Association of prediabetes with clinical outcomes in patients with chronic coronary syndrome: a post hoc analysis of the ISCHEMIA and ISCHEMIA-CKD trials.

BACKGROUND: There is conflicting evidence whether prediabetes is associated with adverse clinical outcomes in patients with chronic coronary syndrome. We aimed to assess the effect of prediabetes in patients with chronic coronary syndrome on clinical outcomes. METHODS: This is a secondary analysis of data from the ISCHEMIA and ISCHEMIA-CKD trials, including patients with chronic coronary syndrome determined by coronary computed tomography angiography or exercise-stress testing. Participants were assigned to the normoglycemia group (HbA1c < 5.7% [< 39 mmol/mol]), prediabetes group (HbA1c 5.7-6.4% [40-47 mmol/mol]), or diabetes group (HbA1c ≥ 6.5% [≥ 48 mmol/mol]). The primary end point of this study was all-cause mortality. Secondary endpoints included major adverse cardiovascular events and composites thereof. RESULTS: Overall, the primary endpoint all-cause mortality occurred in 330 (8.4%) of 3910 patients over a median follow-up time of 3.1 years (IQR 2.1-4.1). The primary endpoint all-cause mortality occurred in 37 (5.2%) of 716 patients in the normoglycemia group, in 63 (6.9%) of 911 in the prediabetes group, and in 230 (10.1%) of 2283 in the diabetes group. In the covariate-adjusted Cox model analysis, the estimated adjusted HR (aHR) in the prediabetes group as compared with the normoglycemia group was 1.45 (95%CI, 0.95-2.20). The aHR in the diabetes group as compared with the normoglycemia group was 1.84 (95%CI, 1.29-2.65). Prediabetes, compared with normoglycemia, was associated with an increased risk of stroke (aHR, 3.44, 95%CI, 1.15-10.25). Subgroup analyses suggested an increased risk of all-cause death associated with prediabetes in males and patients under 65 years. CONCLUSIONS: In patients with chronic coronary syndrome, diabetes but not prediabetes was associated with significantly increased risk of all-cause death within a median follow-up period of 3.1 years. Trial Registration NCT01471522, BioLINCC ID 13936.

A randomized, double-blind study on the safety and immunogenicity of rTSST-1 variant vaccine: phase 2 results.

Background: Toxic shock syndrome toxin-1 (TSST-1) is a superantigen produced by Staphylococcus aureus that causes the life-threatening toxic shock syndrome. The development of a safe and immunogenic vaccine against TSST-1 remains an unmet medical need. We investigated the safety, tolerability and immunogenicity of a recombinant TSST-1 variant vaccine (rTSST-1v) after 1-3 injections in healthy volunteers. Methods: In this randomised, double-blind, adjuvant-controlled, parallel-group, phase 2 trial, healthy adults aged 18-64 were randomly allocated to undergo 1-3 injections of either 10 or 100 µg rTSST-1v or Al(OH)3. The primary endpoint was safety and tolerability of rTSST-1v in the intention-to-treat population. The per-protocol population was used for the immunogenicity analysis. The trial is registered with EudraCT#: 2015-003714-24; ClinicalTrials.gov#: NCT02814708. Findings: Between April and November 2017,140 subjects were enrolled and 126 completed the trial. rTSST-1v showed a good safety and tolerability profile. A total of 855 systemic adverse events occurred, 280 of which were suspected related adverse events, without dose dependency. Two participants were discontinued early because of allergic reactions. Seroconversion occurred in >81% of subjects within 3 months of the first immunisation which was sustained until 18 months after the third immunisation in over 70% of subjects in the pooled low-dose group and in over 85% in the pooled high-dose group. Interpretation: rTSST-1v in cumulative doses of up to 300 µg was safe, well-tolerated and highly immunogenic. Two immunisations with 100 µg rTSST-1v provided the most persistent immune response and may be evaluated in future trials. Funding: Biomedizinische Forschung & Bio-Produkte AG funded this study.

Community-acquired and hospital-acquired bacterial co-infections in patients hospitalized with Covid-19 or influenza: a retrospective cohort study.

BACKGROUND: Bacterial co-infections are believed to be less frequent in patients with Covid-19 than influenza, but frequencies varied between studies. METHODS: This single-center retrospective, propensity score-matched analysis included adult patients with Covid-19 or influenza admitted to normal-care wards between 02/2014 and 12/2021. Covid-19 cases were propensity score matched to influenza cases at a 2:1 ratio. Community-acquired and hospital-acquired bacterial co-infections were defined as positive blood or respiratory cultures ≤ 48 h or > 48 h after hospital admission, respectively. The primary outcome was comparison of community-acquired and hospital-acquired bacterial infections between patients with Covid-19 and influenza in the propensity score-matched cohort. Secondary outcomes included frequency of early and late microbiological testing. RESULTS: A total of 1337 patients were included in the overall analysis, of which 360 patients with Covid-19 were matched to 180 patients with influenza. Early (≤ 48 h) microbiological sampling was performed in 138 (38.3%) patients with Covid-19 and 75 (41.7%) patients with influenza. Community-acquired bacterial co-infections were found in 14 (3.9%) of 360 patients with Covid-19 and 7 (3.9%) of 180 patients with influenza (OR 1.0, 95% CI 0.3-2.7). Late (> 48 h) microbiological sampling was performed in 129 (35.8%) patients with Covid-19 and 74 (41.1%) patients with influenza. Hospital-acquired bacterial co-infections were found in 40 (11.1%) of 360 patients with Covid-19 and 20 (11.1%) of 180 patients with influenza (OR 1.0, 95% CI 0.5-1.8). CONCLUSION: The rate of community-acquired and hospital-acquired bacterial co-infections was similar in hospitalized Covid-19 and influenza patients. These findings contrast previous literature reporting that bacterial co-infections are less common in Covid-19 than influenza.

Prehospital emergency medicine research by additional teams on scene - Concepts and lessons learned.

While the initial minutes of acute emergencies significantly influence clinical outcomes, prehospital research often receives inadequate attention due to several challenges. Retrospective chart reviews carry the risk of incomplete and inaccurate data. Furthermore, prehospital intervention trials frequently encounter difficulties related to extensive training requirements, even during the planning phase. Consequently, we have implemented prospective research concepts involving additional paramedics and physicians directly at the scene during major emergency calls. Three concepts were used: (I) Paramedic field supervisor units, (II) a paramedic + physician field supervisor unit, (III) a special physician-based research car. This paper provides insights into our historical perspective, the current situation, and the lessons learned while overcoming certain barriers and using existing and novel facilitators. Our objective is to support other research groups with our experiences in their planning of upcoming prehospital trials.

Disseminated Intravascular Coagulation in Anaphylaxis.

Anaphylaxis is a life-threatening condition that involves severe cutaneous, respiratory, and cardiovascular symptoms. Disseminated intravascular coagulation (DIC) is an acquired, widespread activation of coagulation that can be caused by infectious conditions (e.g., sepsis) and noninfectious conditions. The onset of DIC following anaphylaxis is not commonly known, and information regarding the pathomechanism linking anaphylaxis to DIC is scarce. Further, demographic and clinical data in anaphylaxis-induced DIC are still missing to this day. Triggered by a case of anaphylaxis-induced DIC that seamlessly transitioned to lethal sepsis-induced DIC, we aimed to characterize the patient population affected by anaphylaxis-induced DIC by performing a review of existing literature and expand the discussion to underlying mechanisms. The overall mortality of the patient cohort (n = 30) identified by the literature review was 50%. All patients that died either suffered a bleeding event or a thrombotic event. The majority of patients (n = 25/30; 83%) had bleeding events; thrombotic events were only reported in nonsurvivors (n = 9/15 or 60% of nonsurvivors; vs. n = 0/15 in survivors; p < 0.001). Nonsurvivors of anaphylaxis-induced DIC were on average 25 years older than survivors (p = 0.068). In conclusion, DIC can complicate anaphylaxis and is expected to contribute to poor microvascular perfusion after anaphylaxis. Particularly, elderly patients with known cardiovascular disease and patients who develop thrombotic events are susceptible to lethal outcomes. As a rare and largely uncharacterized disease entity, further research is needed to investigate the link between DIC and anaphylaxis and to potentially identify better treatment strategies.

Efficacy and Safety of Corticosteroid Therapy for Community-Acquired Pneumonia: A Meta-Analysis and Meta-Regression of Randomized, Controlled Trials.

BACKGROUND: Community-acquired pneumonia (CAP) is associated with high morbidity and mortality. In the present study, we aimed to assess the effect of corticosteroids on all-cause mortality in patients hospitalized with CAP. METHODS: For this meta-analysis and meta-regression, we conducted a systematic search of trials that evaluated the effect of corticosteroid therapy in patients hospitalized with CAP through March 2023. We included randomized, controlled trials, comparing adjunctive corticosteroid therapy with the standard of care alone for treatment of patients hospitalized with CAP and reporting all-cause mortality. We excluded retrospective analyses, observational data, and trial protocols. The primary outcome was all-cause mortality within 30 days after hospital admission. The safety analysis included the frequency of adverse events and steroid-associated adverse events. RESULTS: The literature search identified 35 713 citations, of which 15 studies and 3367 patients were eligible for the final analysis. The all-cause mortality at 30 days was significantly lower in the corticosteroid group (104 of 1690, 6.15%) than in the control group (152 of 1677, 9.06%; risk ratio [RR], 0.67; 95% confidence interval [CI], .53 to .85; P = .001; I2 = 0%). In 9 studies (2549 patients) that reported the occurrence of adverse events, corticosteroid therapy was not associated with an increased risk of developing any adverse event compared with standard care (RR, 0.90; 95% CI, .65 to 1.24; P = .5; I2 = 88%). CONCLUSIONS: Adjunctive systemic corticosteroid therapy in patients hospitalized with CAP was associated with a reduction in all-cause mortality by day 30. The benefits were more pronounced in patients with severe pneumonia.

Monoclonal antibodies for treatment of cold agglutinin disease.

INTRODUCTION: Cold agglutinin disease (CAD) is a difficult-to-treat autoimmune hemolytic anemia and B cell lymphoproliferative disorder associated with fatigue, acrocyanosis, and a risk of thromboembolic events. Cold-induced binding of autoantibody agglutinates red blood cells and triggers the classical complement pathway, leading to predominantly extravascular hemolysis. AREAS COVERED: This review summarizes clinical and experimental antibody-based treatments for CAD and analyzes the risks and benefits of B cell and complement directed therapies, and discusses potential future treatments for CAD. EXPERT OPINION: Conventional treatment of CAD includes a B cell targeted treatment approach with rituximab, yielding only limited treatment success. The addition of a cytotoxic agent (e.g. bendamustine) increases efficacy, but this is accompanied by an increased risk of neutropenia and infection. Novel complement directed therapies have emerged and were shown to have good efficacy against hemolysis and safety profiles but are expensive and unable to address circulatory symptoms. Complement inhibition with sutimlimab may be used as a bridging strategy until B cell directed therapy with rituximab takes effect or continued indefinitely if needed. Future antibody-based treatment approaches for CAD involve the further development of complement directed antibodies, a combination of rituximab and bortezomib, and daratumumab. Non-antibody based prospective treatments may include the use of Bruton tyrosine kinase inhibitors.

Endovascular thrombectomy with or without intravenous thrombolysis in large-vessel ischemic stroke: A non-inferiority meta-analysis of 6 randomised controlled trials.

BACKGROUND: It is unclear whether thrombectomy alone is non-inferior to thrombectomy with intravenous thrombolysis in patients with acute ischemic stroke due to large-vessel occlusion. PURPOSE: To perform a comprehensive, trial-level data, non-inferiority meta-analysis of randomised controlled trials comparing endovascular thrombectomy with and without intravenous thrombolysis in patients with ischemic stroke due to large-vessel occlusion of anterior circulation. METHODS: The prespecified primary efficacy outcome was functional independence, defined as a modified Rankin scale (mRS)score of 0 to 2 at 90 days. The two prespecified non-inferiority margins were risk differences of -10% and - 5%. The study was registered in PROSPERO (CRD42022361110) and conducted according to PRISMA guidelines. RESULTS: Six trials were included in this analysis (DIRECT-MT, DEVT, SKIP, MR CLEAN-NO IV, DIRECT-SAFE and SWIFT DIRECT) comprising a total of 2334 patients. Functional independence at 90 days was achieved by 570 (49·0%) of 1164 patients in the thrombectomy alone group and 595 (50·9%) of 1170 patients in the thrombectomy with thrombolysis group (pooled risk difference - 0·02, [95% CI -0·06-0·02]). Combined thrombectomy and thrombolysis were associated with significantly higher rates of successful reperfusion (pooled risk ratio 0·96 [95% CI, 0·93-0·99], p = 0·006) but at the expense of a significantly increased risk of overall - but not symptomatic - intracranial haemorrhage (pooled risk ratio 0·87 [95% CI, 0·77-0·98], p = 0·02). CONCLUSIONS: Compared with a combined treatment approach, thrombectomy alone was non-inferior at -10% non-inferiority margin, but not at a - 5% inferiority margin for functional independence. Current evidence cannot exclude clinically important differences between the two treatment approaches.

Management of acquired haemophilia A in severe Covid-19: Haemostatic bridging with emicizumab to keep the balance between bleeding and thrombosis.

Acquired haemophilia A (AHA) is an autoimmune bleeding disorder caused by autoantibodies blocking coagulation factor VIII (FVIII). Haemostatic management of AHA and concomitant thrombotic risk is difficult. We cover the management of a 75-year-old male with severe Covid-19, a prothrombotic disease, and de novo AHA with severe muscle bleeding, a disease requiring highly thrombogenic haemostatic therapy and immunosuppression-a challenging combination. FVIII activity was measured using human and bovine reagents to differentiate between endo- and exogenous FVIII activity. For haemostatic control, recombinant human activated FVII was given, followed by emicizumab, as a less thrombogenic long-term haemostatic agent. Steroids were used as initial immunosuppressive therapy. Later, rituximab was used for inhibitor eradication. No thromboembolic events occurred, and bleeding was effectively controlled. Emicizumab achieved haemostatic balance in a patient under haemorrhagic and thrombogenic conditions. Individual risk assessment is needed to guide treatment decisions in patients threatened by simultaneous bleeding and thrombosis.

The von Willebrand factor-binding aptamer rondaptivon pegol as a treatment for severe and nonsevere hemophilia A.

Factor VIII (FVIII) circulates in a noncovalent complex with von Willebrand Factor (VWF), the latter determining FVIII half-life. The VWF-binding aptamer rondaptivon pegol (BT200) increases plasma levels of VWF/FVIII in healthy volunteers. This trial assessed its safety, pharmacokinetics, and pharmacodynamics in hemophilia A. Nineteen adult patients (ages 20-62 years, 4 women) with hemophilia A (8 mild, 2 moderate, and 9 severe) received subcutaneous injections of rondaptivon pegol. After an initial fixed dose of 3 mg on days 0 and 4, patients received weekly doses of 2 to 9 mg until day 28. Severe hemophilia A patients underwent sparse-sampling population pharmacokinetics individual profiling after the final dose of rondaptivon pegol. Adverse events, pharmacokinetics, and pharmacodynamics were assessed. FVIII activity and VWF levels were measured. All patients tolerated rondaptivon pegol well. The geometric mean half-life of rondaptivon pegol was 5.4 days and rondaptivon pegol significantly increased VWF levels. In severe hemophilia A, 6 doses of rondaptivon pegol increased the half-lives of 5 different FVIII products from a median of 10.4 hours to 31.1 hours (range, 20.8-56.0 hours). Median FVIII increased from 22% to 48% in mild hemophilia A and from 3% to 7.5% in moderate hemophilia A. Rondaptivon pegol is a first-in-class prohemostatic molecule that extended the half-life of substituted FVIII approximately 3-fold and increased endogenous FVIII levels approximately 2-fold in hemophilia patients. This trial was registered at www.clinicaltrials.gov as #NCT04677803.

Clinical pharmacology of antiplatelet drugs.

INTRODUCTION: Platelets play a key role in arterial thrombosis and antiplatelet therapy is pivotal in the treatment of cardiovascular disease. Current antiplatelet drugs target different pathways of platelet activation and show specific pharmacodynamic and pharmacokinetic characteristics, implicating clinically relevant drug-drug interactions. AREAS COVERED: This article reviews the role of platelets in hemostasis and cardiovascular thrombosis, and discusses the key pharmacodynamics, drug-drug interactions and reversal strategies of clinically used antiplatelet drugs. EXPERT OPINION: Antiplatelet therapies target distinct pathways of platelet activation: thromboxane A2 synthesis, adenosine diphosphate-mediated signaling, integrin αIIbß3 (GPIIb/IIIa), thrombin-mediated platelet activation via the PAR1 receptor and phosphodiesterases. Key clinical drug-drug interactions of antiplatelet agents involve acetylsalicylic acid - ibuprofen, clopidogrel - omeprazole, and morphine - oral P2Y12 inhibitors, all of which lead to an attenuated antiplatelet effect. Platelet function and genetic testing and the use of scores (ARC-HBR, PRECISE-DAPT, ESC ischemic risk definition) may contribute to a more tailored antiplatelet therapy. High on-treatment platelet reactivity presents a key problem in the acute management of ST-elevation myocardial infarction (STEMI). A treatment strategy involving early initiation of an intravenous antiplatelet agent may be able to bridge the gap of insufficient platelet inhibition in high ischemic risk patients with STEMI.

Multi-phasic life-threatening anaphylaxis refractory to epinephrine managed by extracorporeal membrane oxygenation (ECMO): A case report.

We present a case of a 52-year-old patient suffering from multi-phasic life-threatening anaphylaxis refractory to epinephrine treatment. Extracorporeal membrane oxygenation (ECMO) therapy was initiated as the ultima ratio to stabilize the patient hemodynamically during episodic severe bronchospasm. ECMO treatment was successfully weaned after 4 days. Mastocytosis was diagnosed as the underlying condition. Although epinephrine is recommended as a first-line treatment for anaphylaxis, this impressive case provides clear evidence of its limited therapeutic success and emphasizes the need for causal therapies.

Association Between the Expression of MicroRNA-125b and Survival in Patients With Acute Coronary Syndrome and Coronary Multivessel Disease.

Background: MicroRNAs (miRNA, miR) have an undeniable physiological and pathophysiological significance and act as promising novel biomarkers. The aim of the study was to investigate blood-derived miRNAs and their association with long-term all-cause mortality in patients with multivessel disease (MVD) suffering from acute coronary syndrome (ACS). Materials and Methods: This study was an observational prospective study, which included 90 patients with MVD and ACS. Expression of miR-125a, miR-125b, and miR-223 was analysed by polymerase chain reaction (PCR). Patients were followed-up for a median of 7.5 years. All-cause mortality was considered as the primary endpoint. Adjusted Cox-regression analysis was performed for prediction of events. Results: Elevated expression of miR-125b (>4.6) at the time-point of ACS was associated with increased long-term all-cause mortality (adjusted [adj.] hazard ratio [HR] = 11.26, 95% confidence interval [95% CI]: 1.15-110.38; p = 0.038). The receiver operating characteristic (ROC) analysis showed a satisfactory c-statistics for miR-125b for the prediction of long-term all-cause mortality (area under the curve [AUC] = 0.76, 95% CI: 0.61-0.91; p = 0.034; the negative predictive value of 98%). Kaplan-Meier time to event analysis confirmed an early separation of the survival curves between patients with high vs low expression of miR-125b (p = 0.003). An increased expression of miR-125a and miR-223 was found in patients with non-ST-segment elevation ACS (NSTE-ACS) as compared to those with ST-segment elevation myocardial infarction (STEMI) (p = 0.043 and p = 0.049, respectively) with no difference in the expression of miR-125b between the type of ACS. Conclusion: In this hypothesis generating study, lower values of miR-125b were related to improved long-term survival in patients with ACS and MVD. Larger studies are needed to investigate whether miR-125b can be used as a suitable predictor for long-term all-cause mortality.

The VWF binding aptamer rondoraptivon pegol increases platelet counts and VWF/FVIII in type 2B von Willebrand disease.

Type 2B von Willebrand disease (VWD) is characterized by an increased binding affinity of von Willebrand factor (VWF) to platelet glycoprotein Ib. This can lead to clearance of high-molecular-weight (HMW) multimers and thrombocytopenia with a resulting moderate-severe bleeding phenotype. Rondoraptivon pegol (BT200) is a pegylated aptamer binding to the A1 domain of VWF with a novel mechanism of action: it enhances VWF/factor VIII (FVIII) levels by decreasing their clearance. To study the potential benefit of rondoraptivon pegol in patients with type 2B VWD, we conducted a prospective phase 2 trial. Patients with type 2B VWD received 3 mg rondoraptivon pegol subcutaneously on study days 1, 4, and 7, followed by 6 to 9 mg every week until day 28. Five patients (male:female ratio = 3:2) were included. Rondoraptivon pegol rapidly tripled platelet counts from a median of 60 to 179 × 10E9/L (P < .001). Circulating VWF antigen increased from a median of 64% to 143%, which doubled FVIII activity levels from 67% to 134%. In all thrombocytopenic patients, plasma levels of VWF:GPIbM normalized, VWF ristocetin cofactor and VWF collagen-binding activity increased, and HMW multimers appeared. These pronounced improvements reversed during washout of the drug, thus demonstrating causality. The A1 domain binding aptamer directly corrects the underlying defect of type 2B VWD, thus providing a novel potential option for prophylaxis and treatment of patients with this VWD type. These data provide the basis for a phase 2b/3 trial in such patients. This trial was registered at www.clinicaltrials.gov as #NCT04677803.

Advanced pharmacodynamics of cangrelor in healthy volunteers: a dose-finding, open-label, pilot trial.

BACKGROUND: High on-treatment platelet reactivity (HTPR) remains a major problem in the acute management of ST-elevation myocardial infarction (STEMI), leading to higher rates of stent thrombosis and mortality. We aimed to investigate a novel, prehospital treatment strategy using cangrelor and tested its pharmacodynamic effects in a model using healthy volunteers. METHODS: We conducted a dose-finding, open-label, pilot trial including 12 healthy volunteers and tested three ascending bolus infusions of cangrelor (5 mg, 10 mg and 20 mg) and a bolus infusion followed by a continuous infusion via an intravenous (IV) flow regulator. Platelet function was assessed using multiple electrode aggregometry (MEA), vasodilator-stimulated phosphoprotein phosphorylation assay (VASP-P) and the platelet function analyzer. In an ex vivo experiment, epinephrine was used to counteract the antiplatelet effect of cangrelor. RESULTS: All cangrelor bolus infusions resulted in immediate and pronounced platelet inhibition. Bolus infusions of cangrelor 20 mg resulted in sufficient platelet inhibition assessed by MEA for 20 min in 90% of subjects. Infusion of cangrelor via the IV flow regulator resulted in sufficient platelet inhibition throughout the course of administration. Ex vivo epinephrine, in concentrations of 200 and 500 ng/mL was able to partially reverse the antiplatelet effect of cangrelor in a dose-dependent manner. CONCLUSIONS: Weight-adapted bolus infusions followed by a continuous infusion of cangrelor via IV flow regulator result in immediate and pronounced platelet inhibition in healthy subjects. Cangrelor given as weight-adapted bolus infusion followed by a continuous infusion using an IV flow regulator may be a viable treatment approach for effective and well controllable prehospital platelet inhibition. TRIAL REGISTRATION: EC (Medical University of Vienna) 1835/2019 and EudraCT 2019-002792-34 .

Convalescent Plasma Treatment in Patients with Covid-19: A Systematic Review and Meta-Analysis.

Convalescent plasma is a suggested treatment for Coronavirus disease 2019 (Covid-19), but its efficacy is uncertain. We aimed to evaluate whether the use of convalescent plasma is associated with improved clinical outcomes in patients with Covid-19.In this systematic review and meta-analysis, we searched randomized controlled trials investigating the use of convalescent plasma in patients with Covid-19 in Medline, Embase, Web of Science, Cochrane Library, and medRxiv from inception to October 17th, 2021. Two reviewers independently extracted the data. The primary efficacy outcome was all-cause mortality. The Cochrane Risk of Bias Tool and GRADE (Grading of Recommendations Assessment, Development and Evaluation) method were used. This study was registered with PROSPERO, CRD42021284861. Of the 8874 studies identified in the initial search, sixteen trials comprising 16 317 patients with Covid-19 were included. In the overall population, the all-cause mortality was 23.8% (2025 of 8524) with convalescent plasma and 24.4% (1903 of 7769) with standard of care (risk ratio (RR) 0.97, 95% CI 0.90-1.04) (high-certainty evidence). All-cause mortality did not differ in the subgroups of noncritically ill (21.7% [1288 of 5929] vs. 22.4% [1320 of 5882]) and critically ill (36.9% [518 of 1404] vs. 36.4% [455 of 1247]) patients with Covid-19. The use of convalescent plasma in patients who tested negative for anti-SARS-CoV-2 antibodies at baseline was not associated with significantly improved survival (RR 0.94, 95% CI 0.87-1.02). In the overall study population, initiation of mechanical ventilation (RR 0.97, 95% CI 0.88-1.07), time to clinical improvement (HR 1.09, 95% CI 0.91-1.30), and time to discharge (HR 0.95, 95% CI 0.89-1.02) were similar between the two groups. In patients with Covid-19, treatment with convalescent plasma, as compared with control, was not associated with lower all-cause mortality or improved disease progression, irrespective of disease severity and baseline antibody status. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier PROSPERO (CRD42021284861).

Anticoagulant Treatment Regimens in Patients With Covid-19: A Meta-Analysis.

Coronavirus disease 2019 (COVID-19) is associated with a hypercoagulable state. It has been hypothesized that higher-dose anticoagulation, including therapeutic-dose and intermediate-dose anticoagulation, is superior to prophylactic-dose anticoagulation in the treatment of COVID-19. This meta-analysis evaluated the efficacy and safety of higher-dose anticoagulation compared with prophylactic-dose anticoagulation in patients with COVID-19. Ten randomized controlled open-label trials with a total of 5,753 patients were included. The risk of death and net adverse clinical events (including death, thromboembolic events, and major bleeding) were similar between higher-dose and prophylactic-dose anticoagulation (risk ratio (RR) 0.96, 95% CI, 0.79-1.16, P = 0.66 and RR 0.87, 95% CI, 0.73-1.03, P = 0.11, respectively). Higher-dose anticoagulation, compared with prophylactic-dose anticoagulation, decreased the risk of thromboembolic events (RR 0.63, 95% CI, 0.47-0.84, P = 0.002) but increased the risk of major bleeding (RR 1.76, 95% CI, 1.19-2.62, P = 0.005). The risk of death showed no statistically significant difference between higher-dose anticoagulation and prophylactic-dose anticoagulation in noncritically ill patients (RR 0.87, 95% CI, 0.50-1.52, P = 0.62) and in critically ill patients with COVID-19 (RR 1.04, 95% CI, 0.93-1.17, P = 0.5). The risk of death was similar between therapeutic-dose vs. prophylactic-dose anticoagulation (RR 0.92, 95% CI 0.69-1.21, P = 0.54) and between intermediate-dose vs. prophylactic-dose anticoagulation (RR 1.01, 95% CI 0.63-1.61, P = 0.98). In patients with markedly increased d-dimer levels, higher-dose anticoagulation was also not associated with a decreased risk of death as compared with prophylactic-dose anticoagulation (RR 0.86, 95% CI, 0.64-1.16, P = 0.34). Without any clear evidence of survival benefit, these findings do not support the routine use of therapeutic-dose or intermediate-dose anticoagulation in critically or noncritically ill patients with COVID-19.

The von Willebrand factor A-1 domain binding aptamer BT200 elevates plasma levels of von Willebrand factor and factor VIII: a first-in-human trial.

Von Willebrand factor (VWF) and factor VIII (FVIII) circulate in a noncovalent complex in blood and promote primary hemostasis and clotting, respectively. A new VWF A1-domain binding aptamer, BT200, demonstrated good subcutaneous bioavailability and a long half-life in non-human primates. This first-in-human, randomized, placebo-controlled, doubleblind trial tested the hypothesis that BT200 is well tolerated and has favorable pharmacokinetic and pharmacodynamic effects in 112 volunteers. Participants received one of the following: a single ascending dose of BT200 (0.18-48 mg) subcutaneously, an intravenous dose, BT200 with concomitant desmopressin or multiple doses. Pharmacokinetics were characterized, and the pharmacodynamic effects were measured by VWF levels, FVIII clotting activity, ristocetin-induced aggregation, platelet function under high shear rates, and thrombin generation. The mean half-lives ranged from 7-12 days and subcutaneous bioavailability increased dose-dependently exceeding 55% for doses of 6-48 mg. By blocking free A1 domains, BT200 dose-dependently decreased ristocetin-induced aggregation, and prolonged collagen-adenosine diphosphate and shear-induced platelet plug formation times. However, BT200 also increased VWF antigen and FVIII levels 4-fold (P<0.001), without increasing VWF propeptide levels, indicating decreased VWF/FVIII clearance. This, in turn, increased thrombin generation and accelerated clotting. Desmopressin-induced VWF/FVIII release had additive effects on a background of BT200. Tolerability and safety were generally good, but exaggerated pharmacology was seen at saturating doses. This trial identified a novel mechanism of action for BT200: BT200 dose-dependently increases VWF/FVIII by prolonging half-life at doses well below those which inhibit VWF-mediated platelet function. This novel property can be exploited therapeutically to enhance hemostasis in congenital bleeding disorders.