Good practice statements for antithrombotic therapy in the management of COVID-19: Guidance from the SSC of the ISTH

Prevalence and 3-month follow-up of cerebrovascular MRI markers in hospitalized COVID-19 patients: the CORONIS study

PURPOSE

To investigate the prevalence of cerebrovascular MRI markers in unselected patients hospitalized for COVID-19 (Coronavirus disease 2019), we compared these with healthy controls without previous SARS-CoV-2 infection or hospitalization and subsequently, investigated longitudinal (incidental) lesions in patients after three months.

METHODS

CORONIS (CORONavirus and Ischemic Stroke) was an observational cohort study in adult hospitalized patients for COVID-19 and controls without COVID-19, conducted between April 2021 and September 2022. Brain MRI was performed shortly after discharge and after 3 months. Outcomes included recent ischemic (DWI-positive) lesions, previous infarction, microbleeds, white matter hyperintensities (WMH) and intracerebral hemorrhage and were analysed with logistic regression to adjust for confounders.

RESULTS

125 patients with COVID-19 and 47 controls underwent brain MRI a median of 41.5 days after symptom onset. DWI-positive lesions were found in one patient (1%) and in one (2%) control, both clinically silent. WMH were more prevalent in patients (78%) than in controls (62%) (adjusted OR: 2.95 [95% CI: 1.07-8.57]), other cerebrovascular MRI markers did not differ. Prevalence of markers in ICU vs. non-ICU patients was similar. After three months, five patients (5%) had new cerebrovascular lesions, including DWI-positive lesions (1 patient, 1.0%), cerebral infarction (2 patients, 2.0%) and microbleeds (3 patients, 3.1%).

CONCLUSION

Overall, we found no higher prevalence of cerebrovascular markers in unselected hospitalized COVID-19 patients compared to controls. The few incident DWI-lesions were most likely to be explained by risk-factors of small vessel disease. In the general hospitalized COVID-19 population, COVID-19 shows limited impact on cerebrovascular MRI markers shortly after hospitalization.

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.

COVID-19 and cardiovascular disease in patients with chronic kidney disease

Millions of people worldwide have chronic kidney disease (CKD). Affected patients are at high risk for cardiovascular (CV) disease for several reasons. Among various comorbidities, CKD is associated with the more severe forms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This is particularly true for patients receiving dialysis or for kidney recipients. From the start of the SARS-CoV-2 pandemic, several CV complications have been observed in affected subjects, spanning acute inflammatory manifestations, CV events, thrombotic episodes and arrythmias. Several pathogenetic mechanisms have been hypothesized, including direct cytopathic viral effects on the myocardium, endothelial damage and hypercoagulability. This spectrum of disease can occur during the acute phase of the infection, but also months after recovery. This review is focussed on the CV complications of coronavirus disease 2019 (COVID-19) with particular interest in their implications for the CKD population.

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.

Estimated causal effects of common respiratory infections on cardiovascular risk: a meta-analysis

OBJECTIVE

Literature supports associations between common respiratory tract infections (RTIs) and risk of cardiovascular diseases, yet the importance of RTIs for cardiovascular risk management remains less understood. This systematic review and meta-analysis aimed to estimate the causal effects of RTIs on occurrence of cardiovascular diseases in the general population.

METHODS

MEDLINE and EMBASE were systematically searched up to 4 November 2022. Eligible were all aetiological studies evaluating risk of cardiovascular outcomes after exposure to common RTIs within any follow-up duration. Evidence was pooled using random-effects models if data allowed. The ROBINS-E and GRADE approaches were used to rate risk of bias and certainty of evidence, respectively. All assessments were performed in duplicate.

RESULTS

We included 34 studies (65 678 650 individuals). Most studies had a high risk of bias. COVID-19 likely increases relative risk (RR (95% CI)) of myocardial infarction (3.3 (1.0 to 11.0)), stroke (3.5 (1.2 to 10)), pulmonary embolism (24.6 (13.5 to 44.9)) and deep venous thrombosis (7.8 (4.3 to 14.4)) within 30 days after infection (GRADE: moderate) and about twofold within 1 year (GRADE: low to moderate). Other RTIs also likely increase the RR of myocardial infarction (2.9 (95% CI 1.8 to 4.9)) and stroke (2.6 (95% CI 1.1 to 6.4)) within 30 days (GRADE: moderate), and to a lesser extent with longer follow-up.

CONCLUSIONS

RTIs likely increase the risk of cardiovascular diseases about 1.5-5 fold within 1 month after infection. RTIs may, therefore, have clinical relevance as target for cardiovascular risk management, especially in high-risk populations.

PROSPERO REGISTRATION NUMBER

CRD42023416277.

Incidence and individual risk prediction of post-COVID-19 cardiovascular disease in the general population: a multivariable prediction model development and validation study

Aims

Previous studies suggest relatively increased cardiovascular risk after COVID-19 infection. This study assessed incidence and explored individual risk and timing of cardiovascular disease occurring post-COVID-19 in a large primary care database.

Methods and results

Data were extracted from the UK's Clinical Practice Research Datalink. Incidence rates within 180 days post-infection were estimated for arterial or venous events, inflammatory heart disease, and new-onset atrial fibrillation or heart failure. Next, multivariable logistic regression models were developed on 220 751 adults with COVID-19 infection before 1 December 2020 using age, sex and traditional cardiovascular risk factors. All models were externally validated in (i) 138 034 vaccinated and (ii) 503 404 unvaccinated adults with a first COVID-19 infection after 1 December 2020. Discriminative performance and calibration were evaluated with internal and external validation. Increased incidence rates were observed up to 60 days after COVID-19 infection for venous and arterial cardiovascular events and new-onset atrial fibrillation, but not for inflammatory heart disease or heart failure, with the highest rate for venous events (13 per 1000 person-years). The best prediction models had c-statistics of 0.90 or higher. However, <5% of adults had a predicted 180-day outcome-specific risk larger than 1%. These rare outcomes complicated calibration.

Conclusion

Risks of arterial and venous cardiovascular events and new-onset atrial fibrillation are increased within the first 60 days after COVID-19 infection in the general population. Models' c-statistics suggest high discrimination, but because of the very low absolute risks, they are insufficient to inform individual risk management.

A retrospective multicenter cohort study of the association between anti-Factor Xa values and death, thromboembolism, and bleeding in patients with critical COVID-19

BACKGROUND

Patients with critical COVID-19 have a high risk of thromboembolism, but intensified thromboprophylaxis has not been proven beneficial. The activity of low-molecular-weight heparins can be monitored by measuring anti-Factor Xa. We aimed to study the association between anti-Factor Xa values and death, thromboembolism, and bleeding in patients with critical COVID-19.

METHOD

This retrospective cohort study included adult patients with critical COVID-19 admitted to an intensive care unit at three Swedish hospitals between March 2020 and May 2021 with at least one valid peak and/or trough anti-Factor Xa value. Within the peak and trough categories, patients' minimum, median, and maximum values were determined. Logistic regressions with splines were used to assess associations.

RESULTS

In total, 408 patients had at least one valid peak and/or trough anti-Factor Xa measurement, resulting in 153 patients with peak values and 300 patients with trough values. Lower peak values were associated with thromboembolism for patients' minimum (p = 0.01), median (p = 0.005) and maximum (p = 0.001) values. No association was seen between peak values and death or bleeding. Higher trough values were associated with death for median (p = 0.03) and maximum (p = 0.002) values and with both bleeding (p = 0.01) and major bleeding (p = 0.02) for maximum values, but there were no associations with thromboembolism.

CONCLUSIONS

Measuring anti-Factor Xa activity may be relevant for administrating low-molecular-weight heparin to patients with critical COVID-19. Lower peak values were associated with an increased risk of thromboembolism, and higher trough values were associated with an increased risk of death and bleeding. Prospective studies are needed to confirm the results.

TRIAL REGISTRATION

The study was retrospectively registered at Clinicaltrials.gov, NCT05256524, February 24, 2022.

Outcomes of COVID-19 in immunocompromised patients: a single center experience

Malignancy, bone marrow and organ transplantation are associated with deficient and defective immune systems. Immunocompromised patients are at risk for severe and chronic complication of COVID-19 infection. However, the pathogenesis, diagnosis and management of this comorbidity remain to be elucidated. The purpose of the present study was to describe key aspects of COVID-19 infection in immunocompromised patients. In this retrospective, cross-sectional study, lab findings and outcomes of 418 COVID-19 patients with secondary immunodeficiency disorders admitted to Taleghani Hospital in Tehran, from March 2020 to September 2022 were investigated. Of the 418 immunocompromised patients with COVID-19, 236 (56.5%) ‌ were male and the median age of all studied patients was 56.6 ± 16.4 with range of 14 to 92 years. Totally, 198 (47.4%) of the patients died during hospitalization. Remdesivir was used for treatment of all patients. Mortality rate among patients admitted to ICU ward (86.8%) was significantly higher than non ICU admission (p < 0.001). The death rate in patients with CKD was substantially higher than other underlying disease (p < 0.001). In terms of laboratory finding, there was a significant relationship between ICU admission and worse outcome with WBC count (HR = 1.94, 95% CI = 1. 46-2.59, p < 0.001), PMN count (HR = 1.93, 95% CI = 1.452.56, p < 0.001), Hb (HR = 1.49, 95% CI = 1.042.13, p = 0.028), AST (HR = 2.55, 95% CI = 1.913.41, p < 0.001), BUN (HR = 2.56, 95% CI = 2.063.69, p < 0.001), Cr (HR = 2.63, 95% CI = 1.89-3.64, p < 0.001), Comorbidities index (HR = 1.71, 95% CI = 1.29-2.27, p < 0.001) and aging (HR = 1.91, 95% CI = 1.4-2.54, p < 0.001). Immunocompromised status increased the risk of mortality or worse outcome in patients diagnosed with COVID-19. Our finding showed outcome predicting markers in whom the waned immune system encounter new emerging disease and improved our understanding of COVID-19 virus behavior in immunocompromised individuals.

Assessing the Risk of Stroke in the Elderly in the Context of Long-COVID, Followed Through the Lens of Family Medicine

BACKGROUND/AIM

Patients infected with COVID-19 may experience a range of acute and chronic neurological disorders. While severe neurological complications like strokes and seizures were less common during the acute or post-COVID period, the long-term effects of COVID-19, known as long COVID, have received limited attention. This study aimed to examine the lasting consequences of SARS-CoV-2 infection and establish potential connections with related diseases.

PATIENTS AND METHODS

We followed a group of 157 patients for one year, predominantly from urban areas (61.8%), divided into three groups based on the presence of associated diseases that pose health risks: the control (43 patients), low-risk (67 patients), and high-risk (47 patients) groups.

RESULTS

We observed an inverse relationship between oxygen saturation and erythrocyte sedimentation rate, as well as a direct relationship between varicose disease and dyslipidemia, and gastrointestinal disease. Additionally, we noticed a less significant improvement in oxygen saturation and increased prevalence of psychoanxiety disorders in individuals undergoing anticoagulant treatment.

CONCLUSION

The impact of long COVID and its secondary effects, which persist for an extended period and are influenced by associated diseases, can be effectively monitored and addressed by primary care physicians. These findings can serve as a basis for developing more efficient approaches to managing the long-term consequences of COVID-19.

Prophylactic anticoagulants for non-hospitalised people with COVID-19

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has impacted healthcare systems worldwide. Multiple reports on thromboembolic complications related to COVID-19 have been published, and researchers have described that people with COVID-19 are at high risk for developing venous thromboembolism (VTE). Anticoagulants have been used as pharmacological interventions to prevent arterial and venous thrombosis, and their use in the outpatient setting could potentially reduce the prevalence of vascular thrombosis and associated mortality in people with COVID-19. However, even lower doses used for a prophylactic purpose may result in adverse events such as bleeding. It is important to consider the evidence for anticoagulant use in non-hospitalised people with COVID-19.

OBJECTIVES

To evaluate the benefits and harms of prophylactic anticoagulants versus active comparators, placebo or no intervention, or non-pharmacological interventions in non-hospitalised people with COVID-19.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 18 April 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing prophylactic anticoagulants with placebo or no treatment, another active comparator, or non-pharmacological interventions in non-hospitalised people with COVID-19. We included studies that compared anticoagulants with a different dose of the same anticoagulant. We excluded studies with a duration of under two weeks.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Our primary outcomes were all-cause mortality, VTE (deep vein thrombosis (DVT) or pulmonary embolism (PE)), and major bleeding. Our secondary outcomes were DVT, PE, need for hospitalisation, minor bleeding, adverse events, and quality of life. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included five RCTs with up to 90 days of follow-up (short term). Data were available for meta-analysis from 1777 participants. Anticoagulant compared to placebo or no treatment Five studies compared anticoagulants with placebo or no treatment and provided data for three of our outcomes of interest (all-cause mortality, major bleeding, and adverse events). The evidence suggests that prophylactic anticoagulants may lead to little or no difference in all-cause mortality (risk ratio (RR) 0.36, 95% confidence interval (CI) 0.04 to 3.61; 5 studies; 1777 participants; low-certainty evidence) and probably reduce VTE from 3% in the placebo group to 1% in the anticoagulant group (RR 0.36, 95% CI 0.16 to 0.85; 4 studies; 1259 participants; number needed to treat for an additional beneficial outcome (NNTB) = 50; moderate-certainty evidence). There may be little to no difference in major bleeding (RR 0.36, 95% CI 0.01 to 8.78; 5 studies; 1777 participants; low-certainty evidence). Anticoagulants probably result in little or no difference in DVT (RR 1.02, 95% CI 0.30 to 3.46; 3 studies; 1009 participants; moderate-certainty evidence), but probably reduce the risk of PE from 2.7% in the placebo group to 0.7% in the anticoagulant group (RR 0.25, 95% CI 0.08 to 0.79; 3 studies; 1009 participants; NNTB 50; moderate-certainty evidence). Anticoagulants probably lead to little or no difference in reducing hospitalisation (RR 1.01, 95% CI 0.59 to 1.75; 4 studies; 1459 participants; moderate-certainty evidence) and may lead to little or no difference in adverse events (minor bleeding, RR 2.46, 95% CI 0.90 to 6.72; 5 studies, 1777 participants; low-certainty evidence). Anticoagulant compared to a different dose of the same anticoagulant One study compared anticoagulant (higher-dose apixaban) with a different (standard) dose of the same anticoagulant and reported five relevant outcomes. No cases of all-cause mortality, VTE, or major bleeding occurred in either group during the 45-day follow-up (moderate-certainty evidence). Higher-dose apixaban compared to standard-dose apixaban may lead to little or no difference in reducing the need for hospitalisation (RR 1.89, 95% CI 0.17 to 20.58; 1 study; 278 participants; low-certainty evidence) or in the number of adverse events (minor bleeding, RR 0.47, 95% CI 0.09 to 2.54; 1 study; 278 participants; low-certainty evidence). Anticoagulant compared to antiplatelet agent One study compared anticoagulant (apixaban) with antiplatelet agent (aspirin) and reported five relevant outcomes. No cases of all-cause mortality or major bleeding occurred during the 45-day follow-up (moderate-certainty evidence). Apixaban may lead to little or no difference in VTE (RR 0.36, 95% CI 0.01 to 8.65; 1 study; 279 participants; low-certainty evidence), need for hospitalisation (RR 3.20, 95% CI 0.13 to 77.85; 1 study; 279 participants; low-certainty evidence), or adverse events (minor bleeding, RR 2.13, 95% CI 0.40 to 11.46; 1 study; 279 participants; low-certainty evidence). No included studies reported on quality of life or investigated anticoagulants compared to a different anticoagulant, or anticoagulants compared to non-pharmacological interventions.

AUTHORS' CONCLUSIONS

We found low- to moderate-certainty evidence from five RCTs that prophylactic anticoagulants result in little or no difference in major bleeding, DVT, need for hospitalisation, or adverse events when compared with placebo or no treatment in non-hospitalised people with COVID-19. Low-certainty evidence indicates that prophylactic anticoagulants may result in little or no difference in all-cause mortality when compared with placebo or no treatment, but moderate-certainty evidence indicates that prophylactic anticoagulants probably reduce the incidence of VTE and PE. Low-certainty evidence suggests that comparing different doses of the same prophylactic anticoagulant may result in little or no difference in need for hospitalisation or adverse events. Prophylactic anticoagulants may result in little or no difference in risk of VTE, hospitalisation, or adverse events when compared with antiplatelet agents (low-certainty evidence). Given that there were only short-term data from one study, these results should be interpreted with caution. Additional trials of sufficient duration are needed to clearly determine any effect on clinical 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.

Rivaroxaban to prevent major clinical outcomes in non-hospitalised patients with COVID-19: the CARE - COALITION VIII randomised clinical trial

Background

COVID-19 progression is associated with an increased risk of arterial and venous thrombosis. Randomised trials have demonstrated that anticoagulants reduce the risk of thromboembolism in hospitalised patients with COVID-19, but a benefit of routine anticoagulation has not been demonstrated in the outpatient setting.

Methods

We conducted a randomised, open-label, controlled, multicentre study, evaluating the use of rivaroxaban in mild or moderate COVID-19 patients. Adults ≥18 years old, with probable or confirmed SARS-CoV-2 infection, presenting within ≤7 days from symptom onset with no clear indication for hospitalization, plus at least 2 risk factors for complication, were randomised 1:1 either to rivaroxaban 10 mg OD for 14 days or to routine care. The primary efficacy endpoint was the composite of venous thromboembolic events, need of mechanical ventilation, acute myocardial infarction, stroke, acute limb ischemia, or death due to COVID-19 during the first 30 days. ClinicalTrials.gov: NCT04757857.

Findings

Enrollment was prematurely stopped due to sustained reduction in new COVID-19 cases. From September 29th, 2020, through May 23rd, 2022, 660 patients were randomised (median age 61 [Q1-Q3 47-69], 55.7% women). There was no significant difference between rivaroxaban and control in the primary efficacy endpoint (4.3% [14/327] vs 5.8% [19/330], RR 0.74; 95% CI: 0.38-1.46). There was no major bleeding in the control group and 1 in the rivaroxaban group.

Interpretation

On light of these findings no decision can be made about the utility of rivaroxaban to improve outcomes in outpatients with COVID-19. Metanalyses data provide no evidence of a benefit of anticoagulant prophylaxis in outpatients with COVID-19. These findings were the result of an underpowered study, therefore should be interpreted with caution.

Funding

COALITION COVID-19 Brazil and Bayer S.A.

Coagulopathy and thromboembolic events a pathogenic mechanism of COVID-19 associated with mortality: An updated review

During 2019, the SARS-CoV-2 emerged from China, and during months, COVID-19 spread in many countries around the world. The expanding data about pathogenesis of this virus could elucidate the exact mechanism by which COVID-19 caused death in humans. One of the pathogenic mechanisms of this disease is coagulation. Coagulation disorders that affect both venous and arterial systems occur in patients with COVID-19. The possible mechanism involved in the coagulation could be excessive inflammation induced by SARS-CoV-2. However, it is not yet clear well how SARS-CoV-2 promotes coagulopathy. However, some factors, such as pulmonary endothelial cell damage and some anticoagulant system disorders, are assumed to have an important role. In this study, we assessed conducted studies about COVID-19-induced coagulopathy to obtain clearer vision of the wide range of manifestations and possible pathogenesis mechanisms.

Lipoprotein(a) Does Not Predict Thrombotic Events and In-Hospital Outcomes in Patients with COVID-19

The prothrombotic and proinflammatory properties of lipoprotein(a) (Lp(a)) have been hypothesized to play a role in the pathogenesis of severe COVID-19; however, the prognostic impact of Lp(a) on the clinical course of COVID-19 remains controversial. This study aimed to investigate whether Lp(a) may be associated with biomarkers of thrombo-inflammation and the occurrence of thrombotic events or adverse clinical outcomes in patients hospitalized for COVID-19. We consecutively enrolled a cohort of patients hospitalized for COVID-19 and collected blood samples for Lp(a) assessment at hospital admission. A prothrombotic state was evaluated through D-dimer levels, whereas a proinflammatory state was evaluated through C-reactive protein (CRP), procalcitonin, and white blood cell (WBC) levels. Thrombotic events were marked by the diagnosis of deep or superficial vein thrombosis (DVT or SVT), pulmonary embolism (PE), stroke, transient ischemic attack (TIA), acute coronary syndrome (ACS), and critical limb ischemia (CLI). The composite clinical end point of intensive care unit (ICU) admission/in-hospital death was used to evaluate adverse clinical outcomes. Among 564 patients (290 (51%) men, mean age of 74 ± 17 years) the median Lp(a) value at hospital admission was 13 (10-27) mg/dL. During hospitalization, 64 (11%) patients were diagnosed with at least one thrombotic event and 83 (15%) patients met the composite clinical end point. Lp(a), as either a continuous or categorical variable, was not associated with D-dimer, CRP, procalcitonin, and WBC levels (p > 0.05 for all correlation analyses). In addition, Lp(a) was not associated with a risk of thrombotic events (p > 0.05 for multi-adjusted odds ratios) nor with a risk of adverse clinical outcomes (p > 0.05 for multi-adjusted hazard ratios). In conclusion, Lp(a) does not influence biomarkers of plasma thrombotic activity and systemic inflammation nor has any impact on thrombotic events and adverse clinical outcomes in patients hospitalized for COVID-19.

Antithrombotic therapy in the management of hospitalised patients with COVID-19

Hospitalised patients with coronavirus disease 2019 (COVID-19) are at a significantly higher risk of having thromboembolic events while in hospital and in the immediate post-hospital discharge period. Based on early data from observational studies, multiple high quality randomised controlled trials have been conducted worldwide to evaluate optimal thromboprophylaxis regimens to reduce thromboembolism and other COVID-19-related adverse outcomes in hospitalised patients. The International Society on Thrombosis and Haemostasis has published evidence-based guideline recommendations using established methodology for the management of antithrombotic therapy of COVID-19 patients, both in-hospital and in the immediate post-hospital discharge period. A good clinical practice statement supplemented these guidelines based on topics for which there was no or limited high-quality evidence. This review summarises the main recommendations of these documents to serve as a quick access tool for hospital doctors to use in their everyday practice when treating COVID-19 patients.

Safety and Efficacy of Different Anticoagulant Doses for Patients with COVID-19 in the ICU: A Systematic Review and Meta-Analysis

Critically ill COVID-19 patients have a high incidence of thromboembolic events, which significantly influence the risk of mortality. Anticoagulant therapy is generally recommended to these patients but the optimal dosing regimens require further investigations. The objective of this systematic review and meta-analysis was to assess the efficacy and safety of prophylactic, intermediate and therapeutic dose anticoagulation in COVID-19 patients admitted to the ICU. A systematic search for original prospective observational studies and clinical trials was performed in online databases from 2020 to 2022. A total of 13 studies (3239 patients) were included. The type of anticoagulant dosing showed no significant influence on short-term mortality (p = 0.84), deep vein thrombosis (p = 0.66), arterial thrombosis (p = 0.44), major bleeding (p = 0.35) and minor bleeding incidence (p = 0.46). An anticoagulation regimen significantly influenced pulmonary embolism occurrence (16% for prophylactic dose vs. 4% for therapeutic dose, p = 0.02), but the number of studies in the analysis was relatively low. In conclusion, the results of this meta-analysis suggest that critically ill COVID-19 patients admitted in the ICU have no benefit from therapeutic doses of anticoagulants and that all three thromboprophylaxis regimes have a comparable effect on short term mortality and venous thromboembolism incidence but for pulmonary embolism, for which the results were inconclusive.

Practical Recommendations for Optimal Thromboprophylaxis in Patients with COVID-19: A Consensus Statement Based on Available Clinical Trials

Coronavirus disease 2019 (COVID-19) has been shown to be strongly associated with increased risk for venous thromboembolism events (VTE) mainly in the inpatient but also in the outpatient setting. Pharmacologic thromboprophylaxis has been shown to offer significant benefits in terms of reducing not only VTE events but also mortality, especially in acutely ill patients with COVID-19. Although the main source of evidence is derived from observational studies with several limitations, thromboprophylaxis is currently recommended for all hospitalized patients with acceptable bleeding risk by all national and international guidelines. Recently, high quality data from randomized controlled trials (RCTs) further support the role of thromboprophylaxis and provide insights into the optimal thromboprophylaxis strategy. The aim of this statement is to systematically review all the available evidence derived from RCTs regarding thromboprophylaxis strategies in patients with COVID-19 in different settings (either inpatient or outpatient) and provide evidence-based guidance to practical questions in everyday clinical practice. Clinical questions accompanied by practical recommendations are provided based on data derived from 20 RCTs that were identified and included in the present study. Overall, the main conclusions are: (i) thromboprophylaxis should be administered in all hospitalized patients with COVID-19, (ii) an optimal dose of inpatient thromboprophylaxis is dependent upon the severity of COVID-19, (iii) thromboprophylaxis should be administered on an individualized basis in post-discharge patients with COVID-19 with high thrombotic risk, and (iv) thromboprophylaxis should not be routinely administered in outpatients. Changes regarding the dominant SARS-CoV-2 variants, the wide immunization status (increasing rates of vaccination and reinfections), and the availability of antiviral therapies and monoclonal antibodies might affect the characteristics of patients with COVID-19; thus, future studies will inform us about the thrombotic risk and the optimal therapeutic strategies for these patients.

ISTH guidelines for antithrombotic treatment in COVID-19

Antithrombotic agents reduce risk of thromboembolism in severely ill patients. Patients with coronavirus disease 2019 (COVID-19) may realize additional benefits from heparins. Optimal dosing and timing of these treatments and benefits of other antithrombotic agents remain unclear. In October 2021, ISTH assembled an international panel of content experts, patient representatives, and a methodologist to develop recommendations on anticoagulants and antiplatelet agents for patients with COVID-19 in different clinical settings. We used the American College of Cardiology Foundation/American Heart Association methodology to assess level of evidence (LOE) and class of recommendation (COR). Only recommendations with LOE A or B were included. Panelists agreed on 12 recommendations: three for non-hospitalized, five for non-critically ill hospitalized, three for critically ill hospitalized, and one for post-discharge patients. Two recommendations were based on high-quality evidence, the remainder on moderate-quality evidence. Among non-critically ill patients hospitalized for COVID-19, the panel gave a strong recommendation (a) for use of prophylactic dose of low molecular weight heparin or unfractionated heparin (LMWH/UFH) (COR 1); (b) for select patients in this group, use of therapeutic dose LMWH/UFH in preference to prophylactic dose (COR 1); but (c) against the addition of an antiplatelet agent (COR 3). Weak recommendations favored (a) sulodexide in non-hospitalized patients, (b) adding an antiplatelet agent to prophylactic LMWH/UFH in select critically ill, and (c) prophylactic rivaroxaban for select patients after discharge (all COR 2b). Recommendations in this guideline are based on high-/moderate-quality evidence available through March 2022. Focused updates will incorporate future evidence supporting changes to these recommendations.