Splanchnic Vein Thrombosis: The State-of-the-Art on Anticoagulant Treatment.

Splanchnic vein thrombosis (SVT) is a rare type of venous thromboembolism occurring within the splanchnic venous system. Portal vein thrombosis is the most common presentation, while Budd-Chiari syndrome is the least common. Liver cirrhosis and abdominal solid cancer are the main local risk factors for SVT, whereas myeloproliferative neoplasms are the predominant systemic risk factors. Signs and symptoms of SVT are nonspecific and include abdominal pain, gastrointestinal bleeding, and ascites. Asymptomatic SVT is not uncommon, and the majority would be detected incidentally on routine abdominal imaging performed for the follow-up of liver diseases and tumors. The management of SVT aims to prevent thrombus progression, promote vessel recanalization, and prevent recurrent venous thromboembolism. Anticoagulation should be started early in order to increase the chances of vessel recanalization and reduce the risk of portal hypertension-related complications. Direct oral anticoagulants have been included in recent guidelines, as alternatives to vitamin K antagonists, after clinical stability has been reached; however, caution is required in patients with liver or kidney dysfunction. Treatment duration is based on the presence (or absence) and type (transient vs. permanent) of risk factors. This narrative review aims to summarize the latest evidence on SVT, with a particular focus on the anticoagulant treatment in special categories of patients (e.g., liver cirrhosis, solid cancer, myeloproliferative neoplasms, pancreatitis, incidentally detected SVT, Budd-Chiari syndrome, and chronic SVT).

A comparative in vitro study of the anticoagulant effect of branded versus generic rivaroxaban.

BACKGROUND: Several generic formulations of rivaroxaban were recently marketed to be used interchangeably with their branded equivalent. However, there have been no previously published studies that directly compared the in vitro anticoagulant effect of branded vs. generic rivaroxaban. The aim of this in vitro study was to compare the effects of three raw rivaroxaban materials, obtained from the branded (Xarelto®) and two generic (Rivarolto® and Rivaroxaban Sandoz®) rivaroxaban formulations on an array of coagulation assays. METHODS: A pool of normal plasma was spiked with several concentrations of the three rivaroxaban (range 50-750 ng/ml). The concentrations were assessed with a rivaroxaban calibrated anti-Xa assay and confirmed by ultra-high-performance liquid chromatography-mass spectrometry coupled with tandem mass spectrometry (UHPLC-MS/MS). The following assays were performed: Prothrombin time (PT), activated Partial Thromboplastin time (aPTT), Diluted Russell's Viper Venom Test (dRVVT), Thrombin time (TT), Clauss Fibrinogen, Factor VII, VIII and IX assays, and thromboelastography. RESULTS: The results obtained by the three rivaroxaban at similar concentrations were comparable. Increasing concentrations of the three rivaroxaban showed a strong positive correlation with the PT, aPTT and dRVVT assays (r > 0.95, p < 0.01 for all), and a strong negative correlation with the Factors assays (r < -0.95, p < 0.01 for all). TT and Clauss Fibrinogen were not affected by rivaroxaban. No significant difference was identified in the mean assays' results obtained by the three rivaroxaban. CONCLUSION: This study showed that the branded and generic rivaroxaban exert an identical in vitro anticoagulant effect across a wide range of concentrations.

Cancer-Associated Abdominal Vein Thrombosis.

Cancer is associated with an increased risk of developing venous thromboembolism, due to its direct influence on the three pillars of Virchow's triad (e.g., compression on the blood vessels by the tumour, blood vessels invasion, and cytokine release), together with the effect of exogenous factors (such as chemotherapy, radiotherapy, surgery). In cancer patients, the risk of thrombosis at unusual sites, such as splanchnic, ovarian and renal vein thrombosis, is also increased. Abdominal vein thromboses are frequently incidental findings on abdominal imaging performed as part of the diagnostic/staging workup or the follow-up care of malignancies. There is little evidence on the management of unusual site venous thromboembolism in cancer patients since there are only a few specific recommendations; thus, the management follows the general principles of the treatment of cancer-associated deep vein thrombosis and pulmonary embolism. This narrative review summarises the latest evidence on cancer-associated abdominal vein thrombosis, i.e., thrombosis of the splanchnic, ovarian and renal veins.

Oxidative Stress Induces E-Selectin Expression through Repression of Endothelial Transcription Factor ERG.

Oxidative stress induces a prothrombotic state through enhancement of adhesion properties of the endothelium. E-selectin, an endothelial cell adhesion molecule, becomes a therapeutic target for venous thrombosis, whereas the regulatory mechanisms of its expression have not been fully understood. In the present study, we report that H2O2 treatment increases expression of E-selectin but decreases expression of the endothelial transcription factor ETS-related gene (ERG) in HUVECs in a dose- and time-dependent manner. In BALB/c mice treated with hypochlorous acid, E-selectin expression is increased and ERG expression is decreased in endothelial cells of the brain and lung. RNA interference of ERG upregulates E-selectin expression, whereas transfection of ERG-expressing plasmid downregulates E-selectin expression in HUVECs. Knockdown or overexpression of ERG comprises H2O2-induced E-selectin expression in HUVECs. Deletion of the Erg gene in mice results in embryonic lethality at embryonic days 10.5-12.5, and E-selectin expression is increased in the Erg-/- embryos. No chromatin loop was found on the E-selectin gene or its promoter region by capture high-throughput chromosome conformation capture. Chromatin immunoprecipitation and luciferase reporter assay determined that the -127 ERG binding motif mediates ERG-repressed E-selectin promoter activity. In addition, ERG decreases H2O2-induced monocyte adhesion. Together, ERG represses the E-selectin gene transcription and inhibits oxidative stress-induced endothelial cell adhesion.

Complement factor H inhibits endothelial cell migration through suppression of STAT3 signaling.

Complement factor H (CFH), a major soluble inhibitor of complement, is a plasma protein that directly interacts with the endothelium of blood vessels. Mutations in the CFH gene lead to diseases associated with excessive angiogenesis; however, the underlying mechanisms are unknown. The present study aimed to determine the effects of CFH on endothelial cells and to explore the underlying mechanisms. The adenoviral plasmid expressing CFH was transduced into HepG2 cells, and the culture medium supernatant was collected and co-cultured with human umbilical vein endothelial cells (HUVECs). Cell proliferation was measured by CCK8 and MTT assays, and cell migration was measured by wound healing and Transwell assays. Reverse transcription-quantitative PCR was performed to detect gene transcription. Western blotting was used to determine protein levels. The results revealed that CFH can inhibit migration, but not viability, of HUVECs. In addition, CFH did not significantly alter MAPK or TGF-ß signaling, whereas it decreased STAT3 phosphorylation in HUVECs. Furthermore, CFH failed to reduce migration of HUVECs, with inhibition of STAT3 signaling by STATTIC or activation of STAT3 signaling by overexpression of STAT3 (Y705D) compromising CFH-inhibited HUVEC migration. CFH also decreased the expression levels of vascular endothelial growth factor receptor 2, a downstream effector of STAT3 mediating endothelial cell migration. In conclusion, the present study suggested that CFH may be a potential therapeutic target for angiogenesis-related diseases.

Long COVID Syndrome: A Case-Control Study.

BACKGROUND: Acute coronavirus disease 2019 (COVID-19) causes various cardiovascular complications. However, it is unknown if there are cardiovascular sequelae in the medium and long-term. The aim of this study was dual. Firstly, we wanted to investigate symptomatology and health-related quality of life (HRQoL) at medium-term follow-up (6 months post-COVID). Secondly, we wanted to assess whether history of COVID-19 and persistent shortness of breath at medium-term follow-up are associated with ongoing inflammation, endothelial dysfunction, and cardiac injury. METHODS: A case-control study was performed. Virologically proven COVID-19 cases and age- and gender-matched controls were interviewed to assess symptoms and HRQoL. Biochemical tests were also performed. RESULTS: The study comprised 174 cases and 75 controls. The mean age of the participants was 46.1±13.8 years. The median follow-up was 173.5 days (interquartile range 129-193.25 days). There was no significant difference in the demographics between cases and controls. At follow-up, cases had a higher frequency of shortness of breath, fatigue, arthralgia, abnormal taste of food (P <.001), and anosmia. Cases also exhibited worse scores in the general health and role physical domains of the Short Form Survey-36. High-sensitivity C-reactive protein (hsCRP) was significantly higher in the cases, and there was a positive correlation of hsCRP with time. Significant determinants of shortness of breath were age, female gender and white cell count, troponin I, and lower hemoglobin levels at follow-up. CONCLUSION: Post-COVID-19 patients have persistent symptomatology at medium-term follow-up. Higher hsCRP in cases and the positive association of hsCRP with time suggest ongoing systemic inflammation in patients persisting for months after COVID-19.

Direct Oral Anticoagulants for the Prevention and Acute Treatment of Cancer-Associated Thrombosis.

Cancer is a major risk factor for venous thromboembolism (VTE), and cancer-associated thrombosis (CAT) constitutes approximately 15-25% of all VTE cases. For decades, the standard treatment for CAT used to be daily subcutaneous low molecular weight heparin (LMWH). Data on the safety and efficacy of the direct oral anticoagulants (DOACs) in this population emerged only in recent years and specific DOACs were included into recent guidelines recommendations. In this narrative review of the literature, we reported the results of the phase III randomized controlled trials that evaluated the DOACs for the prevention and the acute treatment of CAT. For the acute phase treatment, the anti-Xa inhibitors (apixaban, edoxaban, rivaroxaban) showed better efficacy than LMWH in preventing VTE recurrence; however, rivaroxaban and edoxaban were also associated with an increased risk of bleeding events. For primary prevention of CAT in ambulatory cancer patients starting chemotherapy, apixaban and rivaroxaban showed better efficacy than placebo but a trend towards higher bleeding rates. Recent guidelines suggest the DOACs for the treatment of CAT in selected cancer patients (eg, low bleeding risk, no luminal gastrointestinal or genitourinary malignancies, no interfering medications). The DOACs are also suggested for primary thromboprophylaxis in selected ambulatory cancer patients at high risk of VTE (eg, Khorana score ≥2 prior to starting new chemotherapy, low bleeding risk, no interfering medications).

Efficacy and safety of the direct oral anti-coagulants in patients with cerebral vein thrombosis: A systematic review and meta-analysis.

Vitamin K antagonists (VKAs) are the standard oral anti-coagulant treatment for patients with cerebral venous thrombosis (CVT). However, the direct oral anti-coagulants (DOACs) started replacing VKAs also in this setting. We aimed to evaluate safety and efficacy of the DOACs for CVT treatment. We performed a systematic review and meta-analysis (PROSPERO protocol registration number CRD42020191472). The electronic databases MEDLINE, EMBASE and CENTRAL were searched from inception to January 2022. We included randomised controlled trials (RCTs) and observational studies, enrolling at least 10 adult patients with CVT treated with any DOACs. Twenty-three studies were included, for a total of 618 CVT patients treated with DOACs (treatment duration range 3-12 months). Mortality rate was 1.76% [95% confidence interval (CI) 0.70%-3.24%; I2  = 0%; 5/428 patients, 18 studies]; major bleeding 2.41% (95% CI 1.26%-3.91%; I2  = 1.5%; 12/534 patients, 21 studies); recurrent thrombosis 2.05% (95% CI 1.04%-3.37%; I2  = 0%; 10/577 patients, 21 studies); excellent neurological outcome 85.9% (95% CI 79.0%-91.7%; I2  = 63.7%; 289/340 patients, 13 studies); vessel recanalisation 89.0% (95% CI 82.9%-93.9%; I2  = 62.7%; 316/359 patients, 16 studies). No significant differences emerged by study design (RCTs vs. observational studies) or by treatment (DOACs vs. VKAs). This systematic review showed that the DOACs might represent a reasonable oral anti-coagulant treatment option for CVT patients.

Diagnostic accuracy of D-dimer in patients at high-risk for splanchnic vein thrombosis: A systematic review and meta-analysis.

BACKGROUND: D-dimer is included in the diagnostic algorithm for deep vein thrombosis and pulmonary embolism. However, its role in the diagnosis of splanchnic vein thrombosis (SVT) is still controversial. The aim of this study was to evaluate the diagnostic accuracy of D-dimer for SVT. METHODS: We performed a systematic review of the literature with meta-analysis (PROSPERO protocol registration number: CRD42020184300). The electronic databases MEDLINE, EMBASE, and CENTRAL were searched from inception to March 2021 week 4. Studies which evaluated D-dimer accuracy for SVT in any category of patients were selected. The index test was any D-dimer assay; the reference standard was any radiological imaging. The QUADAS-2 checklist was used for the risk of bias assessment. A bivariate random-effects regression model was used to calculate summary estimates of sensitivity and specificity. RESULTS: 12 studies (with a total of 1298 patients) evaluating the accuracy of D-dimer in patients at high risk of SVT (surgical patients, patients with liver cirrhosis or hepatocellular carcinoma) were included. None of the included studies was at low risk of bias. The weighted mean prevalence of SVT was 33.4% (95% CI, 22.5-45.2%, I2 = 94.8%). D-dimer accuracy was expressed by sensitivity 96% (95% CI, 72-100%); specificity 25% (95% CI, 5-67%); positive likelihood ratio 1.3 (95% CI, 0.9-1.9); negative likelihood ratio 0.16 (95% CI, 0.03-0.84); area under the ROC curve 0.80 (95% CI, 0.76-0.83). CONCLUSIONS: D-dimer seems to have high sensitivity in the diagnosis of patients at high-risk for SVT. However, there is a strong need for more robust evidence on this topic.

Treatment of portal vein thrombosis: an updated narrative review.

Portal vein thrombosis (PVT) is the most frequent among the splanchnic vein thrombosis, accounting for 90% of cases. More than half of PVT are provoked by liver cirrhosis, solid cancer or myeloproliferative neoplasms. The remaining cases are non-malignant non-cirrhotic PVT and include either unprovoked events or thrombosis secondary to other less common risk factors (e.g. abdominal surgery, intrabdominal inflammations/infections, or hormonal stimuli). Anticoagulant therapy in patients with acute symptomatic PVT should be started early after diagnosis, if no active bleeding, to obtain greater vessel recanalization and reduce the occurrence of portal-hypertension related complications. Gastroesophageal varices do not represent a contraindication to anticoagulant treatment, as long as adequate measures have been undertaken for the prophylaxis of gastroesophageal bleeding. Different treatment options (unfractionated or low molecular weight heparin, vitamin K antagonists and direct oral anticoagulants [DOACs]) can be considered. In this narrative review we will discuss the treatment of PVT in the three most common scenarios (cirrhosis-associated, cancer-associated and non-malignant non-cirrhotic PVT). We will also discuss the role of the DOACs and summarize recent guidelines on this topic.

Effect of anticoagulants on fibrin clot structure: A comparison between vitamin K antagonists and factor Xa inhibitors.

BACKGROUND: Abnormal clot structure has been identified in patients with thrombotic disorders. Anticoagulant therapy offers clear benefits for thrombosis prevention and treatment by reducing blood clot formation and size; nevertheless, there are limited data on the effects of different anticoagulants, where clotting is initiated with different triggers, on clot structure. OBJECTIVES: Our aim was to investigate the effects of vitamin K antagonists and factor Xa inhibitors on clot structure. METHODS: Clots from pooled plasma spiked with rivaroxaban, apixaban, or enoxaparin, as well as plasma from patients on warfarin, were compared to plasma without anticoagulation. The kinetic profile of polymerizing clots was obtained by turbidity, fiber density was determined by confocal microscopy, clot pore size was investigated by permeation, and fiber size was analyzed using scanning electron microscopy. Clotting agonist was either tissue factor or thrombin. RESULTS: Following clotting with tissue factor, all anticoagulated clots had a significantly increased lag time, with the exception of enoxaparin. Rivaroxaban additionally led to significantly less dense and more permeable clots, with thicker fibers. In contrast, turbidity analysis following initiation with thrombin showed few effects of anticoagulation, with only enoxaparin leading to a prolonged lag time. Enoxaparin clots made with thrombin were less dense and more permeable. CONCLUSION: Our results show that anticoagulants modulate clot structure particularly when induced by tissue factor, most likely due to reduction of thrombin generation. We propose that the effects of different anticoagulants could be assessed with a global clot structure measurement such as permeation or turbidity, providing information on clot phenotype.

Anticoagulation in splanchnic and cerebral vein thrombosis: An international vignette-based survey.

BACKGROUND: Anticoagulant treatment of splanchnic (SVT) and cerebral vein thrombosis (CVT) can be challenging due to the rarity of these conditions, the concomitantly high thrombotic and bleeding risks, and the available low-quality evidence. OBJECTIVES: To explore the current therapeutic approaches to SVT and CVT, and the rationale behind the anticoagulant treatment choice. METHODS: A cross-sectional survey was conducted (October 2018-April 2019) among members of three thrombosis and hemostasis societies. The survey consisted of four vignette cases: (i) SVT secondary to transient risk factor; (ii) cirrhotic SVT with esophageal varices; (iii) CVT secondary to transient risk factor; and (iv) unprovoked CVT with intracranial hemorrhage. RESULTS: A total of 397 physicians responded to the survey. There was wide variability in anticoagulant treatment options, starting time, and duration. Vitamin K antagonists were the commonest choice across the four vignette cases (44.2%-63.0%). The direct oral anticoagulants (DOACs) were the second commonest choice in low-bleeding-risk scenarios (27.7% in case 1, 22.9% in case 3), while parenteral anticoagulation alone was the second commonest choice in high-bleeding-risk scenarios (39.9% in case 2, 39.8% in case 4). The most frequent reasons for selecting DOACs were oral route of administration (50.6%), lack of need for laboratory monitoring (48.1%), and favorable safety profile of these drugs (43.4%). CONCLUSIONS: The results of our study showed that, despite being off-label, the DOACs were considered for the treatment of unusual-site venous thromboembolism. The wide variability among different physicians reflected the clinical difficulties and raised the need for more collaborative trials on these disorders.

Patients' satisfaction associated with portable coagulometers for warfarin monitoring: a cross-sectional study.

BACKGROUND: The use of point-of-care (POC) coagulometers for monitoring patients on vitamin K antagonist (VKA) treatment makes international normalised ratio (INR) results immediately available. The aim of this study was to compare patients' satisfaction with VKA treatment in two settings characterised by distinct ways of monitoring: POC INR versus laboratory INR. MATERIALS AND METHODS: We recruited adult patients on long-term warfarin treatment (July 2017-February 2018) from the Anticoagulation Clinics at five district health centres (namely Cospicua, Floriana, Mosta, Qormi, Rabat-POC INR) and at Mater Dei Hospital (Msida - Laboratory INR) in Malta. We administered two psychometric questionnaires: the Duke Anticoagulation Satisfaction Scale (DASS) (range 25-175, lower scores corresponding to higher satisfaction) and the Perception of Anticoagulation Treatment Questionnaire (PACT-Q2) (range 0-100, higher scores corresponding to higher satisfaction). RESULTS: We analysed 313 questionnaires (POC INR n=159, laboratory INR n=154). In the POC INR cohort, median age was 72 years and 59.1% were males; in the laboratory INR cohort, median age was 70.5 years and 46.1% were males. The POC INR cohort obtained significantly lower overall DASS score (p<0.001) and significantly higher PACT-Q2 scores (p<0.001 for the subscale "convenience"; p=0.039 for the subscale "anticoagulant treatment satisfaction") than the laboratory INR cohort. In multiple regression analysis, the use of POC coagulometers was significantly associated with the overall DASS score (p=0.013) and the PACT-Q2 convenience score (p=0.012). DISCUSSION: Patients on warfarin treatment were generally satisfied. Patients monitored with the POC INR with a dedicated time slot reported less inconvenience and burdens and better psychological impact than patients monitored with the traditional laboratory INR.

Impaired platelet-dependent thrombin generation associated with thrombocytopenia is improved by prothrombin complex concentrates in vitro.

BACKGROUND: Impaired thrombin generation (TG) in patients with acquired coagulopathy, is due to low coagulation factors and thrombocytopenia. The latter is typically treated with platelet transfusions and the former with plasma and occasionally with prothrombin complex concentrates (PCCs). We hypothesized that manipulating the concentrations of coagulation factors might result in restoration of platelet-dependent TG over and above that of simple replacement therapy. OBJECTIVE: To investigate the influence of PCCs on impaired TG secondary to thrombocytopenia. METHODS: TG was evaluated by thrombin generation assay using a thrombocytopenia model in which normal plasma samples with varying platelet counts (20-300 × 109/L) were spiked with PCCs (25%-150% increase in plasma PCC levels). RESULTS: PCCs and platelets significantly increased TG in a dose-dependent manner in vitro. Two-way repeated measures of analysis of variance showed variance in peak height, area under the curve, time to peak, and velocity. This variance explained, respectively, by levels of PCC was 47, 59, 25 and 53%; by platelet count was 45, 28, 44, and 14%; by the combination was 80, 67, 70, and 62% variance; and a combination with additional interaction was 91, 84, 76, and 68%. TG at a platelet count 40 × 109/L with an approximate 25% increase in PCC concentration was similar to TG at 150 × 109/L. Similarly, patient samples spiked ex vivo with PCCs also showed highly significant improvements in TG. CONCLUSIONS: Impaired TG of thrombocytopenia is improved by PCCs, supporting the need for additional studies in complex coagulopathies characterized by mild to moderate thrombocytopenia and abnormal coagulation.

Validation and psychometric properties of the Maltese version of the Duke Anticoagulation Satisfaction Scale (DASS).

PURPOSE: Assessing treatment satisfaction can guide specific interventions to improve anticoagulation adherence and reduce adverse outcomes. We aimed to assess the psychometric properties (reliability and validity) of the Maltese translation of the Duke Anticoagulation Satisfaction Scale (DASS). PATIENTS AND METHODS: The DASS explores three dimensions (limitations, hassles/burdens, psychological impact). The translation process included forward and backward translations. Reliability was evaluated through internal consistency and reproducibility. Validity was evaluated through floor/ceiling effect, convergent/discriminant validity, construct validity, and known-group validity. RESULTS: The Maltese version of the DASS, administered to 174 patients on warfarin for different clinical indications, showed good reliability (Cronbach's alpha 0.87; intraclass correlation coefficient for test-retest 0.73). Floor effect was identified mainly in the limitations and hassles/burdens subscales. Significant positive correlations were found between the DASS total score and its subscales (limitations 0.80, hassles/burdens 0.85, psychological impact 0.68). Female sex, shorter warfarin treatment duration (≤5 years), previous hospitalization and history of bleeding were associated with lower satisfaction. CONCLUSION: Psychometric properties of the Maltese DASS were comparable to the original English version. The Maltese version of the DASS is a valid and reliable instrument that can be used by health care professionals to assess the level of satisfaction of Maltese-speaking anticoagulated patients.