Search

Thrombophilia testing is frequently performed after an ischemic stroke, particularly when cryptogenic. However, there is minimal evidence supporting a significant association between most conditions assessed through thrombophilia testing and ischemic stroke, and the rationale for thrombophilia testing in many clinical situations remains uncertain. In this topical review, we review and contextualize the existing data on the risks, predictors, and outcomes of thrombophilic conditions in patients with ischemic stroke. We report that inherited thrombophilias have an uncertain relationship with ischemic stroke. Conversely, antiphospholipid syndrome, an acquired immune-mediated thrombophilia, seems to be a strong risk factor for arterial thromboembolic events, including ischemic stroke, and especially among young patients. Our findings suggest that certain circumstances may warrant targeted thrombophilia testing, such as stroke in the young, cryptogenic stroke, and high estrogen states. Future prospective studies should investigate the utility and cost effectiveness of thrombophilia testing in various stroke settings, including among patients with patent foramen ovale; as well as the optimal secondary stroke prevention regimen in patients with confirmed thrombophilia, particularly if no other potential stroke mechanism is identified.

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection is associated with a clear prothrombotic phenotype. Although the exact pathophysiological mechanisms are not yet fully understood, thrombosis is clearly a highly important in the prognosis and outcome of COVID-19. As such, there is a need for diagnostic analysis and quantification of the coagulation potential in these patients, both at diagnosis and follow-up. Global coagulation assays like thrombin generation (TG) and rotational thromboelastometry (ROTEM) might be suitable in estimating COVID-19 associated coagulopathy and thrombosis risk. Therefore, we aimed at validating both assays for samples with high levels of fibrinogen and in the presence of anticoagulant heparins, such as commonly observed for COVID-19 ICU patients., Materials and Methods: Calibrated Automated Thrombography (CAT) was optimized to assess plasma thrombin generation in the presence of heparins. The final conditions with either 10 μg/mL Ellagic acid (EA) or PPP Reagent HIGH (high tissue factor; HPPH) were validated according to the EP5 protocol for within-run and between-run variability. Overall variability was well below 10%. To estimate the influences of heparins and high fibrinogen levels, CAT was performed on spiked plasma aliquots from 13 healthy volunteers. Comparable to the CAT method, tPA-ROTEM was used to validate the effect of high fibrinogen and heparins on clotting time, clot firmness and clot lysis parameters., Results: Our adjusted COVID-19 assay showed a heparin dose dependent decrease in peak height and endogenous thrombin potential (ETP) for both EA and HPPH triggered variants. High fibrinogen did not alter the inhibitory effect of either LMWH or UFH, nor did it influence the peak height or ETP in any of the conditions. The tPA-ROTEM showed a significant prolongation in clotting time with the additions of heparin, which normalized with the addition of high fibrinogen. MCF was markedly increased in all hyperfibrinogenemic conditions. A trend towards increased lysis time and, thus, decreased fibrinolysis was observed., Conclusion: Thrombin generation and tPA-ROTEM protocols for measurements in the COVID-19 populations were adjusted and validated. The adjusted thrombin generation assay shows good sensitivity for measurements in heparin spiked plasma. High levels of fibrinogen did not alter the assay or the effectiveness of heparins as measured in this assay. t-PA ROTEM was effective in measurement of both high fibrinogen and heparins spiked samples and was sensitive to the expected relevant coagulant changes by these conditions. No clear fibrinolytic effect was observed in different conditions., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Infection with the novel severe acute respiratory syndrome coronavirus 2 has been associated with a hypercoagulable state. Emerging data from China and Europe have consistently shown an increased incidence of venous thromboembolism (VTE). We aimed to identify the VTE incidence and early predictors of VTE at our high-volume tertiary care center., Methods: We performed a retrospective cohort study of 147 patients who had been admitted to Temple University Hospital with coronavirus disease 2019 (COVID-19) from April 1, 2020 to April 27, 2020. We first identified the VTE (pulmonary embolism [PE] and deep vein thrombosis [DVT]) incidence in our cohort. The VTE and no-VTE groups were compared by univariable analysis for demographics, comorbidities, laboratory data, and treatment outcomes. Subsequently, multivariable logistic regression analysis was performed to identify the early predictors of VTE., Results: The 147 patients (20.9% of all admissions) admitted to a designated COVID-19 unit at Temple University Hospital with a high clinical suspicion of acute VTE had undergone testing for VTE using computed tomography pulmonary angiography and/or extremity venous duplex ultrasonography. The overall incidence of VTE was 17% (25 of 147). Of the 25 patients, 16 had had acute PE, 14 had had acute DVT, and 5 had had both PE and DVT. The need for invasive mechanical ventilation (adjusted odds ratio, 3.19; 95% confidence interval, 1.07-9.55) and the admission D-dimer level ≥1500 ng/mL (adjusted odds ratio, 3.55; 95% confidence interval, 1.29-9.78) were independent markers associated with VTE. The all-cause mortality in the VTE group was greater than that in the non-VTE group (48% vs 22%; P = .007)., Conclusions: Our study represents one of the earliest reported from the United States on the incidence rate of VTE in patients with COVID-19. Patients with a high clinical suspicion and the identified risk factors (invasive mechanical ventilation, admission D-dimer level ≥1500 ng/mL) should be considered for early VTE testing. We did not screen all patients admitted for VTE; therefore, the true incidence of VTE could have been underestimated. Our findings require confirmation in future prospective studies., (Copyright © 2020 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Even though it rarely influences venous thromboembolism (VTE) treatment and the fact that it is generally discouraged, thrombophilia testing is still largely prescribed. We assessed: 1) whether/how frequently Italian thrombosis centres requested thrombophilia testing; 2) what results were obtained; and 3) if the results affected treatment and clinical results., Materials and Methods: We examined data from 4,826 VTE patients enrolled by 19 clinical centres participating in the START 2-Register., Results: 57.2% of patients were tested. Numbers varied widely among centres (2.9-99.7%). Thrombophilic alterations were recorded in 18.2% of patients and the percentage of positive results was inversely correlated with that of patients tested. Significantly less patients with deep vein thrombosis (DVT) were tested, whereas more were tested when the event was idiopathic, presenting as isolated pulmonary embolism (PE), or in unusual sites. Patients with thrombophilic alterations were younger, more frequently treated with direct oral anticoagulants (DOACs), with lower mortality and less frequently discontinued anticoagulation. DOACs were more frequently prescribed in patients with heterozygous Factor V (FV) Leiden or prothrombin mutations, whereas vitamin K antagonists were preferred in patients with inhibitor deficiencies, combined alterations or antiphospholipid syndrome (APLS). There was no difference in duration of treatment among those with or without alterations, though more APLS patients received an extended treatment course. Bleeding and thrombotic complications occurred with a similar and fairly low incidence in patients with or without thrombophilic alterations., Discussion: Although general testing for thrombophilia in VTE patients is currently discouraged, more than half of the VTE patients included in the START2-Register were tested. However, there were marked differences in practice between Italian thrombosis centres. About 60% of all patients with alterations were treated with DOACs, confirming that DOACs can be a useful option for treatment of thrombophilic VTE patients, with the exclusion of those with APLS.

Background: The association between coronavirus disease 2019 (COVID-19) and hypercoagulability has been extensively described, and pulmonary embolism is a recognized complication of COVID-19. Currently, the need for computed tomography pulmonary angiogram (CTPA) relies on the Wells score and serum D-dimer levels. However, because COVID-19 patients have a different thrombotic and inflammatory milieu, the usefulness of the Wells score deserves further exploration for this patient population. We aimed to explore the ability of the Wells score to predict pulmonary embolism in patients with COVID-19., Methods: In this retrospective study, patients found to have a CTPA and a COVID-19 diagnosis during the same admission were selected for analysis. Age and sex, CTPA results, and associated D-dimer levels were entered in a database. The Wells score sensitivity and specificity were calculated at different values, and the area under the curve of the receiver operating characteristic curve measured., Results: Of 459 patients with COVID-19, 64 had a CTPA and 12 (19%) had evidence of pulmonary embolism. Previous or current evidence of deep vein thrombosis, a Wells score above 4 points, and serum D-dimer levels 5 times above age-adjusted upper normal values were associated with pulmonary embolism. However, only 33% of patients with pulmonary embolism had a Wells score of 4 points or higher. The area under the curve of the receiver operating characteristic showed non-discriminating values (0.54) CONCLUSIONS: Although a Wells score of 4 or more points predicted pulmonary embolism in our cohort, the outcome can be present even with lower scores., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Severe coronavirus disease 2019 (COVID-19) is commonly complicated with coagulopathy, the difference of coagulation features between severe pneumonia induced by SARS-CoV2 and non-SARS-CoV2 has not been analyzed. Coagulation results and clinical features of consecutive patients with severe pneumonia induced by SARS-CoV2 (COVID group) and non-SARS-CoV2 (non-COVID group) in Tongji hospital were retrospectively analyzed and compared. Whether patients with elevated D-dimer could benefit from anticoagulant treatment was evaluated. There were 449 COVID patients and 104 non-COVID patients enrolled into the study. The 28-day mortality in COVID group was approximately twofold of mortality in non-COVID group (29.8% vs. 15.4%, P = 0.003), COVID group were older (65.1 ± 12.0 vs. 58.4 ± 18.0, years, P < 0.001) and with higher platelet count (215 ± 100 vs. 188 ± 98, ×10 9 /L, P = 0.015), comparing to non-COVID group. The 28-day mortality of heparin users were lower than nonusers In COVID group with D-dimer > 3.0 μg/mL (32.8% vs. 52.4%, P = 0.017). Patients with severe pneumonia induced by SARS-CoV2 had higher platelet count than those induced by non-SARS-CoV2, and only the former with markedly elevated D-dimer may benefit from anticoagulant treatment.

Trauma-induced coagulopathy (TIC) is caused by post-traumatic tissue injury and manifests as hypercoagulability that leads to thromboembolism or hypocoagulability that leads to uncontrollable massive hemorrhage. Previous studies on TIC have mainly focused on hemorrhagic coagulopathy caused by the hypocoagulable phenotype of TIC, while recent studies have found that trauma-induced hypercoagulopathy can occur in as many as 22.2-85.1% of trauma patients, in whom it can increase the risk of thrombotic events and mortality by 2- to 4-fold. Therefore, the Chinese People's Liberation Army Professional Committee of Critical Care Medicine and the Chinese Society of Thrombosis, Hemostasis and Critical Care, Chinese Medicine Education Association jointly formulated this Chinese Expert Consensus comprising 15 recommendations for the definition, pathophysiological mechanism, assessment, prevention, and treatment of trauma-induced hypercoagulopathy.

Abstract: Patients with severe coronavirus disease-2019 (COVID-19) frequently have hypercoagulability caused by the immune response to the severe acute respiratory syndrome coronavirus-2 infection. The pathophysiology of COVID-19 associated hypercoagulability is not fully understood, but characteristic changes include: increased fibrinogen concentration, increased Factor VIII activity, increased circulating von Willebrand factor, and exhausted fibrinolysis. Anticoagulant therapy improves outcomes in mechanically ventilated patients with COVID-19 and viscoelastic coagulation testing offers an opportunity to tailor anticoagulant therapy based on an individual patient's coagulation status. In this narrative review, we summarize clinical manifestations of COVID-19, mechanisms, monitoring considerations, and anticoagulant therapy. We also review unique considerations for COVID-19 patients who are on extracorporeal membrane oxygenation., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 by the Shock Society.)

Chronic lower extremity wounds are defined as wounds that fail to heal within 3 months of defect onset. Free tissue transfer offers an opportunity for limb salvage and length preservation. Preoperative optimization includes a medical and nutritional consult, complete work-up by vascular surgery, and an analysis of bony stability and gait biomechanics by podiatric surgery. In the authors' practice, the thigh has proved the workhorse donor site and offers fasciocutaneous and muscle-based flaps depending on defect characteristics. Postoperative care requires early monitoring for flap compromise and continued long-term follow-up for wound recurrence., Competing Interests: Disclosure The authors have no financial disclosures, commercial associations, or any other conditions posing a conflict of interest to report., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Abstract: Obesity is an inflammatory state related to vascular endothelium dysfunction. It generates a biological situation of hypercoagulability increasing the risk of thrombosis. This prothrombotic condition could be improved by bariatric surgery.The main objective was to analyze the impact of bariatric surgery on cardiovascular risk factors (CVRF) associated with changes in thrombin generation and procoagulant activity of microparticles (MP).We present a prospective longitudinal study including consecutive patients candidate for bariatric surgery. We performed 3 sequential clinical visits: at inclusion, before surgery after completing the modified fasting phase, and 6 months after surgery. We analyzed CVRF, thrombin generation, and MP activity. The data analysis was performed using a logistic regression model to determine changes over time of hemostatic parameters and body mass index (BMI). McNemar test for binary variables was used to analyze the CVRF.We included 94 patients (66 women), with an average age of 45.7 ± 10.1 years. The mean BMI reduction at the end of the follow-up was 15.5 ± 4.2 kg/m2. We detected a statistically significant improvement in CVRF: hypertension, diabetes mellitus, dyslipidemia, and obstructive sleep apnea, as well as a significant reduction in thrombin generation capacity and procoagulant MP activity.Massive weight loss induced by bariatric surgery improves the cardiovascular profile, associated with a reduction in the hypercoagulable status., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Potential causes of embolic stroke of undetermined source (ESUS) include occult malignancy, venous thrombosis (VTE) with paradoxical embolism, and hypercoagulable disorders. Given the association of markers of coagulation and hemostatic activation (MOCHA) with these causes, the objective of this study was to validate the utility of the MOCHA profile in identifying the underlying cause of stroke., Methods: We prospectively identified ESUS patients from January 1, 2017 to December 1, 2019 who underwent MOCHA profile (plasma d-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex, fibrin monomer) testing. Abnormal MOCHA profile was defined as ≥ 2 abnormal markers. New diagnoses of malignancy, VTE, hypercoagulable disorders and recurrent stroke were identified during routine clinical follow-up., Results: Of 236 ESUS patients, 104 (44%) patients had an abnormal MOCHA profile. In multivariable analyses the number of MOCHA abnormalities was significantly associated with malignancy, VTE, and hypercoagulable disorders (OR 2.59, CI 95% 1.78-3.76, p<0.001). Sensitivity, specificity, positive predictive value, and negative predictive value of an abnormal MOCHA profile for the combined outcome of malignancy, VTE, and hypercoagulability was 96%, 62%, 23%, and 99% respectively., Discussion: The MOCHA profile was able to identify ESUS patients more likely to have malignancy, VTE, and hypercoagulable disorders during follow-up. Our results show that a normal MOCHA profile in ESUS patients can effectively rule out these potential causes of ESUS., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Critically ill coronavirus disease 2019 (COVID-19) patients present with a hypercoagulable state with high rates of macrovascular and microvascular thrombosis, for which hypofibrinolysis might be an important contributing factor., Methods: We retrospectively analysed 20 critically ill COVID-19 patients at Innsbruck Medical University Hospital whose coagulation function was tested with ClotPro® and compared with that of 60 healthy individuals at Augsburg University Clinic. ClotPro is a viscoelastic whole blood coagulation testing device. It includes the TPA test, which uses tissue factor (TF)-activated whole blood with added recombinant tissue-derived plasminogen activator (r-tPA) to induce fibrinolysis. For this purpose, the lysis time (LT) is measured as the time from when maximum clot firmness (MCF) is reached until MCF falls by 50%. We compared COVID-19 patients with prolonged LT in the TPA test and those with normal LT., Results: Critically ill COVID-19 patients showed hypercoagulability in ClotPro assays. MCF was higher in the EX test (TF-activated assay), IN test (ellagic acid-activated assay), and FIB test (functional fibrinogen assay) with decreased maximum lysis (ML) in the EX test (hypofibrinolysis) and highly prolonged TPA test LT (decreased fibrinolytic response), as compared with healthy persons. COVID-19 patients with decreased fibrinolytic response showed higher fibrinogen levels, higher thrombocyte count, higher C-reactive protein levels, and decreased ML in the EX test and IN test., Conclusion: Critically ill COVID-19 patients have impaired fibrinolysis. This hypofibrinolytic state could be at least partially dependent on a decreased fibrinolytic response., Competing Interests: Declarations of interest MB has received research funding and travel grants from LFB Biomedicaments, Baxter GmbH, CSL Behring GmbH, Mitsubishi Tanabe and non-financial support from TEM International outside the submitted work. MJ reported receiving grants from Baxter; grants and personal fees from Fresenius Kabi; and speaking, consulting honoraria, or both from Sphingotec, CLS-Behring, Fresenius and Astute Medical outside the submitted work. CT reports grants and personal fees from BrainLab, grants and personal fees from DePuySynthes, grants and personal fees from Intrinsic Therapeutics, grants from TETEC AG, personal fees from Aesculap, grants and personal fees from Signus Medizintechnik, grants and personal fees from Medtronic, grants and personal fees from Icotec AG, grants and personal fees from Edge Therapeutics, grants from BIT-Pharma, outside the submitted work. DF has received study funding, honoraria for consultancy and board activity from Astra Zeneca, AOP orphan, Baxter, Bayer, BBraun, Biotest, CSL Behring, Delta Select, Dade Behring, Edwards, Fresenius, Glaxo, Haemoscope, Hemogem, Lilly, LFB, Mitsubishi Pharma, NovoNordisk, Octapharm, Pfizer, Tem-Innovation outside the submitted work. The other authors declare no conflicts of interest., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Certain miscarriages result from immunologic factors, but there is no clear identification of the precise causes of recurrent pregnancy loss (RPL). Miscarriages and RPL can arise from a disruption of maternal-fetal immune homeostasis. Remodeling of the maternal uterine spiral arteries is one of the key steps for normal growth and development of the fetus. An adequate oxygen supply is necessary for correct placentation, and it is accomplished by proper vascular changes. The development of fetal tissues creates a potential immunologic problem since the fetus can express paternal antigens and, in some cases, antigens of a gamete donor. The maternal immune system actively responds to fetal antigens, and dysregulation of this crosstalk could partly explain pregnancy complications such as miscarriages and RPL. RPL resulting from thrombophilia is primarily due to acquired thrombophilia, and therefore screening and treatment should be focused on antiphospholipid antibody syndrome., (Copyright © 2021 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Recurrent pregnancy loss (RPL) is defined as the loss of two or more pregnancies and is often multifactorial with the majority of miscarriages being due to aneuploidy and anatomic or physiological abnormalities. However, inherited or acquired thrombophilias have also been associated with RPL, albeit inconsistently. While inherited thrombophilias, such as factor V Leiden and prothrombin gene mutation, are relatively prevalent in women with RPL compared with the general population, a causal link has yet to be definitively established. Recently, systemic inflammation, as measured by high-sensitivity C-reactive protein, has also been hypothesized to play a role in infertility. Based on limited prospective trial data, antithrombotic therapy and antiplatelet agents have been proposed as possible tools for the prevention of RPL. Because of the multifactorial nature of RPL and infertility, various clinicians, as obstetricians and gynecologists, endocrinologists, hematologists, or vascular medicine specialists, may be requested to counsel these women. This, together with evidence gaps, frequently leads to distinctly different diagnostic and therapeutic recommendations, especially regarding thrombophilia testing and treatment. Using four case vignettes in this review, we critically appraise the literature and highlight how two clinicians from different subspecialties approach the relationship between RPL, inflammation, and thrombophilia., Competing Interests: Dr. Piazza has received research grant support from Bristol Myers Squibb/Pfizer Alliance, Janssen, Boston Scientific Corporation, Bayer, and Portola and consultant fees from Amgen and Agile Therapeutics. Dr. Grandone has received consultant fees from Italfarmaco and Sanofi., (Thieme. All rights reserved.)

Background: Incidence of thrombotic events associated to Coronavirus disease-2019 (COVID-19) is difficult to assess and reported rates differ significantly. Optimal thromboprophylaxis is unclear., Objectives: We aimed to analyze the characteristics of patients with a confirmed thrombotic complication including inflammatory and hemostatic parameters, compare patients affected by arterial vs venous events and examine differences between survivors and non-survivors. We reviewed compliance with thromboprophylaxis and explored how the implementation of a severity-adjusted protocol could have influenced outcome., Methods: Single-cohort retrospective study of COVID-19 patients admitted, from March 3 to May 3 2020, to the Infanta Leonor University Hospital in Madrid, epicenter of the Spanish outbreak., Results: Among 1127 patients, 80 thrombotic events were diagnosed in 69 patients (6.1% of the entire cohort). Forty-three patients (62%) suffered venous thromboembolism, 18 (26%) arterial episodes and 6 (9%) concurrent venous and arterial thrombosis. Most patients (90%) with a confirmed thrombotic complication where under low-molecular-weight heparin treatment. Overt disseminated intravascular coagulation (DIC) was rare. Initial ISTH DIC score and pre-event CRP were significantly higher among non-survivors. In multivariate analysis, arterial localization was an independent predictor of mortality (OR = 18, 95% CI: 2.4-142, p < .05)., Conclusions: Despite quasi-universal thromboprophylaxis, COVID-19 lead to a myriad of arterial and venous thrombotic events. Considering the subgroup of patients with thrombotic episodes, arterial events appeared earlier in the course of disease and conferred very poor prognosis, and an ISTH DIC score ≥ 3 at presentation was identified as a potential predictor of mortality. Severity-adjusted thromboprophylaxis seemed to decrease the number of events and could have influenced mortality. Randomized controlled trials are eagerly awaited., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objectives: Thrombophilia has been implicated in posttransplant thrombosis. Data concerning the impact of thrombophilia on thrombotic risk in renal graft recipients are inconclusive. We evaluated whether identification of thrombophilia in patients during pretransplant laboratory screening was a predictor of posttransplant outcomes., Materials and Methods: We conducted a prospective single-center longitudinal study that included adult recipients who underwent kidney transplant from January 2011 to December 2017. Cardiovascular risk factors, personal history of thrombosis, and data concerning kidney transplant episodes were recorded. Before kidney transplant, all patients were systematically screened for thrombophilia. For thrombophilia screening for antithrombin, protein C, protein S deficiencies, and activated protein C resistance, reagents from Stago were used (Stachrom AT, Staclot Protein C, Staclot Protein S, and Staclot APCR). The endpoint was a thrombotic event within 2 years after kidney transplant., Results: Among 75 end-stage renal disease candidates for kidney transplant, 46 kidney transplant recipients were screened for thrombophilia. Thirty-six of the patients were men. The median age was 37 years (interquartile range, 33-43 years). Renal replacement therapy (36 hemodialysis and 10 peritoneal dialysis) was started in all patients. Forty-five patients received a kidney from a living donor. Among the 46 patients, 4 (9%) had a thrombophilia abnormality (3 with protein C deficiency and 1 with activated protein C resistance). Thrombotic events occurred during the follow-up in 7 cases (15%) with no anterior thrombophilia abnormality; 2 of these concerned the kidney transplant. Only 1 patient had loss of kidney graft immediately after kidney transplant. There was no association between pretransplant thrombophilia and posttransplant thrombotic events., Conclusions: Our results suggest that the utility of universal, comprehensive preoperative thrombophilia testing is not beneficial to determine risk of postoperative thrombosis. Thrombophilia testing may be considered in a select population with a history of pretransplant thrombotic events.

Competing Interests: The authors declare no conflict of interest.

Abstract: The coronavirus disease (COVID-19) pandemic has threatened millions of lives worldwide with severe systemic inflammation, organ dysfunction, and thromboembolic disease. Within our institution, many critically ill COVID-19-positive patients suffered major thrombotic events, prompting our clinicians to evaluate hypercoagulability outside of traditional coagulation testing.We determined the prevalence of fibrinolysis shutdown via rotational thromboelastometry (ROTEM, Instrumentation Laboratories, Bedford, Mass) in patients admitted to the intensive care unit over a period of 3 weeks. In 25 patients who had a ROTEM test, we found that 11 (44%) met criteria for fibrinolysis shutdown. Eight of 9 (73%) of the VTE patients met criteria for fibrinolysis shutdown.Given the high rate of fibrinolysis shutdown in these patients, our data support using viscoelastic testing to evaluate for the presence of impaired fibrinolysis. This may help identify patient subsets who might benefit from the administration of fibrinolytics., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 by the Shock Society.)

The diagnosis of coagulopathy or thrombophilia in pediatric patients can be challenging. Congenital coagulopathies often present in the pediatric period and require appropriate work-up for diagnosis and ongoing management. Acquired coagulopathies of childhood are frequently encountered in hospitalized children and warrant appropriate coagulation testing for goal-directed therapy. The incidence of thrombosis is increasing in pediatric patients. After identifying the presence of thrombus, acute management includes initiating therapeutic anticoagulation. Choice of anticoagulant depends on patient's clinical status, along with availability of the anticoagulant. Thrombophilia evaluation is performed when children present with spontaneous thrombosis. Thrombophilia tests are inaccurate during acute illness., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: A high number of thrombotic complications have been reported in critically ill patients with coronavirus disease 2019 (COVID-19) and appear to be related to a hypercoagulable state. Evidence regarding detection, management, and monitoring of COVID-19-associated coagulopathy is still missing. We propose to describe the thrombus viscoelastic properties to investigate the mechanisms of hypercoagulability in patients with COVID-19., Methods: Thromboelastography (TEG) was performed in 24 consecutive patients admitted to a single intensive care unit for COVID-19 pneumonia, and 10 had a second TEG before being discharged alive from the intensive care unit., Results: Compared with a group of 20 healthy participants, patients with COVID-19 had significantly decreased values of reaction time, coagulation time, and lysis index and increased values of α angle, maximum amplitude, clot strength, and coagulation index. Velocity curves were consistent with increased generation of thrombin. These values persisted in surviving patients despite their good clinical course., Discussion: In patients with COVID-19, TEG demonstrates a complex and prolonged hypercoagulable state including fast initiation of coagulation and clot reinforcement, low fibrinolysis, high potential of thrombin generation, and high fibrinogen and platelet contribution. The antithrombotic strategy in patients with COVID-19 during intensive care hospitalisation and after discharge should be investigated in further studies., Competing Interests: Conflict of interest On behalf of all the authors, the corresponding author states that there is no conflict of interest., (Copyright © 2020 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.)

We investigated the safety and efficacy of direct oral anticoagulants (DOACs) in patients with venous thromboembolism (VTE) associated with severe inherited thrombophilia. In this single-center cohort study, we enrolled 56 consecutive VTE patients with severe inherited thrombophilia, defined as the presence of antithrombin (n = 18), protein C (n = 12) and protein S (n = 12) deficiencies, homozygous Factor V Leiden (n = 3) and prothrombin G20210AA (n = 4) mutations, or combined defects (n = 7). During a median follow-up of 44.5 (IQR 30-52.5) months, rivaroxaban was used in 30 (53.6%), apixabanin 14 (25%), and dabigatran in 12 (21.4%) subjects. Recurrent nonfatal VTE was observed in 5 (8.9%) patients (2.4 per 100 patient-years), treated with rivaroxaban (n = 4) and apixaban (n = 1). Major bleeding and clinically relevant non-major bleeding (CRNMB) occurred in 2 (3.5%) and 4 (7%) subjects, respectively (0.96 per 100 patient-years and 1.92 per 100 patient-years, respectively), including 4 patients on rivaroxaban. The event-free survival analysis showed that the use of rivaroxaban was associated with increased risk of recurrent VTE or bleeding, compared with apixaban or dabigatran (HR 2.76, 95% CI 1.26-3.92, p = 0.039). In conclusion, the results of our cohort study indicate that full-dose dabigatran or apixaban are effective and safe in patients with severe inherited thrombophilia.

Introduction: Patients with COVID-19 are known to have a coagulopathy with a thrombosis risk. It is unknown whether this is due to a generalized humoral prothrombotic state or endothelial factors such as inflammation and dysfunction. The aim was to further characterize thrombin generation using a novel analyser (ST Genesia, Diagnostica Stago, Asnières, France) and a panel of haematological analytes in patients with COVID-19., Methods: Platelet poor plasma of 34 patients with noncritical COVID-19 was compared with 75 patients with critical COVID-19 (as defined by WHO criteria) in a retrospective study by calibrated automated thrombography and ELISA. Patients were matched for baseline characteristics of age and gender., Results: Critical patients had significantly increased fibrinogen, CRP, interleukin-6 and D-dimer compared to noncritical patients. Thrombin generation, in critical patients, was right shifted without significant differences in peak, velocity index or endogenous thrombin potential. Tissue plasminogen activator (tPA), tissue factor pathway inhibitor (TFPI) and vascular endothelial growth factor (VEGF) were significantly increased in the critical versus noncritical patients. Critically ill patients were on haemodiafiltration (31%; heparin used in the circuit) or often received escalated prophylactic low-molecular weight heparin., Conclusion: These results confirm increased fibrinogen and D-dimer in critical COVID-19-infected patients. Importantly, disease severity did not increase thrombin generation (including thrombin-antithrombin complexes and prothrombin fragment 1 + 2) when comparing both cohorts; counter-intuitively critical patients were hypocoaguable. tPA, TFPI and VEGF were increased in critical patients, which are hypothesized to reflect endothelial dysfunction and/or contribution of heparin (which may cause endothelial TFPI/tPA release)., (© 2020 John Wiley & Sons Ltd.)

Objective: This study aimed at evaluating the effect of thrombophilia on the risk of venous thromboembolism (VTE) in patients undergoing any type of orthopedic surgery., Background: Patients undergoing orthopedic surgery are at high risk for VTE. Although patients with thrombophilia have an increased risk of VTE, it is currently unclear whether there is a synergetic effect in patients with thrombophilia who undergo orthopedic surgery., Methods: Data from a large population-based case-control study (the Multiple Environmental and Genetic Assessment [MEGA] of risk factors for venous thrombosis study) were used. Odds ratios (ORs) with 95% confidence intervals (CIs), adjusted for age, sex, and body mass index (BMI) (ORadj) were calculated for patients undergoing any orthopedic intervention., Results: Of 4721 cases and 5638 controls, 263 cases and 94 controls underwent orthopedic surgery. Patients who had any orthopedic intervention in the year before the index date were at higher risk of VTE (ORadj 3.7; 95% CI, 2.9-4.8) than those who did not undergo any orthopedic surgery. There was an additionally increased risk in patients with factor V Leiden (OR 17.5, 95% CI, 4.1-73.6), non-O blood group (OR 11.2; 95% CI, 3.4-34.0), or elevated plasma levels of factor VIII (OR 18.6; 95% CI, 7.4-46.9) all relative to patients without these defects, not undergoing orthopedic surgery., Conclusions: Patients with factor V Leiden, high levels of factor VIII, or blood group non-O were found to have a high risk of VTE after orthopedic surgery. Identification of these patients may enable individualized thromboprophylactic treatment to efficiently reduce VTE risk., (© 2020 International Society on Thrombosis and Haemostasis.)

Background: Otogenic cerebral sinus vein thrombosis (CSVT) is a rare but severe complication of otitis media in children. To date, the role of prothrombotic evaluation is still controversial., Objectives: To report the clinical manifestations, prothrombotic evaluation, and current management of CSVT., Methods: We performed a retrospective study of nine pediatric patients with otogenic CSVT who underwent prothrombotic evaluation between 2008 and 2018., Results: Prominent clinical features included persistent otorrhea (88.8%), signs of mastoiditis (88.8%), high fever ≥ 38.3°C (100%), a classic spiking fever pattern (55.5%), and neurological signs (55.5%). A subperiosteal abscess (66.6%) was the most common otitis media complication associated with mastoiditis and CSVT. No microorganism was identified in 55.5% of patients. Cultures collected from ear secretions had a low yield (6.25%). However, PCR assays had a high detection rate (100%; n=3). The prothrombotic evaluation demonstrated an abnormal LAC-dRVVT ratio (6/9), elevated Factor VIII (5/8) (and a combination of both in four patients), antiphospholipid antibodies (2/8), and high homocysteine levels (1/5).The surgical intervention of choice included one-sided mastoidectomy with myringotomy and ventilation-tube placement on the affected side (77.7%). There were no mortalities and no long-term sequela except chronic otitis media (22.2%)., Conclusions: Our findings demonstrate good outcomes for otogenic CSVT treatment with intravenous antibiotics, anticoagulation, and conservative surgical intervention, which supports the current trend in management. The prothrombotic evaluation revealed transient inflammation-related risk factors but did not alter management. Further prospective multicenter studies are needed to determine its relevance.

There is a laboratory and clinical need to know the impact of direct oral anticoagulants (DOACs) on diagnostic tests to avoid misinterpretation of results. Although the regulatory labelling documents provide some information about the influences of each DOAC on diagnostic tests, these are usually limited to some of the most common tests and no head to head comparison is available. In this paper, we report the impact of DOACs on several thrombophilia tests, including assessment of antithrombin, protein S and protein C activity assays, detection of activated protein C resistance and assays used for lupus anticoagulant. Results are compared and discussed with data obtained from literature. The final goal of this comprehensive review is to provide practical recommendations for laboratories to avoid misdiagnosis due to oral direct factor Xa (FXa) or IIa (FIIa) inhibitors. Overall, oral direct FXa (apixaban, betrixaban, edoxaban and rivaroxaban) and FIIa (dabigatran) antagonists may affect clot-based thrombophilia diagnostic tests resulting in false-positive or false-negative results. An effect on FIIa-based thrombophilia diagnostic tests is observed with dabigatran but not with anti-FXa DOACs and conversely for FXa-based thrombophilia diagnostic tests. No impact was observed with antigenic/chromogenic methods for the assessment of protein S and C activity. In conclusion, interpretation of thrombophilia diagnostic tests results should be done with caution in patients on DOACs. The use of a device/chemical compound able to remove or antagonize the effect of DOACs or the development of new diagnostic tests insensitive to DOACs should be considered to minimize the risk of false results., (© 2020 John Wiley & Sons Ltd.)

Background: Dyspnoea and syncope are common causes of admission to hospitals. Pulmonary embolism is often a differential diagnosis, and by examining the clinical history the clinician searches for known predisposing factors. This case report highlights the importance of Klinefelter's syndrome as a predisposing factor for venous thromboembolism. The syndrome is caused by an extra X chromosome in men, among whom the prevalence is estimated to be 1:500-1:1000. Probably only 25 % of men with the syndrome are diagnosed., Case Presentation: A man in his forties was admitted to hospital due to dyspnoea and syncope. CT showed submassive pulmonary embolism. The course illustrates the challenges of pulmonary embolism and its association with Klinefelter's syndrome., Interpretation: Several studies have shown an increased incidence of venous thromboembolism in patients with Klinefelter's syndrome. Klinefelter's patients have a higher pre-test likelihood of venous thromboembolism than other patients, similar to patients with hereditary thrombophilia. Klinefelter's syndrome is a persistent risk factor for recurrent thromboembolism. Thus, Klinefelter's syndrome impacts both the diagnosis and treatment of thromboembolic disease.

COVID-19 caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and other respiratory viral (non-CoV-2-RV) infections are associated with thrombotic complications. The differences in prothrombotic potential between SARS-CoV-2 and non-CoV-2-RV have not been well characterised. We compared the thrombotic rates between these two groups of patients directly and further delved into their coagulation profiles. In this single-center, retrospective cohort study, all consecutive COVID-19 and non-CoV-2-RV patients admitted between January 15th and April 10th 2020 were included. Coagulation parameters studied were prothrombin time and activated partial thromboplastin time and its associated clot waveform analysis (CWA) parameter, min1, min2 and max2. In the COVID-19 (n = 181) group there were two (1.0 event/1000-hospital-days) myocardial infarction events while one (1.8 event/1000-hospital-day) was reported in the non-CoV-2-RV (n = 165) group. These events occurred in patients who were severely ill. There were no venous thrombotic events. Coagulation parameters did not differ throughout the course of mild COVID-19. However, CWA parameters were significantly higher in severe COVID-19 compared with mild disease, suggesting hypercoagulability (min1: 6.48%/s vs 5.05%/s, P < 0.001; min2: 0.92%/s 2 vs 0.74%/s 2 , P = 0.033). In conclusion, the thrombotic rates were low and did not differ between COVID-19 and non-CoV-2-RV patients. The hypercoagulability in COVID-19 is a highly dynamic process with the highest risk occurring when patients were most severely ill. Such changes in haemostasis could be detected by CWA. In our population, a more individualized thromboprophylaxis approach, considering clinical and laboratory factors, is preferred over universal pharmacological thromboprophylaxis for all hospitalized COVID-19 patients and such personalized approach warrants further research.

An 18-year-old primigravida was referred to our high risk pregnancy (HRP) department at 34 weeks of gestation for birth panning as she has Budd-Chiari syndrome (BCS). Her history was significant for familial thrombophilia. She had portal hypertension manifestations. Her work-up revealed factor V Leiden gene mutation, hepatic and portal vein thrombosis. A multidisciplinary team of physicians from the gastroenterology and hepatology, haematology and HRP departments puts a management plan; it culminated into safe delivery of the patient at 36 weeks of gestation. The patient was referred to a specialised BCS centre where she had successful liver transplantation done., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

While prompt diagnosis of vasculitis is important, recognition of vasculitis mimics is equally essential. As in the case of vasculitis, an approach to mimics based on the anatomic size of vessels can be useful. Infections can mimic vasculitis of any vessel size, including the formation of aneurysms and induction of ANCAs. Genetic disorders and vasculopathies are important considerations in large and medium vessel vasculitis. Cholesterol emboli, thrombotic conditions and calciphylaxis typically affect the medium and small vessels and, like vasculitis, can cause cutaneous, renal and CNS manifestations. Reversible cerebral vasoconstriction syndrome is important to distinguish from primary angiitis of the CNS. As an incorrect diagnosis of vasculitis can result in harmful consequences, it is imperative that the evaluation of suspected vasculitis includes consideration of mimics. We discuss the above mimics and outline a systematic and practical approach for differentiating vasculitis from its mimics., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Most centers perform some degree of hematologic screening, including thrombophilia testing, on prospective live liver donors. The nature and extent of such screens are not standardized, and there is limited evidence regarding hematologic risk stratification., Methods and Results: We present an experience of hematologic screening among prospective liver donors. Five-hundred-eightyfour patients were screened for liver donation between 1/2013 and 1/2020, of whom 156 (27%) proceeded to donor hepatectomy. Thirty-three of 428 (8%) declined patients were excluded for hematologic indications. Hematologic indications were the 2nd most frequent medical indications for exclusion (trailing only hepatologic indications). The most common reason for hematologic exclusion was concern regarding thrombophilia. Nevertheless, 21 patients with evidence of possible thrombophilia proceeded to donor hepatectomy, and none incurred hematologic complications. Similarly, seven patients with screening findings concerning for increased bleeding risk (most often thrombocytopenia) underwent donor hepatectomy without hematologic complication. Three of 156 (2%) of patients who underwent donor hepatectomy incurred a hematologic complication (all thrombotic, none fatal). None of these patients had any evident hematologic risk factor on screening., Conclusion: This study underscores the difficulty of hematologic risk stratification among prospective living donors, however, suggests that some patients with relatively mild risk factors may be safe for donation., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Acute viral pneumonia, hypoxemic respiratory failure and severe inflammatory response are hallmarks of severe coronavirus disease 2019 (COVID-19). The COVID-19-associated inflammatory state may further lead to symptomatic thromboembolic complications despite prophylaxis. We report a 66-year-old female patient with post-mortem diagnosis of COVID-19 who presented progressive livedo racemosa, acute renal failure and myocardial injury, as well as an absence of respiratory symptoms. Transthoracic echocardiography showed severe spontaneous echo contrast in the right cardiac chambers and right-sided cardiac overload presumed to result from pulmonary microvascular thrombosis or embolism. D-dimer levels were increased. The patient developed an acute ischemic stroke and died 2 days following presentation despite therapeutic anticoagulation. Her predominantly thromboembolic presentation supports the concept of coronavirus infection of endothelial cells and hypercoagulability, or COVID-19 endotheliitis. The case we report highlights that COVID-19-associated hyperacute multi-organ thromboembolic storm may precede or present disproportionately to respiratory involvement.

Identifying a hypercoagulable state in patients with COVID-19 may help identify those at risk for virus-induced thromboembolic events and improve clinical outcomes using personalized therapeutic approaches. Herein, we aimed to perform a global assessment of the patients' hemostatic system with COVID-19 using rotational thromboelastometry (ROTEM) and to describe whether patients with different disease severities present different coagulation profiles. Together with 37 healthy volunteers, a total of 65 patients were included and then classified as having mild, moderate, and severe disease depending on clinical severity. Peripheral blood samples were collected and analyzed using a ROTEM Coagulation Analyzer. Also, complete blood count and coagulation parameters including prothrombin time, activated partial thromboplastin time, fibrinogen levels, and D-dimer levels were measured at admission. EXTEM and INTEM MCF ( P < 0.001) values were significantly higher and the EXTEM CFT ( P = 0.002) value was significantly lower in patients with COVID-19 when compared with controls. In particular, patients with the severe disease showed a significant decrease in CFT ( P < 0.001) and an increase in MCF ( P < 0.001) in both INTEM and EXTEM assays compared with patients with the non-severe disease. Correlation analysis revealed significant correlations between ROTEM parameters and other coagulation parameters. There were significant positive correlations between fibrinogen, D-dimer, platelet count, and MCF in both EXTEM and INTEM assays. Our data demonstrate thromboelastographic signs of hypercoagulability in patients with COVID-19, which is more pronounced in patients with increased disease severity. Therefore, ROTEM analysis can classify subsets of patients with COVID-19 at significant thrombotic risk and assist in clinical decisions.

Hereditary thrombophilia is rare pathology giving rise to a ninefold increase in the risk for the development of thromboembolism in infants. The problem is multifactorial and characterized by high mortality, especially in neonates. Infants who develop thrombosis, particularly those with no family history, are often subjected to testing for hereditary thrombophilia. However, genetic testing for thrombophilia does not change the plan of treatment but makes it possible to perform prevention of thrombosis within the risk periods for the patient. Poor awareness of paediatricians, the complexity of carrying out genetic testing, the absence of approaches supported by evidence-based medicine due to shortage of high-quality clinical trials and no guidelines on prevention of thromboembolism in infants, as well as the frequent occurrence of diversified causes and diseases in different age groups make the problem significant for modern medicine. Further studies are needed to address many unanswered as yet questions.

Recent studies suggest that thrombotic complications are a common phenomenon in the novel SARS-CoV-2 infection. The main objective of our study is to assess cumulative incidence of pulmonary embolism (PE) in non critically ill COVID-19 patients and to identify its predicting factors associated to the diagnosis of pulmonary embolism. We retrospectevely reviewed 452 electronic medical records of patients admitted to Internal Medicine Department of a secondary hospital in Madrid during Covid 19 pandemic outbreak. We included 91 patients who underwent a multidetector Computed Tomography pulmonary angiography(CTPA) during conventional hospitalization. The cumulative incidence of PE was assessed ant the clinical, analytical and radiological characteristics were compared between patients with and without PE. PE incidence was 6.4% (29/452 patients). Most patients with a confirmed diagnosed with PE recieved low molecular weight heparin (LMWH): 79.3% (23/29). D-dimer peak was significatly elevated in PE vs non PE patients (14,480 vs 7230 mcg/dL, p = 0.03). In multivariate analysis of patients who underwent a CTPA we found that plasma D-dimer peak was an independen predictor of PE with a best cut off point of > 5000 µg/dl (OR 3.77; IC95% (1.18-12.16), p = 0.03). We found ninefold increased risk of PE patients not suffering from dyslipidemia (OR 9.06; IC95% (1.88-43.60). Predictive value of AUC for ROC is 75.5%. We found a high incidence of PE in non critically ill hospitalized COVID 19 patients despite standard thromboprophylaxis. An increase in D-dimer levels is an independent predictor for PE, with a best cut-off point of > 5000 µg/ dl.

Background: To investigate the factors associated with elevated fibrinogen (Fbg) levels in COVID-19 patients with and without diabetes (DM) and impaired fasting glucose (IFG)., Methods: According to whether or not their glucose metabolism was impaired, COVID-19 patients were subdivided into 2 groups: 1) with DM and IFG, 2) control group. Their demographic data, medical history, signs and symptoms, laboratory results, and final clinical results were analyzed retrospectively., Results: 28 patients (16.3%) died during hospitalization, including 21 (29.2%) in group 1 and 7 (7.0%) in group 2 (P < 0.001). Fbg levels in groups 1 and 2 were higher than the normal range, at 5.6 g/L (IQR 4.5-7.2 g/L) and 5.0 g/L (IQR 4.0-6.1 g/L), respectively (P = 0.009). Serum ferritin levels, C-reactive protein (CRP), interleukin-6 (IL-6), IL-8, tumor necrosis factor-α (TNF-α), triglycerides (TG) were significantly increased in group 1 compared to those in the control. TG levels were 1.3 mmol/L in the control, while that in group 1 was 1.8 mmol/L. Multiple linear regression showed that the predicting factors of Fbg in the control group were serum ferritin and CRP, R 2 = 0.295; in group 1, serum ferritin, CRP, and TG, R 2 = 0.473., Conclusions: Fbg in all COVID-19 patients is related to serum ferritin and CRP involved in inflammation. Furthermore, in COVID-19 patients with insulin resistance, Fbg is linearly positively correlated with TG. This suggests that regulation of TG, insulin resistance, and inflammation may reduce hypercoagulability in COVID-19 patients, especially those with insulin resistance.

Prolonged tourniquet stasis induced by venepuncture can lead to the release of the plasma of cell lysis products, as well as tissue factor (TF), impairing the quality of coagulation test results. The accidental presence of TF in vitro can trigger the coagulation mechanism, generating a false decrease in prothrombin time (PT). Background and Objectives: Identification of short PT tests below the normal reference value that could suggest a situation of hypercoagulability. The study aimed to compare the results of the shortened PT tests at their first determination with the eventual correction following duplication of the analysis from the same sample. Materials and methods: Identification of the shortened PT tests has been carried out for a period of 4 months, upon 544 coagulation samples referred to the Hematology department of Sf. Spiridon County Clinical Emergency Hospital from Iasi, Romania. Results: Out of the 544 samples of which the results indicated a state of hypercoagulability, by repeating the determination from the same sample, for 200 (36.76%) PT tests ( p = 0.001) the value was corrected, falling within the normal reference range. For 344 (63.24%) tests, the results suggested a situation of hypercoagulability. Conclusions: In order to guarantee the highest quality of the laboratory services, a proper interpretation and report of the patients' results must be congruent and harmoniously associated to the actual clinical condition of the patient. Duplication of the PT determination from the same sample would exclude situations of false hypercoagulability and would provide significant improvement for the patient's safety.

Our view on causes of venous thrombosis changed drastically by the discovery of Factor V Leiden, since unlike other genetic causes of hereditary thrombophilia its prevalence is several percent. It led to major research activities, and the insight that thrombosis is a multicausal disease, invariably the result of an interplay of genetic and environmental factors. Another consequence was a hype of testing of thrombosis patients, and women before starting oral contraceptives. Factor V Leiden became the most performed diagnisticgenetic test worldwide. However, there was no medical rationale for this massive testing. In young women the absolute risk of thrombosis is so low, that enormous numbers of women would need to be tested to prevent one thrombotic event. And tests after a first event in patients were nearly always useless, since Factor V Leiden does not affect the risk of recurrence. It took decennia before the hype faded.

Viscoelastic assays (VEAs) that include thromboelastography and rotational thromboelastometry add value to the investigation of coagulopathies and goal-directed management of bleeding by providing a complete picture of clot formation, strength, and lysis in whole blood that includes the contribution of platelets, fibrinogen, and coagulation factors. Conventional coagulation assays have several limitations, such as their lack of correlation with bleeding and hypercoagulability; their inability to reflect the contribution of platelets, factor XIII, and plasmin during clot formation and lysis; and their slow turnaround times. VEA-guided transfusion algorithms may reduce allogeneic blood exposure during and after cardiac surgery and in the emergency management of trauma-induced coagulopathy and hemorrhage. However, the popularity of VEAs for other indications is driven largely by extrapolation of evidence from cardiac surgery, by the drawbacks of conventional coagulation assays, and by institution-specific preferences. Robust diagnostic studies validating and standardizing diagnostic cutoffs for VEA parameters and randomized trials comparing VEA-guided algorithms with standard care on clinical outcomes are urgently needed. Lack of such studies represents the biggest barrier to defining the role and impact of VEA in clinical care., Competing Interests: Conflict-of-interest disclosure R. S. has no conflicts of interest to declare., (© 2020 by The American Society of Hematology.)

Portal vein thrombosis (PVT) is a rare but severe condition. Several risk factors predispose to PVT. However, it remains unclear to which degree thrombophilia contributes to the risk of PVT and whether PVT patients should be routinely referred for thrombophilia testing. The aim of the present study was to investigate the prevalence of thrombophilia in PVT patients to clarify the relevance of thrombophilia testing in PVT patients. Clinical data and results from thrombophilia investigations were systematically obtained from all PVT patients referred to Centre for Hemophilia and Thrombosis, Aarhus University Hospital, Denmark for thrombophilia testing between 1 st of January 2010 and 31 st of December 2018 ( n  = 93). The investigated thrombophilias included factor V Leiden and prothrombin G20210A mutations, deficiency of protein S, protein C and antithrombin, antiphospholipid syndrome, and increased levels of factor VIII. The prevalence of thrombophilia was compared to healthy controls obtained from previously published data on thrombophilia distribution in cohorts of the Western European adult general population. Comparing PVT patients with healthy controls, significantly increased odds of presence of lupus anticoagulant (crude odds ratio (OR) 6.2, 95% confidence interval (CI) 1.8-20.6) were found, whereas no significantly increased odds of inherited thrombophilia were demonstrated. In conclusion, routine testing for inherited thrombophilia in PVT patients does not seem indicated. However, PVT patients should still be tested for antiphospholipid antibodies because patients meeting the criteria for antiphospholipid syndrome preferentially should receive vitamin K antagonists as anticoagulant therapy.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) initially most appreciated for its pulmonary symptoms, is now increasingly recognized for causing multi-organ disease and stroke in the setting of a hypercoagulable state. We report a case of 33-year-old African American woman with COVID-19 who developed acute malignant middle cerebral artery infarction due to thromboembolic occlusion of the left terminal internal carotid artery and middle cerebral artery stem. Mechanical thrombectomy was challenging and ultimately unsuccessful resulting in limited reperfusion of <67% of the affected vascular territory, and thrombectomized clot was over 50 mm in length, at least three times the average clot length. The final stroke size was estimated at 224 cubic centimeters. On admission her D-dimer level was 94,589 ng/mL (normal 0-500 ng/ml). Throughout the hospitalization D-dimer decreased but never reached normal values while fibrinogen trended upward. Hypercoagulability panel was remarkable for mildly elevated anticardiolipin IgM of 16.3 MPL/mL (normal: 0-11.0 MPL/mL). With respect to remaining stroke workup, there was no evidence of clinically significant stenosis or dissection in the proximal internal carotid artery or significant cardioembolic source including cardiomyopathy, atrial fibrillation, cardiac thrombus, cardiac tumor, valvular abnormality, aortic arch atheroma, or patent foramen ovale. She developed malignant cytotoxic cerebral edema and succumbed to complications. This case underscores the importance of recognizing hypercoagulability as a cause of severe stroke and poor outcome in young patients with COVID-19 and highlights the need for further studies to define correlation between markers of coagulopathy in patients with COVID-19 infection and outcome post stroke., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: Coronavirus disease 2019 (COVID-19) causes a hypercoagulable state. Several autopsy studies have found microthrombi in pulmonary circulation., Methods: In this randomized, open-label, phase II study, we randomized COVID-19 patients requiring mechanical ventilation to receive either therapeutic enoxaparin or the standard anticoagulant thromboprophylaxis. We evaluated the gas exchange over time through the ratio of partial pressure of arterial oxygen (PaO2) to the fraction of inspired oxygen (FiO2) at baseline, 7, and 14 days after randomization, the time until successful liberation from mechanical ventilation, and the ventilator-free days., Results: Ten patients were assigned to the therapeutic enoxaparin and ten patients to prophylactic anticoagulation. There was a statistically significant increase in the PaO2/FiO2 ratio over time in the therapeutic group (163 [95% confidence interval - CI 133-193] at baseline, 209 [95% CI 171-247] after 7 days, and 261 [95% CI 230-293] after 14 days), p = 0.0004. In contrast, we did not observe this improvement over time in the prophylactic group (184 [95% CI 146-222] at baseline, 168 [95% CI 142-195] after 7 days, and 195 [95% CI 128-262] after 14 days), p = 0.487. Patients of the therapeutic group had a higher ratio of successful liberation from mechanical ventilation (hazard ratio: 4.0 [95% CI 1.035-15.053]), p = 0.031 and more ventilator-free days (15 days [interquartile range IQR 6-16] versus 0 days [IQR 0-11]), p = 0.028 when compared to the prophylactic group., Conclusion: Therapeutic enoxaparin improves gas exchange and decreases the need for mechanical ventilation in severe COVID-19., Trial Registration: REBEC RBR-949z6v., (Copyright © 2020. Published by Elsevier Ltd.)

To translate circulating microRNAs (miRNAs) into the clinic, a deeper understanding of the factors affecting their expression is needed. In this study, we explored the features affecting the expression of miRNAs and their genetic regulation using the expression data of 103 miRNAs obtained by qPCR in the platelet-poor plasma of 104 subjects. The principal components (PCs) of the expression of the miRNAs were associated with technical and biological features (e.g., synthetic controls or sex) and with blood cell counts. Also, the associations with proximal genetics variants were analysed. We found that haemolysis marker (dCt hsa-miR-23a-3p-hsa-miR-451a) was correlated strongly (β = 0.84, p = 2.07x10 -29 ) with the second PC, which explained 10.1% of the overall variability. Thus, we identified haemolysis as a source of variability for miRNA expression even in mild hemolyzed samples (haemolysis marker dCt <5). In addition to hsa-miR-23a-3p and hsa-miR-451a, the miRNAs most stable and most susceptible to haemolysis were identified. Then, we discovered that the expression of miRNAs in platelet-poor plasma was not biased by any blood cell count, and thus, our results supported their role as biomarkers of tissue-specific conditions. Finally, we identified 1,323 genetic variants that corresponded to 158 miRNA expression quantitative trait loci for 14 miRNAs (FDR <0.2), which were enriched in promoter regions (p = 0.03). This enrichment corresponded to a range of specific tissues (e.g., breast or fat) although not to blood tissue, supporting the concept that the expression of circulating miRNAs is under the genetic control of different tissues.

Background: Retinal vascular occlusion is a leading cause of sight loss. Both retinal artery occlusion (RAO) and retinal vein occlusion (RVO) have been associated with hypercoagulable states; however, the burden of thrombophilia in these patients is unclear., Objectives: This study aims at estimating the prevalence of inherited and acquired thrombophilias in adults with RAO or RVO through a systematic review and meta-analysis of the literature., Patients/methods: PubMed and EMBASE were systematically searched from inception to 29 February 2020. All studies reporting prevalences of factor V Leiden (FVL) and prothrombin (F-II) G20210A mutations, methylenetetrahydrofolate reductase (MTHFR) C677T and plasminogen activator inhibitor (PAI) 4G polymorphisms, antithrombin III (AT-III), protein C (PC) and protein S (PS) activity deficiencies, hyperhomocysteinemia, and antiphospholipid (APL) antibodies in adults with RAO or RVO were included. Pooled prevalences and 95% confidence intervals (CI) were calculated., Results: Ninety-five studies were included; FVL and F-II mutations were found in 6% (95% CI: 5-8) and 3% (95% CI: 2-4) of individuals with RVO, respectively, whereas AT-III, PC, and PS activity deficiencies were found in <2%. The MTHFR C677T and PAI 4G homozygous polymorphism were observed in 13% (95% CI: 10-17) and 23% (95% CI: 16-31) of RVO, respectively; 8% presented APL antibodies. Similar findings were observed in individuals with RAO., Conclusions: Compared with healthy subjects, patients with retinal vascular occlusion showed similar prevalences of inherited and acquired thrombophilias. These findings do not support routine thrombophilia screening in individuals with RAO or RVO., (© 2020 International Society on Thrombosis and Haemostasis.)