidities, organ dysfunction, and clustering at the hospital level. Results: A total of 1199 patients were included. The median time to operating room (OR) was 8.2 hours (IQR 4.9-20.5 hours). Prolonged time to OR increased the relative likelihood of in-hospital mortality. Patients undergoing an operation between 6.7 and 10.7 hours after first vitals had the highest odds of in-hospital mortality compared with operative times <4.2 hours (reference quintile) (adjusted OR (aOR) 68.994; 95% CI 4.608 to 1032.980, p=0.002). A similar trend was observed among patients with operative times between 24.4 and 70.9 hours (aOR 69.682; 95% CI 2.968 to 1636.038, p=0.008). Conclusion: Our findings suggest that prompt operative intervention is associated with lower in-hospital mortality rates among EGS patients. Further work to identify the most time-sensitive populations is warranted. These results may begin to inform benchmarking for triaging interventions in the EGS population to help reduce mortality rates. Level of evidence: IV.

Early GFAP and UCH-L1 point-of-care biomarker measurements for the prediction of traumatic brain injury and progression in patients with polytrauma and hemorrhagic shock.

OBJECTIVE: Traumatic brain injury (TBI) and hemorrhage are responsible for the largest proportion of all trauma-related deaths. In polytrauma patients at risk of hemorrhage and TBI, the diagnosis, prognosis, and management of TBI remain poorly characterized. The authors sought to characterize the predictive capabilities of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCH-L1) measurements in patients with hemorrhagic shock with and without concomitant TBI. METHODS: The authors performed a secondary analysis on serial blood samples derived from a prospective observational cohort study that focused on comparing early whole-blood and component resuscitation. A convenience sample of patients was used in which samples were collected at three time points and the presence of TBI or no TBI via CT imaging was documented. GFAP and UCH-L1 measurements were performed on plasma samples using the i-STAT Alinity point-of-care platform. Using classification tree recursive partitioning, the authors determined the measurement cut points for each biomarker to maximize the abilities for predicting the diagnosis of TBI, Rotterdam CT imaging scores, and 6-month Glasgow Outcome Scale-Extended (GOSE) scores. RESULTS: Biomarker comparisons demonstrated that GFAP and UCH-L1 measurements were associated with the presence of TBI at all time points. Classification tree analyses demonstrated that a GFAP level > 286 pg/ml for the sample taken upon the patient's arrival had an area under the receiver operating characteristic curve of 0.77 for predicting the presence of TBI. The classification tree results demonstrated that a cut point of 3094 pg/ml for the arrival GFAP measurement was the most predictive for an elevated Rotterdam score on the initial and second CT scans and for TBI progression between scans. No significant associations between any of the most predictive cut points for UCH-L1 and Rotterdam CT scores or TBI progression were found. The predictive capabilities of UCH-L1 were limited by the range allowed by the point-of-care platform. Arrival GFAP cut points remained strong independent predictors after controlling for all potential polytrauma confounders, including injury characteristics, shock severity, and resuscitation. CONCLUSIONS: Early measurements of GFAP and UCH-L1 on a point-of-care device are significantly associated with CT-diagnosed TBI in patients with polytrauma and shock. Early elevated GFAP measurements are associated with worse head CT scan Rotterdam scores, TBI progression, and worse GOSE scores, and these associations are independent of other injury attributes, shock severity, and early resuscitation characteristics.

Machine Learning - Based Bleeding Risk Predictions in Atrial Fibrillation Patients on Direct Oral Anticoagulants.

Importance: Accurately predicting major bleeding events in non-valvular atrial fibrillation (AF) patients on direct oral anticoagulants (DOACs) is crucial for personalized treatment and improving patient outcomes, especially with emerging alternatives like left atrial appendage closure devices. The left atrial appendage closure devices reduce stroke risk comparably but with significantly fewer non-procedural bleeding events. Objective: To evaluate the performance of machine learning (ML) risk models in predicting clinically significant bleeding events requiring hospitalization and hemorrhagic stroke in non-valvular AF patients on DOACs compared to conventional bleeding risk scores (HAS-BLED, ORBIT, and ATRIA) at the index visit to a cardiologist for AF management. Design: Prognostic modeling with retrospective cohort study design using electronic health record (EHR) data, with clinical follow-up at one-, two-, and five-years. Setting: University of Pittsburgh Medical Center (UPMC) system. Participants: 24,468 non-valvular AF patients aged ≥18 years treated with DOACs, excluding those with prior history of significant bleeding, other indications for DOACs, on warfarin or contraindicated to DOACs. Exposures: DOAC therapy for non-valvular AF. Main Outcomes and Measures: The primary endpoint was clinically significant bleeding requiring hospitalization within one year of index visit. The models incorporated demographic, clinical, and laboratory variables available in the EHR at the index visit. Results: Among 24,468 patients, 553 (2.3%) had bleeding events within one year, 829 (3.5%) within two years, and 1,292 (5.8%) within five years of index visit. We evaluated multivariate logistic regression and ML models including random forest, classification trees, k-nearest neighbor, naive Bayes, and extreme gradient boosting (XGBoost) which modestly outperformed HAS-BLED, ATRIA, and ORBIT scores in predicting clinically significant bleeding at 1-year follow-up. The best performing model (random forest) showed area under the curve (AUC-ROC) 0.76 (0.70-0.81), G-Mean score of 0.67, net reclassification index 0.14 compared to 0.57 (0.50-0.63), G-Mean score of 0.57 for HASBLED score, p-value for difference <0.001. The ML models had improved performance compared to conventional risk across time-points of 2-year and 5-years and within the subgroup of hemorrhagic stroke. SHAP analysis identified novel risk factors including measures from body mass index, cholesterol profile, and insurance type beyond those used in conventional risk scores. Conclusions and Relevance: Our findings demonstrate the superior performance of ML models compared to conventional bleeding risk scores and identify novel risk factors highlighting the potential for personalized bleeding risk assessment in AF patients on DOACs.

Characterization of adverse events in injured patients at risk of hemorrhagic shock: a secondary analysis of three harmonized prehospital randomized clinical trials.

Background: The reporting of adverse events (AEs) is required and well defined in the execution of clinical trials, but is poorly characterized particularly in prehospital trials focusing on traumatic injury. In the setting of prehospital traumatic injury trials, no literature currently exists analyzing the clinical implications of AEs and their associations with mortality and morbidity. We sought to analyze AEs from three prehospital hemorrhagic shock trials and characterize their time course, incidence, severity, associated clinical outcomes, and relatedness. Methods: We performed a secondary analysis of three prehospital randomized clinical trials. We analyzed AEs at both the patient level as well as the individual AE level. We categorized patients who had no AEs, a single documented AE and those with multiple events (>1 AE). We characterized AE timing, severity, relatedness and attributable mortality outcomes. Results: We included 1490 patients from the three harmonized clinical trials, with 299 (20.1%) individual patients having at least a single AE documented with 529 AEs documented overall as a proportion of patients had multiple events. Over 44% of patients had a death-related misclassified AE. Patients with at least a single documented AE had a significantly higher 28-day mortality (log-rank χ2=81.27, p<0.001) compared with those without an AE documented. Patients with a single AE had a significant higher mortality than those with multiple AEs, potentially due to survival bias (log-rank χ2=11.80, p=0.006). When relatedness of each individual AE was characterized, over 97% of AEs were classified as 'definitely not related' or 'probably not related' to the intervention. Conclusions: AEs in hemorrhagic shock trials are common, occur early and are associated with mortality and survival bias. The potential for inaccurate reporting exists, and education and training remain essential for appropriate treatment arm comparison. The current results have important relevance to injury-related clinical trials. Trial registration numbers: NCT01818427, NCT02086500 and NCT03477006. Level of evidence: II.

Heparin Dose Intensity and Organ Support-Free Days in Patients Hospitalized for COVID-19.

Background: Clinical trials suggest that therapeutic-dose heparin may prevent critical illness and vascular complications due to COVID-19, but knowledge gaps exist regarding the efficacy of therapeutic heparin including its comparative effect relative to intermediate-dose anticoagulation. Objectives: The authors performed 2 complementary secondary analyses of a completed randomized clinical trial: 1) a prespecified per-protocol analysis; and 2) an exploratory dose-based analysis to compare the effect of therapeutic-dose heparin with low- and intermediate-dose heparin. Methods: Patients who received initial anticoagulation dosed consistently with randomization were included. The primary outcome was organ support-free days (OSFDs), a combination of in-hospital death and days free of organ support through day 21. Results: Among 2,860 participants, 1,761 (92.8%) noncritically ill and 857 (89.1%) critically ill patients were treated per-protocol. Among noncritically ill per-protocol patients, the posterior probability that therapeutic-dose heparin improved OSFDs as compared with usual care was 99.3% (median adjusted OR: 1.36; 95% credible interval [CrI]: 1.07-1.74). Therapeutic heparin had a high posterior probability of efficacy relative to both low- (94.6%; adjusted OR: 1.26; 95% CrI: 0.95-1.64) and intermediate- (99.8%; adjusted OR: 1.80; 95% CrI: 1.22-2.62) dose thromboprophylaxis. Among critically ill per-protocol patients, the posterior probability that therapeutic heparin improved outcomes was low. Conclusions: Among noncritically ill patients hospitalized for COVID-19 who were randomized to and initially received therapeutic-dose anticoagulation, heparin, compared with usual care, was associated with improved OSFDs, a combination of in-hospital death and days free of organ support. Therapeutic heparin appeared superior to both low- and intermediate-dose thromboprophylaxis.

TRAUMA-INDUCED COAGULOPATHY: PREVALENCE AND ASSOCIATION WITH MORTALITY PERSIST 20 YEARS LATER.

ABSTRACT: Introduction: A 2003 landmark study identified the prevalence of early trauma-induced coagulopathy (eTIC) at 28% with a strong association with mortality of 8.9%. Over the last 20 years, there have been significant advances in both the fundamental understanding of eTIC and therapeutic interventions. Methods: A retrospective cohort study was performed from 2018 to 2022 on patients ≥18 using prospectively collected data from two level 1 trauma centers and compared to data from 2003. Demographics, laboratory data, and clinical outcomes were obtained. Results: There were 20,107 patients meeting criteria: 65% male, 85% blunt, mean age 54 ± 21 years, median Injury Severity Score 10 (10, 18), 8% of patients were hypotensive on arrival, with an all-cause mortality 6.0%. The prevalence of eTIC remained high at 32% in patients with an abnormal prothrombin time and 10% with an abnormal partial thromboplastin time, for an overall combined prevalence of 33.4%. Coagulopathy had a major impact on mortality over all injury severity ranges, with the greatest impact with lower Injury Severity Score. In a hybrid logistic regression/Classification and Regression Trees analysis, coagulopathy was independently associated with a 2.1-fold increased risk of mortality (95% confidence interval 1.5-2.9); the predictive quality of the model was excellent [area under the receiver operating characteristic curve (AUROC) 0.932]. Conclusion: The presence of eTIC conferred a higher risk of death across all disease severities and was independently associated with a greater risk of death. Biomarkers of coagulopathy associated with eTIC remain strongly predictive of poor outcome despite advances in trauma care.

A comparison of computational algorithms for the Bayesian analysis of clinical trials.

BACKGROUND: Clinical trials are increasingly using Bayesian methods for their design and analysis. Inference in Bayesian trials typically uses simulation-based approaches such as Markov Chain Monte Carlo methods. Markov Chain Monte Carlo has high computational cost and can be complex to implement. The Integrated Nested Laplace Approximations algorithm provides approximate Bayesian inference without the need for computationally complex simulations, making it more efficient than Markov Chain Monte Carlo. The practical properties of Integrated Nested Laplace Approximations compared to Markov Chain Monte Carlo have not been considered for clinical trials. Using data from a published clinical trial, we aim to investigate whether Integrated Nested Laplace Approximations is a feasible and accurate alternative to Markov Chain Monte Carlo and provide practical guidance for trialists interested in Bayesian trial design. METHODS: Data from an international Bayesian multi-platform adaptive trial that compared therapeutic-dose anticoagulation with heparin to usual care in non-critically ill patients hospitalized for COVID-19 were used to fit Bayesian hierarchical generalized mixed models. Integrated Nested Laplace Approximations was compared to two Markov Chain Monte Carlo algorithms, implemented in the software JAGS and stan, using packages available in the statistical software R. Seven outcomes were analysed: organ-support free days (an ordinal outcome), five binary outcomes related to survival and length of hospital stay, and a time-to-event outcome. The posterior distributions for the treatment and sex effects and the variances for the hierarchical effects of age, site and time period were obtained. We summarized these posteriors by calculating the mean, standard deviations and the 95% equitailed credible intervals and presenting the results graphically. The computation time for each algorithm was recorded. RESULTS: The average overlap of the 95% credible interval for the treatment and sex effects estimated using Integrated Nested Laplace Approximations was 96% and 97.6% compared with stan, respectively. The graphical posterior densities for these effects overlapped for all three algorithms. The posterior mean for the variance of the hierarchical effects of age, site and time estimated using Integrated Nested Laplace Approximations are within the 95% credible interval estimated using Markov Chain Monte Carlo but the average overlap of the credible interval is lower, 77%, 85.6% and 91.3%, respectively, for Integrated Nested Laplace Approximations compared to stan. Integrated Nested Laplace Approximations and stan were easily implemented in clear, well-established packages in R, while JAGS required the direct specification of the model. Integrated Nested Laplace Approximations was between 85 and 269 times faster than stan and 26 and 1852 times faster than JAGS. CONCLUSION: Integrated Nested Laplace Approximations could reduce the computational complexity of Bayesian analysis in clinical trials as it is easy to implement in R, substantially faster than Markov Chain Monte Carlo methods implemented in JAGS and stan, and provides near identical approximations to the posterior distributions for the treatment effect. Integrated Nested Laplace Approximations was less accurate when estimating the posterior distribution for the variance of hierarchical effects, particularly for the proportional odds model, and future work should determine if the Integrated Nested Laplace Approximations algorithm can be adjusted to improve this estimation.

Early Cold Stored Platelet Transfusion Following Severe Injury: A Randomized Clinical Trial.

OBJECTIVE: To determine the feasibility, efficacy, and safety of early cold stored platelet transfusion compared with standard care resuscitation in patients with hemorrhagic shock. BACKGROUND: Data demonstrating the safety and efficacy of early cold stored platelet transfusion are lacking following severe injury. METHODS: A phase 2, multicenter, randomized, open label, clinical trial was performed at 5 US trauma centers. Injured patients at risk of large volume blood transfusion and the need for hemorrhage control procedures were enrolled and randomized. The intervention was the early transfusion of a single apheresis cold stored platelet unit, stored for up to 14 days versus standard care resuscitation. The primary outcome was feasibility and the principal clinical outcome for efficacy and safety was 24-hour mortality. RESULTS: Mortality at 24 hours was 5.9% in patients who were randomized to early cold stored platelet transfusion compared with 10.2% in the standard care arm (difference, -4.3%; 95% CI, -12.8% to 3.5%; P =0.26). No significant differences were found for any of the prespecified ancillary outcomes. Rates of arterial and/or venous thromboembolism and adverse events did not differ across treatment groups. CONCLUSIONS AND RELEVANCE: In severely injured patients, early cold stored platelet transfusion is feasible, safe and did not result in a significant lower rate of 24-hour mortality. Early cold stored platelet transfusion did not result in a higher incidence of arterial and/or venous thrombotic complications or adverse events. The storage age of the cold stored platelet product was not associated with significant outcome differences. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04667468.

Whole Blood and Blood Component Resuscitation in Trauma: Interaction and Association with Mortality.

OBJECTIVE: Evaluate the interaction between whole blood (WB) and blood component resuscitation in relation to mortality following trauma. SUMMARY BACKGROUND DATA: WB is increasingly available in civilian trauma resuscitation, and it is typically transfused concomitantly with blood components. The interaction between WB and blood component transfusions is unclear. METHODS: Adult trauma patients with a shock index >1 who received ≥4 combined units of red blood cells (RBC) or WB within 4 hours across 501 United States trauma centers were included using the American College of Surgeons Trauma Quality Improvement Program (ACS-TQIP) database. The associations between 1)WB resuscitation and mortality, 2)WB to total transfusion volume ratio (WB:TTV) and mortality, 3)balanced blood component transfusion in the setting of combined WB and component resuscitation and mortality were evaluated with multivariable analysis. RESULTS: A total of 12,275 patients were included (WB: 2,884 vs. component-only: 9,391). WB resuscitation was associated with lower odds of 4-hour (adjusted odds ratio [aOR]: 0.81 [0.68-0.97]), 24-hour, and 30-day mortality compared to component-only. Higher WB:TTV ratios were significantly associated with lower 4-hour, 24-hour, and 30-day mortality, with a 13% decrease in odds of 4-hour mortality for each 10% increase in the WB:TTV ratio (0.87 [95%CI:0.80 - 0.94]). Balanced blood component transfusion was associated with significantly lower odds of 4-hour (aOR: 0.45 [95%CI: 0.29 - 0.68]), 24-hour, and 30-day mortality in the setting of combined WB and blood component resuscitation. CONCLUSIONS: WB resuscitation, higher WB:TTV ratios, and balanced blood component transfusion in conjunction with WB were associated with lower mortality in trauma patients presenting in shock requiring 4 units of RBC and/or WB transfusion within 4 hours of arrival.

Sex dimorphisms in coagulation: Implications in trauma-induced coagulopathy and trauma resuscitation.

Trauma-induced coagulopathy (TIC) is one of the leading causes of preventable death in injured patients. Consequently, it is imperative to understand the mechanisms underlying TIC and how to mitigate this mortality. An opportunity for advancement stems from the awareness that coagulation demonstrates a strong sex-dependent effect. Females exhibit a relative hypercoagulability compared to males, which persists after injury and confers improved outcomes. The mechanisms underlying sex dimorphisms in coagulation and its protective effect after injury have yet to be elucidated. This review explores sex dimorphisms in enzymatic hemostasis, fibrinogen, platelets, and fibrinolysis, with implications for resuscitation of patients with TIC.

Four-factor prothrombin complex concentrate is not inferior to andexanet alfa for the reversal or oral factor Xa inhibitors: An Eastern Association for the Surgery of Trauma multicenter study.

BACKGROUND: Andexanet alfa (AA) is the only FDA-approved reversal agent for apixaban and rivaroxaban (DOAC). There are no studies comparing its efficacy with four-factor prothrombin complex concentrate (PCC). This study aimed to compare PCC to AA for DOAC reversal, hypothesizing noninferiority of PCC. METHODS: We performed a retrospective, noninferiority multicenter study of adult patients admitted from July 1, 2018, to December 31, 2019, who had taken a DOAC within 12 hours of injury, were transfused red blood cells (RBCs) or had traumatic brain injury, and received AA or PCC. Primary outcome was PRBC unit transfusion. Secondary outcome with intensive care unit length of stay. MICE imputation was used to account for missing data and zero-inflated Poisson regression was used to account for an excess of zero units of RBC transfused. Two units difference in RBC transfusion was selected as noninferior. RESULTS: Results: From 263 patients at 10 centers, 77 (29%) received PCC and 186 (71%) AA. Patients had similar transfusion rates across reversal treatment groups (23.7% AA vs. 19.5% PCC) with median transfusion in both groups of 0 RBC. According to the Poisson component, PCC increases the amount of RBC transfusion by 1.02 times (95% confidence interval, 0.79-1.33) compared with AA after adjusting for other covariates. The average amount of RBC transfusion (nonzero group) is 6.13. Multiplying this number by the estimated rate ratio, PCC is estimated to have an increase RBC transfusion by 0.123 (95% confidence interval, 0.53-2.02) units compared with AA. CONCLUSION: PCC appears noninferior to AA for reversal of DOACs for RBC transfusion in traumatically injured patients. Additional prospective, randomized trials are necessary to compare PCC and AA for the treatment of hemorrhage in injured patients on DOACs. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level III.

Prehospital tranexamic acid is associated with a survival benefit without an increase in complications: Results of two harmonized randomized clinical trials.

INTRODUCTION: Recent randomized clinical trials have demonstrated that prehospital tranexamic acid (TXA) administration following injury is safe and improves survival. However, the effect of prehospital TXA on adverse events, transfusion requirements, and any dose-response relationships require further elucidation. METHODS: A secondary analysis was performed using harmonized data from two large, double-blinded, randomized prehospital TXA trials. Outcomes, including 28-day mortality, pertinent adverse events, and 24-hour red cell transfusion requirements, were compared between TXA and placebo groups. Regression analyses were used to determine the independent associations of TXA after adjusting for study enrollment, injury characteristics, and shock severity across a broad spectrum of injured patients. Dose-response relationships were similarly characterized based upon grams of prehospital TXA administered. RESULTS: A total of 1,744 patients had data available for secondary analysis and were included in the current harmonized secondary analysis. The study cohort had an overall mortality of 11.2% and a median Injury Severity Score of 16 (interquartile range, 5-26). Tranexamic acid was independently associated with a lower risk of 28-day mortality (hazard ratio, 0.72; 95% confidence interval [CI], 0.54-0.96; p = 0.03). Prehospital TXA also demonstrated an independent 22% lower risk of mortality for every gram of prehospital TXA administered (hazard ratio, 0.78; 95% CI, 0.63-0.96; p = 0.02). Multivariable linear regression verified that patients who received TXA were independently associated with lower 24-hour red cell transfusion requirements ( ß= - 0.31; 95% CI, -0.61 to -0.01; p = 0.04) with a dose-response relationship ( ß= - 0.24; 95% CI, -0.45 to -0.02; p = 0.03). There was no independent association of prehospital TXA administration on thromboembolism, seizure, or stroke. CONCLUSION: In this secondary analysis of harmonized data from two large randomized interventional trials, prehospital TXA administration across a broad spectrum of injured patients is safe. Prehospital TXA is associated with a significant 28-day survival benefit and lower red cell transfusion requirements at 24 hours and demonstrates a dose-response relationship. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level III.

Tranexamic acid in trauma: After 3 hours from injury, when is it safe and effective to use again?

Tranexamic acid (TXA) has proven mortality benefit if used early after traumatic injury, likely related to a combination of bleeding reduction and other non-bleeding effects. If TXA is given more than 3 h after traumatic injury, there is a significant and paradoxical increased risk of death due to bleeding. TXA has level 1 evidence for use as a bleeding reduction agent in isolated orthopedic operations, but in polytrauma patients undergoing orthopedic operations, it is not clear if and when TXA is safe or effective once outside the 3-h window of proven trauma efficacy.

Lung Epithelium Releases Growth Differentiation Factor 15 in Response to Pathogen-mediated Injury.

GDF15 (growth differentiation factor 15) is a stress cytokine with several proposed roles, including support of stress erythropoiesis. Higher circulating GDF15 levels are prognostic of mortality during acute respiratory distress syndrome, but the cellular sources and downstream effects of GDF15 during pathogen-mediated lung injury are unclear. We quantified GDF15 in lower respiratory tract biospecimens and plasma from patients with acute respiratory failure. Publicly available data from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were reanalyzed. We used mouse models of hemorrhagic acute lung injury mediated by Pseudomonas aeruginosa exoproducts in wild-type mice and mice genetically deficient for Gdf15 or its putative receptor, Gfral. In critically ill humans, plasma levels of GDF15 correlated with lower respiratory tract levels and were higher in nonsurvivors. SARS-CoV-2 infection induced GDF15 expression in human lung epithelium, and lower respiratory tract GDF15 levels were higher in coronavirus disease (COVID-19) nonsurvivors. In mice, intratracheal P. aeruginosa type II secretion system exoproducts were sufficient to induce airspace and plasma release of GDF15, which was attenuated with epithelial-specific deletion of Gdf15. Mice with global Gdf15 deficiency had decreased airspace hemorrhage, an attenuated cytokine profile, and an altered lung transcriptional profile during injury induced by P. aeruginosa type II secretion system exoproducts, which was not recapitulated in mice deficient for Gfral. Airspace GDF15 reconstitution did not significantly modulate key lung cytokine levels but increased circulating erythrocyte counts. Lung epithelium releases GDF15 during pathogen injury, which is associated with plasma levels in humans and mice and can increase erythrocyte counts in mice, suggesting a novel lung-blood communication pathway.

Mechanism matters: mortality and endothelial cell damage marker differences between blunt and penetrating traumatic injuries across three prehospital clinical trials.

Injury mechanism is an important consideration when conducting clinical trials in trauma. Mechanisms of injury may be associated with differences in mortality risk and immune response to injury, impacting the potential success of the trial. We sought to characterize clinical and endothelial cell damage marker differences across blunt and penetrating injured patients enrolled in three large, prehospital randomized trials which focused on hemorrhagic shock. In this secondary analysis, patients with systolic blood pressure < 70 or systolic blood pressure < 90 and heart rate > 108 were included. In addition, patients with both blunt and penetrating injuries were excluded. The primary outcome was 30-day mortality. Mortality was characterized using Kaplan-Meier and Cox proportional-hazards models. Generalized linear models were used to compare biomarkers. Chi squared tests and Wilcoxon rank-sum were used to compare secondary outcomes. We characterized data of 696 enrolled patients that met all secondary analysis inclusion criteria. Blunt injured patients had significantly greater 24-h (18.6% vs. 10.7%, log rank p = 0.048) and 30-day mortality rates (29.7% vs. 14.0%, log rank p = 0.001) relative to penetrating injured patients with a different time course. After adjusting for confounders, blunt mechanism of injury was independently predictive of mortality at 30-days (HR 1.84, 95% CI 1.06-3.20, p = 0.029), but not 24-h (HR 1.65, 95% CI 0.86-3.18, p = 0.133). Elevated admission levels of endothelial cell damage markers, VEGF, syndecan-1, TM, S100A10, suPAR and HcDNA were associated with blunt mechanism of injury. Although there was no difference in multiple organ failure (MOF) rates across injury mechanism (48.4% vs. 42.98%, p = 0.275), blunt injured patients had higher Denver MOF score (p < 0.01). The significant increase in 30-day mortality and endothelial cell damage markers in blunt injury relative to penetrating injured patients highlights the importance of considering mechanism of injury within the inclusion and exclusion criteria of future clinical trials.