Hypercoagulable states in arterial and venous thrombosis: When, how, and who to test?

Thrombophilia Testing in Stroke: A Case Report and Review of Evidence

Thrombophilia is commonly associated with venous thromboembolism, but its relationship with arterial thrombosis, specifically stroke, is not as clearly established. Several large studies have failed to establish a significant connection between inherited thrombophilia and stroke. While tests for Factor V Leiden mutation, prothrombin mutation, protein C deficiency, protein S deficiency, antithrombin deficiency, and antiphospholipid antibodies are typically done for thrombophilia diagnosis, there appears to be little or no correlation between these markers and stroke. In this article, we discuss a case of a 26-year-old male admitted with right neck pain that developed after playing basketball; he was found to have a right cerebellar infarction. He underwent extensive tests for hypercoagulable disorders, which were negative. We also review current evidence and reassess the value of thrombophilia testing in stroke patients.

Adherence to thrombophilia testing guidelines and its influence on anticoagulation therapy: A single-center cross-sectional study

INTRODUCTION

The collected evidence on thrombophilia guidelines is scarce and data about their impact on clinical decisions are unknown. We aimed to investigate the adherence to thrombophilia testing guidelines, its therapeutic impact in patients with guideline-adherent and non-adherent testing and identify the patients' clinical characteristics mostly associated with treatment decisions.

MATERIALS AND METHODS

We conducted a single-center cross-sectional study of patients referred for thrombophilia testing at the outpatient clinic of a tertiary hospital between 01/2010-10/2020. We systematically evaluated the adherence of thrombophilia testing to internal guidelines and the influence of test results on anticoagulation therapy. Using multivariable logistic regression, we evaluated the association between clinical characteristics and influence of thrombophilia tests on anticoagulation therapy in the entire cohort and by indication for referral.

RESULTS

Of 3686 included patients, mostly referred for venous thromboembolism (2407, 65 %) or arterial thrombosis (591, 16 %), 3550 patients (96 %) underwent thrombophilia testing. Indication for testing was according to guidelines in 1208 patients (33 %). Test results influenced treatment decisions in 56 of 1102 work-ups (5.1 %) that were adherent to guidelines, and in 237 of 2448 (9.7 %) non-adherent work-ups (absolute difference, 4.3 %; 95 % confidence interval, 2.9-6.3 %). Age < 50 years, female sex, absence of risk factors and co-morbidities, weakly provoked venous thromboembolism and referral indication other than venous thromboembolism were associated with influence on anticoagulation therapy.

CONCLUSIONS

Adherence to guidelines for thrombophilia testing was poor and did not have an impact on treatment decisions. Refinement of selection criteria is needed to increase the therapeutic impact of thrombophilia testing.

Fibrinolytic Status and Risk of Death After Acute Pulmonary Embolism

BACKGROUND

Acute pulmonary embolism (PE) is a heterogeneous disease process with variable presentation and outcomes. The endogenous fibrinolytic system is a complex framework of regulatory pathways that maintains homeostasis by dissolving overabundant thrombi. We sought to investigate phenotypic profiles of the endogenous fibrinolytic system among patients presenting with acute PE and their impact on mortality.

METHODS

We enrolled all consecutive patients with acute PE in our institutional Pulmonary Embolism Response Team registry. We collected blood samples at the time of PE diagnosis and analyzed concentrations of plasminogen activator inhibitor 1 (PAI-1), thrombin-activatable fibrinolysis inhibitor (TAFI), and alpha-2-antiplasmin (A2A). We assessed the association of concentration of fibrinolytic inhibitors and 1-year all-cause mortality and various echocardiographic markers of right ventricular (RV) dysfunction.

RESULTS

There is significant variability of PAI-1, A2A, and TAFI concentrations across the spectrum of PE risk profiles with high PAI-1, low TAFI, and low A2A (herein referred to as a high-risk biomarker profile) correlating with worse PE severity. High-risk biomarker profile correlated with high-risk echocardiographic features of RV dysfunction, including increased RV/left ventricular (LV) ratio, low tricuspid annular plane systolic excursion, and low right ventricular outflow tract velocity time integral. Higher-risk biomarker profile was able to discriminate and independently identify patients at high risk of all-cause mortality (Group 2 HR 6 95% CI 1.3-27.8, Group 3 HR 12, 95% CI 1.7-86).

CONCLUSIONS

Further studies are needed to assess the exact pathophysiological link between fibrinolytic status and poor outcome after acute PE and to ascertain the impact of anti-inhibitors of the fibrinolytic system on response to therapy and outcomes after acute PE.

Hypercoagulability in patients with indirect carotid cavernous fistulas

BACKGROUND

To assess patients with indirect carotid-cavernous fistulas (CCF) for evidence of hypercoagulable state (HS) by combination of comprehensive medical questionnaire and laboratory testing.

METHODS

Patients with confirmed diagnosis of CCF treated between 2003 and 2019 were included and administered a questionnaire screening for HS risk factors and undergone laboratory investigations which included complete blood count (CBC), prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen, antiphospholipid antibodies (lupus anticoagulant and anticardiolipin antibody titres), Factor V Leiden, prothrombin, protein C, protein S, antithrombin III, homocysteine, prothrombin G20210, CALR and JAK2 mutation screening. Participants with abnormal laboratory testing and/or past history of ischemic stroke, atrial fibrillation, cancer or hypercoagulability-associated hereditary disorders were deemed to have HS.

RESULTS

Twenty-two patients were enrolled. Seventeen were women and the mean age at diagnosis was 60. Fourteen (64%) had evidence of HS: six on medical history, three with laboratory evidence and five with both. Eight (36%) had current abnormal hypercoagulability markers. One had a diagnosis of Klippel-Trenaunay Syndrome, but no others had evidence of hereditary thrombophilia. Nine were on anti-coagulation initiated after diagnosis of stroke or atrial fibrillation discovered on average 5.5 years after the diagnosis of CCF.

CONCLUSION

A total of 64% percent of patients with previous indirect CCF had evidence of underlying HS indicating that hypercoagulability might play a role in the pathogenesis of CCF. The results support need for comprehensive testing for underlying HS in patients with indirect CCFs to better identify, manage, and prevent further thromboembolic events.

Testing for Thrombophilia in Young Cryptogenic Stroke Patients: Does the Presence of Patent Foramen Ovale Make a Difference?

Background and Objectives: The diagnostic value of thrombophilia remains unknown in young patients with patent foramen ovale (PFO) and stroke. In this study we hypothesized that inherited thrombophilias that lead to venous thrombosis are more prevalent in patients with PFO. Materials and Methods: The study included patients of the tertiary center Vilnius University Hospital Santaros Klinikos who had a cryptogenic ischemic stroke between the ages of 18 and 50 between the years 2008 and 2021. Transient ischemic attacks were excluded. Contrast-enhanced transcranial Doppler ultrasound and extensive laboratory testing were performed. Results: The study included 161 cryptogenic stroke patients (mean age 39.2 ± 7.6 years; 54% female), and a right-to-left shunt was found in 112 (69.6%). The mean time between stroke and thrombophilia testing was 210 days (median 98 days). In total, 61 (39.8%) patients were diagnosed with thrombophilia. The most common finding was hyperhomocysteinemia (26.7%), 14.3% of which were genetically confirmed. Two patients (1.2%) were diagnosed with factor V Leiden mutation, three patients (1.9%) with prothrombin G20210A mutation, one patient (0.6%) had a protein C mutation and one patient (0.6%) had a protein S mutation. No antithrombin mutations were diagnosed in our study population. A total of 45.5% of patients with inherited thrombophilia had a right-to-left shunt, while 54.5% did not, p = 0.092. Personal thrombosis anamnesis was positive significantly more often in patients with antiphospholipid syndrome. Conclusions: The hypothesis of the study was rejected since inherited venous thrombophilia was not significantly more common in patients with PFO. Due to the rarity of thrombophilias in general, more research with a larger sample size is required to further verify our findings.

Coagulation Factor XIII Val34Leu Polymorphism in the Prediction of Premature Cardiovascular Events-The Results of Two Meta-Analyses

Background: Polymorphisms within the gene that encodes for coagulation factor XIII (FXIII) have been suggested to be involved in the pathogeneses of ischemic stroke (IS) and myocardial infarction (MI). The Val34Leu polymorphism is one of the most commonly analysed FXIII polymorphisms. However, studies on the role of the Val34Leu polymorphism in the aetiology of vascular diseases often show contradictory results. In the present meta-analysis, we aimed to pool data from available articles to assess the relationship between the FXIII Val34Leu polymorphism and the susceptibilities to IS of undetermined source and premature MI in patients aged below 55 years. Methods: We searched databases (PubMed, Embase, Google Scholar, SciELO, and Medline) using specific keywords (the last search was in January 2022). Eventually, 18 studies (627 cases and 1639 controls for IS; 2595 cases and 4255 controls for MI) met the inclusion criteria. Data were analysed using RevMan 5.4 and StatsDirect 3 link software. The relation between Val34Leu polymorphism and disease was analysed in five genetic models, i.e., dominant, recessive, additive, heterozygous, and allelic. Results: No relation between Val34Leu polymorphism and IS in young adults was observed in all analysed genetic models. For premature MI, significant pooled OR was found between the carrier state of the Leu allele (Val/Leu + Leu/Leu vs. Val/Val) and a lack of MI, suggesting its protective role (OR = 0.80 95%CI 0.64–0.99, p = 0.04). A similar finding was observed for the heterozygous model in MI (Val/Leu vs. Val/Val) (OR = 0.77 95%CI 0.61–0.98, p = 0.03). No relation was found for the recessive, additive, and allelic models in MI. Conclusions: In the population of young adults, no positive correlation was found between the FXIII Val34Leu polymorphism and IS of undetermined source in any of the analysed genetic models. In turn, the carrier state of the 34Leu allele as well as FXIII heterozygotes themselves were found to play a protective role in relation to premature MI.

Hypercoagulable Disorders in Orthopaedics: Etiology, Considerations, and Management

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Hypercoagulable disorders (HCDs) can be inherited or acquired. An HCD of either etiology increases the chance of venous thromboembolic events (VTEs).

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Patients with an HCD often have the condition discovered only after surgical complications.

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We recommend that patients with a concern for or a known HCD be referred to the appropriate hematological specialist for workup and treatment.

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Tourniquet use in the orthopaedic patient with an HCD is understudied and controversial. We recommend that tourniquets be avoided in the surgical management of patients with an HCD, if possible. When tourniquets are applied to patients with unknown HCD status, close follow-up and vigilant postoperative examinations should be undertaken.

Optimal Medical Therapy Following Deep Venous Interventions: Proceedings from the Society of Interventional Radiology Foundation Research Consensus Panel

The optimal medical management of patients following endovascular deep venous interventions remains ill-defined. As such, the Society of Interventional Radiology Foundation (SIRF) convened a multidisciplinary group of experts in a virtual Research Consensus Panel (RCP) to develop a prioritized research agenda regarding antithrombotic therapy following deep venous interventions. The panelists presented the gaps in knowledge followed by discussion and ranking of research priorities based on clinical relevance, overall impact, and technical feasibility. The following research topics were identified as high priority: 1) characterization of biological processes leading to in-stent stenosis/rethrombosis; 2) identification and validation of methods to assess venous flow dynamics and their effect on stent failure; 3) elucidation of the role of inflammation and anti-inflammatory therapies; and 4) clinical studies to compare antithrombotic strategies and improve venous outcome assessment. Collaborative, multicenter research is necessary to answer these questions and thereby enhance the care of patients with venous disease.

Vena Cava Atresia and Deep Vein Thrombosis: A Case Report and Systematic Review

Congenital anomalies of the vena cava often go unnoticed, and their incidental finding is frequent in imaging tests performed for another cause in asymptomatic patients. However, an association with the development of thromboembolic disease has been described, mainly in young patients.

We report the case of a young woman with deep vein thrombosis associated with vena cava atresia.

We conducted a search of the PubMed/Medline database. The search identified 17 articles, of which 5 were selected for extraction and data analysis. Twelve studies were excluded because they failed to match the main criteria.

We identified six new cases of deep vein thrombosis associated with vena cava abnormalities, with a mean age of 42.5 years; 83.3% were male. Regarding clinical manifestations, all patients presented as deep vein thrombosis, one case of recurrence, and another case associated with the kidney and inferior vena cava abnormalities with leg thrombosis syndrome. Only one patient had a target triggering factor (cholecystectomy postoperative). The thrombophilia study was negative in all cases and none of the patients died. Treatment included enoxaparin and vitamin K antagonists.

This is the first study to report on a systematic review of vena cava atresia associated with deep vein thrombosis in Spain. It shows that in this region, the disease affects young population—even in the absence of risk factors—and is linked to a low mortality. The most frequent presentation form was deep vein thrombosis. Therefore, congenital abnormalities of the vena cava should be suspected in young patients with thromboembolic disease, due to their implications regarding to the duration of anticoagulant treatment, as well as their possible association with other prothrombotic factors.

Thrombophilia, Inflammation, and Recurrent Pregnancy Loss: A Case-Based Review

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.

A Review of Biomarkers for Ischemic Stroke Evaluation in Patients With Non-valvular Atrial Fibrillation

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia worldwide and results in a significantly increased ischemic stroke (IS) risk. IS risk stratification tools are widely being applied to guide anticoagulation treatment decisions and duration in patients with non-valvular AF (NVAF). The CHA₂DS₂-VASc score is largely validated and currently recommended by renowned guidelines. However, this score is heavily dependent on age, sex, and comorbidities, and exhibits only moderate predictive power. Finding effective and validated clinical biomarkers to assist in personalized IS risk evaluation has become one of the promising directions in the prevention and treatment of NVAF. A number of studies in recent years have explored differentially expressed biomarkers in NVAF patients with and without IS, and the potential role of various biomarkers for prediction or early diagnosis of IS in patients with NVAF. In this review, we describe the clinical application and utility of AF characteristics, cardiac imaging and electrocardiogram markers, arterial stiffness and atherosclerosis-related markers, circulating biomarkers, and novel genetic markers in IS diagnosis and management of patients with NVAF. We conclude that at present, there is no consensus understanding of a desirable biomarker for IS risk stratification in NVAF, and enrolling these biomarkers into extant models also remains challenging. Further prospective cohorts and trials are needed to integrate various clinical risk factors and biomarkers to optimize IS prediction in patients with NVAF. However, we believe that the growing insight into molecular mechanisms and in-depth understanding of existing and emerging biomarkers may further improve the IS risk identification and guide anticoagulation therapy in patients with NVAF.

The importance of antiphospholipid syndrome testing in venous thromboembolism after varicose vein surgery

Anticoagulation treatment after a venous thromboembolism event is usually managed on a case-by-case basis. The risk of thrombosis must be weighed against the risk of bleeding. Identifying patients who could benefit from anticoagulation therapy requires the thromboembolism event to be assessed with respect to its presentation and the severity of the triggering factors. A case report is employed to explain the important aspects of practical approaches to venous thromboembolism events after vein surgery. The Trial on Rivaroxaban in AntiPhospholipid Syndrome (TRAPS) study has prompted new considerations for anticoagulation management. Patients with antiphospholipid syndrome need to be identified early to lower the risk of thromboembolism also during anticoagulation treatment.

Pulmonary Embolism

Venous thromboembolism (VTE) includes pulmonary embolism (PE) and deep vein thrombosis. PE is the third most common cause of cardiovascular death worldwide after stroke and heart attack. Management of PE has evolved recently with the availability of local thrombolysis; mechanical extraction devices; hemodynamic support devices, like extracorporeal membrane oxygenation; and surgical embolectomy. There has been development of multidisciplinary PE response teams nationwide to optimize the care of patients with VTE. This review describes the epidemiology of PE, discusses diagnostic strategies and current and emerging treatments for VTE, and considers post-PE follow-up care.

Danger of false negative (exclusion) or false positive (diagnosis) for ‘congenital thrombophilia’ in the age of anticoagulants

Background

Most guidelines and experts recommend against performance of thrombophilia testing in general, and specifically against testing patients on pharmacological anticoagulants, due to substantially increased risk of false positive identification. For example, vitamin K antagonist (VKA) therapy affects protein C (PC) and protein S (PS), as well as some clotting assays (e.g. as used to investigate activated PC resistance [APCR]). Although heparin may also affect clotting assays, most commercial methods contain neutralisers to make them ‘insensitive’ to therapeutic levels. Direct oral anticoagulants (DOACs) also affect a wide variety of thrombophilia assays, although most reported data has employed artificial in vitro spiked samples.

Methods

In the current report, data from our facility for the past 2.5 years has been assessed for all ‘congenital thrombophilia’ related tests, as evaluated against patient anticoagulant status. We processed 10,571 ‘thrombophilia’ related test requests, including antithrombin (AT; n=3470), PC (n=3569), PS (n=3585), APCR (n=2359), factor V Leiden (FVL; n=2659), and prothrombin gene mutation (PGM; n=2103).

Results

As expected, VKA therapy affected PC and PS, and despite manufacturer claims, also APCR. Most assays, as suggested by manufacturers, were largely resistant to heparin therapy. DOACs’ use was associated with falsely low APCR ratios (i.e. FVL-like effect) and somewhat unexpectedly, anti-Xa agents apixaban and rivaroxaban were also associated with lower AT and higher PS values.

Conclusions

It is concluded that ex-vivo data appears to confirm the potential for both false positive and false negative ‘thrombophilia’ events in patients on anticoagulant (including DOAC) treatment.