Impact of High-Dose Prophylactic Anticoagulation in Critically Ill Patients With COVID-19 Pneumonia

Prevalence, clinical significance, and persistence of autoantibodies in COVID-19

BACKGROUND

Interest in complications and sequelae following Coronavirus disease 2019 (COVID-19) is increasing. Several articles have reported COVID-19-associated autoimmune diseases and the association between autoantibodies and the severity of COVID-19. Thromboembolic complications are frequent in patients with COVID-19, and the anti-phospholipid antibodies (aPL) is frequently detected. We conducted this study to investigate the prevalence, clinical significance, and persistence of anti-nuclear antibodies (ANA) and aPLs in COVID-19.

METHODS

We enrolled patients diagnosed with COVID-19 with oxygen demand and admitted to a tertiary hospital in South Korea between July 2020 and March 2022. ANA and aPLs levels were assessed using an immunoassay kit.

RESULTS

A total of 248 patients were enrolled in the study. Among them, five patients were ANA-positive, and 41 were aPL-positive (IgM anti-cardiolipin (aCL) antibody in seven patients, IgG aCL in seven patients, IgM anti-β2Glycoprotein1 antibody (aβ2-GPI) in 32 patients, and IgG aβ2-GPI in one patient). Two of five ANA-positive patients, 13 of 32 IgM aβ2-GPI-positive patients, 5 of 7 IgM aCL-positive patients, and 2 of 7 IgG aCL-positive patients were eligible for follow-up analysis, and 100%, 69.2%, 40%, and 50% of the patients remained autoantibody-positive, respectively. There were no differences in clinical outcomes between the autoantibody-positive and autoantibody-negative groups, except for the IgG aCL group showing a tendency for worse outcomes.

CONCLUSION

A significant proportion of COVID-19 patients with oxygen demand were autoantibody-positive, and autoantibodies persisted for several months after symptom onset. Whether these autoantibodies are related to long-term sequelae in COVID-19 patients requires further investigation.

Effects of Different Anticoagulation Doses on Moderate-to-Severe COVID-19 Pneumonia With Hypoxemia

Background COVID-19 is a prothrombotic disease that can cause thromboembolism and microthrombi, which could lead to multiorgan failure and death. Since COVID-19 is a relatively new disease, there are guidelines for anticoagulation dosing for COVID-19 patients without consensus on the dosing. We studied the effects of different doses of anticoagulation in hospitalized patients with COVID-19 pneumonia and hypoxemia on any differences in need for high-flow oxygen, mechanical ventilation, and mortality. We also analyzed the patient population who benefited most from anticoagulation. Methodology We performed a retrospective chart review of all patients who were admitted with the diagnosis of COVID-19 infection with positive polymerase chain reaction, pneumonia (confirmed either by chest X-ray or CT chest), and hypoxemia (oxygen saturation of <94%, while on room air). These patients were studied for outcomes (the need for high-flow oxygen, the requirement for mechanical ventilation, and overall mortality) for different doses of anticoagulation (prophylactic, escalated, and therapeutic). Results The sample consists of 132 subjects, predominantly males (116, 87%), with a mean age of 59 years and a standard deviation of 15. About one-third of the participants had diabetes, and more than 50% had hypertension. Additionally, 27 (20.3%) had a history of heart disease, and 70 (53%) of the subjects were admitted to the intensive care unit (ICU) at some point during the study. Among those admitted to the ICU, about 11 (8%) subjects required mechanical ventilation and 16 (12%) passed away during the study. Those who died had higher use of high-flow oxygen, noninvasive mechanical ventilation, and invasive mechanical ventilation and had a longer stay on mechanical ventilation. There was no significant difference in mortality or need for mechanical ventilation for any strategy of anticoagulation. Conclusions Different doses of anticoagulation did not show any statistically significant relationship between the need for mechanical ventilation and mortality. More patients on high-flow oxygen had received escalated doses of anticoagulation as compared to those who were not on high-flow oxygen. Anticoagulation levels did not have any statistically significant effect on overall survival of patients.

High-Dose Prophylactic Anticoagulation for COVID-19 Pneumonia: A Review of Benefits and Risks

The COVID-19 pandemic has had a devastating impact on a global scale, causing significant morbidity and mortality. The virus affects multiple organ systems, including the respiratory, cardiovascular, and coagulation systems, leading to severe pneumonia in some patients. Moreover, COVID-19 patients with severe pneumonia have a high incidence of thrombotic events, which can result in significant morbidity and mortality. Given the potential benefits of anticoagulation therapy in COVID-19 patients with thrombotic complications, recent studies have proposed high-dose prophylactic anticoagulation (HD-PA) therapy as a potential treatment option. In fact, some studies have suggested that HD-PA therapy may be more effective in reducing thrombotic events and mortality rates than other treatment options. This review aims to provide a comprehensive overview of the benefits and risks of HD-PA therapy for COVID-19 pneumonia patients. By synthesizing and analyzing the latest available research, we highlight patient selection criteria and discuss the optimal dosage, duration, and timing of therapy. Additionally, we review the potential risks associated with HD-PA therapy and provide recommendations for clinical practice. Ultimately, this review provides valuable insights into the use of HD-PA therapy in COVID-19 pneumonia patients and paves the way for further research in this critical area. By exploring the benefits and risks of this treatment option, we hope to provide healthcare professionals with the information they need to make informed decisions about the best course of treatment for their patients.

Arterial Thrombotic Events in Hospitalized COVID-19 Patients: A Short Review and Meta-Analysis

It is well established that the risk of venous thromboembolism is high in coronavirus disease 19 (COVID-19). The frequency of arterial thromboembolic events (ATEs) in hospitalized patients with COVID-19 is unclear, as is the magnitude of these events in comparison with other infections. We searched MEDLINE from February 2020 to February 2022 for prospective or retrospective cohort studies and randomized clinical trials that reported the number of acute myocardial infarction (AMI), acute ischemic stroke (AIS), acute limb ischemia (ALI), or other ATE as defined by the original authors in hospitalized patients with COVID-19. The pooled frequencies were calculated through meta-analysis using random effects model with logit transformation and presented with relative 95% prediction intervals (95% PI). We retrieved a total of 4,547 studies, 36 of which (28 retrospective cohorts, five prospective cohorts and three randomized trials) were finally included in our analysis. The resulting cohort counted 100,949 patients, 2,641 (2.6%) of whom experienced ATE. The pooled ATE frequency was 2.0% (95% PI, 0.4-9.6%). The pooled ATE frequency for AMI, AIS, ALI, and other ATE was 0.8% (95% PI, 0.1-8.1%), 0.9% (95% PI, 0.3-2.9%), 0.2% (95% PI, 0.0-4.2%), and 0.5% (95% PI, 0.1-3.0%), respectively. In comparison with the ATE incidence reported in three studies on non-COVID viral pneumonia, we did not detect a significant difference from the results in our analysis. In conclusion, we found a non-negligible proportion of ATE in patients hospitalized for COVID-19. Our results are similar to those found in hospitalized patients with influenza or with non-COVID viral pneumonia.

Platelet dysfunction and thrombus instability in flow conditions in patients with severe COVID-19

Severe COVID-19 has been associated with a high rate of thrombotic events but also of bleeding events, particularly when the level of prophylactic anticoagulation was increased. Data on the contribution of platelets to these thrombotic events are discordant between reports, while the involvement of platelets in bleeding events has never been investigated. The objective of the present study was to assess platelet function during the first week of ICU hospitalization in patients with severe COVID-19 pneumonia. A total of 35 patients were prospectively included and blood samples were drawn on day (D) 0, D2 and D7. COVID-19 pneumonia was severe with a median PaO₂/FiO₂ ratio of 91 [68-119] on D0. Platelets from these patients showed evidence of pre-activation and exhaustion with a significant reduction in the surface expression of GPVI, GPIb and GPIIbIIIa, together with a decrease in serotonin content. Platelets from patients with severe COVID-19 were hyporesponsive with a reduced maximal aggregation response to several platelet agonists and decreased adhesion to immobilized fibrinogen. Aggregation of washed platelets and plasma substitution experiments indicated that a plasma factor was at least partially responsible for this hyporeactivity of platelets. Blood flow experiments showed that severe COVID-19 platelets formed smaller, less stable aggregates on a collagen-coated surface, which could explain why some patients develop bleeding events. These findings should prompt us to carefully evaluate the risks and benefits of high-dose prophylactic anticoagulation, and to decrease the level of anticoagulation once the initial phase of the disease has resolved. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04359992.

COVID-19 Adenoviral Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT), COVID-19-Related Thrombosis, and the Thrombotic Thrombocytopenic Syndromes

Adenoviral-based vaccines such as ChadoX1 CoV-19 (AstraZeneca) and Ad26.COV2.S (J&J) were developed to prevent infection and reduce hospitalization or death in Coronavirus Disease 2019 (COVID-19) patients. Although these vaccines passed safety and efficacy trials with excellent neutralizing capabilities against SARS-CoV-2, very rare reports of acute thrombotic thrombocytopenic events following administration emerged in certain populations, which triggered a series of clinical investigations that gave rise to a novel phenomenon called vaccine-induced immune thrombotic thrombocytopenia (VITT). Several converging pathways exist between VITT and other forms of thrombotic thrombocytopenic syndromes, specifically that of heparin-induced thrombocytopenia, which involves the formation of anti-PF4 antibodies and the activation of platelets leading to thrombocytopenia and thrombin-mediated clotting. Interestingly, certain differences in the presentation also exist in VITT, and guidelines have been published in recent months to assist clinicians in recognizing VITT to achieve desired outcomes. In this paper, we first discuss the clotting phenomenon in COVID-19 and delineate it from VITT, followed by a review of current knowledge on the clinical manifestations of VITT in lieu of other thrombotic thrombocytopenic syndromes. Likewise, emerging evidence on the role of adenoviral vectors and vaccine constituents is also discussed briefly.

Thromboprophylaxis with standard-dose vs. flexible-dose heparin for hospitalized COVID-19 patients: a target trial emulation

OBJECTIVES

To compare mortality of hospitalized COVID-19 patients under two low-molecular weight heparin (LMWH) thromboprophylaxis strategies: standard dose and variable dose (standard dose increased to intermediate dose in the presence of laboratory abnormalities indicating an increased thrombosis risk).

STUDY DESIGN AND SETTING

Target trial emulation using observational data from 2,613 adults admitted with a COVID-19 diagnosis in Madrid, Spain between March 16 and April 15, 2020.

RESULTS

A total of 1,284 patients were eligible. Among 503 patients without increased baseline thrombotic risk, 28-day mortality risk (95% confidence interval [CI]) was 9.0% (6.6, 11.7) under the standard dose strategy and 5.6% (3.3, 8.3) under the variable dose strategy; risk difference 3.4% (95% CI: -0.24, 6.9); mortality hazard ratio 1.61 (95% CI: 0.97, 2.89). Among 781 patients with increased baseline thrombotic risk, the 28-day mortality risk was 25.8% (22.7, 29.0) under the standard dose strategy and 18.1% (9.3, 28.9) under the intermediate dose strategy; risk difference 7.7% (95% CI: -3.5, 17.2); mortality hazard ratio 1.45 (95% CI: 0.81, 3.17). Major bleeding and LMWH-induced coagulopathy were rare under all strategies.

CONCLUSION

Escalating anticoagulation intensity after signs of thrombosis risk may increase the survival of hospitalized COVID-19 patients. However, effect estimates were imprecise and additional studies are warranted.

In-hospital Mortality Rates in SARS-CoV-2 Patients Treated with Enoxaparin and Heparin

OBJECTIVES

This study aimed to investigate in-hospital mortality rates in patients with coronavirus disease (COVID-19) according to enoxaparin and heparin use.

METHODS

This retrospective cohort study included 962 patients admitted to two hospitals in Kuwait with a confirmed diagnosis of COVID-19. Cumulative all-cause mortality rate was the primary outcome.

RESULTS

A total of 302 patients (males, 196 [64.9%]; mean age, 57.2 ± 14.6 years; mean body mass index, 29.8 ± 6.5 kg/m²) received anticoagulation therapy. Patients receiving anticoagulation treatment tended to have pneumonia (n = 275 [91.1%]) or acute respiratory distress syndrome (n = 106 [35.1%]), and high D-dimer levels (median [interquartile range]: 608 [523;707] ng/mL). The mortality rate in this group was high (n = 63 [20.9%]). Multivariable logistic regression, the Cox proportional hazards, and Kaplan-Meier models revealed that the use of therapeutic anticoagulation agents affected the risk of all-cause cumulative mortality.

CONCLUSION

Age, hypertension, pneumonia, therapeutic anticoagulation, and methylprednisolone use were found to be strong predictors of in-hospital mortality. In elderly hypertensive COVID-19 patients on therapeutic anticoagulation were found to have 2.3 times higher risk of in-hospital mortality. All cause in-hospital mortality rate in the therapeutic anticoagulation group was up to 21%.

Use of low molecular weight heparin and hemoglobin fall in COVID-19 patients: A STROBE-compliant study

In patients with coronavirus disease 2019 (COVID-19), anticoagulation was suggested as a mitigating strategy. However, little research has been conducted on the adverse consequences of anticoagulant medication. This study aimed to investigate the adverse effect of low molecular weight heparin (LMWH) on hemoglobin fall in COVID-19 treatment. The electronic medical records of COVID-19 patients with pneumonia were collected (including clinical characteristics, vaccination status, complete blood count, coagulation profile, inflammatory cytokines, serum biochemical indicators, and computerized tomography imaging score). Whether they received LMWH, patients were divided into the LMWH group and the control group. Count data were represented as frequency distribution, and a 2-tailed test was used to compare the 2 groups. Spearman rank correlation was used to evaluate the interrelation between changes in hemoglobin and LMWH. The confounding factors were excluded by logistic regression analysis. A total of 179 COVID-19 pneumonia patients were enrolled (81 in the LMWH group and 98 in the control group). The change in hemoglobin was -6.0g/L (IQR -10.8 to 1.0) in the LMWH group and -2.0g/L (IQR -7.0 to 4.0) in the control group (P < .001, between-group difference, -5.0 g/L; 95% confidence interval, -7.0 to -3.0, calculated with the use of the Mann-Whitney U test and the Hodges-Lehmann estimate of confidence intervals for pseudo-medians). The results of multivariate regression analysis showed that after adjusting for confounding factors, LMWH use was not associated with a decrease in hemoglobin (P > .05). In nonsevere COVID-19 patients with pneumonia, the preventive use of LMWH did not lower hemoglobin.

Bleeding and thrombotic events in patients with severe COVID-19 supported with extracorporeal membrane oxygenation: a nationwide cohort study

PURPOSE

To describe bleeding and thrombotic events and their risk factors in patients receiving extracorporeal membrane oxygenation (ECMO) for severe coronavirus disease 2019 (COVID-19) and to evaluate their impact on in-hospital mortality.

METHODS

The ECMOSARS registry included COVID-19 patients supported by ECMO in France. We analyzed all patients included up to March 31, 2022 without missing data regarding bleeding and thrombotic events. The association of bleeding and thrombotic events with in-hospital mortality and pre-ECMO variables was assessed using multivariable logistic regression models.

RESULTS

Among 620 patients supported by ECMO, 29% had only bleeding events, 16% only thrombotic events and 20% both bleeding and thrombosis. Cannulation site (18% of patients), ear nose and throat (12%), pulmonary bleeding (9%) and intracranial hemorrhage (8%) were the most frequent bleeding types. Device-related thrombosis and pulmonary embolism/thrombosis accounted for most of thrombotic events. In-hospital mortality was 55.7%. Bleeding events were associated with in-hospital mortality (adjusted odds ratio (adjOR) = 2.91[1.94-4.4]) but not thrombotic events (adjOR = 1.02[0.68-1.53]). Intracranial hemorrhage was strongly associated with in-hospital mortality (adjOR = 13.5[4.4-41.5]). Ventilation duration before ECMO ≥ 7 days and length of ECMO support were associated with bleeding. Thrombosis-associated factors were fibrinogen ≥ 6 g/L and length of ECMO support.

CONCLUSIONS

In a nationwide cohort of COVID-19 patients supported by ECMO, bleeding incidence was high and associated with mortality. Intracranial hemorrhage incidence was higher than reported for non-COVID patients and carried the highest risk of death. Thrombotic events were less frequent and not associated with mortality. Length of ECMO support was associated with a higher risk of both bleeding and thrombosis, supporting the development of strategies to minimize ECMO duration.

Extracorporeal Membrane Oxygenation for Respiratory Failure Related to COVID-19: A Nationwide Cohort Study

Despite expanding use, knowledge on extracorporeal membrane oxygenation support during the COVID-19 pandemic remains limited. The objective was to report characteristics, management, and outcomes of patients receiving extracorporeal membrane oxygenation with a diagnosis of COVID-19 in France and to identify pre-extracorporeal membrane oxygenation factors associated with in-hospital mortality. A hypothesis of similar mortality rates and risk factors for COVID-19 and non–COVID-19 patients on venovenous extracorporeal membrane oxygenation was made.

In this investigation, most patients were cannulated by a mobile extracorporeal membrane oxygenation unit without a negative impact on mortality. Based on this report, venovenous extracorporeal membrane oxygenation support should be considered within the first week of mechanical ventilation initiation for optimal outcomes.

Persistent Lung Injury and Prothrombotic State in Long COVID

Lung injury may persist during the recovery period of COVID-19 as shown through imaging, six-minute walk, and lung function tests. The pathophysiological mechanisms leading to long COVID have not been adequately explained. Our aim is to investigate the basis of pulmonary susceptibility during sequelae and the possibility that prothrombotic states may influence long-term pulmonary symptoms of COVID-19. The patient’s lungs remain vulnerable during the recovery stage due to persistent shedding of the virus, the inflammatory environment, the prothrombotic state, and injury and subsequent repair of the blood-air barrier. The transformation of inflammation to proliferation and fibrosis, hypoxia-involved vascular remodeling, vascular endothelial cell damage, phosphatidylserine-involved hypercoagulability, and continuous changes in serological markers all contribute to post-discharge lung injury. Considering the important role of microthrombus and arteriovenous thrombus in the process of pulmonary functional lesions to organic lesions, we further study the possibility that prothrombotic states, including pulmonary vascular endothelial cell activation and hypercoagulability, may affect long-term pulmonary symptoms in long COVID. Early use of combined anticoagulant and antiplatelet therapy is a promising approach to reduce the incidence of pulmonary sequelae. Essentially, early treatment can block the occurrence of thrombotic events. Because impeded pulmonary circulation causes large pressure imbalances over the alveolar membrane leading to the infiltration of plasma into the alveolar cavity, inhibition of thrombotic events can prevent pulmonary hypertension, formation of lung hyaline membranes, and lung consolidation.

Cardiac Registries During the COVID-19 Pandemic: Lessons Learned

Purpose of this Review

We discuss the role of observational studies and cardiac registries during the COVID-19 pandemic. We focus on published cardiac registries and highlight contributions to the field that have had clinical implications.

Recent Findings

We included observational studies of COVID-19 patients published in peer-reviewed medical journals with defined inclusion and exclusion criteria, defined study design, and primary outcomes. A PubMed and MEDLINE literature review results in 437 articles, of which 52 include patients with COVID-19 with cardiac endpoints. From July 2020 to December 2021, the average time from last data collected to publication was 8.9 ± 4.1 months, with an increasing trend over time (R = 0.9444, p < 0.0001). Of the 52 articles that met our inclusion criteria, we summarize main findings of 4 manuscripts on stroke, 14 on acute coronary syndrome, 4 on cardiac arrest, 7 on heart failure, 7 on venous thromboembolism, 5 on dysrhythmia, and 11 on different populations at risk for cardiovascular.

Summary

Registries are cost effective, not disruptive to essential health services, and can be rapidly disseminated with short intervals between last data point collected and publication. In less than 2 years, cardiac registries have filled important gaps in knowledge and informed the care of COVID-19 patients with cardiovascular conditions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11886-022-01686-5.

Awaiting a cure for COVID-19: therapeutic approach in patients with different severity levels of COVID-19

COVID-19 is an unpredictable infectious disease caused by SARS-CoV-2. The development of effective anti-COVID-19 vaccines has enormously minimized the risk of severe illness in most immunocompetent patients. However, unvaccinated patients and non-responders to the COVID-19 vaccine are at risk of shortand long-term consequences. In these patients, the outcome of COVID-19 relies on an interplay of multiple factors including age, immunocompetence, comorbidities, inflammatory response triggered by the virus as well as the virulence of SARS-CoV-2 variants. Generally, COVID-19 is asymptomatic or mildly symptomatic in young people, but it may manifest with respiratory insufficiency requiring mechanical ventilation in certain susceptible groups of patients. Furthermore, severe SARS-CoV-2 infection induces multiorgan failure syndrome by affecting liver, kidney heart and nervous system. Since December 2019, multiple drugs have been tested to treat COVID-19, but only a few have been proven effective to mitigate the course of the disease that continues to cause death and comorbidity worldwide. Current treatment of COVID-19 patients is essentially based on the administration of supportive oxygen therapy and the use of specific drugs such as steroids, anticoagulants, antivirals, anti-SARS-CoV-2 antibodies and immunomodulators. However, the rapid spread of new variants and the release of new data coming from the numerous ongoing clinical trials have created the conditions for maintaining a continuous updating of the therapeutic management of COVID-19 patients. Furthermore, we believe that a well-established therapeutic strategy along with the continuum of medical care for all patients with COVID-19 is pivotal to improving disease outcomes and restoring healthcare care fragmentation caused by the pandemic. This narrative review, focusing on the therapeutic management of COVID-19 patients, aimed to provide an overview of current therapies for (i) asymptomatic or mildly/moderate symptomatic patients, (ii) hospitalized patients requiring low-flow oxygen, (iii) high-flow oxygen and (iv) mechanical ventilation.

Anticoagulation in Patients With COVID-19: JACC Review Topic of the Week

Clinical, laboratory, and autopsy findings support an association between coronavirus disease-2019 (COVID-19) and thromboembolic disease. Acute COVID-19 infection is characterized by mononuclear cell reactivity and pan-endothelialitis, contributing to a high incidence of thrombosis in large and small blood vessels, both arterial and venous. Observational studies and randomized trials have investigated whether full-dose anticoagulation may improve outcomes compared with prophylactic dose heparin. Although no benefit for therapeutic heparin has been found in patients who are critically ill hospitalized with COVID-19, some studies support a possible role for therapeutic anticoagulation in patients not yet requiring intensive care unit support. We summarize the pathology, rationale, and current evidence for use of anticoagulation in patients with COVID-19 and describe the main design elements of the ongoing FREEDOM COVID-19 Anticoagulation trial, in which 3,600 hospitalized patients with COVID-19 not requiring intensive care unit level of care are being randomized to prophylactic-dose enoxaparin vs therapeutic-dose enoxaparin vs therapeutic-dose apixaban. (FREEDOM COVID-19 Anticoagulation Strategy [FREEDOM COVID]; NCT04512079)

Anticoagulants for people hospitalised with COVID-19

BACKGROUND

The primary manifestation of coronavirus disease 2019 (COVID-19) is respiratory insufficiency that can also be related to diffuse pulmonary microthrombosis and thromboembolic events, such as pulmonary embolism, deep vein thrombosis, or arterial thrombosis. People with COVID-19 who develop thromboembolism have a worse prognosis. Anticoagulants such as heparinoids (heparins or pentasaccharides), vitamin K antagonists and direct anticoagulants are used for the prevention and treatment of venous or arterial thromboembolism. Besides their anticoagulant properties, heparinoids have an additional anti-inflammatory potential. However, the benefit of anticoagulants for people with COVID-19 is still under debate.

OBJECTIVES

To assess the benefits and harms of anticoagulants versus active comparator, placebo or no intervention in people hospitalised with COVID-19.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, LILACS and IBECS databases, the Cochrane COVID-19 Study Register and medRxiv preprint database from their inception to 14 April 2021. We also checked the reference lists of any relevant systematic reviews identified, and contacted specialists in the field for additional references to trials.

SELECTION CRITERIA

Eligible studies were randomised controlled trials (RCTs), quasi-RCTs, cluster-RCTs and cohort studies that compared prophylactic anticoagulants versus active comparator, placebo or no intervention for the management of people hospitalised with COVID-19. We excluded studies without a comparator group and with a retrospective design (all previously included studies) as we were able to include better study designs. Primary outcomes were all-cause mortality and necessity for additional respiratory support. Secondary outcomes were mortality related to COVID-19, deep vein thrombosis, pulmonary embolism, major bleeding, adverse events, length of hospital stay and quality of life.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We used Cochrane RoB 1 to assess the risk of bias for RCTs, ROBINS-I to assess risk of bias for non-randomised studies (NRS) and GRADE to assess the certainty of evidence. We meta-analysed data when appropriate.

MAIN RESULTS

We included seven studies (16,185 participants) with participants hospitalised with COVID-19, in either intensive care units, hospital wards or emergency departments. Studies were from Brazil (2), Iran (1), Italy (1), and the USA (1), and two involved more than country. The mean age of participants was 55 to 68 years and the follow-up period ranged from 15 to 90 days. The studies assessed the effects of heparinoids, direct anticoagulants or vitamin K antagonists, and reported sparse data or did not report some of our outcomes of interest: necessity for additional respiratory support, mortality related to COVID-19, and quality of life. Higher-dose versus lower-dose anticoagulants (4 RCTs, 4647 participants) Higher-dose anticoagulants result in little or no difference in all-cause mortality (risk ratio (RR) 1.03, 95% CI 0.92 to 1.16, 4489 participants; 4 RCTs) and increase minor bleeding (RR 3.28, 95% CI 1.75 to 6.14, 1196 participants; 3 RCTs) compared to lower-dose anticoagulants up to 30 days (high-certainty evidence). Higher-dose anticoagulants probably reduce pulmonary embolism (RR 0.46, 95% CI 0.31 to 0.70, 4360 participants; 4 RCTs), and slightly increase major bleeding (RR 1.78, 95% CI 1.13 to 2.80, 4400 participants; 4 RCTs) compared to lower-dose anticoagulants up to 30 days (moderate-certainty evidence). Higher-dose anticoagulants may result in little or no difference in deep vein thrombosis (RR 1.08, 95% CI 0.57 to 2.03, 3422 participants; 4 RCTs), stroke (RR 0.91, 95% CI 0.40 to 2.03, 4349 participants; 3 RCTs), major adverse limb events (RR 0.33, 95% CI 0.01 to 7.99, 1176 participants; 2 RCTs), myocardial infarction (RR 0.86, 95% CI 0.48 to 1.55, 4349 participants; 3 RCTs), atrial fibrillation (RR 0.35, 95% CI 0.07 to 1.70, 562 participants; 1 study), or thrombocytopenia (RR 0.94, 95% CI 0.71 to 1.24, 2789 participants; 2 RCTs) compared to lower-dose anticoagulants up to 30 days (low-certainty evidence). It is unclear whether higher-dose anticoagulants have any effect on necessity for additional respiratory support, mortality related to COVID-19, and quality of life (very low-certainty evidence or no data). Anticoagulants versus no treatment (3 prospective NRS, 11,538 participants) Anticoagulants may reduce all-cause mortality but the evidence is very uncertain due to two study results being at critical and serious risk of bias (RR 0.64, 95% CI 0.55 to 0.74, 8395 participants; 3 NRS; very low-certainty evidence). It is uncertain if anticoagulants have any effect on necessity for additional respiratory support, mortality related to COVID-19, deep vein thrombosis, pulmonary embolism, major bleeding, stroke, myocardial infarction and quality of life (very low-certainty evidence or no data). Ongoing studies We found 62 ongoing studies in hospital settings (60 RCTs, 35,470 participants; 2 prospective NRS, 120 participants) in 20 different countries. Thirty-five ongoing studies plan to report mortality and 26 plan to report necessity for additional respiratory support. We expect 58 studies to be completed in December 2021, and four in July 2022. From 60 RCTs, 28 are comparing different doses of anticoagulants, 24 are comparing anticoagulants versus no anticoagulants, seven are comparing different types of anticoagulants, and one did not report detail of the comparator group.

AUTHORS' CONCLUSIONS

When compared to a lower-dose regimen, higher-dose anticoagulants result in little to no difference in all-cause mortality and increase minor bleeding in people hospitalised with COVID-19 up to 30 days. Higher-dose anticoagulants possibly reduce pulmonary embolism, slightly increase major bleeding, may result in little to no difference in hospitalisation time, and may result in little to no difference in deep vein thrombosis, stroke, major adverse limb events, myocardial infarction, atrial fibrillation, or thrombocytopenia.  Compared with no treatment, anticoagulants may reduce all-cause mortality but the evidence comes from non-randomised studies and is very uncertain. It is unclear whether anticoagulants have any effect on the remaining outcomes compared to no anticoagulants (very low-certainty evidence or no data). Although we are very confident that new RCTs will not change the effects of different doses of anticoagulants on mortality and minor bleeding, high-quality RCTs are still needed, mainly for the other primary outcome (necessity for additional respiratory support), the comparison with no anticoagulation, when comparing the types of anticoagulants and giving anticoagulants for a prolonged period of time.

An observational study of intermediate- or high-dose thromboprophylaxis for critically ill COVID-19 patients

BACKGROUND

Critically ill COVID-19 patients have a high reported incidence of thromboembolic complications and the optimal dose of thromboprophylaxis is not yet determined. The aim of this study was to investigate if 90-day mortality differed between patients treated with intermediate- or high-dose thromboprophylaxis.

METHOD

In this retrospective study, all critically ill COVID-19 patients admitted to intensive care from March 6th until July 15th, 2020, were eligible. Patients were categorized into groups according to daily dose of thromboprophylaxis. Dosing was based on local standardized recommendations, not on degree of critical illness or risk of thrombosis. Cox proportional hazards regression was used to estimate hazard ratios of death within 90 days from ICU admission. Multivariable models were adjusted for sex, age, body-mass index, Simplified Acute Physiology Score III, invasive respiratory support, glucocorticoids, and dosing strategy of thromboprophylaxis.

RESULTS

A total of 165 patients were included; 92 intermediate- and 73 high-dose thromboprophylaxis. Baseline characteristics did not differ between groups. The 90-day mortality was 19.6% in patients with intermediate-dose and 19.2% in patients with high-dose thromboprophylaxis. Multivariable hazard ratio of death within 90 days was 0.74 (95% CI, 0.36-1.53) for the high-dose group compared to intermediate-dose group. Multivariable hazard ratio for thromboembolic events and bleedings within 28 days was 0.93 (95% CI 0.37-2.29) and 0.84 (95% CI 0.28-2.54) for high versus intermediate dose, respectively.

CONCLUSIONS

A difference in 90-day mortality between intermediate- and high-dose thromboprophylaxis could neither be confirmed nor rejected due to a small sample size.

COVID-19-Induced Hypercoagulability: A Case Report

We report a case of atherothrombotic microembolism in a 53-year-old male diagnosed with coronavirus disease 2019 (COVID-19) prior to hospital admission. Upon admission, Day 9 after diagnosis, he presented with COVID-19 pneumonia and mottling of the lower extremities. The patient was treated with anticoagulation therapy. The lower extremity angiogram showed a patent posterior tibial artery and a patent peroneal artery. Despite initial anticoagulation therapy, toe and transmetatarsal amputations were required. However, a below-the-knee amputation was subsequently required due to continued worsening and extension of mottling. Unfortunately, the patient ultimately expired from cardiopulmonary arrest before any other surgical intervention could be done.

Methylprednisolone, venous thromboembolism, and association with heparin to 30 days in hospital survival in severe Covid-19 pneumonia

BACKGROUND

Mortality in severe COVID-19 pneumonia is associated with thrombo-inflammation. Corticosteroids are given to attenuate the inflammation, but they are associated with thrombosis. The aims of this study were to determine the risk of venous thromboembolism between no methylprednisolone and methylprednisolone (dose versus duration) and to evaluate any synergistic dose-dependent association of heparin and methylprednisolone to 30 days in hospital survival.

METHODS

This was a secondary analysis of a retrospective cohort. Patients included in this study were ≥ 18 years of age and admitted for severe COVID-19 pneumonia between March and June 2020 in 13 hospitals in New Jersey, United States. A propensity score analysis between administration of methylprednisolone and no methylprednisolone was fitted for 11 variables and Youden Index Method was used to determine cut-off between low dose and high dose methylprednisolone. Multivariate cox regression was to assess risk.

RESULTS

In 759 patients, the incidence of venous thromboembolism was 9% of patients who received methylprednisolone and 3% of patients who did not receive methylprednisolone with a [RR 2.92 (95% CI 1.54, 5.55 P < 0.0001)]. There was a higher incidence of mechanical ventilation in the methylprednisolone group. The median d-dimer between patients with venous thromboembolism was higher compared to those without (P < 0.0003). However, the d-dimer was not statistically significant between those who had venous thromboembolism between methylprednisolone and no methylprednisolone groups (P = 0.40). There was no higher risk in high dose versus low dose [RR = 0.524 (95% CI 0.26, 1.06 P 0.4)]; however, the risk for venous thromboembolism between methylprednisolone for > 7 days and ≤ 7 days was statistically significant (RR 5.46 95% CI 2.87, 10.34 P < 0.0001). Patients who received low dose methylprednisolone and therapeutic heparin had a trend towards higher risk of mortality compared to prophylactic heparin (HR 1.81 95% CI 0.994 to 3.294) (P = 0.0522). There was no difference in 30 days in hospital survival between high dose methylprednisolone with prophylactic or therapeutic heparin (HR 0.827 95% CI 0.514 to 1.33) (P = 0.4335).

CONCLUSION

Methylprednisolone for > 7 days had a higher association of venous thromboembolism. There was no added benefit of therapeutic heparin to methylprednisolone on mechanically ventilated patients.

Anti-Xa Directed Thromboprophylaxis in Critically Ill Patients with Coronavirus Disease 2019

Objective: To compare Anti-Xa directed thromboprophylaxis using low molecular weight heparin (LMWH) (anti-Xa peak goal 0.2-0.5 IU/mL) to alternative anticoagulation strategies in critically ill COVID-19 patients. Methods: This was a retrospective, multicenter, single health-system study. Primary outcomes were thromboembolic events and clinically important bleeding events. Secondary outcomes included dosing comparisons between LMWH cohorts. Main Results: A total of 695 patients were included. No differences were found in the incidence of thrombotic events with any of the dosing strategies. The incidence of major bleeding was significantly higher in the standard dose thromboprophylaxis, intermediate dose subcutaneous heparin (SQH), and therapeutic anticoagulation cohorts. Forty-nine percent of patients within the anti-Xa directed group had their first anti-Xa peak at goal, while 43% were above goal. Patients who had levels above goal had dose modifications made, therefore anti-Xa directed LMWH resulted in significantly lower total daily doses compared to intermediate dose LMWH. Conclusions: Anti-Xa directed LMWH dosing provided comparable thromboprophylaxis with lower total daily doses of LMWH in critically ill COVID-19 patients. Further randomized controlled trials are needed to confirm our findings.

Acute and chronic neurological disorders in COVID-19: potential mechanisms of disease

Coronavirus disease 2019 (COVID-19) is a global pandemic caused by SARS-CoV-2 infection and is associated with both acute and chronic disorders affecting the nervous system. Acute neurological disorders affecting patients with COVID-19 range widely from anosmia, stroke, encephalopathy/encephalitis, and seizures to Guillain-Barré syndrome. Chronic neurological sequelae are less well defined although exercise intolerance, dysautonomia, pain, as well as neurocognitive and psychiatric dysfunctions are commonly reported. Molecular analyses of CSF and neuropathological studies highlight both vascular and immunologic perturbations. Low levels of viral RNA have been detected in the brains of few acutely ill individuals. Potential pathogenic mechanisms in the acute phase include coagulopathies with associated cerebral hypoxic-ischaemic injury, blood-brain barrier abnormalities with endotheliopathy and possibly viral neuroinvasion accompanied by neuro-immune responses. Established diagnostic tools are limited by a lack of clearly defined COVID-19 specific neurological syndromes. Future interventions will require delineation of specific neurological syndromes, diagnostic algorithm development and uncovering the underlying disease mechanisms that will guide effective therapies.

Differences between surviving and non-surviving venous thromboembolism COVID-19 patients: a systematic review

BACKGROUND

To our knowledge, the treatment, outcome, clinical presentation, risk stratification of patients with venous thromboembolism and COVID-19 have not been well characterized.

METHODS

We searched for systematic reviews, cohorts, case series, case reports, editor letters, and venous thromboembolism COVID-19 patients' abstracts following PRISMA and PROSPERO statements. We analyzed therapeutic approaches and clinical outcomes of venous thromboembolism COVID-19 patients. Inclusion: COVID-19 patients with venous thromboembolism confirmed by an imaging method (venous doppler ultrasound, ventilation-perfusion lung scan, computed tomography pulmonary angiogram, pulmonary angiography). We assessed and reported the original Pulmonary Embolism Severity Index for each pulmonary embolism patient. In addition, we defined major bleedings according to the International Society of Thrombosis and Haemostasis criteria.

RESULTS

We performed a systematic review from August 9 to August 30, 2020. We collected 1,535 papers from PubMed, Scopus, Web of Science, Wiley, and Opengrey. We extracted data from 89 studies that describe 143 patients. Unfractionated and low-molecular-weight heparin was used as parenteral anticoagulation in 85/143 (59%) cases. The Food and Drug Administration-approved alteplase regimen guided the advanced treatment in 39/143 (27%) patients. The mortality was high (21.6%, CI 95% 15.2-29.3). The incidence of major bleeding complications was 1 (0.9%) in the survival group and 1 (3.2%) in the death group. Pulmonary Embolism Severity Index was class I in 11.6% and II in 22.3% in survivors compared to 0% and 6.5% in non-survivors, respectively. Patients who experienced venous thromboembolism events at home were more likely to live than in-hospital events.

CONCLUSIONS

We determined a high mortality incidence of pulmonary embolism and a low rate of bleeding. Unfractionated and low-molecular-weight heparin drove parenteral anticoagulation and alteplase the advanced treatment in both groups. The original Pulmonary Embolism Severity Index could be helpful in the risk stratification.

Internal Bleeding Extending to the Retroperitoneum and Right Psoas With Severe Acute Respiratory Syndrome Coronavirus 2 Infection

Coronavirus disease 2019 (COVID-19 - severe acute respiratory syndrome coronavirus 2 {SARS-CoV-2}) infection has been associated with thromboembolic events and coagulopathy, leading to a surge in the use of anticoagulants. The dose and duration of therapy differ according to the followed protocol. Several case reports documented fatal bleeding as an adverse effect of anticoagulation. We report a case of nearly fatal retroperitoneal bleed in an otherwise healthy 60-year-old man who developed severe COVID-19 requiring ICU stay and mechanical ventilation. The development of retroperitoneal bleed led to a 50% drop in his hemoglobin. The patient happens to be a Jehovah's Witness, and the family refused blood transfusion, which added to the complexity of the situation. Anticoagulation is associated with a potential risk of fatal bleed in critically ill COVID-19 patients. There are different protocols of anticoagulation in the management of SARS-CoV-2. The risk of bleeding vs thrombosis should be weighed on a case-by-case basis. A high degree of suspicion, early intervention, and knowledge of alternatives to blood transfusion can improve outcomes.

Factors Associated With Risk of Postdischarge Thrombosis in Patients With COVID-19

IMPORTANCE

COVID-19 is associated with a high incidence of thrombotic events; however, the need for extended thromboprophylaxis after hospitalization remains unclear.

OBJECTIVE

To quantify the rate of postdischarge arterial and venous thromboembolism in patients with COVID-19, identify the factors associated with the risk of postdischarge venous thromboembolism, and evaluate the association of postdischarge anticoagulation use with venous thromboembolism incidence.

DESIGN, SETTING, AND PARTICIPANTS

This is a cohort study of adult patients hospitalized with COVID-19 confirmed by a positive SARS-CoV-2 test. Eligible patients were enrolled at 5 hospitals of the Henry Ford Health System from March 1 to November 30, 2020. Data analysis was performed from April to June 2021.

EXPOSURES

Anticoagulant therapy after discharge.

MAIN OUTCOMES AND MEASURES

New onset of symptomatic arterial and venous thromboembolic events within 90 days after discharge from the index admission for COVID-19 infection were identified using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes.

RESULTS

In this cohort study of 2832 adult patients hospitalized with COVID-19, the mean (SD) age was 63.4 (16.7) years (IQR, 53-75 years), and 1347 patients (47.6%) were men. Thirty-six patients (1.3%) had postdischarge venous thromboembolic events (16 pulmonary embolism, 18 deep vein thrombosis, and 2 portal vein thrombosis). Fifteen (0.5%) postdischarge arterial thromboembolic events were observed (1 transient ischemic attack and 14 acute coronary syndrome). The risk of venous thromboembolism decreased with time (Mann-Kendall trend test, P < .001), with a median (IQR) time to event of 16 (7-43) days. There was no change in the risk of arterial thromboembolism with time (Mann-Kendall trend test, P = .37), with a median (IQR) time to event of 37 (10-63) days. Patients with a history of venous thromboembolism (odds ratio [OR], 3.24; 95% CI, 1.34-7.86), peak dimerized plasmin fragment D (D-dimer) level greater than 3 μg/mL (OR, 3.76; 95% CI, 1.86-7.57), and predischarge C-reactive protein level greater than 10 mg/dL (OR, 3.02; 95% CI, 1.45-6.29) were more likely to experience venous thromboembolism after discharge. Prescriptions for therapeutic anticoagulation at discharge were associated with reduced incidence of venous thromboembolism (OR, 0.18; 95% CI, 0.04-0.75; P = .02).

CONCLUSIONS AND RELEVANCE

Although extended thromboprophylaxis in unselected patients with COVID-19 is not supported, these findings suggest that postdischarge anticoagulation may be considered for high-risk patients who have a history of venous thromboembolism, peak D-dimer level greater than 3 μg/mL, and predischarge C-reactive protein level greater than 10 mg/dL, if their bleeding risk is low.

Intermediate- vs. Standard-Dose Prophylactic Anticoagulation in Patients With COVID-19 Admitted in Medical Ward: A Propensity Score-Matched Cohort Study

Background: Microthrombosis and large-vessel thrombosis are the main triggers of COVID-19 worsening. The optimal anticoagulant regimen in COVID-19 patients hospitalized in medical wards remains unknown. Objectives: To evaluate the effects of intermediate-dose vs. standard-dose prophylactic anticoagulation (AC) among patients with COVID-19 hospitalized in medical wards. Methods and results: We used a large French multicentric retrospective study enrolling 2,878 COVID-19 patients hospitalized in medical wards. After exclusion of patients who had an AC treatment before hospitalization, we generated a propensity-score-matched cohort of patients who were treated with intermediate-dose or standard-dose prophylactic AC between February 26 and April 20, 2020 (intermediate-dose, n = 261; standard-dose prophylactic anticoagulation, n = 763). The primary outcome of the study was in-hospital mortality; this occurred in 23 of 261 (8.8%) patients in the intermediate-dose group and 74 of 783 (9.4%) patients in the standard-dose prophylactic AC group (p = 0.85); while time to death was also the same in both the treatment groups (11.5 and 11.6 days, respectively, p = 0.17). We did not observe any difference regarding venous and arterial thrombotic events between the intermediate dose and standard dose, respectively (venous thrombotic events: 2.3 vs. 2.4%, p=0.99; arterial thrombotic events: 2.7 vs. 1.2%, p = 0.25). The 30-day Kaplan-Meier curves for in-hospital mortality demonstrate no statistically significant difference in in-hospital mortality (HR: 0.99 (0.63-1.60); p = 0.99). Moreover, we found that no particular subgroup was associated with a significant reduction in in-hospital mortality. Conclusion: Among COVID-19 patients hospitalized in medical wards, intermediate-dose prophylactic AC compared with standard-dose prophylactic AC did not result in a significant difference in in-hospital mortality.

Pulmonary Thrombosis and Thromboembolism in COVID-19

COVID-19, the disease responsible for the devastating pandemic that began at the end of 2019, has been associated with a significantly increased risk of pulmonary thrombosis, even in patients receiving prophylactic anticoagulation. The predilection for thrombosis in COVID-19 may be driven by at least two distinct, but interrelated, processes: a hypercoagulable state responsible for large-vessel thrombosis and thromboembolism and direct vascular and endothelial injury responsible for in situ microvascular thrombosis. The presence of pulmonary thrombosis may explain why hypoxemia is out of proportion to impairment in lung compliance in some patients with COVID-19 pneumonia. Because pulmonary embolism (PE) and COVID-19 pneumonia share many signs and symptoms, diagnosing PE in patients with COVID-19 can be challenging. Given the high mortality and morbidity associated with severe COVID-19 and the concern that aspects of the disease may be driven by thrombosis, many hospital systems have instituted aggressive anticoagulation protocols above standard VTE prophylaxis. In this review, the epidemiologic and pathophysiologic features, diagnosis, and treatment of COVID-19 pulmonary thrombosis and thromboembolism are discussed.

Incidence of Venous Thromboembolism and Effect of Anticoagulant Dosing in Hospitalized COVID-19 Patients

Background

Coronavirus disease 2019 (COVID-19) is characterized by coagulopathy and thrombotic events. We examined factors associated with development of venous thromboembolism (VTE) in COVID-19 and to discern if higher dose of anticoagulation was beneficial in these patients.

Methods

This study involves an observational study of prospectively collected data in the setting of a large community hospital in a rural setting in Northeast Georgia with COVID-19 between March 1, 2020 and February 5, 2021. Anticoagulation dose (none, standard, intermediate, and therapeutic dosages) was studied in adult patients (≥ 18 years). We constructed multivariable logistic regression model to examine the association of clinical characteristics with VTE. To examine the effect of dose of anticoagulation in preventing VTE, we used inverse probability weighted regression adjustment.

Results

Of the 4,645 patients with COVID-19, 251 (5.4%) patients were found to have VTE. Of these, 91 had pulmonary embolism, 148 had deep venous thrombosis (DVT) and 12 had both. A total of 129 of VTE cases were diagnosed at admission. Of all admissions, 12.9% did not receive any DVT prophylaxis, 70.4% received prophylactic dose, 1.3% received intermediate dose and 15.5% received therapeutic dose. Male gender (odds ratio (OR): 1.55, 95% confidence interval (CI): 1.0 - 2.4, P = 0.04) and Black race (OR: 2.0, 95% CI: 1.2 - 3.4, P = 0.01), along with higher levels of lactate dehydrogenase (LDH) and D-dimer were associated with higher odds of developing VTE. Patients receiving steroids had lower rates of VTE (3.9% vs. 8.3%, P < 0.001). Use of intermediate or therapeutic anticoagulation was not associated with lower odds of developing VTE. However, patients on therapeutic anticoagulation had lower odds of in hospital mortality when compared to standard dose (OR: 0.47, 95% CI: 0.27 - 0.80, P = 0.006).

Conclusions

In COVID-19, D-dimer and LDH can be useful in predicting VTE. Steroids appear to have some protective role in development of VTE. Therapeutic anticoagulation did not result in lower rates of VTE but was associated with in-hospital mortality.

Impact of COVID-19 and lockdown regarding blood transfusion

BACKGROUND

The outbreak of a SARS-CoV-2 resulted in a massive afflux of patients in hospital and intensive care units with many challenges. Blood transfusion was one of them regarding both blood banks (safety, collection, and stocks) and consumption (usual care and unknown specific demand of COVID-19 patients). The risk of mismatch was sufficient to plan blood transfusion restrictions if stocks became limited.

STUDY DESIGN AND METHODS

Analyses of blood transfusion in a tertiary hospital and blood collection in the referring blood bank between February 24 and May 31, 2020.

RESULTS

Withdrawal of elective surgery and non-urgent care and admission of 2291 COVID-19 patients reduced global activity by 33% but transfusion by 17% only. Only 237 (10.3) % of COVID-19 patients required blood transfusion, including 45 (2.0%) with acute bleeding. Lockdown and cancellation of mobile collection resulted in an 11% reduction in blood donation compared to 2019. The ratio of reduction in blood transfusion to blood donation remained positive and stocks were slightly enhanced.

DISCUSSION

Reduction of admissions due to SARS-CoV-2 pandemic results only in a moderate decrease of blood transfusion. Incompressible blood transfusions concern urgent surgery, acute bleeding (including some patients with COVID-19, especially under high anticoagulation), or are supportive for chemotherapy-induced aplasia or chronic anemia. Lockdown results in a decrease of blood donation by cancellation of mobile donation but with little impact on a short period by mobilization of usual donors. No mismatch between demand and donation was evidenced and no planned restriction to blood transfusion was necessary.

Lung Perfusion Scintigraphy Early After COVID-19: A Single-Center Retrospective Study

The incidence of thromboembolic complications in coronavirus disease 2019 (COVID-19) infection is well recognized. The present study retrospectively evaluated the type and prevalence of lung perfusion defects in early–post-COVID-19 patients with hypoxia and was aimed to identify the risk factors for mismatched perfusion defects. Methods: We analyzed SPECT/CT images of 54 early–post-COVID-19 patients (44 men and 10 women). Logistic regression analysis was used to examine the risk. Results: The mean age of the study population was 55.4 y (range, 34–76 y). All received prophylactic anticoagulation from the day of hospitalization to the date of perfusion scanning. The median interval between COVID-19–positive reports and lung perfusion scanning was 22 d. Lung perfusion defects (of any type) were observed in most (87%). Twenty-three subjects (42.6%) had mismatched perfusion defects. Mismatched perfusion defects were segmental in 14 subjects (25.9%) and subsegmental in 11 (20.4%). Higher age was a risk factor for mismatched perfusion defects (odds ratio, 1.06; 95% CI, 0.99–1.13; P = 0.06). Subjects with a serum D-dimer level of at least 2,500 ng/mL on the day before the scan were not at higher risk for having mismatched perfusion defects (odds ratio, 1.14; 95% CI, 0.34–3.9; P = 0.83). Conclusion: Despite prophylactic anticoagulation, mismatched perfusion defects suggestive of pulmonary thromboembolism were observed. Serum D-dimer level in patients early after COVID-19 is a poor predictor of mismatched perfusion defects. Confirmed evidence of pulmonary embolism by imaging studies should support the decision to extend anticoagulant prophylaxis in post-COVID-19 patients.

Severe COVID-19 pneumonia: Perfusion analysis in correlation with pulmonary embolism and vessel enlargement using dual-energy CT data

BACKGROUND

Gas exchange in COVID-19 pneumonia is impaired and vessel obstruction has been suspected to cause ventilation-perfusion mismatch. Dual-energy CT (DECT) can depict pulmonary perfusion by regional assessment of iodine uptake.

OBJECTIVE

The purpose of this study was the analysis of pulmonary perfusion using dual-energy CT in a cohort of 27 consecutive patients with severe COVID-19 pneumonia.

METHOD

We retrospectively analyzed pulmonary perfusion with DECT in 27 consecutive patients (mean age 57 years, range 21-73; 19 men and 8 women) with severe COVID-19 pneumonia. Iodine uptake (IU) in regions-of-interest placed into normally aerated lung, ground-glass opacifications (GGO) and consolidations was measured using a dedicated postprocessing software. Vessel enlargement (VE) within opacifications and presence of pulmonary embolism (PE) was assessed by subjective analysis. Linear mixed models were used for statistical analyses.

RESULTS

Compared to normally aerated lung 106/151 (70.2%) opacifications without upstream PE demonstrated an increased IU, 9/151 (6.0%) an equal IU and 36/151 (23.8%) a decreased IU. The estimated mean iodine uptake (EMIU) in opacifications without upstream PE (GGO 1.77 mg/mL; 95%-CI: 1.52-2.02; p = 0.011, consolidations 1.82 mg/mL; 95%-CI: 1.56-2.08, p = 0.006) was significantly higher compared to normal lung (1.22 mg/mL; 95%-CI: 0.95-1.49). In case of upstream PE, EMIU of opacifications (combined GGO and consolidations) was significantly decreased compared to normal lung (0.52 mg/mL; 95%-CI: -0.07-1.12; p = 0.043). The presence of VE in opacifications correlated significantly with iodine uptake (p<0.001).

CONCLUSIONS

DECT revealed the opacifications in a subset of patients with severe COVID-19 pneumonia to be perfused non-uniformly with some being hypo- and others being hyperperfused. Mean iodine uptake in opacifications (both ground-glass and consolidation) was higher compared to normally aerated lung except for areas with upstream pulmonary embolism. Vessel enlargement correlated with iodine uptake: In summary, in a cohort of 27 consecutive patients with severe COVID-19 pneumonia, dual-energy CT demonstrated a wide range of iodine uptake in pulmonary ground-glass opacifications and consolidations as a surrogate marker for hypo- and hyperperfusion compared to normally aerated lung. Applying DECT to determine which pathophysiology is predominant might help to tailor therapy to the individual patient´s needs.

Spontaneous psoas haematoma: a life-threatening complication of anticoagulation in COVID-19. A case series of four episodes

BACKGROUND

Anticoagulant prophylaxis is part of the standard management of hospitalized COVID-19 patients. Despite adequate thromboprophylaxis, one-third of COVID-19 patients with pneumonia developed pulmonary embolism. This high rate of thrombotic complications has led to higher doses of anticoagulants according to clinical complexity (e.g. intensive care unit (ICU) patients) and D-dimer levels. On the other side of the coin, haemorrhagic complications are being increasingly reported.

CASES PRESENTATION

We herein report four cases of spontaneous psoas haematomas (SPH) among 548 patients hospitalized for SARS-CoV-2 pneumonia between March 2020 and January 2021 (incidence of 7.3 cases per 1000 patients). All patients had pneumonia, with age ranging between 62 and 83 years. All patients received anticoagulant therapy with low weight molecular heparin (100 U.I. anti-Xa/kg 2 times/d) from admission: in two cases, a diagnosis of pulmonary embolism was made. In another case, a thrombosis of left axillary and basilic veins was found, and only in one case anticoagulant therapy was started because of elevated levels of D-dimer. In all cases, signs of anaemia were detected and patients experienced low back or abdominal pain. The diagnosis of spontaneous psoas haematoma was made by computed tomography (CT) after a median of 12.5 d (9;16) from admission and 19.5 d (14.75; 24.25) from the beginning of COVID-19 symptoms. Half of these patients died from haemorrhagic shock.

CONCLUSIONS

Given the potential life-threatening of SPH and the possible subtle clinical presentation, we believe it is crucial to raise clinicians awareness of this complication among COVID-19 patients undergoing anticoagulants.

Platelet Count Rose While D-Dimer Levels Dropped as Deaths and Thrombosis Declined-An Observational Study on Anticoagulation Shift in COVID-19

BACKGROUND

 High levels of D-dimer and low platelet counts are associated with poor outcome in coronavirus disease 2019 (COVID-19). As anticoagulation appeared to improve survival, hospital-wide recommendations regarding higher doses of anticoagulation were implemented on April 9, 2020.

OBJECTIVES

 To investigate if trends in D-dimer levels and platelet counts were associated with death, thrombosis, and the shift in anticoagulation.

METHODS

 Retrospective cohort study of 429 patients with COVID-19 at Karolinska University Hospital. Information on D-dimer levels and platelet counts was obtained from laboratory databases and clinical data from medical records.

RESULTS

 Thirty-day mortality and thrombosis rates were 19% and 18%, respectively. Pulmonary embolism was common, 65/83 (78%). Increased D-dimer levels in the first week in hospital were significantly associated with death and thrombosis (odds ratio [OR]: 6.06; 95% confidence interval [CL]: 2.10-17.5 and 3.11; 95% CI: 1.20-8.10, respectively). If platelet count increased more than 35 × 10⁹/L per day, the mortality and thrombotic risk decreased (OR: 0.16; 95% CI: 0.06-0.41, and OR: 0.36; 95% CI: 0.17-0.80). After implementation of updated hospital-wide recommendations, the daily mean significantly decreased regarding D-dimer levels while platelet counts rose; -1.93; 95% CI: -1.00-2.87 mg/L FEU (fibrinogen-equivalent unit) and 65; 95% CI: 54-76 ×10⁹/L, and significant risk reductions for death and thrombosis were observed; OR: 0.48; 95% CI: 0.25-0.92 and 0.35; 95% CI: 0.17-0.72.

CONCLUSION

 In contrast to D-dimer levels, increase of platelet count over the first week in hospital was associated with improved survival and reduced thrombotic risk. The daily mean levels of D-dimer dropped while the platelet counts rose, coinciding with increased anticoagulation and a decline in thrombotic burden and mortality.

SARS-CoV-2 Infection: Modulator of Pulmonary Embolism Paradigm

Pulmonary embolism (PE) is a life-threatening complication arising from venous thromboembolism with a difficult diagnosis and treatment and is often associated with increased mortality and morbidity. PE had a significantly low incidence prior to the COVID-19 epidemic. This condition saw a sharp surge during the COVID-19 pandemic, indicating an evident viral influence on PE's pathophysiology in COVID-19 patients. The hypercoagulable state induced by the viral load seems to be the major contributor, and the classical causative factors seem to play a lesser role. PE in COVID-19 infection has become a mammoth challenge since the diagnosis is quite challenging due to overlapping symptoms, lack of prior-known predisposing risk factors, limited resources, and viral transmittance risk. Numerous factors arising out of the viral load or treatment lead to an increased risk for PE in COVID-19 patients, besides the fact that certain unknown risk factors may also contribute to the incidence of PE in COVID-19 patients. The management of PE in COVID-19 infection mainly comprises thromboprophylaxis and anticoagulant therapy with mechanical ventilation, depending on the risk stratification of the patient, with a post-COVID-19 management that prevents recurrent PE and complications. This review aims to discuss various aspects of COVID-19-infection-associated PE and major differential aspects from non-COVID-19 PE.