The use of direct oral anticoagulants in inherited thrombophilia

Direct oral anticoagulants for deep vein thrombosis among patients with hereditary thrombophilia-A cohort study

OBJECTIVES

to evaluate direct oral anticoagulants (DOACs) in patients with hereditary thrombophilia and deep venous thrombosis (DVT).

METHODS

This is a retrospective observational study.

RESULTS

In total, 45 patients were treated between 01/2012 and 12/2022 (mean follow-up: 1.5 +/- 0.3 years). The most frequent thrombophilias were heterozygous V Leiden (20%), heterozygous MTHFR C677T (37.8%), heterozygous MTHFR A1298C (24.4%), and hyperhomocysteinemia (26.7%). The patients received rivaroxaban (n = 19), apixaban (n = 15), and dabigatran (n = 11). Three cases presented symptoms' recurrence without evidence of thrombosis' recurrence (two under rivaroxaban and one under apixaban; p > .05). These patients improved under parenteral anticoagulation and were further treated with dabigatran. No other event or major bleeding occurred during the follow-up. The presence of more than two factors was associated with acute recurrence of symptoms (OR = 25.9; 95% CI [1.454-461.262]; p = .026).

CONCLUSIONS

DOACs seem to be safe and efficient for patients with hereditary thrombophilia and DVT. The presence of more than two thrombophilia factors is associated with a higher risk for symptom recurrence. Although statistically non-significant, symptoms' recurrence was also observed more frequently among patients under anti-Xa inhibitors than antithrombin inhibitors. This should be verified in larger comparative studies.

Combination Treatment of Balloon Pulmonary Angioplasty and Direct Oral Anticoagulant in a Patient with Chronic Thromboembolic Pulmonary Hypertension Complicated by Protein S Deficiency

Introduction: Chronic thromboembolic pulmonary hypertension (CTEPH) is a phenotype of pulmonary hypertension due to chronic and multiple organized thrombus. The therapeutic strategy for patients with CTEPH and comorbid protein S deficiency remains unknown due to its rarity. Case: We encountered a 49-year-old male patient with CTEPH and concomitant mild protein S deficiency (type III). We could successfully perform balloon pulmonary angioplasty without any major complications, including thromboembolism and bleeding, followed by standard-dose oral anticoagulation therapy instead of warfarin. Conclusion: A currently established standard therapeutic strategy for CTEPH, including pulmonary angioplasty, may be safe and effective even in patients with concomitant inherent coagulation abnormalities.

Five Challenging Cases of Hereditary Antithrombin Deficiency Characterized by Thrombosis or Complicated Pregnancy

Hereditary antithrombin deficiency (ATD) is a rare autosomal dominant condition (estimated prevalence 1:500-1:5000). Most ATD patients have AT activity levels 40-60% of normal. We present treatments for venous thromboembolism (VTE) in five cases of hereditary ATD. Four patients had a family history of ATD, and one had a de novo mutation. The majority of patients had a VTE while on prophylactic anticoagulation. AT concentrate augmentation was added in these cases to treat the VTE and for prophylaxis against further episodes. Two patients had significant bleeding events, one had permanent physical sequelae. Two of the patients were pregnant. VTE is a common cause of morbidity and mortality during pregnancy. Although low molecular weight heparins are the drugs of choice during pregnancy, this treatment was inadequate in one patient (developed VTE on therapy). These cases emphasize the need to screen for ATD in young patients (<55 years) presenting with VTE. AT augmentation therapy may be necessary in patients inadequately treated with conventional anticoagulants. Careful monitoring and individualized care are needed in ATD patients, especially those with demonstrated bleeding tendencies.

Activated protein C resistance impact on Syrian candidates for in vitro fertilisation and the benefit of anticoagulation therapy: a retrospective cohort study

Activated protein C resistance (APCR) is a common thrombophilia, caused mainly by a mutation. The impact of APCR on the efficacy of In Vitro Fertilization (IVF) are still unclear, and no solid recommendations for its management were published. To investigate the effect of APCR on IVF outcomes and assess the efficacy of our management protocol, we retrospectively scanned the medical records of women who were tested with APCR assay in 2019 at our fertility centre. The 66 women (12%) positive for APCR had lower odds of reaching clinical pregnancies after IVF 0.18 [95% CI: 0.07-0.47] and fewer live births. The administration of low-molecular-weight heparin and aspirin associated with more implantation in treated compared to untreated APCR-positive women with an odds ratio of 43.2 [7.51-248.6]. In conclusion, APCR negatively affects the number of clinical pregnancies after IVF, but anticoagulation therapy can mitigate this effect and significantly increase clinical pregnancies.Impact StatementWhat is already known on this subject? The evidence about the impact of APCR on IVF outcomes is still inconclusive. According to the Canadian guideline, routine screening for thrombophilia in patients with recurrent pregnancy loss is not recommended. No clear recommendations regarding the management of APCR in the planning for IVF are yet available.What do the results of this study add? APCR significantly increases implantation failure among infertile women who conduct IVF. Management of APCR using LMWH and aspirin was effective in mitigating this effect and increasing successful implantation.What are the implications of these findings for clinical practice and/or further research? Our findings can support the recommendation to include APCR assay in the routine tests for infertile women conducting IVF, and suggest the combination between LMWH and aspirin as an effective therapy to increase successful implantation in APCR positive candidates. However, more controlled clinical trials are still needed to confirm our results.

Homozygous factor V leiden mutation: Rare etiology of pulmonary embolism

Introduction and importance

Venous thromboembolic disease (VTE), which includes pulmonary embolism (PE) and deep vein thrombosis (DVT), is a major public health problem with high morbidity and mortality. The main risk factors for VTE are surgery, active cancer, immobilization, trauma or fracture, pregnancy and estrogen therapy. Genetic risk factors are also present and are dominated by the factor V Leiden mutation, which is present in 20% of VTE and in 2–5% of the general population with an annual incidence of 0.1% (Margaglione and Grandone, 2011; Ridker et al., 1995) [4,5]. This mutation can be heterozygous or homozygous, which is rarer. In this context, we report the case of a 37-year-old patient with no medical or surgical history and no notable risk factors who was admitted to the emergency room for the management of acute dyspnea at rest in connection with a bilateral proximal pulmonary embolism originating from a homozygous factor V Leiden mutation.

Despite the efforts of the World Health organization, pulmonary embolism remains a major cause of morbidity and mortality in our days, and the etiological assessment is performed in a very few cases, which makes the management standardized and not specific. That is why it is important to make an etiological assessment in a systematic way especially in young subjects for an optimal management and to avoid recurrences.

Case presentation

Here, we report a rare case of a 37-year-old patient, who was admitted for the management of resting dyspnea related to bilateral proximal pulmonary embolism, in whom the etiological work-up was in favor of a homozygous factor V Leiden mutation. This case shows diagnostic difficulties and management of this rare disease.

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Pulmonary embolism is a frequent and potentially serious pathology.

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The etiological assessment of pulmonary embolism is not carried out in a systematic way which makes the management not optimal with the possibility of repeated pulmonary embolism.

•

Long-term anticoagulation is the mainstay of treatment for pulmonary embolism secondary to factor V Leiden mutation.

Evolving Knowledge on Primary and Secondary Prevention of Venous Thromboembolism in Carriers of Hereditary Thrombophilia: A Narrative Review

The association between heritability of venous thromboembolism (VTE) and thrombophilia was first reported clinically in 1956, later followed by the first description of a congenital cause of hypercoagulability-antithrombin deficiency-in 1965. Since then, our knowledge of hereditary causes of hypercoagulability, which may predispose carriers to VTE has improved greatly. Novel genetic defects responsible for severe thrombophilia have been recently identified and we have learned that a wide range of interactions between thrombophilia and other genetic and acquired risk factors are important determinants of the overall individual risk of developing VTE. Furthermore, therapeutic strategies in thrombophilic patients have benefited significantly from the introduction of direct oral anticoagulants. The present review is an overview of the current knowledge on the mechanisms underlying inherited thrombophilia, with a particular focus on the latest achievements in anticoagulation protocols and prevention strategies for thrombosis in carriers of this prothrombotic condition.

Evolving Knowledge on Primary and Secondary Prevention of Venous Thromboembolism in Carriers of Hereditary Thrombophilia: A Narrative Review

The association between heritability of venous thromboembolism (VTE) and thrombophilia was first reported clinically in 1956, later followed by the first description of a congenital cause of hypercoagulability-antithrombin deficiency-in 1965. Since then, our knowledge of hereditary causes of hypercoagulability, which may predispose carriers to VTE has improved greatly. Novel genetic defects responsible for severe thrombophilia have been recently identified and we have learned that a wide range of interactions between thrombophilia and other genetic and acquired risk factors are important determinants of the overall individual risk of developing VTE. Furthermore, therapeutic strategies in thrombophilic patients have benefited significantly from the introduction of direct oral anticoagulants. The present review is an overview of the current knowledge on the mechanisms underlying inherited thrombophilia, with a particular focus on the latest achievements in anticoagulation protocols and prevention strategies for thrombosis in carriers of this prothrombotic condition.

Apixaban Use in Patients with Protein C and S Deficiency: A Case Series and Review of Literature

Background

Case(s) Presentation

Conclusion

Multiple thrombotic sources and embolic events at arterial sites in a patient with protein-C deficiency

Protein-C deficiency causes a thrombophilic environment in circulation. Although venous thromboembolism is the most common presentation, arterial events are rare. A 45 year-old woman with protein-C deficiency presented with multiple thromboembolic events including bilateral renal infarct and inferior ST-elevation myocardial infarction 3-days after coronary angiography via femoral approach which were normal coronary arteries. Computed tomographic angiography and transesophageal echocardioraphy displayed multiple thrombi sources including left atrium, left subclavian artery, sinus valsalva and descending aorta. Unfractionated-heparin and tissue plasminogen activator infusion were given. Although regression in ST-segment elevation and chest pain, no reduction in sizes of left atrial and aortic thrombus was observed by imaging modality. The patient refused surgical removal of thrombi, then warfarin therapy was planned. In patients with congenital thrombophilia and history of thromboembolism, anticoagulant treatment should be carefully managed during percutaneous diagnostic and interventional treatments and they should be performed by radial approach without interruption of anticoagulants.

Cerebral vein thrombosis associated with MTHFR A1289C mutation gene in a young postpartum woman

Cerebral venous thrombosis is a rare cerebrovascular disease that accounts for approximately 1% of strokes, with an incidence of 3-4 cases / million inhabitants per year, with a significant mortality rate of 10-13%. Pregnancy and puerperal period are physiological states that predispose to thrombosis through hypercoagulability due to hormonal change. These alterations occur in blood flow, vascular wall and clotting factors and while superimposed on a genetically predisposing field, create the optimal conditions for the occurrence of embolic phenomena. Here we present the case of a young, secondipara woman with recurrent thrombotic events, even under optimal anticoagulation therapy, where the extensive laboratory investigations identified the predisposing terrain: the heterozygous mutation of the MTHFR A1289C gene.

Successful endovascular therapy for an adolescent patient with cerebral venous sinus thrombosis: A case report

RATIONALE

Cerebral venous sinus thrombosis associated with protein S deficiency is rare in adolescent patients and has high disability and fatality.Patient concerns: A 15-year-old male student presented in the hospital with sudden headache, nausea, and vomiting and was diagnosed with protein S deficiency by gene testing.

DIAGNOSES

Cerebral venous sinus thrombosis due to protein S deficiency was diagnosed in this adolescent patient, who underwent successful endovascular therapy (EVT).

INTERVENTIONS

The patient was treated with standard anti-coagulation therapy including low-molecular-weight heparin (90 IU/kg/Q12 h) and dehydrant (mannitol 125 mL Q8 h); however, the symptoms were not alleviated. Successful EVT was implemented.

OUTCOMES

Both the superior sagittal sinus and bilateral transverse sinus were recanalized after thrombus clearance. The patient achieved a complete recovery without any other stroke recurrence during follow-up.

LESSONS

EVT can be performed with favorable and effective clinical outcomes in adolescent cerebral venous sinus thrombosis patients with protein S deficiency. EVT associated with standard anti-coagulation therapy may improve the prognosis and reduce mortality among such patients.

Is routine screening for silent pulmonary embolism justified in patients with deep vein thrombosis?

The incidence of asymptomatic pulmonary embolism (PE) exceeds 70% in patients with deep venous thrombosis (DVT), even in cases of distal deep vein thrombosis. We report the case of a patient with a diagnosis of DVT in the lower left limb associated with asymptomatic PE who presented late symptoms due to this same PE. The absence of acute symptoms and the late onset of symptoms could have provoked doubts about the most appropriate treatment, resulting in unnecessary interventions, if pulmonary embolism had not already been diagnosed with tomography. In the present case, we demonstrate that computed tomography angiography conducted at the time of DVT diagnosis accurately diagnosed PE and prevented any misinterpretation of recurrent DVT in a patient already being medicated, which could have been mistakenly interpreted as demonstrating failure of anticoagulant therapy. Such a situation could lead to unnecessary intervention to fit an inferior vena cava filter. We cannot suggest that a classic medical conduct should be reformulated simply on the basis of a case report. However, we would be remiss not to suggest that well-designed studies should be carried out in the future to assess the need for this examination in the acute phase.

[Actual use of direct oral anticoagulants in venous thromboembolic disease]

Direct oral anticoagulants recently became the first-line choice for anticoagulation in venous thromboembolic disease. Many studies have shown its non-inferiority regarding the risk of thromboembolic recurrence compared to anti-vitamin K without increasing the risk of bleeding in the general population. However, specific populations such as patients with cancer, patients with kidney failure, patients with constitutional thrombophilia, elderly patients, or patients with extreme weight are at risk of intolerance to the use of direct oral anticoagulants. Precautions in use may be necessary as discussed in recently published guidelines about antiphospholipid syndrome. This review aims to list the main clinical trials investigating direct oral anticoagulants in venous thromboembolic disease in the general population and populations at risk, as well as to provide an update on current international and French guidelines.

A Case of Treatment With Dabigatran for Cerebral Venous Thrombosis Caused by Hereditary Protein C Deficiency

A 37-year-old woman was admitted to our hospital with involuntary movements. She had no medical or family history of thromboembolism, nor was she on any medication. She showed no impaired consciousness, cranial nerve abnormalities, abnormal breathing, stiff neck or paralysis. Magnetic resonance venography exhibited poor visualization of intracranial vein. The protein C activity level reduced but the protein C antigen level was normal. Genetic analysis revealed a heterozygous mutation in exon 7 c.577-579delAAG, p.Lys193del on protein C gene. She was diagnosed with cerebral venous thrombosis and hereditary protein C deficiency type II. She received heparin in acute phase, and switched to dabigatran in chronic phase. Consequently, she had no recurrence of cerebral venous thrombosis and other complications. Dabigatran might be one of the alternative choices for patients with cerebral venous thrombosis and protein C deficiency.

A Case of Duodenal Resection and Duodenojejunostomy for Multiple Small Bowel Infarction in Patient With Inherited Thrombophilia and Vitamin K Antagonist Induced Critical Hypocoagulation

We present a case of the multiple venous intestinal infarction in patient with two inherited thrombophilias: Leiden factor V (LFV) and factor VIII elevation. The patient had a critical hypocoagulation caused by vitamin K antagonist (VKA) overdose. At laparotomy, several intestinal segments were necrotic and ischemic. Coagulopathy was corrected by the transfusion of the fresh frozen plasma. Because of the 4th duodenal segment infarction distal segmental duodenectomy with side-to-side duodenojejunostomy was done, which is a rarely performed procedure. On postoperative day 6 deep vein thrombosis developed, despite nadroparin profillaxes, early mobilisation and compressive stockings.

Our case demonstrated that in patients with congenital thrombophilia, development of the mesenteric venous thrombosis is possible even with VKA induced severe hypocoagulation. Venous infarction of the small bowel can be associated with the hemoperitoneum and gastrointestinal bleeding. After resection of the fourth duodenal segment, side-to-side duodenojejunostomy is a feasible method of reconstruction.

Rivaroxaban in Recurrent Ischemic Stroke Due to Protein S Deficiency: A Case Report

Protein S deficiency is a thrombophilia associated with an increased risk of thromboembolism. Previous studies have shown its role as a predisposing factor for venous thromboembolism, but its role in recurrent arterial ischemic stroke remains uncertain. Here we report a patient with recurrent ischemic stroke due to protein S deficiency. Oral anticoagulant treatment with vitamin K antagonist (VKA) drugs is used to treat and prevent thromboembolic events caused by thrombophilia, but it has many limitations, especially in the case of recurrent thromboembolic events. Direct oral anticoagulants (DOACs) have many advantages over VKA. Previous studies have shown that they are safe in cases of thrombophilia, but they are not well studied in recurrent ischemic stroke due to protein S deficiency. In this study our patient was treated with rivaroxaban. Protein S deficiency may be a predisposing factor in recurrent ischemic stroke, and rivaroxaban can be a safe and effective treatment option. Further studies are needed to confirm our findings.

Case Report: Successful Long-Term Management of a Low-Birth Weight Preterm Infant With Compound Heterozygous Protein C Deficiency With Subcutaneous Protein C Concentrate Up to Adolescence

Homozygous/compound heterozygous forms of congenital protein C deficiency are often associated with severe antenatal and postnatal thrombotic or hemorrhagic complications. Protein C deficiency frequently leads to severe adverse outcomes like blindness and neurodevelopmental delay in children and may even lead to death. The most widely used long-term postnatal treatment consists of oral anticoagulation with vitamin K antagonists (e.g., warfarin), which is supplemented with protein C concentrate in acute phases. Subcutaneous infusions have been described in infants mostly from 2 months of age after severe postnatal thrombosis, but not in newborns or premature infants without thromboembolism. We report the first case of a compound heterozygous protein C-deficient preterm infant, born at 31+5 weeks of gestation to parents with heterozygous protein C deficiency (protein C activity 0.9% at birth). We focus on both prenatal and perinatal management including antithrombotic treatment during pregnancy, the cesarean section, and continuous postnatal intravenous and consecutive subcutaneous therapy with protein C concentrate followed by a change of therapy to direct oral anticoagulants (DOACs) (apixaban). We report successful home treatment with subcutaneous protein C concentrate substitution overnight (target protein C activity >25%) without complication up to 12.5 years of age. We propose that early planned cesarean section at 32 or preferably 34 weeks of gestation limits potential maternal side effects of anticoagulation with vitamin K antagonists and reduces fetal thromboembolic complications during late pregnancy. Intravenously administered protein C and early switch to subcutaneous infusions (reaching about 3 kg body weight) resulted in sufficient protein C activity and has guaranteed an excellent quality of life without any history of thrombosis for 13 years now. In older children with protein C deficiency, as in our case, DOACs could be a new therapeutic option.

Direct Oral Anticoagulants in Patients With Inherited Thrombophilia and Venous Thromboembolism: A Prospective Cohort Study

Background

In this prospective cohort study, we aimed to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) versus heparin/vitamin K antagonists for the treatment of venous thromboembolism (VTE) in patients with inherited thrombophilia.

Methods and Results

We enrolled consecutive patients with acute VTE and inherited thrombophilia treated with DOACs (cases) or heparin/vitamin K antagonists (controls), matched for age, sex, ethnicity, and thrombophilia type. End points were VTE recurrence and bleeding complications; residual vein thrombosis and post‐thrombotic syndrome; VTE recurrence after anticoagulant discontinuation. Two hundred fifty‐five cases (age 52.4±17.3 years, Female 44.3%, severe thrombophilia 33.1%) and 322 controls (age 49.7±18.1 years, Female 50.3%, severe thrombophilia 35.1%) were included. The cumulative incidence of VTE recurrence during anticoagulation was 1.09% in cases versus 1.83%, adjusted hazard ratio (HR) 0.67 (95% CI, 0.16–2.77). The cumulative incidence of bleeding was 10.2% in cases versus 4.97%, HR 2.24 (95% CI 1.10–4.58). No major bleedings occurred in cases (versus 3 in controls). No significant differences regarding residual vein thrombosis and post‐thrombotic syndrome. After anticoagulant discontinuation, DOACs yielded a significantly lower 2‐year VTE recurrence risk versus traditional anticoagulants (HR, 0.61 [95% CI, 0.47–0.82]).

Conclusions

DOACs and heparin/vitamin K antagonists showed a similar efficacy in treating VTE in patients with thrombophilia. Although major bleeding episodes were recorded solely with heparin/vitamin K antagonists, we noted an overall increased bleeding rate with DOACs. The use of DOACs was associated with a lower 2‐year risk of VTE recurrence after anticoagulant discontinuation.

Successful management of portal vein thrombosis in a Yorkshire Terrier with protein-losing enteropathy

Background

Portal vein thrombosis (PVT) is a rare presentation in dogs with protein-losing enteropathy (PLE). Rivaroxaban, an oral, selective, direct factor Xa inhibitor, has not been reported to be administrated for canine PVT and the effect is unclear in dogs with PLE.

Case presentation

An 11-year-old Yorkshire Terrier presented with moderate ascites. The dog had severe hypoalbuminemia (1.2 g/dL), and a portal vein thrombus was confirmed on computed tomographic angiography (CTA). On endoscopic examination, it became apparent that the hypoalbuminemia was caused by PLE, which was consequent of lymphatic dilation and lymphoplasmacytic enteritis. Therefore, the dog was initially treated with oral administrations of spironolactone and clopidogrel, with dietary fat restriction. However, a follow-up CTA showed no changes in the ascites, thrombus, and portal vein to aorta (PV/Ao) ratio. Therefore, the dog was additionally prescribed rivaroxaban and low-dose prednisolone for the portal vein thrombus and hypoalbuminemia due to lymphoplasmacytic enteritis, respectively. Following the treatment, the PV/Ao ratio decreased because of a decrease in the thrombus and the ascites disappeared completely with an elevation of albumin concentration (1.9 g/dL).

Conclusions

This case report demonstrated that oral administration of rivaroxaban combined with low-dose glucocorticoid was effective management for PVT in a dog with PLE.

Recurrent Cerebral Venous Thrombosis Treated with Direct Oral Anticoagulants in a Japanese Man with Hereditary Protein C Deficiency

We herein report a case involving a 32-year-old Japanese man with recurrent cerebral venous thrombosis due to hereditary protein C deficiency. He was admitted to our hospital with impaired consciousness. Brain magnetic resonance imaging demonstrated high intensities diffusely along the bilateral sulci and magnetic resonance venography revealed left transverse sinus and superior sagittal sinus stenoses. His father had a history of cerebral infarction and venous thrombosis. The protein C activity level examined by chromogenic synthetic substrate assay was markedly reduced. He was diagnosed with protein C deficiency, and a genetic analysis revealed a heterozygous mutation at exon 3 c.199G>A,p.Glu67Lys on the protein C gene. Four months later, at his second admission, he had transient aphasia, and his protein C activity was under 10%. We switched warfarin to the direct oral anticoagulants edoxaban. He remains fully recovered with no adverse events after the administration of edoxaban for a year. Direct oral anticoagulants may be a new tool for treating cerebral venous thrombosis due to hereditary protein C deficiency.

Cerebral Venous Sinus Thrombosis and Acute Myocardial Infarction in a Patient with PAI-1 4G/4G Homozygosity

The plasminogen activator inhibitor-1 (PAI-1) 4G/4G homozygous genotype represents a genetic thrombophilia that has been associated with enhanced risk of arterial and venous thrombotic events. The optimal anticoagulation strategy for PAI-1 4G homozygous patients is unclear. Herein we present a case of a patient with PAI-1 4G/4G homozygosity who was placed on dabigatran after developing cerebral venous sinus thrombosis (CVST), but who then suffered an acute myocardial infarction several weeks later. We seek to highlight the relationship between the PAI-1 4G/4G genotype and risk of CVST, as well as discuss our management strategy in the aftermath of dabigatran failure.

The Use of Rivaroxaban for Unprovoked Pulmonary Embolism in the Setting of Antithrombin Deficiency

A 24-year-old woman with antithrombin (AT) deficiency presented with right-sided pleuritic chest pain of five days duration with diagnosis of pulmonary embolism (PE) made at an outside hospital. After discussion of treatment options with the patient, her treatment was changed to rivaroxaban protocol. The case illustrates an appropriate treatment plan for patients with AT deficiency presenting with unprovoked PE, especially when prioritizing ease of use.

Complete Superior and Inferior Vena Cava Obstruction Associated with Systemic-to-Pulmonary Venous Shunts in a Young Female with Heterozygous Prothrombin G20210A Gene Mutation

Complete superior vena cava (SVC) and inferior vena cava (IVC) obstruction is not uncommon and most commonly associated with malignancy. The risk increases in patients with central lines and hypercoagulable states such as with malignancy, thrombophilia, or use of oral contraceptive pills. According to our knowledge, complete SVC and IVC obstruction associated with systemic-to-pulmonary venous shunts in patients with prothrombin G20210A gene mutation has not been reported in the literature. Here we report the case of a 34-year-old female with complete SVC and IVC obstruction presenting with oxygen desaturation and shortness of breath due to systemic-to-pulmonary venous shunts. The unusual collateral pathway was secondary to SVC obstruction. The patient was managed conservatively, and she remained stable.

Congenital protein C deficiency and thrombosis in a dog

Congenital protein C deficiency is an important cause of thrombosis in humans but is not described in dogs. A 4‐year‐old Hungarian Vizsla was presented for investigation of acute onset of ascites. Computed tomography of the chest and abdomen and echocardiography confirmed a large thrombus within the right ventricle. A cause for thrombosis was not initially identified. The clinical signs resolved rapidly and the dog was administered clopidogrel and discharged. Plasma protein C activity measured 2 and 6 weeks later was markedly lower than expected on both occasions. All known causes of acquired protein C deficiency were excluded, and the dog was diagnosed with a congenital protein C deficiency. After diagnosis, the administration of clopidogrel was stopped and administration of rivaroxaban was started. The dog remains well with no evidence of recurrent thrombosis with 6 months of follow‐up.

Chronic Thromboembolic Pulmonary Hypertension Secondary to Thrombophilia and Incidentally Diagnosed Atrial Septal Defect

A 46-year-old man developed chronic thromboembolic pulmonary hypertension and atrial fibrillation after acute pulmonary embolism. He was found incidentally to have an isolated secundum atrial septal defect, as well as a homozygous mutation for the plasminogen activator inhibitor-1 gene. He was successfully treated with pulmonary endarterectomy and atrial septal defect repair. He has continued to do well on a regimen of dabigatran. (Level of Difficulty: Beginner.)

A Novel Heterozygous Variant in F2 Gene in a Chinese Patient With Coronary Thrombosis and Acute Myocardial Infarction Leads to Antithrombin Resistance

Thrombophilia refers to a group of conditions where the blood clots more easily than normal. These blood clots can cause problems such as deep vein thrombosis or pulmonary embolism. Most kinds of mutated coagulation factors II (F2) exhibit lower procoagulant activity, but in some cases, a higher coagulation rate has been observed. The underlying mechanism is that those variations can prevent F2s from being inhibited by antithrombin, leading to a contiguous activation of procoagulation, and causing recurrent thromboembolism. In this study, a patient was admitted to our hospital due to repeated chest pain for 2 days and aggravated for 4 h. A medical history investigation showed that he had three deep venous thromboses in the lower limbs and one portal vein thrombosis events during the past 10 years. The electrocardiogram showed Q wave elevation and slight ST segment elevation in lead V2, and coronary angiogram showed a total occlusion of the left anterior descending artery. Laboratory testing found that troponin I was obviously elevated. Family history also indicated that both his father (II-3) and grandfather (I-1) died from pulmonary thromboembolism. Whole-exome sequencing was performed to detect the genetic lesion of the patient, and a novel mutation (c.1621 C>T/p.R541W) of F2 was identified in the patient. This novel mutation resulted in a substitution of arginine by tryptophan, leading to antithrombin resistance (ATR). Our study is consistent with previously published papers. In conclusion, this study not only identifies a novel mutation of F2 and will contribute to the genetic diagnosis and counseling of families with thrombosis but also suggests that the site p.R541 of F2 may play a crucial role in thrombosis.

An exceptional case of severe combined inherited thrombophilia successfully treated with rivaroxaban

: We herein report the case of a young patient who presented with premature thromboembolic venous disease secondary to combined heterozygous G20210A prothrombin mutation, dual homozygosity for Factor V Leiden, and severe protein S deficiency. This association has never been reported to date and is likely to be exceptional, even in populations wherein these thrombophilia traits are more common. Long-term antithrombotic prophylaxis with rivaroxaban has proven successful in preventing clinical recurrence under prolonged treatment.

Successful treatment with rivaroxaban of an extended deep vein thrombosis complicated by pulmonary embolism in a patient with familial antithrombin III deficiency: a case report

BACKGROUND

Patients with low levels of antithrombin III (AT III) are at an increased risk of developing arteriovenous thromboembolic disease.

CASE SUMMARY

We report a case of a 28-year-old woman who presented with a 1-week history of spontaneous right calf pain and swelling. A heterozygous AT III deficiency, phenotypically expressed as deep vein thrombosis, was reported in the patient's mother and sister. Blood workup revealed residual AT III activity at 58% with normal protein C and protein S levels. Computed tomographic angiography (CTA) revealed subsegmental bilateral pulmonary embolism (PE) and deep vein thrombosis in the right leg extending into the inferior vena cava up to the confluence of the left renal vein. Placement of an inferior vena cava filter was not considered. Given the patient's haemodynamic stability, anticoagulant therapy with 15 mg of rivaroxaban twice a day was initiated instead. Echocardiography after 10 days of treatment revealed complete resolution of the thrombus located in the inferior vena cava, while CTA revealed complete resolution of the PE.

DISCUSSION

Patients with AT III deficiency are likely to be heparin-resistant and will require higher heparin doses or the administration of AT III replacement therapy for the treatment of thrombosis, both of which are associated with an increased risk for haemorrhagic complications. Direct factor Xa inhibition by rivaroxaban provided an alternative mechanism for anticoagulation, which was found to be particularly useful in this patient with familial AT III deficiency, deep vein thrombosis, and PE.

Ischemic Stroke with Protein S Deficiency Treated by Apixaban

A 57-year-old man with atherosclerosis obliterans was admitted with sudden-onset sensory aphasia and right hemiparesis. Brain MRI revealed acute cerebral infarctions in the left temporal lobe and magnetic resonance angiography showed occlusion of the posterior branch of the left middle cerebral artery. Transesophageal echocardiography and ultrasonography respectively confirmed a patent foramen ovale and deep vein thrombosis in the bilateral femoral veins. Blood findings showed low protein S antigen, low protein S activity, and a missense mutation of the PROS 1 gene. The administration of apixaban 10 mg BID prevented ischemic stroke recurrence and decreased the deep vein thrombosis. These outcomes indicated that apixaban may be alternative to warfarin for the secondary prevention of ischemic stroke in a patient with a protein S deficiency.

Comparison of Two Different Techniques Of Warfarin Dosing Determination - A Chemometrics Study

A high prevalence of genetic polymorphisms increases sensitivity to warfarin therapy. In this study, we investigated 47 patients with effective long-term therapy by warfarin well-controlled by monitoring of International Normalised Ratio (INR). All patients were tested for gene polymorphisms VKORC1, CYP2C9*C2, and CYP2C9*C3, which were used for a dose calculation employing a program www.WarfarinDosing.org. The main goal was to investigate whether the warfarin doses determined by INR are in accordance with the doses calculated according to the pharmacogenetic algorithm. For this purpose, several chemometric tools, namely principal component analysis, cluster analysis, correlation analysis, correspondence analysis, Passing-Bablock regression, Bland-Altman method, descriptive statistics, and ANOVA were used. We also analysed the relationship between the dose of warfarin determined by INR and several constitutional and genetic factors. Statistically significant association between clinically optimized warfarin dose and indication for the treatment, age, and warfarin sensitivity determined by VKORC1, CYP2C9 gene polymorphisms were confirmed. Finally, we confirmed a good concordance between the INR determined warfarin doses and pharmacogenetic approach.

Antithrombotic Therapy to Prevent Recurrent Strokes in Ischemic Cerebrovascular Disease: JACC Scientific Expert Panel

Stroke survivors carry a high risk of recurrence. Antithrombotic medications are paramount for secondary prevention and thus crucial to reduce the overall stroke burden. Appropriate antithrombotic agent selection should be based on the best understanding of the physiopathological mechanism that led to the initial ischemic injury. Antiplatelet therapy is preferred for lesions characterized by atherosclerosis and endothelial injury, whereas anticoagulant agents are favored for cardiogenic embolism and highly thrombophilic conditions. Large randomized controlled trials have provided new data to support recommendations for the evidence-based use of antiplatelet agents and anticoagulant agents after stroke. In this review, the authors cover recent trials that have altered clinical practice, cite systematic reviews and meta-analyses, review evidence-based recommendations based on older landmark trials, and indicate where there are still evidence-gaps and new trials being conducted.

The Role of Novel Oral Anticoagulants and Antiplatelet Therapy after Percutaneous Coronary Intervention: Individualizing Therapy to Optimize Outcomes

The number of patients undergoing percutaneous coronary intervention (PCI) who mandate additional oral anticoagulant therapy has been increasing. Dual antiplatelet therapy (DAPT) is associated with reduced ischemic events including stent thrombosis, myocardial infarction and stroke following PCI. However, the tradeoff is an increased risk for bleeding while on DAPT. The addition of a novel oral anticoagulant (NOAC) further increases the likelihood of bleeding while on antiplatelet therapy. Thus, the overall risks and benefits for each patient undergoing PCI on NOAC must be assessed and therapy individualized to ensure optimal therapy for each unique situation. Patients on NOAC undergoing PCI should undergo routine assessment with intravascular imaging as the role of high-risk lesion-related features have increased importance prior to determining optimal duration of treatment with DAPT. We review the best practices for the pharmacologic management of patients requiring anticoagulation with NOAC who are treated with PCI and require antiplatelet therapy.

Acute pulmonary thromboembolism caused by factor V Leiden mutation in South Korea: A case report

RATIONALE

Although Factor V Leiden (FVL) mutation is a major cause of inherited thrombophilia in Western populations; the mutation is extremely rare in Asia.

PATIENT CONCERNS

Here we report a case of a 28-year old Korean woman admitted to our hospital with extensive pulmonary embolism.

DIAGNOSIS

She was heterozygous for FVL mutation up on evaluation, and screening for asymptomatic family members also revealed heterozygous FVL mutation for her mother.

INTERVENTIONS

Enoxaparin 1 mg/kg was initiated, followed by rivaroxaban 15 mg every 12 hours.

OUTCOMES

The patient showed improvement in both subjective dyspnea and right ventricular dysfunction and was successfully discharged after five hospital days.

LESSONS

FVL mutation screening may be considered in Asian patients with thrombophilia of uncertain etiology in the future.

Management of severe congenital protein C deficiency with a direct oral anticoagulant, edoxaban: A case report

A male patient diagnosed with severe congenital protein C (PC) deficiency during the neonatal period was treated with long-term warfarin but frequently developed purpura fulminans and bleeding. At four years of age, edoxaban was initiated (direct oral anticoagulant [DOAC]). His d-dimer and fibrin/fibrinogen degradation product levels were closely monitored. His PC activity increased from below the sensitivity range to 17%; this increase was thought to be due to a reduction in PC consumption during edoxaban therapy. After edoxaban introduction, he experienced just one episode of purpura fulminans over two years without any adverse events. Thus, DOAC may be a promising alternative for the management of congenital PC deficiency.

Management of antithrombin deficiency: an update for clinicians

Introduction. Antithrombin is a serpin that inhibits multiple procoagulant serine proteases and acts as an endogenous anticoagulant. Thus, congenital antithrombin deficiency constitutes a major thrombophilic state, the most severe so far. Areas covered. In the present work, we globally review the biology, genetics, diagnosis, and management of congenital antithrombin deficiency, and also discuss puzzling questions and future perspectives regarding this severe inherited thrombophilia. Expert opinion. Although this disorder exerts high clinical heterogeneity, many carriers will need careful and long-term anticoagulation and/or thromboprophylaxis, especially in high-risk situations, such as surgery and pregnancy. Notably, antithrombin concentrates constitute a considerable arsenal for both treatment and prevention of acute venous thrombosis in subjects with antithrombin deficiency. Current evidences are based almost exclusively on retrospective case series, so an integrated functional, biochemical and molecular characterization will be of clinical relevance and guide hematologists' personalized decisions.

Direct oral anticoagulants in patients with venous thromboembolism and thrombophilia: a systematic review and meta-analysis

Essentials We investigated direct oral anticoagulant (DOAC) use in venous thromboembolism and thrombophilia. A comprehensive search identified 10 studies, 8 of which were included in a meta-analysis. DOACs were overall safe and effective in patients with venous thromboembolism and thrombophilia. Efficacy/safety of DOACs was maintained in low-risk antiphospholipid syndrome patient subgroup. SUMMARY: Background Direct oral anticoagulants (DOACs) are increasingly used in acute and long-term treatment of venous thromboembolism (VTE). However, their role in management of thrombophilia-associated VTE is controversial. Methods Through a comprehensive search on MEDLINE, Cochrane Library, and Clinicaltrials.gov, we identified 10 eligible studies, 8 of which reporting data on 1994 thrombophilia patients were included in a random-effects meta-analysis. Eligible studies were phase 2 to 3 randomized controlled trials comparing DOACs to vitamin K antagonists (VKAs) in patients with VTE, including those with thrombophilia. Results Of eight studies included in meta-analysis, four evaluated rivaroxaban, three dabigatran, and one edoxaban. No results could be obtained on apixaban use. The rates of VTE recurrence (RR, 0.70; 95% CI, 0.34-1.44; I2  = 0%) and major/clinically relevant non-major bleeding events (RR, 0.92; 95% CI, 0.62-1.36; I2  = 23%) were similar between thrombophilia patients treated with DOACs compared to VKAs. Results were comparable to findings in patients without known thrombophilia: RR, 1.02; 95% CI, 0.80-1.30; I2  = 46% for VTE recurrence and RR, 0.72; 95% CI, 0.57-0.90; I2  = 84% for major/clinically relevant non-major bleeding events. Conclusions Rates of VTE recurrence and bleeding events were both low and comparable in patients with various thrombophilias receiving either treatment, suggesting that DOACs are an appropriate treatment option in this population. Due to limited data, it is unclear whether these findings apply to specific subgroups such as high-risk antiphospholipid syndrome, uncommon thrombophilias, or the use of apixaban.

Efficacy and safety of apixaban in a patient with systemic venous thromboembolism associated with hereditary antithrombin deficiency

A 40-year-old man with progressively worsening dyspnea was admitted to our hospital. On physical examination, pulse oximetry results demonstrated 80% oxygen saturation in room air. The lungs sounded clear, and both extremities appeared normal, without pitting edema. His echocardiography revealed a pressure overload in the right ventricle. Suspecting the presence of pulmonary thromboembolism, we performed an enhanced computed tomography (CT). CT results revealed systemic venous thromboembolism (VTE) involving the superior mesenteric vein, inferior vena cava (IVC), right common iliac vein and pulmonary arteries, as well as splenomegaly and edema of the small intestine with ascites. After insertion of a retrievable IVC filter, we prescribed 10 mg of apixaban twice daily for the first 7 days, followed by 5 mg twice daily as long-term therapy. Confirming no exacerbation of the VTE symptoms, we removed the IVC filter 14 days after admission. Additionally, hereditary antithrombin deficiency was unraveled as the etiology of systemic VTE. Although an enhanced CT at 6 months follow-up showed that almost all previous VTE had dissolved, we decided to prescribe apixaban indefinitely. Fortunately, he has not experienced a recurrence of VTE or any bleeding events to date. <Learning objective: Hereditary antithrombin (AT) deficiency is a thrombophilia, which has a high potential to develop venous thromboembolism (VTE). Direct oral anticoagulant (DOAC) therapy can substitute for conventional therapy, including parenteral anticoagulant plus warfarin. However, the efficacy and safety of DOAC treatments for patients with hereditary AT deficiency with systemic VTE have not yet been clarified. This report highlights the efficacy of a single apixaban prescription in achieving excellent outcomes in resolving systemic VTE with no bleeding events.>.

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

Evaluation for underlying hypercoagulable states in patients with thrombosis is a frequent clinical conundrum. Testing for thrombophilias is often reflexively performed without strategic approach nor clear appreciation of the clinical implications of such results. Guidelines vary in the appropriate utilization of thrombophilia testing. In this review, we discuss the more commonly encountered inherited and acquired thrombophilias, their association with initial and recurrent venous thromboembolism, arterial thromboembolism, and role in women's health. We suggest an approach to thrombophilia testing guided by the clinical presentation, suspected pathophysiology, and an understanding of how such results may affect patient care.

Recurrent esophagogastric variceal bleeding due to portal vein thrombosis caused by protein S deficiency

Background and study aims  Esophagogastric variceal bleeding (EGVB) is common in patients with portal vein thrombosis (PVT). Hereditary deficiencies in natural anticoagulant proteins, such as protein S, might contribute to PVT. However, recurrent EGVB caused by PVT in patients with protein S deficiency is seldom reported. Herein, we present the case of a 38-year-old man with protein S deficiency complicated with PVT. The patient suffered recurrent EGVB for 7 years. He underwent splenectomy plus pericardial revascularization and sequential endoscopic therapy, including one gastric variceal obturation (GVO) procedure and two esophageal variceal ligations (EVL) to eradicate the varices. Rivaroxaban was administrated to reduce risk of thrombotic events. The patient is currently well without rebleeding after 1 year of follow-up. To our knowledge there is no consensus on management of recurrent EGVB on the basis of thrombophilia complicated with PVT. According to our practice, sequential endoscopic therapy combined with anticoagulant appears to be effective and safe.

Efficacy of Oral Factor Xa Inhibitor for Venous Thromboembolism in a Patient with Antithrombin Deficiency

A 19-year-old man was referred due to sudden onset of right foot pain and chest discomfort. Contrast-enhanced computed tomography revealed massive thrombi in the right pulmonary artery and femoral vein. The patient's father had experienced multiple recurrences of venous thromboembolism (VTE) and was diagnosed with inherited antithrombin deficiency by a genetic examination. The patient was administered the oral factor Xa inhibitor rivaroxaban (30 mg). After seven days, the thrombus disappeared. Rivaroxaban (15 mg) was continued for 6 months with no recurrence, indicating the efficacy of this factor Xa inhibitor for the treatment and prevention of VTE in patients with antithrombin deficiency.

Preventative management against thromboembolism using fresh frozen plasma in a coronary artery bypass graft patient with protein S deficiency: a case report

Protein S deficiency patient is characterized by recurrent thrombosis, and its risk is higher intraoperatively, especially in cardiac surgery involving cardiopulmonary bypass. Two heparin cessation periods are defined in cardiac surgery. One is the period between the cessation of heparin 4 to 5 h before surgery and the heparinization prior to cardiopulmonary bypass. The other is the period between protamine administration and resumption of heparin postoperatively. Because the risk of thromboembolism is high during the period of heparin cessation, other anticoagulants are necessary. Although fresh frozen plasma, rich in protein S, is often used in cardiac surgery for protein S deficiency patients, the most appropriate times and volume of its administration to prevent thromboembolism remain poorly understood. We herein report a case of on-pump coronary artery bypass grafting in a patient with protein S deficiency who received fresh frozen plasma targeting the two heparin cessation periods. Some qualitative measurements to identify the effect of fresh frozen plasma on the protein S level are desirable to evaluate whether our present administration strategy has any beneficial effects on protein S deficiency patients.

Rivaroxaban Treatment for Warfarin-Refractory Thrombosis in a Patient with Hereditary Protein S Deficiency

Protein S (PS) deficiency, an autosomal dominant hereditary thrombophilia, is more prevalent in East Asian populations than in Caucasians. PS-deficient patients have historically been administered a heparin product followed by warfarin for the treatment and secondary prevention of venous thromboembolism (VTE). However, warfarin can be ineffective or causes detrimental effects in rare cases. While direct oral anticoagulants (DOACs) are being increasingly used for the treatment and prevention of VTE, their efficacy in PS-deficient patients has not been established. We describe a 91-year-old woman who presented with chronic bilateral lower leg swelling with VTE that was refractory to warfarin anticoagulation therapy for over 1 year. Her recurrent VTE was diagnosed as quantitative hereditary PS deficiency. Rivaroxaban was administered as maintenance therapy instead of warfarin; after 8 weeks, the severities of the patient's leg swelling and venous ulcerations were significantly reduced with rivaroxaban compared to warfarin, thus demonstrating the efficacy of rivaroxaban for warfarin-refractory chronic VTE associated with hereditary PS deficiency. This case illustrates that rivaroxaban can potentially serve as therapeutic agents to treat warfarin-refractory VTE in PS-deficient patients. Further investigations are required to confirm the efficacy of rivaroxaban on the long term in this regard.

Acute Anorectal Thrombophlebitis Caused by a Protein C Deficiency

A 46-year-old man visited the emergency department of our hospital with a 3-day history of anal pain, hemorrhaging, and a slight fever. He had previously been diagnosed with protein C deficiency and was prescribed dabigatran, a direct oral anticoagulant. Contrast-enhanced computed tomography showed severe rectal wall thickening with partial defect of enhancement. In addition, sigmoidoscopy revealed a dusky purplish swollen anorectal mucosa just above the dentate line. He was diagnosed with acute anorectal thrombophlebitis, and anticoagulant therapy with heparin was initiated. To our knowledge, this is the first case report of acute anorectal thrombophlebitis caused by protein C deficiency.