Safety and efficacy of different prophylactic anticoagulation dosing regimens in critically and non-critically ill patients with COVID-19: A systematic review and meta-analysis of randomized controlled trials

COVID-19 venous thromboembolism prophylaxis guidelines in pediatrics

INTRODUCTION

SARS-CoV-2 (COVID-19) infection and multisystem inflammatory syndrome in children (MIS-C) are risk factors for venous thromboembolism (VTE). Guidelines for VTE prophylaxis were established at our institution at the beginning of the pandemic. Patients who had any VTE risk factors in addition to COVID-19 met criteria for anticoagulation prophylaxis. Patients who were diagnosed with MIS-C met criteria regardless of additional risk factors.

MATERIALS AND METHODS

We conducted a retrospective review of patients admitted with COVID-19 or MIS-C to determine compliance with VTE prophylaxis guidelines and to evaluate the incidence of VTE and bleeding events in our population.

RESULTS AND CONCLUSIONS

Among a total of 678 patients admitted with COVID-19 or MIS-C, 519 (76 %) patients met criteria for VTE prophylaxis and 348 (65.6 %) started prophylaxis. Logistic regression analysis identified a personal or family history of thrombosis or thrombophilia, diagnosis of MIS-C, admission to the intensive care unit, and presence of a central venous catheter as significantly associated with starting VTE prophylaxis. There were 18 patients who developed VTE. Minor bleeding events occurred in 19 patients (5 %), patient important bleeding, no intervention occurred in 8 patients (2 %), clinically relevant nonmajor bleeding in 8 patients (2 %), and major bleeding in 10 patients (3 %). The incidence of VTE in our patients with COVID-19 and MIS-C is similar to VTE rates at other institutions. We found that universally recognized VTE risk factors were appropriate to include as risk factors for thrombosis in hospitalized children with COVID-19 and MIS-C.

Effect of Metagenomic Next-Generation Sequencing on Clinical Outcomes of Patients With Severe Community-Acquired Pneumonia in the ICU: A Multicenter, Randomized Controlled Trial

BACKGROUND

Metagenomic next-generation sequencing (mNGS) was previously established as a method that can increase the pathogen identification rate in patients with severe community-acquired pneumonia (SCAP).

RESEARCH QUESTION

What is the impact on clinical outcomes of mNGS of BAL fluid (BALF) in patients with SCAP in the ICU?

STUDY DESIGN AND METHODS

A multicenter, randomized controlled, open-label clinical trial was conducted in 10 ICUs. Patients were randomized in a 1:1 ratio to undergo BALF assessment with conventional microbiological tests (CMTs) only (ie, the CMT group) or BALF assessment with both mNGS and CMTs (ie, the mNGS group). The primary outcome was the time to clinical improvement, defined as the time from randomization to either an improvement of two points on a six-category ordinal scale or discharge from the ICU, whichever occurred first.

RESULTS

A total of 349 patients were randomized to treatment between January 1, 2021, and November 18, 2022; 170 were assigned to the CMT group and 179 to the mNGS group. In the intention-to-treat analysis, the time to clinical improvement was better in the mNGS group than in the CMT group (10 days vs 13 days; difference, -2.0 days; 95% CI, -3.0 to 0.0 days). Similar results were obtained in the per-protocol analysis. The proportion of patients with clinical improvement within 14 days was significantly higher in the mNGS group (62.0%) than in the CMT group (46.5%). There was no significant difference in other secondary outcomes.

INTERPRETATION

Compared with the use of CMTs alone, mNGS combined with CMTs reduced the time to clinical improvement for patients with SCAP.

CLINICAL TRIAL REGISTRATION

ChiCTR2000037894.

Impact of the COVID-19 Pandemic on Pharmacist Interventions: A Retrospective Study with Inpatients in a University Hospital

Background

Despite growing interest in understanding the challenges faced by multidisciplinary health teams during the COVID-19 pandemic, there is a lack of studies specifically focusing on changes in pharmacist interventions and drug-related problems.

Objectives

To analyze and compare the interventions performed by pharmacists during comprehensive medication management in the adult intensive care unit and general internal medicine ward of the University Hospital of the University of São Paulo, Brazil, for defined periods before the onset of the COVID-19 pandemic and during the pandemic itself.

Methods

All pharmacist interventions performed in relation to inpatient prescriptions from March to December 2019 (before the pandemic) and from March to December 2021 (during the pandemic) were collected and tabulated. These interventions were then classified according to the Pharmaceutical Care Network Europe (PCNE) system, version 9.1, and categorized based on first-level codes of the Anatomical Therapeutic Chemical classification system.

Results

The analysis revealed substantial changes in the patterns of pharmacist interventions and the therapeutic classes of drugs for COVID-19-positive and COVID-19-negative patients during the pandemic relative to patients in the pre-pandemic period. Among COVID-19-positive patients, interventions were predominantly related to enhancing patient safety (PCNE code P2), drug selection (C1), dose selection (C3), prescribing and dispensing processes (C5), the drug-use process (C6), and patient transfers between different levels of care (C8). The drug-related problems addressed by pharmacist interventions primarily involved COVID-19-positive patients in the pandemic period and were related to systemic hormonal preparations (excluding sex hormones and insulins), anti-infective agents for systemic use, nervous system and drugs for the blood and blood-forming organs.

Conclusion

The results of this study highlight the adaptability and competence of pharmacists in responding to critical scenarios such as the COVID-19 pandemic. These scenarios are characterized by new work dynamics, the hiring of additional professionals, an increase in the number of beds, the rapid evolution of evidence-based information, and drug shortages that necessitate the use of alternative medications. Pharmacists play a crucial role in ensuring patient safety during these difficult times.

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.

Risk of venous thromboembolic events after COVID-19 infection: a systematic review and meta-analysis

Data regarding the occurrence of venous thromboembolic events (VTE), including acute pulmonary embolism (PE) and deep vein thrombosis (DVT) in recovered COVID-19 patients are scant. We performed a systematic review and meta-analysis to assess the risk of acute PE and DVT in COVID-19 recovered subject. Following the PRIMSA guidelines, we searched Medline and Scopus to locate all articles published up to September 1st, 2022, reporting the risk of acute PE and/or DVT in patients recovered from COVID-19 infection compared to non-infected patients who developed VTE over the same follow-up period. PE and DVT risk were evaluated using the Mantel-Haenszel random effects models with Hazard ratio (HR) as the effect measure with 95% confidence interval (CI) while heterogeneity was assessed using Higgins I2 statistic. Overall, 29.078.950 patients (mean age 50.2 years, 63.9% males), of which 2.060.496 had COVID-19 infection, were included. Over a mean follow-up of 8.5 months, the cumulative incidence of PE and DVT in COVID-19 recovered patients were 1.2% (95% CI:0.9-1.4, I2: 99.8%) and 2.3% (95% CI:1.7-3.0, I2: 99.7%), respectively. Recovered COVID-19 patients presented a higher risk of incident PE (HR: 3.16, 95% CI: 2.63-3.79, I2 = 90.1%) and DVT (HR: 2.55, 95% CI: 2.09-3.11, I2: 92.6%) compared to non-infected patients from the general population over the same follow-up period. Meta-regression showed a higher risk of PE and DVT with age and with female gender, and lower risk with longer follow-up. Recovered COVID-19 patients have a higher risk of VTE events, which increase with aging and among females.

The intersection of obesity and (long) COVID-19: Hypoxia, thrombotic inflammation, and vascular endothelial injury

The role of hypoxia, vascular endothelial injury, and thrombotic inflammation in worsening COVID-19 symptoms has been generally recognized. Damaged vascular endothelium plays a crucial role in forming in situ thrombosis, pulmonary dysfunction, and hypoxemia. Thrombotic inflammation can further aggravate local vascular endothelial injury and affect ventilation and blood flow ratio. According to the results of many studies, obesity is an independent risk factor for a variety of severe respiratory diseases and contributes to high mechanical ventilation rate, high mortality, and slow recovery in COVID-19 patients. This review will explore the mechanisms by which obesity may aggravate the acute phase of COVID-19 and delay long COVID recovery by affecting hypoxia, vascular endothelial injury, and thrombotic inflammation. A systematic search of PubMed database was conducted for papers published since January 2020, using the medical subject headings of "COVID-19" and "long COVID" combined with the following keywords: "obesity," "thrombosis," "endothelial injury," "inflammation," "hypoxia," "treatment," and "anticoagulation." In patients with obesity, the accumulation of central fat restricts the expansion of alveoli, exacerbating the pulmonary dysfunction caused by SARS-CoV-2 invasion, inflammatory damage, and lung edema. Abnormal fat secretion and immune impairment further aggravate the original tissue damage and inflammation diffusion. Obesity weakens baseline vascular endothelium function leading to an early injury and pre-thrombotic state after infection. Enhanced procoagulant activity and microthrombi promote early obstruction of the vascular. Obesity also prolongs the duration of symptoms and increases the risk of sequelae after hospital discharge. Persistent viral presence, long-term inflammation, microclots, and hypoxia may contribute to the development of persistent symptoms, suggesting that patients with obesity are uniquely susceptible to long COVID. Early interventions, including supplemental oxygen, comprehensive antithrombotic therapy, and anti-inflammatory drugs, show effectiveness in many studies in the prevention of serious hypoxia, thromboembolic events, and systemic inflammation, and are therefore recommended to reduce intensive care unit admission, mortality, and sequelae.

The Effect of Heparin Full-Dose Anticoagulation on Survival of Hospitalized, Non-critically Ill COVID-19 Patients: A Meta-analysis of High Quality Studies

BACKGROUND

International COVID-19 guidelines recommend thromboprophylaxis for non-critically ill inpatients to prevent thrombotic complications. It is still debated whether full-dose thromboprophylaxis reduces all-cause mortality. The main aim of this updated systematic review and meta-analysis is to evaluate the effect of full-dose heparin-based thromboprophylaxis on survival in hospitalized non-critically ill COVID-19 patients.

METHODS

A systematic review was performed across Pubmed/Medline, EMBASE, Cochrane Central Register of clinical trials, Clinicaltrials.gov, and medRxiv.org from inception to November 2022. We conducted a meta-analysis of randomized clinical trials (RCTs) comparing full-dose heparin-based anticoagulation to prophylactic or intermediate dose anticoagulation or standard treatment in hospitalized non-critically ill COVID-19 patients. The risk of bias was assessed using the Cochrane risk-of-bias tool for randomized trials and Grading of Recommendations Assessment, Development and Evaluation was applied. The primary outcome was all-cause mortality at the longest follow-up available.

RESULTS

We identified 6 multicenter RCTs involving 3297 patients from 13 countries across 4 continents. The rate of all-cause mortality was 6.2% (103/1662) in the full-dose group vs 7.7% (126/1635) in the prophylactic or intermediate dose group (Risk Ratio [RR] = 0.76; 95% confidence interval [CI] = 0.59-0.98; P = 0.037). The probabilities of any mortality difference and of NNT ≤ 100 were estimated at 98.2% and 84.5%, respectively. The risk of bias was low for all included RCTs and the strength of the evidence was "moderate."

CONCLUSION

Our meta-analysis of high-quality multicenter RCTs suggests that full-dose anticoagulation with heparin or low molecular weight heparin reduces all-cause mortality in hospitalized non-critically ill COVID-19 patients.

STUDY REGISTRATION

PROSPERO, review no. CRD42022348993.

The Conundrum of Anticoagulation for Hospitalized Patients with Covid-19

Thrombosis in patients with coronavirus disease 2019 (Covid-19) is driven by complex interactions between immune, complement, fibrinolytic, endothelial, and coagulation systems.1 In addition to venous thromboembolism (VTE), microthrombi have also been implicated in contributing to end-organ damage, such as acute respiratory distress syndrome and kidney dysfunction, as well as to overall mortality.1 As available therapies, variants, and vaccines have evolved, so have reported rates of VTE attributable to Covid-19.

Thromboprophylaxis in Hospitalized Non-Critically Ill Patients With Mild-to-Moderate COVID-19 Infection: A Systematic Review and Meta-Analysis

The prevalence of venous thromboembolism is high in patients with COVID-19, despite prophylactic anticoagulation. The evidence that supports the preferred thromboprophylaxis regimen in non-critically ill patients with mild to moderate COVID-19 is still limited. Therefore, this systematic review and meta-analysis aimed to compare the clinical outcomes of hospitalized patients with mild to moderate COVID-19 who received standard thromboprophylaxis anticoagulation with intermediate to high prophylaxis regimens. We systematically searched MEDLINE and Embase databases for published studies until August 17th, 2022. We included studies on patients with mild to moderate COVID-19 who received thromboprophylaxis during their hospital stay. Patients who received standard prophylaxis dose "control group" were compared to patients who received intermediate to high prophylaxis "intervention group". Random effect models were used when pooling crude numbers and adjusted effect estimates of study outcomes. A comprehensive analysis was conducted, encompassing seven studies involving a total of 1931 patients. The risk of all-cause thrombosis was not statistically different between the two groups (risk ratio [RR] 1.48, 95% confidence interval [CI] [0.11, 20.21]). The risk of minor bleeding was reported to be lower in patients who received intermediate to high prophylaxis (RR 0.64, 95% CI 0.21, 1.97), while had a higher risk of major bleeding compared with the standard prophylaxis (RR 1.40, 95% CI 0.43, 4.61); however, did not reach the statistical significance. The overall risk for all hospital mortality favored the utilization of intermediate to high doses over the standard thromboprophylaxis dosing (RR 0.47, 95%CI 0.29, 0.75). In medically ill patients with COVID-19, there is no difference between standard and intermediate to high prophylaxis dosing regarding thrombosis and bleeding. However, it appears that intermediate to high prophylaxis regimens are linked to additional survival benefits.

Efficacy and safety of two heparin regimens for prevention of venous thromboembolism in hospitalized patients with COVID-19: a meta-analysis

Venous thromboembolism (VTE) is common in patients with coronavirus disease-2019 (COVID-19). The optimal heparin regimen remains unknown and should balance thromboembolic and bleeding risks. The aim of this study was to evaluate the efficacy and safety of standard or higher heparin regimens for the prevention of VTE in patients hospitalized due to COVID-19. We performed a systematic literature search; studies reporting on hospitalized patients with COVID-19 who received standard heparin prophylaxis vs. high (intermediate or therapeutic) heparin regimens were included if outcome events were reported by treatment group and more than 10 patients were included. Primary study outcome was in-hospital VTE. Secondary study outcomes were major bleeding (MB), all-cause death, fatal bleeding and fatal pulmonary embolism. Overall, 33 studies (11,387 patients) were included. Venous thromboembolic events occurred in 5.2% and in 8.2% of patients who received heparin prophylaxis with at high-dose or standard-dose, respectively (RR 0.71, 95% CI 0.55-0.90, I2 48.8%). MB was significantly higher in patients who received high- compared to the standard-dose (4.2% vs 2.2%, RR 1.94, 95% CI 1.47-2.56, I2 18.1%). Sub-analyses showed a slight benefit associated with high-dose heparin in patients admitted to non-intensive care unit (ICU) but not in those to ICU. No significant differences were observed for mortality outcomes. Heparin prophylaxis at high-dose reduces the risk of VTE, but increased the risk of MB compared to the standard-dose. No clinical benefit for heparin high-dose was observed for ICU setting, but its role in the non-ICU deserves further evaluation. PROSPERO registration number: CRD42021252550.

Therapeutic vs. prophylactic anticoagulation in COVID-19 patients: a systematic review and meta-analysis of real-world studies

INTRODUCTION

Coagulopathy, in the form of either venous or arterial thromboembolism, is one of the most severe sequelae of coronavirus disease (COVID-19) and has been associated with poorer outcomes. However, the role of therapeutic anticoagulation (tAC) or prophylactic anticoagulation (pAC) in COVID-19 patients has not been definitely established. Therefore, the aim of this systematic review and meta-analysis was to gather all the available real-world data in the field and to provide a reliable effect size of the effect on mortality of tAC compared to pAC in COVID-19 patients.

EVIDENCE ACQUISITION

Real-world studies (RWS) were identified by searching electronic databases from inception to 31st October, 2021. Randomized controlled trials were excluded. Mortality and bleedings were considered as primary and secondary outcomes, respectively.

EVIDENCE SYNTHESIS

10 RWS and 5541 patients were included in the analysis. Overall, tAC was associated with lower mortality (HR=0.62, 95% CI: 0.54-0.71). There was asymmetry at the funnel plot suggesting publication bias, that was not confirmed at the Egger test (P=0.07). For the secondary endpoint, there was a non-statistically significant tendency for more bleedings in patients treated with tAC compared to pAC (RR=1.75, 95% CI: 0.81-3.81).

CONCLUSIONS

Our meta-analysis, based on RWS and adjusted estimates of risk, suggests a survival benefit of tAC over pAC in COVID-19 patients in the real world.

Anti-coagulation therapy on COVID-19 patients: A systematic review and meta-analysis

A once often neglected virus from common practice has been demanding the attention of all researchers for the past decade ever since it started to infect humans from its usual wild habitats. The severe acute respiratory syndrome coronavirus 2 infection in humans is now found to have frequent manifestations of thromboembolic events as a result of a hyper-coagulable state. Anti-coagulants (ACs) have been suggested to overcome such a state, and studies have been conducted to assess its role. The objective of this meta-analysis is to determine the existence of such a role and its nature, either beneficial or not, and to assess the strength of this role if it exists. We have conducted an online search in the databases such as PubMed, Google scholar, Lancet, Elsevier, JAMA, Medline, and so on and concluded ten studies among 2562 that had results which were more precise and of better quality. The results of six studies favored the use of ACs, whereas one study showed no beneficial response and four studies discussed the effects of therapeutic versus prophylactic anti-coagulation. The result of our statistical analysis was that the odds ratio for mortality reduction of ACs in coronavirus disease 2019 (COVID-19) patients is 0.6757 (95% CI; 0.5148 to 0.961) and that for benefits of therapeutic ACs versus prophylactic ACs in COVID-19 patients is 0.809 (95% CI; 0.6137 to 1.1917). AC was associated with lower mortality and intubation among hospitalised COVID-19 patients. Compared with therapeutic AC, prophylactic AC was associated with lower mortality, although not statistically significant, and lower bleeding risks.

Anticoagulation and Antiplatelet Therapy for Prevention of Venous and Arterial Thrombotic Events in Critically Ill Patients With COVID-19: COVID-PACT

BACKGROUND

The efficacy and safety of prophylactic full-dose anticoagulation and antiplatelet therapy in critically ill COVID-19 patients remain uncertain.

METHODS

COVID-PACT (Prevention of Arteriovenous Thrombotic Events in Critically-ill COVID-19 Patients Trial) was a multicenter, 2×2 factorial, open-label, randomized-controlled trial with blinded end point adjudication in intensive care unit-level patients with COVID-19. Patients were randomly assigned to a strategy of full-dose anticoagulation or standard-dose prophylactic anticoagulation. Absent an indication for antiplatelet therapy, patients were additionally randomly assigned to either clopidogrel or no antiplatelet therapy. The primary efficacy outcome was the hierarchical composite of death attributable to venous or arterial thrombosis, pulmonary embolism, clinically evident deep venous thrombosis, type 1 myocardial infarction, ischemic stroke, systemic embolic event or acute limb ischemia, or clinically silent deep venous thrombosis, through hospital discharge or 28 days. The primary efficacy analyses included an unmatched win ratio and time-to-first event analysis while patients were on treatment. The primary safety outcome was fatal or life-threatening bleeding. The secondary safety outcome was moderate to severe bleeding. Recruitment was stopped early in March 2022 (≈50% planned recruitment) because of waning intensive care unit-level COVID-19 rates.

RESULTS

At 34 centers in the United States, 390 patients were randomly assigned between anticoagulation strategies and 292 between antiplatelet strategies (382 and 290 in the on-treatment analyses). At randomization, 99% of patients required advanced respiratory therapy, including 15% requiring invasive mechanical ventilation; 40% required invasive ventilation during hospitalization. Comparing anticoagulation strategies, a greater proportion of wins occurred with full-dose anticoagulation (12.3%) versus standard-dose prophylactic anticoagulation (6.4%; win ratio, 1.95 [95% CI, 1.08-3.55]; P=0.028). Results were consistent in time-to-event analysis for the primary efficacy end point (full-dose versus standard-dose incidence 19/191 [9.9%] versus 29/191 [15.2%]; hazard ratio, 0.56 [95% CI, 0.32-0.99]; P=0.046). The primary safety end point occurred in 4 (2.1%) on full dose and in 1 (0.5%) on standard dose (P=0.19); the secondary safety end point occurred in 15 (7.9%) versus 1 (0.5%; P=0.002). There was no difference in all-cause mortality (hazard ratio, 0.91 [95% CI, 0.56-1.48]; P=0.70). There were no differences in the primary efficacy or safety end points with clopidogrel versus no antiplatelet therapy.

CONCLUSIONS

In critically ill patients with COVID-19, full-dose anticoagulation, but not clopidogrel, reduced thrombotic complications with an increase in bleeding, driven primarily by transfusions in hemodynamically stable patients, and no apparent excess in mortality.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04409834.

Clinical and Genetic Risk Factors for Acute Incident Venous Thromboembolism in Ambulatory Patients With COVID-19

IMPORTANCE

The risk of venous thromboembolism (VTE) in ambulatory COVID-19 is controversial. In addition, the association of vaccination with COVID-19-related VTE and relevant clinical and genetic risk factors remain to be elucidated.

OBJECTIVE

To quantify the association between ambulatory COVID-19 and short-term risk of VTE, study the potential protective role of vaccination, and investigate clinical and genetic risk factors for post-COVID-19 VTE.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study of patients with COVID-19 from UK Biobank included participants with SARS-CoV-2 infection that was confirmed by a positive polymerase chain test reaction result between March 1, 2020, and September 3, 2021, who were then propensity score matched to COVID-19-naive people during the same period. Participants with a history of VTE who used antithrombotic drugs (1 year before index dates) or tested positive in hospital were excluded.

EXPOSURES

First infection with SARS-CoV-2, age, sex, ethnicity, socioeconomic status, obesity, vaccination status, and inherited thrombophilia.

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite VTE, including deep vein thrombosis or pulmonary embolism, which occurred 30 days after the infection. Hazard ratios (HRs) with 95% CIs were calculated using cause-specific Cox models.

RESULTS

In 18 818 outpatients with COVID-19 (10 580 women [56.2%]; mean [SD] age, 64.3 [8.0] years) and 93 179 matched uninfected participants (52 177 women [56.0%]; mean [SD] age, 64.3 [7.9] years), the infection was associated with an increased risk of VTE in 30 days (incidence rate of 50.99 and 2.37 per 1000 person-years for infected and uninfected people, respectively; HR, 21.42; 95% CI, 12.63-36.31). However, risk was substantially attenuated among the fully vaccinated (HR, 5.95; 95% CI, 1.82-19.5; interaction P = .02). In patients with COVID-19, older age, male sex, and obesity were independently associated with higher risk, with adjusted HRs of 1.87 (95% CI, 1.50-2.33) per 10 years, 1.69 (95% CI, 1.30-2.19), and 1.83 (95% CI, 1.28-2.61), respectively. Further, inherited thrombophilia was associated with an HR of 2.05 (95% CI, 1.15-3.66) for post-COVID-19 VTE.

CONCLUSIONS AND RELEVANCE

In this population-based cohort study of patients with COVID-19, ambulatory COVID-19 was associated with a substantially increased risk of incident VTE, but this risk was greatly reduced in fully vaccinated people with breakthrough infection. Older age, male sex, and obesity were clinical risk factors for post-COVID-19 VTE; factor V Leiden thrombophilia was additionally associated with double the risk, comparable with the risk of 10-year aging. These findings may reinforce the need for vaccination, inform VTE risk stratification, and call for targeted VTE prophylaxis strategies for unvaccinated outpatients with COVID-19.

Incidence, risk factors, and clinical impact of major bleeding in hospitalized patients with COVID-19: a sub-analysis of the CLOT-COVID Study

Background

The coronavirus disease 2019 (COVID-19) causes extensive coagulopathy and a potential benefit of anticoagulation therapy has been documented for prevention of thromboembolic events. Bleeding events has also been reported as a notable complication; whereas, the incidence, risks, and clinical impact of bleeding remain unclear.

Method

The CLOT-COVID Study was a nationwide, retrospective, multicenter cohort study on consecutive hospitalized patients with COVID-19 in Japan between April 2021 and September 2021. In this sub-analysis, we compared the characteristics of patients with and without major bleeding; moreover, we examined the risk factors for and clinical impact of bleeding events.

Results

Among 2882 patients with COVID-19, 57 (2.0%) had major bleeding. The incidence of major bleeding increased with COVID-19 severity as follows: 0.5%, 2.3%, and 12.3% in patients with mild, moderate, and severe COVID-19, respectively. COVID-19 severity, history of major bleeding, and anticoagulant type/dose were independently and additively associated with the bleeding incidence. Compared with patients without major bleeding, those with major bleeding exhibited a longer duration of hospitalization (9 [6–14] vs 28 [19–43] days, P < 0.001) and higher mortality during hospitalization (4.9% vs. 35.1%, P < 0.001).

Conclusions

In the real-world clinical practice, the incidence of major bleeding was not uncommon, especially in patients with severe COVID-19. Independent risk factors for major bleeding included history of major bleeding, COVID-19 severity, and anticoagulant use, which could be associated with poor clinical outcomes including higher mortality. Precise recognition of the risks for bleeding may be helpful for an optimal use of anticoagulants and for better outcomes in patients with COVID-19.

American Society of Hematology living guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19: January 2022 update on the use of therapeutic-intensity anticoagulation in acutely ill patients

BACKGROUND

COVID-19-related acute illness is associated with an increased risk of venous thromboembolism (VTE).

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in making decisions about the use of anticoagulation in patients with COVID-19.

METHODS

ASH formed a multidisciplinary guideline panel that included patient representatives and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process and performed systematic evidence reviews (through November 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess evidence and make recommendations, which were subject to public comment. This is an update to guidelines published in February 2021 as part of the living phase of these guidelines.

RESULTS

The panel made one additional recommendation. The panel issued a conditional recommendation in favor of therapeutic-intensity over prophylactic-intensity anticoagulation in patients with COVID-19-related acute illness who do not have suspected or confirmed VTE. The panel emphasized the need for an individualized assessment of risk of thrombosis and bleeding. The panel also noted that heparin (unfractionated or low molecular weight) may be preferred because of a preponderance of evidence with this class of anticoagulants.

CONCLUSION

This conditional recommendation was based on very low certainty in the evidence, underscoring the need for additional, high-quality, randomized controlled trials comparing different intensities of anticoagulation in patients with COVID-19-related acute illness.

Higher Dose Anticoagulation Cannot Prevent Disease Progression in COVID-19 Patients: A Systematic Review and Meta-Analysis

Implementation of higher dose (HD) thromboprophylaxis has been considered in patients infected with coronavirus disease 2019 (COVID-19). Our aim was to compare HD to standard dose (SD) thromboprophylaxis in COVID-19 patients. The protocol is registered on PROSPERO (CRD42021284808). We searched for randomised controlled studies (CENTRAL, Embase, Medline and medRxviv) that compared HD to SD anticoagulation in COVID-19 and analysed outcomes such as mortality, thrombotic events, bleedings, and disease progression. The statistical analyses were made using the random effects model. Fourteen articles were included (6253 patients). HD compared with SD showed no difference in mortality (OR 0.83 [95% CI 0.54−1.28]). The use of HD was associated with a decreased risk of thrombosis (OR 0.58 [95% CI 0.44−0.76]), although with an increased risk of major bleeding (OR 1.64 [95% CI 1.25−2.16]). The cohort with D-dimer < 1 mg/mL showed no effect (OR 1.19 [95% CI 0.67−2.11]), but in the case of D-dimer > 1 mg/mL, a tendency of lower risk in the HD group was observed (OR 0.56 [95% CI 0.31−1.00]). The need for intubation in moderately ill patients showed a nonsignificant lower likelihood in the HD group (OR 0.82 [95% CI 0.63−1.08]). We cannot advocate for HD in all COVID-19 patients, although it shows some nonsignificant benefits on disease progression in those with elevated D-dimer who do not need ICU admission.

Effect of therapeutic versus prophylactic anticoagulation therapy on clinical outcomes in COVID-19 patients: a systematic review with an updated meta-analysis

Background

Previous studies demonstrate a reduced risk of thrombosis and mortality with anticoagulant treatment in patients with COVID-19 than in those without anticoagulation treatment. However, an open question regarding the efficacy and safety of therapeutic anticoagulation (T-AC) versus a lower dose, prophylaxis anticoagulation (P-AC) in COVID-19 patients is still controversial.

Methods

We systematically reviewed currently available randomized clinical trials (RCTs) and observational studies (OBs) from January 8, 2019, to January 8, 2022, and compared prophylactic and therapeutic anticoagulant treatment in COVID-19 patients. The primary outcomes were risk of mortality, major bleeding, and the secondary outcomes included venous and arterial thromboembolism. Subgroup analysis was also performed between critically ill and non-critically ill patients with COVID-19 and between patients with higher and lower levels of D-dimer. Sensitivity analysis was performed to decrease the bias and the impact of population heterogeneity.

Results

We identified 11 RCTs and 17 OBs fulfilling our inclusion criteria. In the RCTs analyses, there was no statistically significant difference in the relative risk of mortality between COVID-19 patients with T-AC treatment and those treated with P-AC (RR 0.95, 95% CI, 0.78–1.15, P = 0.60). Similar results were also found in the OBs analyses (RR 1.21, 95% CI, 0.98–1.49, P = 0.08). The pooling meta-analysis using a random-effects model combined with effect sizes showed that in the RCTs and OBs analyses, patients with COVID-19 who received T-AC treatment had a significantly higher relative risk of the major bleeding event than those with P-AC treatment in COVID-19 patients (RCTs: RR 1.76, 95% CI, 1.19–2.62, P = 0.005; OBs: RR 2.39, 95% CI, 1.56–3.68, P < 0.0001). Compared with P-AC treatment in COVID-19 patients, patients with T-AC treatment significantly reduced the incidence of venous thromboembolism (RR 0.51, 95% CI, 0.39–0.67, P<0.00001), but it is not associated with arterial thrombosis events (RR 0.97, 95% CI, 0.66–1.42, P = 0.87). The subgroup analysis of OBs shows that the mortality risk significantly reduces in critically ill COVID-19 patients treated with T-AC compared with those with P-AC treatment (RR 0.58, 95% CI, 0.39–0.86, P = 0.007), while the mortality risk significantly increases in non-critically ill COVID-19 patients treated with T-AC (RR 1.56, 95% CI, 1.34–1.80, P < 0.00001). In addition, T-AC treatment does not reduce the risk of mortality in COVID-19 patients with high d-dimer levels in RCTs. Finally, the overall sensitivity analysis after excluding two RCTs studies remains consistent with the previous results.

Conclusions

In our integrated analysis of included RCTs and OBs, there is no significant difference between the mortality of T-AC and P-AC treatment in unselected patients with COVID-19. T-AC treatment in COVID-19 patients significantly reduced the incidence of venous thromboembolism but showed a higher risk of bleeding than those with P-AC treatment. In addition, P-AC treatment was superior to T-AC treatment in non-critically ill COVID-19 patients, the evidence supporting the necessity for T-AC treatment in critically ill COVID-19 patients came only from OBs.

Trial registration

Protocol registration: The protocol was registered at PROSPERO (CRD42021293294).

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00408-9.

A comparison of three thromboprophylaxis regimens in critically ill COVID-19 patients: An analysis of real-world data

Introduction

Thrombotic complications of coronavirus disease 2019 (COVID-19) have received considerable attention. Although numerous conflicting findings have compared escalated thromboprophylaxis doses with a standard dose to prevent thrombosis, there is a paucity of literature comparing clinical outcomes in three different anticoagulation dosing regimens. Thus, we investigated the effectiveness and safety profiles of standard, intermediate, and high-anti-coagulation dosing strategies in COVID-19 critically ill patients.

Methodology

This retrospective multicenter cohort study of intensive care unit (ICU) patients from the period of April 2020 to August 2021 in four Saudi Arabian centers. Inclusion criteria were age ≥ 18 years, diagnosis with severe or critical COVID-19 infection, and receiving prophylactic anticoagulant dose within 24-48 h of ICU admission. The primary endpoint was a composite of thrombotic events, with mortality rate and minor or major bleeding serving as secondary endpoints. We applied survival analyses with a matching weights procedure to control for confounding variables in the three arms.

Results

A total of 811 patient records were reviewed, with 551 (standard-dose = 192, intermediate-dose = 180, and high-dose = 179) included in the analysis. After using weights matching, we found that the standard-dose group was not associated with an increase in the composite thrombotic events endpoint when compared to the intermediate-dose group {19.8 vs. 25%; adjusted hazard ratio (aHR) =1.46, [95% confidence of interval (CI), 0.94-2.26]} or when compared to high-dose group [19.8 vs. 24%; aHR = 1.22 (95% CI, 0.88-1.72)]. Also, there were no statistically significant differences in overall in-hospital mortality between the standard-dose and the intermediate-dose group [51 vs. 53.4%; aHR = 1.4 (95% CI, 0.88-2.33)] or standard-dose and high-dose group [51 vs. 61.1%; aHR = 1.3 (95% CI, 0.83-2.20)]. Moreover, the risk of major bleeding was comparable in all three groups [standard vs. intermediate: 4.8 vs. 2.8%; aHR = 0.8 (95% CI, 0.23-2.74); standard vs. high: 4.8 vs. 9%; aHR = 2.1 (95% CI, 0.79-5.80)]. However, intermediate-dose and high-dose were both associated with an increase in minor bleeding incidence with aHR = 2.9 (95% CI, 1.26-6.80) and aHR = 3.9 (95% CI, 1.73-8.76), respectively.

Conclusion

Among COVID-19 patients admitted to the ICU, the three dosing regimens did not significantly affect the composite of thrombotic events and mortality. Compared with the standard-dose regimen, intermediate and high-dosing thromboprophylaxis were associated with a higher risk of minor but not major bleeding. Thus, these data recommend a standard dose as the preferred regimen.

Clinical features of thrombosis and bleeding in COVID-19

Infection with the SARS-CoV-2 virus, resulting in COVID-19 disease, has presented a unique scenario associated with high rates of thrombosis. The risk of venous thrombosis is some three- to sixfold higher than for patients admitted to a hospital for other indications, and for patients who have thrombosis, mortality appears to increase. Thrombosis may be a presenting feature of COVID-19. Pulmonary thrombi are the most frequent events, some related to deep vein thrombosis, but also to in situ microvascular and macrovascular thrombosis. Other venous thromboses include catheter- and circuit-associated in patients requiring hemofiltration and extracorporeal membrane oxygenation. Arterial thrombosis is less commonly documented, with 3% of patients in intensive care units having major arterial strokes and up to 9% having myocardial infarction, both of which are most likely multifactorial. Risk factors for thrombosis above those already documented in hospital settings include duration of COVID-19 symptoms before admission to the hospital. Laboratory parameters associated with higher risk of thrombosis include higher D-dimer, low fibrinogen, and low lymphocyte count, with higher factor VIII and von Willebrand factor levels indicative of more severe COVID-19 infection. All patients should receive thromboprophylaxis when admitted with COVID-19 infection, but the dose and length of treatment are still debated. Thrombosis continues to be treated according to standard VTE guidelines, but adjustments may be needed depending on other factors relevant to the patient's admission.

Efficacy and safety of hyperbaric oxygen treatment to treat COVID-19 pneumonia: a living systematic review update

INTRODUCTION

As the COVID-19 pandemic evolves, new effective treatment options are essential for reducing morbidity and mortality as well as the strain placed on the healthcare system. Since publication of our initial review on hyperbaric oxygen treatment (HBOT) for hypoxaemic COVID-19 patients, interest in HBOT for COVID-19 has grown and additional studies have been published.

METHODS

For this living systematic review update the previously published search strategy (excluding Google Scholar) was adopted with an extension from 01 February 2021 to 01 April 2022. Study inclusion criteria, data extraction, risk of bias estimation and dispute resolution methods were repeated.

RESULTS

Two new studies enrolling 127 patients were included in this update, taking the total to eight studies with 224 patients. Both new studies were randomised controlled trials, one at moderate and one at high risk of bias. Across these eight studies, 114 patients were treated with HBOT. All reported improved clinical outcomes without observation of any serious adverse events. Meta-analysis remained unjustified given the high heterogeneity between studies and incomplete reporting.

CONCLUSIONS

This updated living systematic review provides further evidence on the safety and effectiveness of HBOT to treat acute hypoxaemic COVID-19 patients.

Use of anticoagulants in patients with COVID-19: a living systematic review and meta-analysis

OBJECTIVE

To answer questions related to the use of anticoagulants in the treatment of COVID-19 patients.

METHODS

This was a systematic review and meta-analysis of phase 3 randomized controlled trials comparing the use of anticoagulants in non-hospitalized and hospitalized COVID-19 patients. We searched the following databases: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov from their inception to January 22, 2022. The risk of bias was assessed by the Cochrane risk-of-bias tool, and the quality of evidence was assessed by the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

A total of 401 studies were initially selected. Of those, 9 met the inclusion criteria and were therefore analyzed (a total of 6,004 patients being analyzed). In non-hospitalized COVID-19 patients, no significant difference was found between post-discharge prophylactic anticoagulation and no intervention regarding venous thromboembolism or bleeding at 30 days. In hospitalized COVID-19 patients, full anticoagulation resulted in a slight reduction in thrombotic events at 30 days (risk difference, -0.03; 95% CI, -0.06 to -0.00; p = 0.04; I2 = 78%), the quality of evidence being moderate. However, no significant difference was found between full anticoagulation and no intervention regarding the risk of major bleeding, the quality of evidence being very low. No significant difference was found between intermediate- and standard-dose prophylactic anticoagulation (risk difference, -0.01; 95% CI, -0.07 to 0.06; p = 0.81; I2 = 0%), the quality of evidence being very low.

CONCLUSIONS

Therapeutic anticoagulation appears to have no effect on mortality in COVID-19 patients, resulting in a slight reduction in venous thromboembolism in hospitalized patients.

Efficacy and safety of intensified versus standard prophylactic anticoagulation therapy in patients with Covid-19: a systematic review and meta-analysis

Background

Randomized controlled trials (RCTs) have reported inconsistent effects from intensified anticoagulation on clinical outcomes in coronavirus disease 2019 (COVID-19). We performed an aggregate data meta-analysis from available trials to quantify effect on nonfatal and fatal outcomes and identify subgroups who may benefit.

Methods

We searched multiple databases for RCTs comparing intensified (intermediate or therapeutic dose) vs prophylactic anticoagulation in adults with laboratory-confirmed COVID-19 through 19 January 2022. We used random-effects meta-analysis to estimate pooled risk ratios for mortality, thrombotic, and bleeding events (at end of follow-up or discharge) and performed subgroup analysis for clinical setting and dose of intensified anticoagulation.

Results

Eleven RCTs were included (N = 5873). Intensified vs prophylactic anticoagulation was not associated with a mortality reduction up to 45 days (risk ratio [RR], 0.93 [95% confidence interval {CI}, .79–1.10]). There was a possible signal of mortality reduction for non–intensive care unit (ICU) patients, although with low precision and high heterogeneity (5 studies; RR, 0.84 [95% CI, .49–1.44]; I² = 75%). Risk of venous thromboembolism was reduced (RR, 0.53 [95% CI, .41–.69]; I² = 0%), with effect driven by therapeutic rather than intermediate dosing (interaction P = .04). Major bleeding was increased with intensified anticoagulation (RR, 1.73 [95% CI, 1.17–2.56]) with no interaction for dosing and clinical setting.

Conclusions

Intensified anticoagulation has no effect on mortality among hospitalized adults with COVID-19 and is associated with increased bleeding risk. The observed reduction in venous thromboembolism risk and trend toward reduced mortality in non-ICU settings requires exploration in additional RCTs.

Clinical Trials Registration. CRD42021273449 (PROSPERO).

Clinical update on COVID-19 for the emergency and critical care clinician: Medical management

INTRODUCTION

Coronavirus disease of 2019 (COVID-19) has resulted in millions of cases worldwide. As the pandemic has progressed, the understanding of this disease has evolved.

OBJECTIVE

This is the second part in a series on COVID-19 updates providing a focused overview of the medical management of COVID-19 for emergency and critical care clinicians.

DISCUSSION

COVID-19, caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), has resulted in significant morbidity and mortality worldwide. A variety of medical therapies have been introduced for use, including steroids, antivirals, interleukin-6 antagonists, monoclonal antibodies, and kinase inhibitors. These agents have each demonstrated utility in certain patient subsets. Prophylactic anticoagulation in admitted patients demonstrates improved outcomes. Further randomized data concerning aspirin in outpatients with COVID-19 are needed. Any beneficial impact of other therapies, such as colchicine, convalescent plasma, famotidine, ivermectin, and vitamins and minerals is not present in reliable medical literature. In addition, chloroquine and hydroxychloroquine are not recommended.

CONCLUSION

This review provides a focused update of the medical management of COVID-19 for emergency and critical care clinicians to help improve care for these patients.

Anticoagulant Treatment in Severe ARDS COVID-19 Patients

Patients with COVID-19 may complicate their evolution with thromboembolic events. Incidence of thromboembolic complications are high and also, patients with the critically-ill disease showed evidence of microthrombi and microangiopathy in the lung probably due to endothelial damage by directly and indirectly injured endothelial and epithelial cells. Pulmonary embolism, deep venous thrombosis and arterial embolism were reported in patients with COVID-19, and several analytical abnormal coagulation parameters have been described as well. D-dimer, longer coagulation times and lower platelet counts have been associated with poor outcomes. The use of anticoagulation or high doses of prophylactic heparin is controversial. Despite the use of anticoagulation or high prophylactic dose of heparin have been associated with better outcomes in observational studies, only in patients with non-critically ill disease benefits for anticoagulation was observed. In critically-ill patient, anticoagulation was not associated with better outcomes. Other measures such as antiplatelet therapy, fibrinolytic therapy or nebulized anticoagulants are being studied in ongoing clinical trials.

Short and Long-Term Impact of COVID-19 Infection on Previous Respiratory Diseases

On March 11, 2020, the World Health Organization declared Coronavirus Disease 2019 (COVID-19) a pandemic. Till now, it affected 452.4 million (Spain, 11.18 million) persons all over the world with a total of 6.04 million of deaths (Spain, 100,992). It is observed that 75% of hospitalized COVID-19 patients have at least one COVID-19 associated comorbidity. It was shown that people with underlying chronic illnesses are more likely to get it and grow seriously ill. Individuals with COVID-19 who have a past medical history of cardiovascular disorder, cancer, obesity, chronic lung disease, diabetes, or neurological disease had the worst prognosis and are more likely to develop acute respiratory distress syndrome or pneumonia. COVID-19 can affect the respiratory system in a variety of ways and across a spectrum of levels of disease severity, depending on a person's immune system, age and comorbidities. Symptoms can range from mild, such as cough, shortness of breath and fever, to critical disease, including respiratory failure, shock and multi-organ system failure. So, COVID-19 infection can cause overall worsening of these previous respiratory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), interstitial lung disease, etc. This review aims to provide information on the impact of the COVID-19 disease on pre-existing lung comorbidities.

Efficacy and safety of intensified versus standard prophylactic anticoagulation therapy in patients with Covid-19: a systematic review and meta-analysis

Background

Randomised controlled trials (RCTs) have reported inconsistent effects from intensified anticoagulation on clinical outcomes in Covid-19. We performed an aggregate data meta-analysis from available trials to quantify effect on non-fatal and fatal outcomes and identify subgroups who may benefit.

Methods

We searched multiple databases for RCTs comparing intensified (intermediate or therapeutic dose) versus standard prophylactic dose anticoagulation in adults with laboratory-confirmed Covid-19 through 19 January 2022. The primary efficacy outcome was all-cause mortality at end of follow-up or discharge. We used random effects meta-analysis to estimate pooled risk ratios for mortality, thrombotic, and bleeding events, and performed subgroup analysis for clinical setting and dose of intensified anticoagulation.

Results

Eleven RCTs were included (n = 5873). Intensified anticoagulation was not associated with a reduction in mortality for up to 45 days compared with prophylactic anticoagulation: 17.5% (501/2861) died in the intensified anticoagulation group and 18.8% (513/2734) died in the prophylactic anticoagulation group, relative risk (RR) 0.93; 95%CI, 0.79 - 1.10. On subgroup analysis, there was a possible signal of mortality reduction for inpatients admitted to general wards, although with low precision and high heterogeneity (5 studies; RR 0.84; 95% CI, 0.49 - 1.44; I 2 = 75%) and not significantly different to studies performed in the ICU (interaction P = 0.51). Risk of venous thromboembolism was reduced with intensified anticoagulation compared with prophylaxis (8 studies; RR 0.53, 95%CI 0.41 - 0.69; I 2 = 0%). This effect was driven by therapeutic rather than intermediate dosing on subgroup analysis (interaction P =0.04). Major bleeding was increased with use of intensified anticoagulation (RR 1.73, 95% CI 1.17 - 2.56) with no interaction for dosing and clinical setting.

Conclusion

Intensified anticoagulation has no effect on short term mortality among hospitalised adults with Covid-19 and is associated with increased risk of bleeding. The observed reduction in venous thromboembolism risk and trend towards reduced mortality in non-ICU hospitalised patients requires exploration in additional RCTs.

Summary

In this aggregate data meta-analysis, use of intensified anticoagulation had no effect on short term mortality among hospitalised adults with Covid-19 and was associated with increased risk of bleeding.

The association between anticoagulation and adverse outcomes after a positive SARS-CoV-2 test among older outpatients: A population-based cohort study

Introduction

Anticoagulation may improve outcomes in patients with COVID-19 when started early in the course of illness.

Materials and methods

This was a population-based cohort study using linked administrative datasets of outpatients aged ≥65 years old testing positive for SARS-CoV-2 between January 1 and December 31, 2020 in Ontario, Canada. The key exposure was anticoagulation with warfarin or direct oral anticoagulants before COVID-19 diagnosis. We calculated propensity scores and used matching weights (MWs) to reduce baseline differences between anticoagulated and non-anticoagulated patients. The primary outcome was a composite of death or hospitalization within 60 days of a positive SARS-CoV-2 test. We used the Kaplan-Meier method and cumulative incidence functions to estimate risk of the primary and component outcomes at 60 days.

Results

We studied 23,159 outpatients (mean age 78.5 years; 13,474 [58.2%] female), among whom 3200 (13.8%) deaths and 3183 (13.7%) hospitalizations occurred within 60 days of the SARS-CoV-2 test. After application of MWs, the 60-day risk of death or hospitalization was 29.2% (95% CI 27.4%–31.2%) for anticoagulated individuals and 32.1% (95% CI 30.7%–33.5%) without anticoagulation (absolute risk difference [ARD], −2.9%; p = 0.005). Anticoagulation was also associated with a lower risk of death: 18.6% (95% CI 17.0%–20.2%) with anticoagulation and 20.9% (95% CI 19.7%–22.2%) in non-anticoagulated patients (ARD -2.3%; p = 0.005).

Conclusions

Among outpatients aged ≥65 years, oral anticoagulation at the time of a positive SARS-CoV-2 test was associated with a lower risk of a composite of death or hospitalization within 60 days.

The Anti-Coronavirus Therapy (ACT) trials: design, baseline characteristics, and challenges

Background

Effective treatments for COVID-19 are urgently needed, but conducting randomized trials during the pandemic has been challenging.

Methods

The Anti-Coronavirus Therapy (ACT) trials are parallel factorial international trials that aimed to enroll 3500 outpatients and 2500 inpatients with symptomatic COVID-19. The outpatient trial is evaluating colchicine vs usual care, and aspirin vs usual care. The primary outcome for the colchicine randomization is hospitalization or death, and for the aspirin randomization, it is major thrombosis, hospitalization, or death. The inpatient trial is evaluating colchicine vs usual care, and the combination of rivaroxaban 2.5 mg twice daily and aspirin 100 mg once daily vs usual care. The primary outcome for the colchicine randomization is need for high-flow oxygen, need for mechanical ventilation, or death, and for the rivaroxaban plus aspirin randomization, it is major thrombotic events, need for high-flow oxygen, need for mechanical ventilation, or death.

Results

At the completion of enrollment on February 10, 2022, the outpatient trial had enrolled 3917 patients, and the inpatient trial had enrolled 2611 patients. Challenges encountered included lack of preliminary data about the interventions under evaluation, uncertainties related to the expected event rates, delays in regulatory and ethics approvals, and in obtaining study interventions, as well as the changing pattern of the COVID-19 pandemic.

Conclusions

The ACT trials will determine the efficacy of anti-inflammatory therapy with colchicine, and antithrombotic therapy with aspirin given alone or in combination with rivaroxaban, across the spectrum of mild, moderate, and severe COVID-19. Lessons learned from the conduct of these trials will inform planning of future trials.

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

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

Randomized trials of therapeutic heparin for COVID-19: A meta-analysis

BACKGROUND

Pulmonary endothelial injury and microcirculatory thromboses likely contribute to hypoxemic respiratory failure, the most common cause of death, in patients with COVID-19. Randomized controlled trials (RCTs) suggest differences in the effect of therapeutic heparin between moderately and severely ill patients with COVID-19. We did a systematic review and meta-analysis of RCTs to determine the effects of therapeutic heparin in hospitalized patients with COVID-19.

METHODS

We searched PubMed, Embase, Web of Science, medRxiv, and medical conference proceedings for RCTs comparing therapeutic heparin with usual care, excluding trials that used oral anticoagulation or intermediate doses of heparin in the experimental arm. Mantel-Haenszel fixed-effect meta-analysis was used to combine odds ratios (ORs).

RESULTS AND CONCLUSIONS

There were 3 RCTs that compared therapeutic heparin to lower doses of heparin in 2854 moderately ill ward patients, and 3 RCTs in 1191 severely ill patients receiving critical care. In moderately ill patients, there was a nonsignificant reduction in all-cause death (OR, 0.76; 95% CI, 0.57-1.02), but significant reductions in the composite of death or invasive mechanical ventilation (OR, 0.77; 95% CI, 0.60 0.98), and death or any thrombotic event (OR, 0.58; 95% CI, 0.45-0.77). Organ support-free days alive (OR, 1.29; 95% CI, 1.07-1.57) were significantly increased with therapeutic heparin. There was a nonsignificant increase in major bleeding. In severely ill patients, there was no evidence for benefit of therapeutic heparin, with significant treatment-by-subgroup interactions with illness severity for all-cause death (P = .034). In conclusion, therapeutic heparin is beneficial in moderately ill patients but not in severely ill patients hospitalized with COVID-19.

Acute and Chronic Effects of COVID-19 on the Cardiovascular System

COVID-19 has shown significant morbidity with the involvement of multiple systems, including the cardiovascular system. Cardiovascular manifestations in the acute phase can include myocardial injury itself, myocardial infarction, venous thromboembolic events, myocarditis, Takotsubo syndrome, and different arrhythmic events. Myocardial injury defined by the rise of cardiac biomarkers in blood has been found in multiple studies with a prevalence of about 20%. Its presence is related to worse clinical outcomes and in-hospital mortality. The mechanisms of myocardial injury have been the subject of intense research but still need to be clarified. The characterization of the cardiac affectation with echocardiography and cardiac magnetic resonance has found mixed results in different studies, with a striking incidence of imaging criteria for myocarditis. Regarding post-acute and chronic follow-up results, the persistence of symptoms and imaging changes in recovered COVID-19 patients has raised concerns about the duration and the possible significance of these findings. Even though the knowledge about this disease has increased incredibly in the last year, many aspects are still unclear and warrant further research.