Effect of Antiplatelet Therapy on Survival and Organ Support-Free Days in Critically Ill Patients With COVID-19: A Randomized Clinical Trial

Drug treatments for mild or moderate covid-19: systematic review and network meta-analysis

OBJECTIVE

To compare the effects of treatments for mild or moderate (that is, non-severe) coronavirus disease 2019 (covid-19).

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

Covid-19 Living Overview of Evidence Repository (covid-19 L-OVE) by the Epistemonikos Foundation, a public, living repository of covid-19 articles, from 1 January 2023 to 19 May 2024. The search also included the WHO covid-19 database (up to 17 February 2023) and six Chinese databases (up to 20 February 2021). The analysis included studies identified between 1 December 2019 and 28 June 2023.

STUDY SELECTION

Randomised clinical trials in which people with suspected, probable, or confirmed mild or moderate covid-19 were allocated to drug treatment or to standard care or placebo. Pairs of reviewers independently screened potentially eligible articles.

METHODS

After duplicate data abstraction, a bayesian network meta-analysis was conducted. Risk of bias was assessed by use of a modification of the Cochrane risk of bias 2.0 tool, and the certainty of the evidence using the grading of recommendations assessment, development, and evaluation (GRADE) approach. For each outcome, following GRADE guidance, drug treatments were classified in groups from the most to the least beneficial or harmful.

RESULTS

Of 259 trials enrolling 166 230 patients, 187 (72%) were included in the analysis. Compared with standard care, two drugs probably reduce hospital admission: nirmatrelvir-ritonavir (25 fewer per 1000 (95% confidence interval 28 fewer to 20 fewer), moderate certainty) and remdesivir (21 fewer per 1000 (28 fewer to 7 fewer), moderate certainty). Molnupiravir and systemic corticosteroids may reduce hospital admission (low certainty). Compared with standard care, azithromycin probably reduces time to symptom resolution (mean difference 4 days fewer (5 fewer to 3 fewer), moderate certainty) and systemic corticosteroids, favipiravir, molnupiravir, and umifenovir probably also reduce duration of symptoms (moderate to high certainty). Compared with standard care, only lopinavir-ritonavir increased adverse effects leading to discontinuation.

CONCLUSION

Nirmatrelvir-ritonavir and remdesivir probably reduce admission to hospital, and systemic corticosteroids and molnupiravir may reduce admission to hospital. Several medications including systemic corticosteroids and molnupiravir probably reduce time to symptom resolution.

SYSTEMATIC REVIEW REGISTRATION

This review was not registered. The protocol is publicly available in the supplementary material.

The Impact of Medication Regimen Complexity Score on Multi-Organ Dysfunction and Clinical Outcomes in Critically Ill Patients: A Cohort Study

BACKGROUND

Evidence is limited on the utilization of the Medication Regimen Complexity - Intensive Care Unit (MRC-ICU) scores for predicting clinical outcomes in critically ill patients. Therefore, this study aims to examine the impact of the MRC-ICU score on clinical outcomes for critically ill patients.

RESEARCH DESIGN AND METHODS

A single-center retrospective cohort study included adult ICU patients admitted for >72 hours between January and December 2021. Patients were categorized into two groups based on MRC-ICU scores assessed within 24 hours of ICU admission. The primary endpoint was the Multiorgan Dysfunction (MOD) score at 72 hours of ICU admission. Other clinical outcomes were considered secondary.

RESULTS

Of the 1406 patients included, 718 had an MRC-ICU score of nine or higher. Patients with MRC-ICU scores ≥9 had significantly higher MOD scores at 72 hours (median 5 vs 3, p < 0.001), longer hospital LOS, and higher mortality rates in crude analyses. Regression analysis showed a significant association between MRC-ICU score and MOD score at day 3 of ICU admission (coefficient: 0.49, 95% CI 0.07 to 0.92, p = 0.02). However, no significant differences were observed with ICU-LOS, vasopressor-free days, or mortality.

CONCLUSIONS

Higher MRC-ICU scores might be linked to worse clinical outcomes, including greater organ dysfunction, and longer hospital stay.

Effect of hydrocortisone on mortality in patients with severe community-acquired pneumonia : The REMAP-CAP Corticosteroid Domain Randomized Clinical Trial

PURPOSE

To determine whether hydrocortisone improves mortality in severe community-acquired pneumonia (CAP).

METHODS

In an international adaptive randomized controlled platform trial testing multiple interventions, adults admitted to the intensive care unit (ICU) with severe CAP were randomized to a 7-day course of intravenous hydrocortisone (50 mg every 6 h) or control (no corticosteroid). The primary end point was 90-day all-cause mortality, analyzed iteratively by a Bayesian hierarchical model estimating distinct treatment effects for patients presenting with influenza (Y/N) and shock (Y/N).

RESULTS

Fixed 7-day course hydrocortisone enrollment was stopped for futility (< 5% probability of > 20% relative improvement). Of 658 patients enrolled, 536 were randomized to hydrocortisone and 122 to control. Vital status at day 90 was missing for 15 patients. Day 90 mortality was 15% (78/521) and 9.8% (12/122) for the hydrocortisone and control groups. The adjusted odds ratio ranged from 1.52 to 1.63 (with all 95% CrI crossing 1), while the probability of > 20% relative reduction of day 90 mortality ranged from 7.1 to 3.3% across influenza and shock strata. Results were consistent in sensitivity and pre-specified secondary outcomes. In exploratory analyses, the duration of shock appeared lower in the hydrocortisone group compared with control (median (IQR) of 2 (2-5) days compared to control 3 (2-6.75) days, p value = 0.05).

CONCLUSIONS

Among patients with severe CAP, treatment with a 7-day course of hydrocortisone, compared with no hydrocortisone, appears unlikely to yield a large reduction in mortality. Smaller benefits and possible harm are not excluded.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02735707 (registration date: November 4th, 2016).

Pediatric Randomized Clinical Trials in Community Hospitals: Strategies to Enhance Site Participation and Engagement

OBJECTIVE

Community hospitals provide the majority of inpatient pediatric care in the United States but face significant barriers to conducting research. More equitable research participation across the spectrum of hospital types that deliver inpatient pediatric care can improve pediatric care quality and generalizability of research findings. Thus, we sought to identify strategies to promote community hospital participation in pediatric randomized clinical trials (RCTs).

METHODS

We convened an interdisciplinary group of 33 panelists with expertise across clinical roles (eg, physicians, nurses), nonclinical partners (eg, parents, clinical trialists), and practice environments (eg, children's and community hospitals). We conducted 2 rounds of consensus building using the nominal group technique. Panelists brainstormed, discussed, and scored strategies in each round. Round 1 was conducted within small groups to broadly identify potential strategies. Round 2 was conducted as a large group to refine and rescore top strategies. We performed descriptive analyses of scores and qualitative content analysis of identified strategies (including member checking).

RESULTS

Panelists identified 119 ideas in round 1. The 20 highest scoring ideas from round 1 were presented in round 2, where 19 strategies were scored then refined into 14 specific strategies. We identified 3 overarching domains: (1) policy changes in funding prioritization and scientific review guidelines, (2) systems for providing centralized resources, and (3) research design and planning tailored to community hospital participation.

CONCLUSION

We identified 14 strategies for supporting the conduct of pediatric RCTs in community hospitals. Implementing these strategies will require structural changes to RCT design and recruitment for hospitals, funders, and investigators.

Acetylsalicylic Acid Treatment in Patients With Sepsis and Septic Shock: A Phase 2, Placebo-Controlled, Randomized Clinical Trial

OBJECTIVES

Platelets play a critical role in the inflammatory response and coagulation. We aimed to evaluate whether the use of acetylsalicylic acid (ASA) would reduce the intensity of organ dysfunction in septic patients.

DESIGN

Randomized, blinded, parallel-group, placebo-controlled trial.

SETTING

Five general ICUs in Brazil.

PATIENTS

Adults with sepsis for no longer than 48 hours who had at least one severe organ dysfunction (lactate > 4 mmol/L, platelets < 100,000/mm3, Pao2/Fio2 ratio < 200, or septic shock).

INTERVENTIONS

Patients were randomized to receive 200 mg of ASA or placebo for 7 days.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the change in the Sequential Organ Failure Assessment (SOFA) score between day 0 and day 7 or date of discharge/death. Safety outcomes were major bleeding and the number of blood transfusions within 14 days. The planned sample size was 218 with interim safety analyses after enrolling 109 and 163 patients. The study was discontinued due to higher frequency of major bleeding in the ASA group. We included 166 patients (ASA: 82 patients, placebo: 84). In the adjusted analysis, there was no difference in the SOFA change between the groups (mean placebo to ASA group difference, 0.60; 95% CI, -0.55 to 1.75; p = 0.30). There were no differences in any of the secondary outcomes. In the intervention group, there were a higher number of serious adverse events (9 [11%] vs. 1 [1.2%]; p = 0.009) and major bleeding (8 [8.5%] vs. 1 [1.2%]; p = 0.02).

CONCLUSIONS

In this population of septic patients, ASA did not reduce the intensity of organ dysfunction. ASA increased the risk of severe bleeding compared with placebo.

Eligibility Criteria of Randomized Clinical Trials in Critical Care Medicine

Importance

Eligibility criteria for randomized clinical trials (RCTs) are designed to select clinically relevant patient populations. However, not all eligibility criteria are strongly justified, potentially excluding marginalized groups, and limiting the generalizability of trial findings.

Objective

To summarize and evaluate the justification of exclusion criteria in published RCTs in critical care medicine.

Evidence Review

A systematic sampling review of parallel-group RCTs published in the top 5 general internal medicine journals by impact factor (The Lancet, New England Journal of Medicine, Journal of the American Medical Association, British Medical Journal, and Annals of Internal Medicine) between January 1, 2018, and February 23, 2023, was conducted. RCTs enrolling adults in intensive care units (ICUs) and RCTs enrolling critically ill patients who required life-sustaining interventions typically initiated in the ICU were included. All study exclusion criteria were categorized as either poorly justified, potentially justified, or strongly justified, adapting previously established criteria, independently and in duplicate.

Findings

In total, 225 studies were identified, 75 of which were included. The median (IQR) number of exclusion criteria per trial was 19 (14-24), with 1455 total exclusion criteria. Common exclusion criteria were related to the risk of adverse reaction to interventions (302 criteria [20.8%]), followed by inability to obtain consent (120 criteria [8.2%]), and treatment limitation decisions (97 criteria [6.7%]). Most exclusion criteria were either strongly justified (1080 criteria [74.2%]) or potentially justified (297 criteria [20.4%]), whereas 5.4% (78 criteria) were poorly justified. Of the 78 poorly justified exclusion criteria, the most common were pregnancy (19 criteria [24.4%]), communication barriers (11 criteria [14.1%]), lactation (10 criteria [12.8%]), and lack of health insurance (10 criteria [12.8%]). Overall, 45 of 75 studies (60.0%) had at least 1 poorly justified exclusion criteria.

Conclusions and Relevance

Most exclusion criteria in critical care medicine RCTs were strongly justifiable. Across poorly justified criteria, the most common exclusions were pregnant or lactating persons, those with communication barriers, and individuals without health insurance. This highlights the need to carefully consider exclusion criteria when designing trials to minimize the inappropriate exclusion of participants and enhance generalizability.

Incidence of Thrombotic Complications in COVID-19 Patients and the Impact of Antithrombotic Therapy on ICU Mortality

Aim We aimed to determine the incidence of thrombotic complications and outcomes of critically ill COVID-19 patients admitted to the intensive care unit (ICU) and evaluate the association between combined antithrombotic therapy and mortality in ICU patients admitted for COVID-19 pneumonia. Methods We retrospectively collected data of adult critically ill patients with COVID-19 admitted to the ICU in a major hospital in Dubai during the COVID-19 pandemic. The primary outcome was in-hospital mortality. Secondary outcomes included the incidence of major complications, such as thrombotic complications during the ICU stay. The study population was classified into two groups based on the type of prophylactic anticoagulant and antiplatelet therapy received. Results The study included 257 ICU patients admitted with COVID-19 pneumonia. The mean duration of their ICU stay was 24.95 days, ranging from one day to 327 days. The primary outcome was in-hospital mortality. In our study, 151 patients (58.7%) suffered in-hospital mortality. Secondary outcomes included the incidence of major complications during the ICU stay. A total of 202 patients (78.6%) presented with acute respiratory distress syndrome. Ninety-nine (38.5%) of the patients had progressed to acute kidney injury. Thirty-three patients (12.8%) had various thrombotic complications. Three of these (9%) had venous thrombosis, and 30 patients (91%) had arterial thrombosis. Ischemic stroke was the major thrombotic complication of COVID-19 (36.3% of overall thrombotic events, n = 12), followed by myocardial infarction (27.2%; n = 9) and pulmonary embolism (21.2%; n = 7). Out of 257 COVID-19 ICU patients, 73 patients (28.4%) received both anticoagulants and antiplatelet therapy, and 183 patients (70.8%) received only anticoagulant therapy. We compared the mortality of COVID-19 ICU patients who received anticoagulants alone to those with added antiplatelets. The application of combined antiplatelet and anticoagulants as thromboprophylaxis for COVID-19 ICU patients was not associated with a significant reduction in mortality (P = 0.868). Peak serum levels of D-dimer significantly correlate with the length of ICU stay (rho = 0.137, P = 0.031). Peak D-dimer level during the ICU stay was statistically significantly higher in non-survivors (mean = 11.87) compared to survivors (mean = 8.59) (P < 0.001). D-dimer on ICU admission had a good prognostic value for ICU patients with COVID-19 infection (P = 0.018). Conclusion The incidence of thrombotic complications among COVID-19 pneumonia patients admitted to ICU is remarkably high, which reinforces the recommendation to apply thrombosis prophylaxis strictly to all ICU patients admitted with COVID-19. The application of combined antiplatelets with anticoagulants as thromboprophylaxis for COVID-19 ICU patients was not associated with a significant reduction in ICU mortality. D-dimer has a significant correlation with prognosis and length of ICU stay of COVID-19 patients.

The COVID-19 thrombus: distinguishing pathological, mechanistic, and phenotypic features and management

A heightened risk for thrombosis is a hallmark of COVID-19. Expansive clinical experience and medical literature have characterized small (micro) and large (macro) vessel involvement of the venous and arterial circulatory systems. Most events occur in patients with serious or critical illness in the hyperacute (first 1-2 weeks) or acute phases (2-4 weeks) of SARS-CoV-2 infection. However, thrombosis involving the venous, arterial, and microcirculatory systems has been reported in the subacute (4-8 weeks), convalescent (> 8-12 weeks) and chronic phases (> 12 weeks) among patients with mild-to-moderate illness. The purpose of the current focused review is to highlight the distinguishing clinical features, pathological components, and potential mechanisms of venous, arterial, and microvascular thrombosis in patients with COVID-19. The overarching objective is to better understand the proclivity for thrombosis, laying a solid foundation for screening and surveillance modalities, preventive strategies, and optimal patient management.

Prothrombotic state and thrombotic events in COVID-19 pandemic period, including portal vein and splenic artery thromboses

This editorial article is intended to perform a discussion on the manuscript entitled "Simultaneous portal vein thrombosis and splenic vein thrombosis in a COVID-19 patient: A case report and review of literature" written by Abramowitz et al. The article focuses on the diagnostic processes in a 77-year-old-male patient with a simultaneous portal vein and splenic artery thrombosis accompanying coronavirus disease 2019 (COVID-19). The authors postulated that splanchnic thrombosis should be on the list of differential diagnoses in a patient presenting with abdominal pain in presence of a COVID-19 infection. The tendency for venous and arterial thrombosis in COVID-19 patients is encountered, largely attributed to hypercoagulopathy. In general, venous thromboembolism mostly manifest as deep vein thrombosis (DVT), pulmonary embolism (PE) or catheter-related thromboembolic events. Acute PE, DVT, cerebrovascular events and myocardial infarction are seen as the most common thromboembolic complications in COVID-19 patients. COVID-19-associated hemostatic abnormalities include mild thrombocytopenia and increased D-dimer level. Similar to other coagulopathies, the treatment of the underlying condition is the mainstay. Addition of antiplatelet agents can be considered in critically ill patients at low bleeding risk, not on therapeutic anticoagulation, and receiving gastric acid suppression Early administration of antithrombotic drugs will have a beneficial effect in both the prevention and treatment of thrombotic events, especially in non-ambulatory patients. Low molecular weight heparin (LMWH) should be started if there is no contraindication, including in non-critical patients who are at risk of hospitalization LMWH (enoxaparin) is preferred to standard heparin.

Examining Brain Structures and Cognitive Functions in Patients with Recovered COVID-19 Infection: A Multicenter Study Using 7T MRI

Importance

Emerging evidence suggests that severe acute respiratory syndrome, COVID-19, negatively impacts brain health, with clinical magnetic resonance imaging (MRI) showing a wide range of neurologic manifestations but no consistent pattern. Compared with 3 Tesla (3T) MRI, 7 Tesla (7T) MRI can detect more subtle injuries, including hippocampal subfield volume differences and additional standard biomarkers such as white matter lesions. 7T MRI could help with the interpretation of the various persistent post-acute and distal onset sequelae of COVID-19 infection.

Objective

To investigate the differences in white matter hyperintensity (WMH), hippocampal subfields volumes, and cognition between patients hospitalized with COVID-19 and non-hospitalized participants in a multi-site/multi-national cohort.

Design

Original investigation of patients hospitalized with COVID-19 between 5/2020 and 10/2022 in 3 USA and 1 UK medical centers with follow-up at hospital discharge.

Participants

A total of 179 participants without a history of dementia completed cognitive, mood and other assessments and MRI scans.

Exposure

COVID-19 severity, as measured by hospitalization vs no hospitalization.

Main Outcomes and Measures

7T MRI scans were acquired. All WMH and hippocampal subfield volumes were corrected for intracranial volumes to account for subject variability. Cognition was assessed using a comprehensive battery of tests. Pearson correlations and unpaired t-tests were performed to assess correlations and differences between hospitalized and non-hospitalized groups.

Results

We found similar WMH volume (4112 vs 3144mm³, p=0.2131), smaller hippocampal volume (11856 vs 12227mm³, p=0.0497) and lower cognitive and memory performance, especially the MoCA score (24.9 vs 26.4 pts, p=0.0084), duration completing trail making test B (97.6 vs 79.4 seconds, p=0.0285), Craft immediate recall (12.6 vs 16.4 pts, p<0.0001), Craft delay recall (12.0 vs 15.6 pts, p=0.0001), and Benson figure copy (15.2 vs 16.1 pts, p=0.0078) in 52 patients hospitalized for COVID-19 (19[37%] female; mean[SD] age, 61.1[7.4] years) compared with 111 age-matched non-hospitalized participants (66[59%] female; mean[SD] age, 61.5[8.4] years).

Conclusions and Relevance

Our results indicate that hospitalized COVID-19 cases show lower hippocampal volume when compared to non-hospitalized participants. We also show that WMH and hippocampal volumes correlate with worse cognitive scores in hospitalized patients compared with non-hospitalized participants, potentially indicating recent lesions and atrophy.

Key Points

Question: Do white matter hyperintensity burden, hippocampal whole and subfield volumes, and cognition differ between patients hospitalized with COVID-19 versus participants without hospitalization?Findings: We found no significant difference in white matter hyperintensity volume, but hippocampal volume was reduced, and cognitive and memory performance were worse in those hospitalized for COVID-19 compared with age-matched non-hospitalized group (either mild COVID-19 or no COVID-19 reported). In the hospitalized group, increased white matter hyperintensity and reduced hippocampal volumes are significantly higher correlated with worse cognitive and memory scores.Meaning: Adults hospitalized for COVID-19 had lower hippocampal volumes and worse cognitive performance than adults with COVID-19 that did not lead to hospitalization or without reported COVID-19 infection.

COVID-19 Is a Coronary Artery Disease Risk Equivalent and Exhibits a Genetic Interaction With ABO Blood Type

BACKGROUND

COVID-19 is associated with acute risk of major adverse cardiac events (MACE), including myocardial infarction, stroke, and mortality (all-cause). However, the duration and underlying determinants of heightened risk of cardiovascular disease and MACE post-COVID-19 are not known.

METHODS

Data from the UK Biobank was used to identify COVID-19 cases (n=10 005) who were positive for polymerase chain reaction (PCR+)-based tests for SARS-CoV-2 infection (n=8062) or received hospital-based International Classification of Diseases version-10 (ICD-10) codes for COVID-19 (n=1943) between February 1, 2020 and December 31, 2020. Population controls (n=217 730) and propensity score-matched controls (n=38 860) were also drawn from the UK Biobank during the same period. Proportional hazard models were used to evaluate COVID-19 for association with long-term (>1000 days) risk of MACE and as a coronary artery disease risk equivalent. Additional analyses examined whether COVID-19 interacted with genetic determinants to affect the risk of MACE and its components.

RESULTS

The risk of MACE was elevated in COVID-19 cases at all levels of severity (HR, 2.09 [95% CI, 1.94-2.25]; P<0.0005) and to a greater extent in cases hospitalized for COVID-19 (HR, 3.85 [95% CI, 3.51-4.24]; P<0.0005). Hospitalization for COVID-19 represented a coronary artery disease risk equivalent since incident MACE risk among cases without history of cardiovascular disease was even higher than that observed in patients with cardiovascular disease without COVID-19 (HR, 1.21 [95% CI, 1.08-1.37]; P<0.005). A significant genetic interaction was observed between the ABO locus and hospitalization for COVID-19 (Pinteraction=0.01), with risk of thrombotic events being increased in subjects with non-O blood types (HR, 1.65 [95% CI, 1.29-2.09]; P=4.8×10-5) to a greater extent than subjects with blood type O (HR, 0.96 [95% CI, 0.66-1.39]; P=0.82).

CONCLUSIONS

Hospitalization for COVID-19 represents a coronary artery disease risk equivalent, with post-acute myocardial infarction and stroke risk particularly heightened in non-O blood types. These results may have important clinical implications and represent, to our knowledge, one of the first examples of a gene-pathogen exposure interaction for thrombotic events.

Statistical Power and Performance of Strategies to Analyze Composites of Survival and Duration of Ventilation in Clinical Trials

BACKGROUND

Patients with acute hypoxemic respiratory failure are at high risk of death and prolonged time on the ventilator. Interventions often aim to reduce both mortality and time on the ventilator. Many methods have been proposed for analyzing these endpoints as a single composite outcome (days alive and free of ventilation), but it is unclear which analytical method provides the best performance. Thus, we aimed to determine the analysis method with the highest statistical power for use in clinical trials.

METHODS

Using statistical simulation, we compared multiple methods for analyzing days alive and free of ventilation: the t, Wilcoxon rank-sum, and Kryger Jensen and Lange tests, as well as the proportional odds, hurdle-Poisson, and competing risk models. We compared 14 scenarios relating to: 1) varying baseline distributions of mortality and duration of ventilation, which were based on data from a registry of patients with acute hypoxemic respiratory failure and 2) the varying effects of treatment on mortality and duration of ventilation.

RESULTS AND CONCLUSIONS

All methods have good control of type 1 error rates (i.e., avoid false positive findings). When data are simulated using a proportional odds model, the t test and ordinal models have the highest relative power (92% and 90%, respectively), followed by competing risk models. When the data are simulated using survival models, the competing risk models have the highest power (100% and 92%), followed by the t test and a ten-category ordinal model. All models struggled to detect the effect of the intervention when the treatment only affected one of mortality and duration of ventilation. Overall, the best performing analytical strategy depends on the respective effects of treatment on survival and duration of ventilation and the underlying distribution of the outcomes. The evaluated models each provide a different interpretation for the treatment effect, which must be considered alongside the statistical power when selecting analysis models.

von Willebrand factor antigen, von Willebrand factor propeptide and ADAMTS13 activity in TIA or ischaemic stroke patients changing antiplatelet therapy

Data are limited on the impact of commencing antiplatelet therapy on von Willebrand Factor Antigen (VWF:Ag) or von Willebrand Factor propeptide (VWFpp) levels and ADAMTS13 activity, and their relationship with platelet reactivity following TIA/ischaemic stroke. In this pilot, observational study, VWF:Ag and VWFpp levels and ADAMTS13 activity were quantified in 48 patients ≤4 weeks of TIA/ischaemic stroke (baseline), and 14 days (14d) and 90 days (90d) after commencing aspirin, clopidogrel or aspirin+dipyridamole. Platelet reactivity was assessed at moderately-high shear stress (PFA-100® Collagen-Epinephrine / Collagen-ADP / INNOVANCE PFA P2Y assays), and low shear stress (VerifyNow® Aspirin / P2Y12, and Multiplate® Aspirin / ADP assays). VWF:Ag levels decreased and VWFpp/VWF:Ag ratio increased between baseline and 14d and 90d in the overall population (P ≤ 0.03). In the clopidogrel subgroup, VWF:Ag levels decreased and VWFpp/VWF:Ag ratio increased between baseline and 14d and 90d (P ≤ 0.01), with an increase in ADAMTS13 activity between baseline vs. 90d (P ≤ 0.03). In the aspirin+dipyridamole subgroup, there was an inverse relationship between VWF:Ag and VWFpp levels with both PFA-100 C-ADP and INNOVANCE PFA P2Y closure times (CTs) at baseline (P ≤ 0.02), with PFA-100 C-ADP, INNOVANCE PFA P2Y and C-EPI CTs at 14d (P ≤ 0.05), and between VWF:Ag levels and PFA-100 INNOVANCE PFA P2Y CTs at 90d (P = 0.03). There was a positive relationship between ADAMTS13 activity and PFA-100 C-ADP CTs at baseline (R2 = 0.254; P = 0.04). Commencing/altering antiplatelet therapy, mainly attributed to commencing clopidogrel in this study, was associated with decreasing endothelial activation following TIA/ischaemic stroke. These data enhance our understanding of the impact of VWF:Ag and VWFpp especially on ex-vivo platelet reactivity status at high shear stress after TIA/ischaemic stroke.

The association of antiplatelet agents with mortality among patients with non-COVID-19 community-acquired pneumonia: a systematic review and meta-analysis

Background

Community-acquired pneumonia (CAP) triggers inflammatory and thrombotic host responses driving morbidity and mortality. Antiplatelet agents may favorably modulate these pathways; however, their role in non-COVID-19 CAP remains uncertain.

Objectives

To evaluate the association of antiplatelet agents with mortality in hospitalized patients with non-COVID-19 CAP.

Methods

We conducted a systematic review and meta-analysis of observational studies and randomized controlled trials (RCTs) of adult patients hospitalized for non-COVID-19 CAP exposed to antiplatelet agents (acetylsalicylic acid or P2Y12 inhibitors). We searched MEDLINE, Embase, and CENTRAL from inception to August 2023. Our primary outcome was all-cause mortality: meta-analyzed (random-effects models) separately for observational studies and RCTs. For observational studies, we used adjusted mortality estimates.

Results

We included 13 observational studies (123,012 patients; 6 reported adjusted mortality estimates) and 2 RCTs (225 patients; both high risk of bias). In observational studies reporting hazard ratio, antiplatelet agents were associated with lower mortality (hazard ratio, 0.65; 95% CI, 0.46-0.91; I 2  = 85%; 4 studies, 91,430 patients). In studies reporting adjusted odds ratio, antiplatelet agent exposure was associated with reduced odds of mortality (odds ratio, 0.67; 95% CI, 0.45-1.00; I 2  = 0%; 2 studies, 24,889 patients). Among RCTs, there was a nonsignificant association with mortality (risk ratio, 0.66; 95% CI, 0.20-2.25; I 2  = 54%; 2 studies, 225 patients). By the Grading of Recommendations, Assessment, Development, and Evaluation criteria, the certainty of the evidence was low, primarily due to risk of bias.

Conclusion

In hospitalized patients with non-COVID-19 CAP, antiplatelet agents may be associated with reduced mortality compared with usual care or placebo, but the certainty of evidence is low.

Critical Illness Outside the Intensive Care Unit: Research Challenges in Emergency and Prehospital Settings

Patients with acute critical illness require prompt interventions, yet high-quality evidence supporting many investigations and treatments is lacking. Clinical research in this setting is challenging due to the need for immediate treatment and the inability of patients to provide informed consent. Attempts to obtain consent from surrogate decision-makers can be intrusive and lead to unacceptable delays to treatment. These problems may be overcome by pragmatic approaches to study design and the use of supervised waivers of consent, which is ethical and appropriate in situations where there is high risk of poor outcome and a paucity of proven effective treatment.

NOVEL ECHOCARDIOGRAM ANALYSIS OF CARDIAC DYSFUNCTION IS ASSOCIATED WITH MORTALITY IN PEDIATRIC SEPSIS

ABSTRACT

Objectives: The objective of our study was to semiautomatically generate echocardiogram indices in pediatric sepsis using novel algorithms and determine which indices were associated with mortality. We hypothesized that strain and diastolic indices would be most associated with mortality. Design: Retrospective cohort study of children with sepsis from 2017 to 2022. Survivors and nonsurvivors were compared for echocardiogram indices. Multivariate Cox proportional hazard models were constructed for our primary outcome of in-hospital mortality. Linear regression was performed for secondary outcomes, which included multiple composite 28-day outcomes. Results: Of the 54 patients in the study, 9 (17%) died. Multiple echocardiogram indices of both right (RV) and left ventricles (LV) were associated with in-hospital mortality [RV GLS adjusted hazard ratio (aHR): 1.16 (1.03-1.29), P = 0.011; RV global longitudinal early diastolic strain rate (GLSre) aHR: 0.24 (0.07 to 0.75), P = 0.014; LV GLSre aHR: 0.33 (0.11-0.97), P = 0.044]. Impairment in GLS was associated with fewer ventilator-free days [RV GLS β-coefficient: -0.47 (-0.84 to -0.10), P = 0.013; LV GLS β-coefficient -0.62 (-1.07 to -0.17), P = 0.008], organ-support free days [RV GLS β-coefficient: -0.49 (-0.87 to -0.11), P = 0.013; LV GLS β-coefficient: -0.64 (-1.10 to -0.17), P = 0.008], and days free from ICU [RV GLS β-coefficient: -0.42 (-0.79 to -0.05), P = 0.026; LV GLS β-coefficient: -0.58 (-1.03 to -0.13), P = 0.012]. Systolic indices were not associated with mortality in this cohort. Conclusion: Our study demonstrates the feasibility of obtaining echocardiogram indices in a semiautomatic method using our algorithms. We showed that abnormal strain is associated with worse outcomes in a cohort of children with sepsis.

Targeting GPVI with glenzocimab in COVID-19 patients: Results from a randomized clinical trial

BACKGROUND

Glenzocimab is a novel antithrombotic agent which targets platelet glycoprotein VI (GPVI) and does not induce haemorrhage. SARS-CoV-2 triggers a prothrombotic state and lung injury whose mechanisms include coagulopathy, endothelial dysfunction, and inflammation with dysregulated platelets.

METHODS AND PATIENTS

GARDEN was a randomised double-blind, exploratory phase II study of glenzocimab in SARS-CoV-2 respiratory failure (NCT04659109). PCR+ adults in Brazil and France (7 centres) were randomized to standard-of-care (SOC) plus glenzocimab (1000 mg/dayx3 days) or placebo, followed for 40 days. Primary efficacy endpoint was clinical progression at Day 4. All analyses concerned the intention-to-treat population.

RESULTS

Between December 2020 and August 2021, 61 patients received at least one dose (30 glenzocimab vs 32 placebo) and 58 completed the study (29 vs 29). Clinical progression of COVID-19 ARDS was not statistically different between glenzocimab and placebo arms (43.3% and 29.0%, respectively; p = 0.245). Decrease in the NEWS-2 category at D4 was statistically significant (p = 0.0290) in the glenzocimab arm vs placebo. No Serious Adverse Event (SAE) was deemed related to study drug; bleeding related events were reported in 6 patients (7 events) and 4 patients (4 events) in glenzocimab and placebo arms, respectively.

CONCLUSIONS

Therapeutic GPVI inhibition assessment during COVID-19 was conducted in response to a Public Health emergency. Glenzocimab in coagulopathic patients under therapeutic heparin was neither associated with increased bleeding, nor SAE. Clinical impact of glenzocimab on COVID-19 ARDS was not demonstrated. A potential role for GPVI inhibition in other types of ARDS deserves further experimentation. Glenzocimab is currently studied in stroke (ACTISAVE: NCT05070260) and cardiovascular indications.

The response of Canada's clinical health research ecosystem to the COVID-19 pandemic

BACKGROUND

The response of Canada's research community to the COVID-19 pandemic provides a unique opportunity to examine the country's clinical health research ecosystem. We sought to describe patterns of enrolment across Canadian Institutes of Health Research (CIHR)-funded studies on COVID-19.

METHODS

We identified COVID-19 studies funded by the CIHR and that enrolled participants from Canadian acute care hospitals between January 2020 and April 2023. We collected information on study-and site-level variables from study leads, site investigators, and public domain sources. We described and evaluated factors associated with cumulative enrolment.

RESULTS

We obtained information for 23 out of 26 (88%) eligible CIHR-funded studies (16 randomized controlled trials [RCTs] and 7 cohort studies). The 23 studies were managed by 12 Canadian and 3 international coordinating centres. Of 419 Canadian hospitals, 97 (23%) enrolled a total of 28 973 participants - 3876 in RCTs across 78 hospitals (median cumulative enrolment per hospital 30, interquartile range [IQR] 10-61), and 25 097 in cohort studies across 62 hospitals (median cumulative enrolment per hospital 158, IQR 6-348). Of 78 hospitals recruiting participants in RCTs, 13 (17%) enrolled 50% of all RCT participants, whereas 6 of 62 hospitals (9.7%) recruited 54% of participants in cohort studies.

INTERPRETATION

A minority of Canadian hospitals enrolled the majority of participants in CIHR-funded studies on COVID-19. This analysis sheds light on the Canadian health research ecosystem and provides information for multiple key partners to consider ways to realize the full research potential of Canada's health systems.

Appropriate thromboprophylaxis strategy for COVID-19 patients on dosage, antiplatelet therapy, outpatient, and postdischarge prophylaxis: a meta-analysis of randomized controlled trials

BACKGROUND

There was controversy surrounding the optimal thromboprophylaxis strategy for coronavirus disease 2019 (COVID-19) patients. This included debates on the dosage of anticoagulants for thromboembolism prophylaxis, the requirement for additional antiplatelet therapy, and the necessity of prophylaxis for outpatients and postdischarge. To explore this, the authors performed a meta-analysis of randomized controlled trials.

METHODS

PubMed, Cochrane Library, Embase, and Web of Science were last searched on 26 July 2023 for studies comparing the effect of different dose of anticoagulation, additional antiplatelet, and postdischarge prophylaxis for COVID-19 patients. The results of eligible studies were analyzed in terms of thromboembolism events, major bleeding and all-cause mortality during follow-up.

RESULTS

Our study included a total of 25 randomized controlled trials, involving 17 911 patients. Our results revealed that, compared to prophylactic dose, therapeutic dose showed lower thrombotic risk (RR, 0.66; 95% CI: 0.45-0.96) but had similar major bleeding risk for critically ill patients with COVID-19. On the other hand, intermediate dose and prophylactic dose demonstrated similar thromboembolism risk and major bleeding risk. For noncritically ill patients with COVID-19, therapeutic dose of anticoagulants was associated with lower thrombotic risk (RR, 0.50; 95% CI: 0.34-0.72) but, at the same time, increased the risk of major bleeding (RR, 2.01; 95% CI: 1.22-3.33). However, intermediate dose showed lower thromboembolism risk (RR, 0.38; 95% CI: 0.21-0.69) while maintaining a similar major bleeding risk. In critically ill patients, additional antiplatelet therapy showed similar thromboembolism, major bleeding risk, and mortality when compared to no treatment. For outpatients, additional prophylactic anticoagulation showed similar thromboembolism, major bleeding risk, and mortality when compared to no treatment. For postdischarge patients, postdischarge prophylaxis reduced thromboembolism risk (RR, 0.49; 95% CI: 0.31-0.76) but increased major bleeding risk (RR, 2.63; 95% CI: 1.13-6.14).

CONCLUSION

For noncritically ill patients, therapeutic dose prophylactic anticoagulation significantly reduced venous thromboembolism but increases major bleeding risk. Intermediate dose effectively lowered venous thromboembolism without raising major bleeding risk. The optimal dose and need for additional antiplatelet therapy in critically ill patients, as well as the necessity of prophylactic anticoagulation in outpatient and postdischarge patients, required further investigation and confirmation through rigorous evidence studies.

2023 ISTH update of the 2022 ISTH guidelines for antithrombotic treatment in COVID-19

Based on emerging evidence from the COVID-19 pandemic, the International Society on Thrombosis and Haemostasis (ISTH) guidelines for antithrombotic treatment in COVID-19 were published in 2022. Since then, at least 16 new randomized controlled trials have contributed additional evidence, which necessitated a modification of most of the previous recommendations. We used again the American College of Cardiology Foundation/American Heart Association methodology for assessment of level of evidence (LOE) and class of recommendation (COR). Five recommendations had the LOE upgraded to A and 2 new recommendations on antithrombotic treatment for patients with COVID-19 were added. Furthermore, a section was added to answer questions about COVID-19 vaccination and vaccine-induced immune thrombotic thrombocytopenia (VITT), for which studies have provided some evidence. We only included recommendations with LOE A or B. Panelists agreed on 19 recommendations, 4 for nonhospitalized, 5 for noncritically ill hospitalized, 3 for critically ill hospitalized, and 2 for postdischarge patients, as well as 5 for vaccination and VITT. A strong recommendation (COR 1) was given for (a) use of prophylactic dose of low-molecular-weight heparin or unfractionated heparin in noncritically ill patients hospitalized for COVID-19, (b) for select patients in this group, use of therapeutic-dose low-molecular-weight heparin/unfractionated heparin in preference to prophylactic dose, and (c) for use of antiplatelet factor 4 enzyme immunoassays for diagnosing VITT. A strong recommendation was given against (COR 3) the addition of an antiplatelet agent in hospitalized, noncritically ill patients. These international guidelines provide recommendations for countries with diverse healthcare resources and COVID-19 vaccine availability.

Automatic Population of the Case Report Forms for an International Multifactorial Adaptive Platform Trial Amid the COVID-19 Pandemic

OBJECTIVES

To automatically populate the case report forms (CRFs) for an international, pragmatic, multifactorial, response-adaptive, Bayesian COVID-19 platform trial.

METHODS

The locations of focus included 27 hospitals and 2 large electronic health record (EHR) instances (1 Cerner Millennium and 1 Epic) that are part of the same health system in the United States. This paper describes our efforts to use EHR data to automatically populate four of the trial's forms: baseline, daily, discharge, and response-adaptive randomization.

RESULTS

Between April 2020 and May 2022, 417 patients from the UPMC health system were enrolled in the trial. A MySQL-based extract, transform, and load pipeline automatically populated 499 of 526 CRF variables. The populated forms were statistically and manually reviewed and then reported to the trial's international data coordinating center.

CONCLUSIONS

We accomplished automatic population of CRFs in a large platform trial and made recommendations for improving this process for future trials.

Major Bleeding Events in Hospitalized COVID-19 Patients: A Retrospective Observational Study

Thromboprophylaxis/anticoagulation treatment is often required in hospitalized COVID-19 patients. We aimed to estimate the prevalence of major bleeding events in hospitalized COVID-19 patients. This was a retrospective observational study including all COVID-19 hospitalized patients ≥18 years of age at one reference center in northern Italy. The crude prevalence (between February 2020-2022) of major bleeding events was estimated as the number of major bleeding episodes divided by patients at risk. Uni- and multivariable Cox models were built to assess factors potentially associated with major bleeding events. Twenty-nine (0.98%) out of 2,945 COVID-19 patients experienced a major bleeding event [prevalence of 0.55% (95%CI 0.37-0.79)], of which five were fatal. Patients who experienced a major bleeding event were older [78 years (72-84 IQR) vs. 67 years (55-78 IQR), p-value < 0.001] and more frequently exposed to anti-aggregating therapy (44.8% vs. 20.0%, p-value 0.002) when compared to those who did not. In the multivariable Cox model, age [per 1 year more AHR 1.05 (CI95% 1.02-1.09)] was independently associated with an increased risk of major bleeding events. A strict monitoring of older hospitalized COVID-19 patients is warranted due to the risk of major bleeding events.

Lessons we learned during the past four challenging years in the COVID-19 era: pharmacotherapy, long COVID complications, and vaccine development

About four years have passed since the detection of the first cases of COVID-19 in China. During this lethal pandemic, millions of people have lost their lives around the world. Since the first waves of COVID-19 infection, various pharmacotherapeutic agents have been examined in the management of COVID-19. Despite all these efforts in pharmacotherapy, drug repurposing, and design and development of new drugs, multiple organ involvement and various complications occurred during COVID-19. Some of these complications became chronic and long-lasting which led to the "long COVID" syndrome appearance. Therefore, the best way to eradicate this pandemic is prophylaxis through mass vaccination. In this regard, various vaccine platforms including inactivated vaccines, nucleic acid-based vaccines (mRNA and DNA vaccines), adenovirus-vectored vaccines, and protein-based subunit vaccines have been designed and developed to prevent or reduce COVID-19 infection, hospitalization, and mortality rates. In this focused review, at first, the most commonly reported clinical presentations of COVID-19 during these four years have been summarized. In addition, different therapeutic regimens and their latest status in COVID-19 management have been listed. Furthermore, the "long COVID" and related signs, symptoms, and complications have been mentioned. At the end, the effectiveness of available COVID-19 vaccines with different platforms against early SARS-CoV-2 variants and currently circulating variants of interest (VOI) and the necessity of booster vaccine shots have been summarized and discussed in more detail.

COVID-19 and Long-COVID Thrombosis: From Clinical and Basic Science to Therapeutics

Coronavirus infectious disease-19 (COVID-19) is a pandemic characterized by serious lung disease and thrombotic events in the venous and circulation trees, which represent a harmful clinical sign of poor outcome. Thrombotic events are more frequent in patients with severe disease requiring intensive care units and are associated with platelet and clotting activation. However, after resolution of acute infection, patients may still have clinical sequelae, the so-called long-COVID-19, including thrombotic events again in the venous and arterial circulation. The mechanisms accounting for thrombosis in acute and long COVID-19 have not been fully clarified; interactions of COVID-19 with angiotensin converting enzyme 2 or toll-like receptor family or infection-induced cytokine storm have been suggested to be implicated in endothelial cells, leucocytes, and platelets to elicit clotting activation in acute as well in chronic phase of the disease. In acute COVID-19, prophylactic or full doses of anticoagulants exert beneficial effects even if the dosage choice is still under investigation; however, a residual risk still remains suggesting a need for a more appropriate therapeutic approach. In long COVID-19 preliminary data provided useful information in terms of antiplatelet treatment but definition of candidates for thrombotic prophylaxis is still undefined.

Association between loss of hypercoagulable phenotype, clinical features and complement pathway consumption in COVID-19

Background

Coronavirus disease 2019 (COVID-19) features a hypercoagulable state, but therapeutic anticoagulation effectiveness varies with disease severity. We aimed to evaluate the dynamics of the coagulation profile and its association with COVID-19 severity, outcomes, and biomarker trajectories.

Methods

This multicenter, prospective, observational study included patients with COVID-19 requiring respiratory support. Rotational thromboelastometry findings were evaluated for coagulation and fibrinolysis status. Hypercoagulable status was defined as supranormal range of maximum clot elasticity in an external pathway. Longitudinal laboratory parameters were collected to characterize the coagulation phenotype.

Results

Of 166 patients, 90 (54%) were severely ill at inclusion (invasive mechanical ventilation, 84; extracorporeal membrane oxygenation, 6). Higher maximum elasticity (P=0.02) and lower maximum lysis in the external pathway (P=0.03) were observed in severely ill patients compared with the corresponding values in patients on non-invasive oxygen supplementation. Hypercoagulability components correlated with platelet and fibrinogen levels. Hypercoagulable phenotype was associated with favorable outcomes in severely ill patients, while normocoagulable phenotype was not (median time to recovery, 15 days vs. 27 days, P=0.002), but no significant association was observed in moderately ill patients. In patients with severe COVID-19, lower initial C3, minimum C3, CH50, and greater changes in CH50 were associated with the normocoagulable phenotype. Changes in complement components correlated with dynamics of coagulation markers, hematocrit, and alveolar injury markers.

Conclusions

While hypercoagulable states become more evident with increasing severity of respiratory disease in patients with COVID-19, normocoagulable phenotype is associated with triggered by alternative pathway activation and poor outcomes.

Identifying prognostic factors for survival in intensive care unit patients with SIRS or sepsis by machine learning analysis on electronic health records

BACKGROUND

Systemic inflammatory response syndrome (SIRS) and sepsis are the most common causes of in-hospital death. However, the characteristics associated with the improvement in the patient conditions during the ICU stay were not fully elucidated for each population as well as the possible differences between the two.

GOAL

The aim of this study is to highlight the differences between the prognostic clinical features for the survival of patients diagnosed with SIRS and those of patients diagnosed with sepsis by using a multi-variable predictive modeling approach with a reduced set of easily available measurements collected at the admission to the intensive care unit (ICU).

METHODS

Data were collected from 1,257 patients (816 non-sepsis SIRS and 441 sepsis) admitted to the ICU. We compared the performance of five machine learning models in predicting patient survival. Matthews correlation coefficient (MCC) was used to evaluate model performances and feature importance, and by applying Monte Carlo stratified Cross-Validation.

RESULTS

Extreme Gradient Boosting (MCC = 0.489) and Logistic Regression (MCC = 0.533) achieved the highest results for SIRS and sepsis cohorts, respectively. In order of importance, APACHE II, mean platelet volume (MPV), eosinophil counts (EoC), and C-reactive protein (CRP) showed higher importance for predicting sepsis patient survival, whereas, SOFA, APACHE II, platelet counts (PLTC), and CRP obtained higher importance in the SIRS cohort.

CONCLUSION

By using complete blood count parameters as predictors of ICU patient survival, machine learning models can accurately predict the survival of SIRS and sepsis ICU patients. Interestingly, feature importance highlights the role of CRP and APACHE II in both SIRS and sepsis populations. In addition, MPV and EoC are shown to be important features for the sepsis population only, whereas SOFA and PLTC have higher importance for SIRS patients.

Transforming research to improve therapies for trauma in the twenty-first century

Improvements have been made in optimizing initial care of trauma patients, both in prehospital systems as well as in the emergency department, and these have also favorably affected longer term outcomes. However, as specific treatments for bleeding are largely lacking, many patients continue to die from hemorrhage. Also, major knowledge gaps remain on the impact of tissue injury on the host immune and coagulation response, which hampers the development of interventions to treat or prevent organ failure, thrombosis, infections or other complications of trauma. Thereby, trauma remains a challenge for intensivists. This review describes the most pressing research questions in trauma, as well as new approaches to trauma research, with the aim to bring improved therapies to the bedside within the twenty-first century.

The role of platelet P2Y12 receptors in inflammation

Inflammation is a complex pathophysiological process underlying many clinical conditions. Platelets contribute to the thrombo-inflammatory response. Platelet P2Y12 receptors amplify platelet activation, potentiating platelet aggregation, degranulation and shape change. The contents of platelet alpha granules, in particular, act directly on leucocytes, including mediating platelet-leucocyte aggregation and activation via platelet P-selectin. Much evidence for the role of platelet P2Y12 receptors in inflammation comes from studies using antagonists of these receptors, such as the thienopyridines clopidogrel and prasugrel, and the cyclopentyltriazolopyrimidine ticagrelor, in animal and human experimental models. These suggest that antagonism of P2Y12 receptors decreases markers of inflammation with some evidence that this reduces incidence of adverse clinical sequelae during inflammatory conditions. Interpretation is complicated by pleiotropic effects such as those of the thienopyridines on circulating leucocyte numbers and of ticagrelor on adenosine reuptake. The available evidence suggests that P2Y12 receptors are prominent mediators of inflammation and P2Y12 receptor antagonism as a potentially powerful strategy in a broad range of inflammatory conditions. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.

Effect of antiplatelet therapy after COVID-19 diagnosis: A systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) may predispose patients to thrombotic disease in the venous and arterial circulations.

METHODS

Based on the current debate on antiplatelet therapy in COVID-19 patients, we performed a systematic review and meta-analysis to investigate the effect of antiplatelet treatments. We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science on February 1, 2023, and only included Randomized clinical trials. The study followed PRISMA guidelines and used Random-effects models to estimate the pooled percentage and its 95% CI.

RESULTS

Five unique eligible studies were included, covering 17,950 patients with COVID-19. The result showed no statistically significant difference in the relative risk of all-cause death in antiplatelet therapy versus non-antiplatelet therapy (RR 0.94, 95% CI, 0.83-1.05, P = 0.26, I2 = 32%). Compared to no antiplatelet therapy, patients who received antiplatelet therapy had a significantly increased relative risk of major bleeding (RR 1.81, 95%CI 1.09-3.00, P = 0.02, I2 = 16%). The sequential analysis suggests that more RCTs are needed to draw more accurate conclusions. This systematic review and meta-analysis revealed that the use of antiplatelet agents exhibited no significant benefit on all-cause death, and the upper bound of the confidence interval on all-cause death (RR 95% CI, 0.83-1.05) suggested that it was unlikely to be a substantiated harm risk associated with this treatment. However, evidence from all RCTs suggested a high risk of major bleeding in antiplatelet agent treatments.

CONCLUSION

According to the results of our sequential analysis, there is not enough evidence available to support or negate the use of antiplatelet agents in COVID-19 cases. The results of ongoing and future well-designed, large, randomized clinical trials are needed.

Thromboinflammation in acute injury: infections, heatstroke, and trauma

Tissue microcirculation is essential for the maintenance of organ homeostasis. Following acute infections, activation of coagulation and inflammation, which are critical interconnected responses, lead to thromboinflammation and microthrombosis, thereby contributing to multiorgan dysfunction. Sepsis is the most common underlying disease and has been extensively studied. However, the COVID-19 pandemic further illustrated the pathomechanisms of diseases in which thromboinflammation plays a critical role. During thromboinflammation, injury to monocytes, neutrophils, platelets, and endothelial cells, along with coagulation and complement activation, was further characterized. Thrombin is pivotal in orchestrating thrombosis and inflammation and has long been considered a potential therapeutic target in sepsis. Although thromboprophylaxis for venous thromboembolism with heparins is part of standard management for COVID-19, it also potentially attenuates organ dysfunction due to thrombotic sequela. In contrast, the effectiveness of anticoagulation with heparin, antithrombin, or thrombomodulin to reduce mortality has not conclusively been proven in sepsis. Nonetheless, thromboinflammation has also been reported as an important pathophysiologic mechanism in other critical illnesses, including heatstroke, trauma, and ischemia/reperfusion injury, and may provide a potential therapeutic target for future clinical studies.

Real-world causal evidence for planned predictive enrichment in critical care trials: A scoping review

BACKGROUND

Randomised clinical trials in critical care are prone to inconclusiveness due, in part, to undue optimism about effect sizes and suboptimal accounting for heterogeneous treatment effects. Although causal evidence from rich real-world critical care can help overcome these challenges by informing predictive enrichment, no overview exists.

METHODS

We conducted a scoping review, systematically searching 10 general and speciality journals for reports published on or after 1 January 2018, of randomised clinical trials enrolling adult critically ill patients. We collected trial metadata on 22 variables including recruitment period, intervention type and early stopping (including reasons) as well as data on the use of causal evidence from secondary data for planned predictive enrichment.

RESULTS

We screened 9020 records and included 316 unique RCTs with a total of 268,563 randomised participants. One hundred seventy-three (55%) trials tested drug interventions, 101 (32%) management strategies and 42 (13%) devices. The median duration of enrolment was 2.2 (IQR: 1.3-3.4) years, and 83% of trials randomised less than 1000 participants. Thirty-six trials (11%) were restricted to COVID-19 patients. Of the 55 (17%) trials that stopped early, 23 (42%) used predefined rules; futility, slow enrolment and safety concerns were the commonest stopping reasons. None of the included RCTs had used causal evidence from secondary data for planned predictive enrichment.

CONCLUSION

Work is needed to harness the rich multiverse of critical care data and establish its utility in critical care RCTs. Such work will likely need to leverage methodology from interventional and analytical epidemiology as well as data science.

Thrombosis in Critically Ill Influenza Patients: Incidence and Risk Factors

Influenza infection is associated with a risk of thrombosis. Whether factors associated with reduced thrombosis might also be associated with reduced risk in patients with severe influenza is unknown. To investigate risk factors associated with thrombosis in patients with severe influenza. We used a cohort data set to identify adults diagnosed with severe influenza. Univariable and multivariable logistic regression models explored potential risk factors for thrombosis events in patients with severe influenza. Cox regression analysis was used to examine the risk factors for mortality in patients with severe influenza. A total of 854 patients with severe influenza were included in the analysis. The incidence of VTE was 9.37% (80/854). Multivariable regression analysis showed that previous aspirin medication (OR: 0.37; 95%CI: 0.14-0.84; P = .029) could reduce the risk factor of thrombosis in patients with severe influenza. Compared with patients in the non-thrombosis group, patients in the thrombosis group required more mechanical ventilation (P < .001), tracheostomy (P < .001), ECMO (P = .046), and high-frequency ventilation (P = .004). The incidence of co-infection was higher in the thrombosis group compared to the non-thrombosis group (P = .025). Univariable Cox regression analysis showed that previous aspirin medication (HR 0.52, 95%CI: 0.33-0.82, P = .005) and previous statin medication (HR 0.54, 95%CI: 0.34-0.87, P = .011) were risk factors for 60-day mortality in patients with severe influenza. Patients with severe influenza are at high risk for thrombosis. The effect of aspirin on thrombosis in patients with severe influenza needs further investigation.

COVID-19 thromboprophylaxis. New evidence

Recent publications have questioned the efficacy of using therapeutic or intermediate doses of low molecular weight heparin (LMWH) in COVID-19 patients, especially in the most severe patients. In order to update these recommendations, a non-systematic review has been carried out in the main medical databases. A total of 14 randomized clinical trials, 14 meta-analyses and the recommendations of 12 scientific societies were selected, stratified according to the type of patient (outpatient, hospitalized, admitted to critical care or post-discharge). The efficacy of LMWH and other therapeutic approaches (rivaroxaban, apixaban, sulodexide, acetylsalicylic acid and P2Y12 inhibitors) has been analyzed. The findings recommend using standard doses of LMWH as thromboprophylaxis in critically hospitalized COVID-19 patients and therapeutic doses in non-critically hospitalized patients if the risk of bleeding is low. In outpatients and those discharged from the hospital, LMWH could be used at a prophylactic dose if there are thrombotic risk factors, and the bleeding risk is low. It is not recommended to associate antiplatelet agents with LMWH unless previously indicated.

Simvastatin in Critically Ill Patients with Covid-19

BACKGROUND

The efficacy of simvastatin in critically ill patients with coronavirus disease 2019 (Covid-19) is unclear.

METHODS

In an ongoing international, multifactorial, adaptive platform, randomized, controlled trial, we evaluated simvastatin (80 mg daily) as compared with no statin (control) in critically ill patients with Covid-19 who were not receiving statins at baseline. The primary outcome was respiratory and cardiovascular organ support-free days, assessed on an ordinal scale combining in-hospital death (assigned a value of -1) and days free of organ support through day 21 in survivors; the analyis used a Bayesian hierarchical ordinal model. The adaptive design included prespecified statistical stopping criteria for superiority (>99% posterior probability that the odds ratio was >1) and futility (>95% posterior probability that the odds ratio was <1.2).

RESULTS

Enrollment began on October 28, 2020. On January 8, 2023, enrollment was closed on the basis of a low anticipated likelihood that prespecified stopping criteria would be met as Covid-19 cases decreased. The final analysis included 2684 critically ill patients. The median number of organ support-free days was 11 (interquartile range, -1 to 17) in the simvastatin group and 7 (interquartile range, -1 to 16) in the control group; the posterior median adjusted odds ratio was 1.15 (95% credible interval, 0.98 to 1.34) for simvastatin as compared with control, yielding a 95.9% posterior probability of superiority. At 90 days, the hazard ratio for survival was 1.12 (95% credible interval, 0.95 to 1.32), yielding a 91.9% posterior probability of superiority of simvastatin. The results of secondary analyses were consistent with those of the primary analysis. Serious adverse events, such as elevated levels of liver enzymes and creatine kinase, were reported more frequently with simvastatin than with control.

CONCLUSIONS

Although recruitment was stopped because cases had decreased, among critically ill patients with Covid-19, simvastatin did not meet the prespecified criteria for superiority to control. (REMAP-CAP ClinicalTrials.gov number, NCT02735707.).

To Gain Insights into the Pathophysiological Mechanisms of the Thrombo-Inflammatory Process in the Atherosclerotic Plaque

Thromboinflammation, the interplay between thrombosis and inflammation, is a significant pathway that drives cardiovascular and autoimmune diseases, as well as COVID-19. SARS-CoV-2 causes inflammation and blood clotting issues. Innate immune cells have emerged as key modulators of this process. Neutrophils, the most predominant white blood cells in humans, are strategically positioned to promote thromboinflammation. By releasing decondensed chromatin structures called neutrophil extracellular traps (NETs), neutrophils can initiate an organised cell death pathway. These structures are adorned with histones, cytoplasmic and granular proteins, and have cytotoxic, immunogenic, and prothrombotic effects that can hasten disease progression. Protein arginine deiminase 4 (PAD4) catalyses the citrullination of histones and is involved in the release of extracellular DNA (NETosis). The neutrophil inflammasome is also required for this process. Understanding the link between the immunological function of neutrophils and the procoagulant and proinflammatory activities of monocytes and platelets is important in understanding thromboinflammation. This text discusses how vascular blockages occur in thromboinflammation due to the interaction between neutrophil extracellular traps and ultra-large VWF (von Willebrand Factor). The activity of PAD4 is important for understanding the processes that drive thromboinflammation by linking the immunological function of neutrophils with the procoagulant and proinflammatory activities of monocytes and platelets. This article reviews how vaso-occlusive events in thrombo-inflammation occur through the interaction of neutrophil extracellular traps with von Willebrand factor. It highlights the relevance of PAD4 in neutrophil inflammasome assembly and neutrophil extracellular traps in thrombo-inflammatory diseases such as atherosclerosis and cardiovascular disease. Interaction between platelets, VWF, NETs and inflammasomes is critical for the progression of thromboinflammation in several diseases and was recently shown to be active in COVID-19.

Alveolar Hyperoxia and Exacerbation of Lung Injury in Critically Ill SARS-CoV-2 Pneumonia

Acute hypoxic respiratory failure (AHRF) is a prominent feature of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) critical illness. The severity of gas exchange impairment correlates with worse prognosis, and AHRF requiring mechanical ventilation is associated with substantial mortality. Persistent impaired gas exchange leading to hypoxemia often warrants the prolonged administration of a high fraction of inspired oxygen (FiO2). In SARS-CoV-2 AHRF, systemic vasculopathy with lung microthrombosis and microangiopathy further exacerbates poor gas exchange due to alveolar inflammation and oedema. Capillary congestion with microthrombosis is a common autopsy finding in the lungs of patients who die with coronavirus disease 2019 (COVID-19)-associated acute respiratory distress syndrome. The need for a high FiO2 to normalise arterial hypoxemia and tissue hypoxia can result in alveolar hyperoxia. This in turn can lead to local alveolar oxidative stress with associated inflammation, alveolar epithelial cell apoptosis, surfactant dysfunction, pulmonary vascular abnormalities, resorption atelectasis, and impairment of innate immunity predisposing to secondary bacterial infections. While oxygen is a life-saving treatment, alveolar hyperoxia may exacerbate pre-existing lung injury. In this review, we provide a summary of oxygen toxicity mechanisms, evaluating the consequences of alveolar hyperoxia in COVID-19 and propose established and potential exploratory treatment pathways to minimise alveolar hyperoxia.

Risk Factors for Postdischarge Major Thromboembolism and Mortality in Hospitalized Patients with COVID-19 with Cardiovascular Comorbidities: Insights from the CORE-19 Registry

BACKGROUND

 Coronavirus disease 2019 (COVID-19) is associated with venous and arterial thromboembolism (VTE and ATE) and all-cause mortality (ACM) in hospitalized patients. High-quality data are needed on postdischarge outcomes in patients with cardiovascular disease.

OBJECTIVES

 To analyze outcomes and identify risk factors for ATE, VTE, and ACM in a high-risk subgroup of hospitalized COVID-19 patients with baseline cardiovascular disease.

METHODS

 We investigated postdischarge rates and associated risk factors of ATE, VTE, and ACM in 608 hospitalized COVID-19 patients with coronary artery disease, carotid artery stenosis (CAS), peripheral arterial disease (PAD), or ischemic stroke.

RESULTS

 Through 90 days postdischarge, outcome rates were: ATE 27.3% (10.2% myocardial infarction, 10.1% ischemic stroke, 13.2% systemic embolism, 12.7% major adverse limb event); VTE 6.9% (4.1% deep vein thrombosis, 3.6% pulmonary embolism); composite of ATE, VTE, or ACM 35.2% (214/608). Multivariate analysis showed significant association between this composite endpoint and age >75 years (odds ratio [OR]: 1.90, 95% confidence interval [CI]: 1.22-2.94, p = 0.004), PAD (OR: 3.23, 95% CI: 1.80-5.81, p ≤ 0.0001), CAS (OR: 1.74, 95% CI: 1.11-2.75, p = 0.017), congestive heart failure (CHF) (OR: 1.84, 95% CI: 1.02-3.35, p = 0.044), previous VTE (OR: 3.08, 95% CI: 1.75-5.42, p < 0.0001), and intensive care unit (ICU) admission (OR: 2.93, 95% CI: 1.81-4.75, p < 0.0001).

CONCLUSION

 COVID-19 inpatients with cardiovascular disease experience high rates of ATE, VTE, or ACM through 90 days postdischarge. Age >75 years, PAD, CAS, CHF, previous VTE, and ICU admission are independent risk factors.

Alterations in the megakaryocyte transcriptome impacts platelet function in sepsis and COVID-19 infection

Platelets and their parent cell, the megakaryocyte (MK), are increasingly recognized for their roles during infection and inflammation. The MK residing in the bone marrow or arising from precursors trafficked to other organs for development go on to form platelets through thrombopoiesis. Infection, by direct and indirect mechanisms, can alter the transcriptional profile of MKs. The altered environment, whether mediated by inflammatory cytokines or other signaling mechanisms results in an altered platelet transcriptome. Platelets released into the circulation, in turn, interact with each other, circulating leukocytes and endothelial cells and contribute to the clearance of pathogens or the potentiation of pathophysiology through such mechanisms as immunothrombosis. In this article we hope to identify key contributions that explore the impact of an altered transcriptomic landscape during severe, systemic response to infection broadly defined as sepsis, and viral infections, including SARS-CoV2. We include current publications that outline the role of MKs from bone-marrow and extra-medullary sites as well as the circulating platelet. The underlying diseases result in thrombotic complications that exacerbate organ dysfunction and mortality. Understanding the impact of platelets on the pathophysiology of disease may drive therapeutic advances to improve the morbidity and mortality of these deadly afflictions.

COVID-19-Associated Pulmonary Embolism: Review of the Pathophysiology, Epidemiology, Prevention, Diagnosis, and Treatment

COVID-19 is associated with endothelial activation in the setting of a potent inflammatory reaction and a hypercoagulable state. The end result of this thromboinflammatory state is an excess in thrombotic events, in particular venous thromboembolism. Pulmonary embolism (PE) has been of special interest in patients with COVID-19 given its association with respiratory deterioration, increased risk of intensive care unit admission, and prolonged hospital stay. The pathophysiology and clinical characteristics of COVID-19-associated PE may differ from the conventional non-COVID-19-associated PE. In addition to embolic events from deep vein thrombi, in situ pulmonary thrombosis, particularly in smaller vascular beds, may be relevant in patients with COVID-19. Appropriate prevention of thrombotic events in COVID-19 has therefore become of critical interest. Several changes in viral biology, vaccination, and treatment management during the pandemic may have resulted in changes in incidence trends. This review provides an overview of the pathophysiology, epidemiology, clinical characteristics, and risk factors of COVID-19-associated PE. Furthermore, we briefly summarize the results from randomized controlled trials of preventive antithrombotic therapies in COVID-19, focusing on their findings related to PE. We discuss the acute treatment of COVID-19-associated PE, which is substantially similar to the management of conventional non-COVID-19 PE. Ultimately, we comment on the current knowledge gaps in the evidence and the future directions in the treatment and follow-up of COVID-19-associated PE, including long-term management, and its possible association with long-COVID.

Adaptive designs in critical care trials: a simulation study

BACKGROUND

Adaptive clinical trials are growing in popularity as they are more flexible, efficient and ethical than traditional fixed designs. However, notwithstanding their increased use in assessing treatments for COVID-19, their use in critical care trials remains limited. A better understanding of the relative benefits of various adaptive designs may increase their use and interpretation.

METHODS

Using two large critical care trials (ADRENAL.

CLINICALTRIALS

gov number, NCT01448109. Updated 12-12-2017; NICE-SUGAR.

CLINICALTRIALS

gov number, NCT00220987. Updated 01-29-2009), we assessed the performance of three frequentist and two bayesian adaptive approaches. We retrospectively re-analysed the trials with one, two, four, and nine equally spaced interims. Using the original hypotheses, we conducted 10,000 simulations to derive error rates, probabilities of making an early correct and incorrect decision, expected sample size and treatment effect estimates under the null scenario (no treatment effect) and alternative scenario (a positive treatment effect). We used a logistic regression model with 90-day mortality as the outcome and the treatment arm as the covariate. The null hypothesis was tested using a two-sided significance level (α) at 0.05.

RESULTS

Across all approaches, increasing the number of interims led to a decreased expected sample size. Under the null scenario, group sequential approaches provided good control of the type-I error rate; however, the type I error rate inflation was an issue for the Bayesian approaches. The Bayesian Predictive Probability and O'Brien-Fleming approaches showed the highest probability of correctly stopping the trials (around 95%). Under the alternative scenario, the Bayesian approaches showed the highest overall probability of correctly stopping the ADRENAL trial for efficacy (around 91%), whereas the Haybittle-Peto approach achieved the greatest power for the NICE-SUGAR trial. Treatment effect estimates became increasingly underestimated as the number of interims increased.

CONCLUSIONS

This study confirms the right adaptive design can reach the same conclusion as a fixed design with a much-reduced sample size. The efficiency gain associated with an increased number of interims is highly relevant to late-phase critical care trials with large sample sizes and short follow-up times. Systematically exploring adaptive methods at the trial design stage will aid the choice of the most appropriate method.

Designing and Implementing "Living and Breathing" Clinical Trials: An Overview and Lessons Learned from the COVID-19 Pandemic

The practice of medicine is characterized by uncertainty, and the findings of randomized clinical trials (RCTs) are meant to help curb that uncertainty. Traditional RCTs, however, have many limitations. To overcome some of these limitations, new trial paradigms rooted in the origins of evidence-based medicine are beginning to disrupt the traditional mold. These new designs recognize uncertainty permeates medical decision making and aim to capitalize on modern health system infrastructure to integrate investigation as a component of care delivery. This article provides an overview of "living, breathing" trials, including current state, anticipated developments, and areas of controversy.

Extending the vision of adaptive point-of-care platform trials to improve targeted use of drug therapy regimens: An agile approach in the learning healthcare system toolkit

OBJECTIVES

Improving the targeted use of drug regimens requires robust real-world evidence (RWE) to address the uncertainties that remain regarding their real-world performance following market entry. However, challenges in the current state of RWE production limit its impact on clinical decisions, as well as its operational scalability and sustainability. We propose an adaptive point-of-care (APoC) platform trial as an approach to RWE production that improves both clinical and operational efficiencies.

METHODS AND FINDINGS

We explored design innovations, operational challenges, and infrastructure needs within a multi-stakeholder consortium to evaluate the potential of an APoC platform trial for studying chronic disease treatment regimens using rheumatoid arthritis as a case study. The concept integrates elements from adaptive clinical trials (dynamic treatment regimen strategies) and point-of-care trials (research embedded into routine clinical care) under a perpetual platform infrastructure. The necessary components to implement an APoC platform trial within outpatient settings exist, and present an opportunity for a cross-disciplinary, multi-stakeholder approach. Effective engagement of key stakeholders involved in and impacted by the platform is critical to success. Our collaborative design process identified three high-impact stakeholder-engagement areas: (1) focus on research question(s), (2) design and implementation planning such that it is feasible and fit-for-purpose, and (3) measurement, or meaningful metrics for both clinical (patient outcomes) and system (operational efficiencies) impact.

CONCLUSIONS

An APoC platform trial for rheumatoid arthritis integrating innovative design elements in a scalable infrastructure has the potential to reduce important uncertainties about the real-world performance of biomedical innovations and improve clinical decisions.

How Electronic Medical Record Integration Can Support More Efficient Critical Care Clinical Trials

Large volumes of data are collected on critically ill patients, and using data science to extract information from the electronic medical record (EMR) and to inform the design of clinical trials represents a new opportunity in critical care research. Using improved methods of phenotyping critical illnesses, subject identification and enrollment, and targeted treatment group assignment alongside newer trial designs such as adaptive platform trials can increase efficiency while lowering costs. Some tools such as the EMR to automate data collection are already in use. Refinement of data science approaches in critical illness research will allow for better clinical trials and, ultimately, improved patient outcomes.

Endothelium dysfunction and thrombosis in COVID-19 with type 2 diabetes

SARS-CoV-2 can directly or indirectly damage endothelial cells. Endothelial injury, especially phosphatidylserine (PS) exposure on the outer membrane of cells, can more easily promote thrombosis. Type 2 diabetes(T2D) patients were more susceptible to COVID-19, they had more severe symptoms, higher risk of thrombotic complications, and longer duration of post-COVID-19 sequelae. This review provided a detailed overview of the mechanisms underlying endothelial dysfunction in T2D patients with COVID-19 (including long COVID), which may be influenced by hyperglycemia, hypoxia, and pro-inflammatory environments. The mechanisms of thrombosis in T2D patients with COVID-19 are also explored, particularly the effects of increased numbers of PS-exposing particles, blood cells, and endothelial cells on hypercoagulability. Given the high risk of thrombosis in T2D patients with COVID-19, early antithrombotic therapy can both minimize the impact of the disease on patients and maximize the chances of improvement, thereby alleviating patient suffering. We provided detailed guidance on antithrombotic drugs and dosages for mild, moderate, and severe patients, emphasizing that the optimal timing of thromboprophylaxis is a critical factor in influencing prognosis. Considering the potential interactions between antidiabetic, anticoagulant, and antiviral drugs, we proposed practical and comprehensive management recommendations to supplement the incomplete efficacy of vaccines in the diabetic population, reduce the incidence of post-COVID-19 sequelae, and improve patient quality of life.

Antiplatelet agents for the treatment of adults with COVID-19

BACKGROUND

Severe coronavirus disease 2019 (COVID-19) can cause thrombotic events that lead to severe complications or death. Antiplatelet agents, such as acetylsalicylic acid, have been shown to effectively reduce thrombotic events in other diseases: they could influence the course of COVID-19 in general.

OBJECTIVES

To assess the efficacy and safety of antiplatelets given with standard care compared to no treatment or standard care (with/without placebo) for adults with COVID-19.

SEARCH METHODS

We searched the Cochrane COVID-19 Study Register (which comprises MEDLINE (PubMed), Embase, ClinicalTrials.gov, WHO ICTRP, medRxiv, CENTRAL), Web of Science, WHO COVID-19 Global literature on coronavirus disease and the Epistemonikos COVID-19 L*OVE Platform to identify completed and ongoing studies without language restrictions to December 2022.

SELECTION CRITERIA

We followed standard Cochrane methodology. We included randomised controlled trials (RCTs) evaluating antiplatelet agents for the treatment of COVID-19 in adults with COVID-19, irrespective of disease severity, gender or ethnicity.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology. To assess bias in included studies, we used the Cochrane risk of bias tool (RoB 2) for RCTs. We rated the certainty of evidence using the GRADE approach for the outcomes.

MAIN RESULTS

Antiplatelets plus standard care versus standard care (with/without placebo) Adults with a confirmed diagnosis of moderate to severe COVID-19 We included four studies (17,541 participants) that recruited hospitalised people with a confirmed diagnosis of moderate to severe COVID-19. A total of 8964 participants were analysed in the antiplatelet arm (either with cyclooxygenase inhibitors or P2Y12 inhibitors) and 8577 participants in the control arm. Most people were older than 50 years and had comorbidities such as hypertension, lung disease or diabetes. The studies were conducted in high- to lower middle-income countries prior to wide-scale vaccination programmes. Antiplatelets compared to standard care: - probably result in little to no difference in 28-day mortality (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.85 to 1.05; 3 studies, 17,249 participants; moderate-certainty evidence). In absolute terms, this means that for every 177 deaths per 1000 people not receiving antiplatelets, there were 168 deaths per 1000 people who did receive the intervention (95% CI 151 to 186 per 1000 people); - probably result in little to no difference in worsening (new need for invasive mechanical ventilation or death up to day 28) (RR 0.95, 95% CI 0.90 to 1.01; 2 studies, 15,266 participants; moderate-certainty evidence); - probably result in little to no difference in improvement (participants discharged alive up to day 28) (RR 1.00, 95% CI 0.96 to 1.04; 2 studies, 15,454 participants; moderate-certainty evidence); - probably result in a slight reduction of thrombotic events at longest follow-up (RR 0.90, 95% CI 0.80 to 1.02; 4 studies, 17,518 participants; moderate-certainty evidence); - may result in a slight increase in serious adverse events at longest follow-up (Peto odds ratio (OR) 1.57, 95% CI 0.48 to 5.14; 1 study, 1815 participants; low-certainty evidence), but non-serious adverse events during study treatment were not reported; - probably increase the occurrence of major bleeding events at longest follow-up (Peto OR 1.68, 95% CI 1.29 to 2.19; 4 studies, 17,527 participants; moderate-certainty evidence). Adults with a confirmed diagnosis of asymptomatic SARS-CoV-2 infection or mild COVID-19 We included two RCTs allocating participants, of whom 4209 had confirmed mild COVID-19 and were not hospitalised. A total of 2109 participants were analysed in the antiplatelet arm (treated with acetylsalicylic acid) and 2100 participants in the control arm. No study included people with asymptomatic SARS-CoV-2 infection. Antiplatelets compared to standard care: - may result in little to no difference in all-cause mortality at day 45 (Peto OR 1.00, 95% CI 0.45 to 2.22; 2 studies, 4209 participants; low-certainty evidence); - may slightly decrease the incidence of new thrombotic events up to day 45 (Peto OR 0.37, 95% CI 0.09 to 1.46; 2 studies, 4209 participants; low-certainty evidence); - may make little or no difference to the incidence of serious adverse events up to day 45 (Peto OR 1.00, 95% CI 0.60 to 1.64; 1 study, 3881 participants; low-certainty evidence), but non-serious adverse events were not reported. The evidence is very uncertain about the effect of antiplatelets on the following outcomes (compared to standard care plus placebo): - admission to hospital or death up to day 45 (Peto OR 0.79, 95% CI 0.57 to 1.10; 2 studies, 4209 participants; very low-certainty evidence); - major bleeding events up to longest follow-up (no event occurred in 328 participants; very low-certainty evidence). Quality of life and adverse events during study treatment were not reported.

AUTHORS' CONCLUSIONS

In people with confirmed or suspected COVID-19 and moderate to severe disease, we found moderate-certainty evidence that antiplatelets probably result in little to no difference in 28-day mortality, clinical worsening or improvement, but probably result in a slight reduction in thrombotic events. They probably increase the occurrence of major bleeding events. Low-certainty evidence suggests that antiplatelets may result in a slight increase in serious adverse events. In people with confirmed COVID-19 and mild symptoms, we found low-certainty evidence that antiplatelets may result in little to no difference in 45-day mortality and serious adverse events, and may slightly reduce thrombotic events. The effects on the combined outcome admission to hospital or death up to day 45 and major bleeding events are very uncertain. Quality of life was not reported. Included studies were conducted in high- to lower middle-income settings using antiplatelets prior to vaccination roll-outs. We identified a lack of evidence concerning quality of life assessments, adverse events and people with asymptomatic infection. The 14 ongoing and three completed, unpublished RCTs that we identified in trial registries address similar settings and research questions as in the current body of evidence. We expect to incorporate the findings of these studies in future versions of this review.

Composite Interventions on Outcomes of Severely and Critically Ill Patients with COVID-19 in Shanghai, China

Background: The sixty-day effects of initial composite interventions for the treatment of severely and critically ill patients with COVID-19 are not fully assessed. Methods: Using a Bayesian piecewise exponential model, we analyzed the 60-day mortality, health-related quality of life (HRQoL), and disability in 1082 severely and critically ill patients with COVID-19 between 8 December 2022 and 9 February 2023 in Shanghai, China. The final 60-day follow-up was completed on 10 April 2023. Results: Among 1082 patients (mean age, 78.0 years, 421 [38.9%] women), 139 patients (12.9%) died within 60 days. Azvudine had a 99.8% probability of improving 2-month survival (adjusted HR, 0.44 [95% credible interval, 0.24-0.79]), and Paxlovid had a 91.9% probability of improving 2-month survival (adjusted HR, 0.71 [95% credible interval, 0.44-1.14]) compared with the control. IL-6 receptor antagonist, baricitinib and a-thymosin each had a high probability of benefit (99.5%, 99.4%, and 97.5%, respectively) compared to their controls, while the probability of trail-defined statistical futility (HR > 0.83) was high for therapeutic anticoagulation (99.8%; HR, 1.64 [95% CrI, 1.06-2.50]) and glucocorticoid (91.4%; HR, 1.20 [95% CrI, 0.71-2.16]). Paxlovid, Azvudine, and therapeutic anticoagulation showed a significant reduction in disability (p < 0.05) Conclusions: Among severely and critically ill patients with COVID-19 who received 1 or more therapeutic interventions, treatment with Azvudine had a high probability of improved 60-day mortality compared with the control, indicating its potential in a resource-limited scenario. Treatment with an IL-6 receptor antagonist, baricitinib, and a-thymosin also had high probabilities of benefit in improving 2-month survival, among which a-thymosin could improve HRQoL. Treatment with Paxlovid, Azvudine, and therapeutic anticoagulation could significantly reduce disability at day 60.

A Contemporary Review of Antiplatelet Therapies in Current Clinical Practice

Antiplatelet therapy plays a crucial role in a number of cardiovascular disorders. We currently have a range of antiplatelet agents in our armamentarium. In this review, we aim to summarise the common antiplatelet agents currently available, and their use in clinic practice. We not only highlight recent trials exploring antiplatelet therapy in atherosclerotic cardiovascular disease, but also in trials related to transcatheter aortic valve implantation and coronavirus disease 2019. Inevitably, the antithrombotic benefits of these drugs are accompanied by an increase in bleeding complications. Therefore, an individualised approach to weighing each patient's thrombotic risk versus bleeding risk is imperative, in order to improve clinical outcomes.

Glycoprotein VI interplay with fibrin(ogen) in thrombosis

Platelets play a central role in the arrest of bleeding. The ability of platelets to engage with extracellular matrix proteins of the subendothelium has long been recognized as a pivotal platelet attribute, underpinning adequate hemostasis. The propensity of platelets to rapidly bind and functionally respond to collagen was one of the earliest documented events in platelet biology. The receptor primarily responsible for mediating platelet/collagen responses was identified as glycoprotein (GP) VI and successfully cloned in 1999. Since that time, this receptor has held the attention of many research groups, and through these efforts, we now have an excellent understanding of the roles of GPVI as a platelet- and megakaryocyte-specific adheso-signaling receptor in platelet biology. GPVI is considered a viable antithrombotic target, as data obtained from groups across the world is consistent with GPVI being less involved in physiological hemostatic processes but participating in arterial thrombosis. This review will highlight the key aspects of GPVI contributions to platelet biology and concentrate on the interaction with recently identified ligands, with a focus on fibrin and fibrinogen, discussing the role of these interactions in the growth and stability of thrombi. We will also discuss important therapeutic developments that target GPVI to modulate platelet function while minimizing bleeding outcomes.

Long-term hypercoagulability, endotheliopathy and inflammation following acute SARS-CoV-2 infection

INTRODUCTION

both symptomatic and asymptomatic SARS-CoV-2 infections - coined Coronavirus disease 2019 (COVID-19) - have been linked to a higher risk of cardiovascular events after recovery.

AREAS COVERED

our review aims to summarize the latest evidence on the increased thrombotic and cardiovascular risk in recovered COVID-19 patients and to examine the pathophysiological mechanisms underlying the interplay among endothelial dysfunction, inflammatory response and coagulation in long-COVID. We performed a systematic search of studies on hypercoagulability, endothelial dysfunction and inflammation after SARS-CoV-2 infection.

EXPERT OPINION

endothelial dysfunction is a major pathophysiological mechanism responsible for most clinical manifestations in COVID-19. The pathological activation of endothelial cells by a virus infection results in a pro-adhesive and chemokine-secreting phenotype, which in turn promotes the recruitment of circulating leukocytes. Cardiovascular events after COVID-19 appear to be related to persistent immune dysregulation. Patients with long-lasting symptoms display higher amounts of proinflammatory molecules such as tumor necrosis factor-α, interferon γ and interleukins 2 and 6. Immune dysregulation can trigger the activation of the coagulation pathway. The formation of extensive microclots in vivo, both during acute COVID-19 and in long-COVID-19, appears to be a relevant mechanism responsible for persistent symptoms and cardiovascular events.