Rivaroxaban Prophylaxis in Noncirrhotic Portal Vein Thrombosis

Safety of Anticoagulant Treatment in Patients With Splanchnic Vein Thrombosis and History of Portal Hypertension-Related Bleeding

Splanchnic vein thrombosis (SVT) can be associated with liver cirrhosis or prothrombotic conditions, including myeloproliferative disorders, intra-abdominal inflammation, solid cancers or surgery. While anticoagulation therapy improves outcomes in noncirrhotic patients and reduces all-cause mortality in cirrhotic populations, its safety in patients with a history of portal hypertension (PH)-related bleeding is less clear. This systematic review examines the impact of anticoagulant therapy on rebleeding risk in SVT patients with a history of PH-related bleeding. A systematic review and meta-analysis were conducted according to PRISMA guidelines. A comprehensive search of PubMed, Web of Science and Scopus was performed for studies published up to September 2024. Studies were included if they compared SVT patients with a history of PH-related bleeding receiving anticoagulant therapy versus those not receiving anticoagulants. The primary outcome was the cumulative incidence of PH-related rebleedings. Of 2853 identified studies, five (186 participants) met the inclusion criteria: two randomised controlled trials (RCTs) and three observational studies. The cumulative incidence of PH-related rebleeding was significantly lower in the anticoagulant group at 17.10% [95% CI 17.02, 17.19] compared to the control group at 40.00% [95% CI 39.90, 40.09]. The overall odds ratio (OR) from observational studies was 0.15 [95% CI 0.04, 0.52], indicating a reduced bleeding risk, while the OR from RCTs was 0.84 [95% CI 0.31, 2.32], showing a nonsignificant trend. Anticoagulant therapy may reduce rebleeding risk in SVT patients with a history of PH-related bleeding, but further high-quality studies are needed.

Contemporary management of portal vein thromboses in patients with and without cirrhosis

PURPOSE OF REVIEW

Portal vein thromboses (PVT) is a common clotting disorder that can be seen in patients with and without cirrhosis. There are no current clinical guidelines on management of portal vein thromboses in these two distinct populations given most studies are retrospective and comprised of heterogenous cohorts.

RECENT FINDINGS

When evaluating PVT, patients must first be stratified into those with cirrhosis and those without cirrhosis. In addition, a novel nomenclature can help categorize specific PVT types and determine the need and response to anticoagulation. The management of PVT in patients with cirrhosis varies and is primarily dependent on whether the PVT is recent or chronic. In contrast, patients without cirrhosis are almost always anticoagulated to avoid complications of PVT. Direct oral anticoagulants, low-molecular weight heparin, and vitamin-K antagonists have all been used in patients with and without cirrhosis, without clear guidance on optimal treatment duration and surveillance.

SUMMARY

Direct oral anticoagulants are increasingly used for patients with PVT though there is limited data on the safety and efficacy of these medications. The risk/benefit profiles of various anticoagulants must be considered when choosing a therapeutic anticoagulant. There are ongoing studies evaluating outcome measures of different anticoagulants in patients with PVT. Large, multicenter, randomized controlled trials may help elucidate the efficacy of anticoagulants on various outcome measures in PVT, including recanalization, bleeding, and survival.

How I approach the treatment of thrombotic complications in patients with myeloproliferative neoplasms

ABSTRACT

Arterial and venous thromboses are the most significant complications in patients with myeloproliferative neoplasms (MPNs), with the primary treatment goal being thrombotic risk reduction. In MPN with no history of thrombosis, primary prevention mainly involves the use of aspirin, and cytoreduction is added in high-risk patients. However, thrombotic complications can unveil an MPN in ∼20% of cases, necessitating the initiation of both antithrombotic therapy for the thrombosis and cytoreductive treatment for the MPN. The duration of anticoagulant therapy after an initial venous thromboembolic event is subject to discussion. Furthermore, the occurrence of a thrombotic complication in patients with a known diagnosis of MPN prompts a reconsideration of both antithrombotic and hematologic management. This review uses case-based discussions to explore the management of thrombotic complications in patients with MPN. It addresses the nature and duration of antithrombotic treatments, as well as the approach to cytoreduction. Special attention is given to the place of direct oral anticoagulants and to the management of patients with MPN with splanchnic vein thrombosis, which is disproportionately common in this group.

Portal Vein Thrombosis in Patients Without Cirrhosis: Current Practical Approaches and Treatment Strategies

Portal vein thrombosis in non-cirrhotic individuals, although uncommon, is an increasingly explored condition that affects mainly young people, consequently representing a significant disease burden. Reports primarily including western European populations have recently shed light regarding the pathophysiology, risk factors, natural history, treatment, and prognosis of this entity. Underlying predisposing conditions are documented in ~70% of cases, encompassing local risk factors, inherited and acquired thrombophilia, cancer, and systemic inflammatory conditions. Non-cirrhotic portal vein thrombosis can cause significant portal hypertension in the acute setting, but, more frequently, significant portal hypertension-related complications arise when the condition becomes chronic and portosystemic collaterals develop, increasing the risk for variceal bleeding and ascites. The diagnostic approach to screen for underlying thrombophilia remains a challenge, and recommendations in this regard, although scarce and backed by scarce evidence, have changed notably in the last years, leaning toward a universal screen in patients who develop this condition without a clear provoking factor. Recently, studies have shown that long-term anticoagulation may be appropriate even in the absence of clear provoking factors or underlying thrombophilia. Future studies should address which patients may benefit from this approach, which patients may not need it, and what the most appropriate strategies are to approach patients who do not recover portal vein patency with anticoagulation to further prevent portal hypertension-related complications.

Direct Oral Anticoagulants for the Treatment of Unusual-Site Venous Thrombosis: An Update

Direct oral anticoagulants (DOACs) have emerged as the preferred oral anticoagulant therapy for patients with deep vein thrombosis of the lower extremities and pulmonary embolism. DOACs offer several advantages over vitamin K antagonists, including fixed dosage, fewer drug interactions, faster onset of action, and a lower risk of major bleeding, especially intracranial. Although evidence on the use of DOACs in unusual-site venous thrombosis (USVT) is limited, their use in such cases is becoming increasingly common. This narrative review examines the evidence derived from randomized controlled trials, and large observational studies focused on the use of the DOACs in USVT, including cerebral, splanchnic, upper extremity, ovarian, renal, and retinal vein thrombosis. In addition, it also provides practical advice for their use in these clinical settings according to the updated scientific literature.

The management of splanchnic vein thrombosis in acute pancreatitis: a global DELPHI consensus study

BACKGROUND

Splanchnic vein thrombosis (SpVT) occurs in 17%-23 % of acute pancreatitis cases. Serious sequelae include hepatic and bowel ischaemia. However, management with therapeutic anticoagulation remains controversial due to potential bleeding risk. We aim to determine the level of consensus on prognosis, diagnosis, management, and outcomes of SpVT through a DELPHI process.

METHODS

Using purposive, non-probability sampling and DELPHI methodology, 173 clinicians with experience of SpVT in acute pancreatitis were approached. From April 2022 to April 2023, a three-round DELPHI process was implemented to completion. A total of 88 statements were posed for ranking via a four-point Likert scale.

RESULTS

The mean acute pancreatitis caseload per respondent per year was 68·0, 72·6 and 73·0 for DELPHI rounds 1,2 and 3 respectively. For SpVT anatomical location, there was strong consensus favouring anticoagulation for portal vein (89·1 %) and SMV thrombosis (90·9 %), and no consensus to treat splenic vein thrombosis (47·3 %). 74·1 % rejected radiological resolution as a definitive anticoagulation endpoint. Majority consensus favoured death, bleeding risk, bowel or liver ischaemia, hospital admission length and ITU admission as significant outcomes for experimental research design.

CONCLUSION

There was significant consensus for anticoagulation treatment of SpVT of the portal and superior mesenteric veins, especially with complete occlusion by thrombosis. Randomised controlled trials are required to grade management recommendations.

Experience With Dabigatran on Rate of Portal Vein Thrombosis Recanalization, Disease Progression and Survival

BACKGROUND AND AIMS

We assessed clinical, procoagulant and genetic risk factors and clinical outcomes in dabigatran-treated patients with non-tumoural acute and acute-on-chronic portal vein thrombosis (PVT).

METHODS

Patients with a new diagnosis of non-tumoural acute and acute-on-chronic PVT between January 2021 and January 2024 (aged ≥ 18 years) in those without/with cirrhosis (Child-Pugh (CP)-A/B/C ≤ 10) were started on dabigatran and followed and compared with those on vitamin K antagonist (VKA) and untreated individuals.

RESULTS

Dabigatran was prescribed in 119 patients with PVT type 1 (61, 51.3%), type 2 (34, 28.6%), type 3 (24, 20.2%); 72 (60.5%) with cirrhosis [CP-A (27, 37.5%), CP-B (43, 59.7%) and CP-C10 (2, 2.8%)]. Procoagulant factors noted were JAK2V617F (10.1%), CALR (2.5%) and factor V Leiden (1.6%) mutations, antiphospholipid syndrome (APS, 15.2%), isolated Protein C (14.3%) and Protein S (16.8%) deficiency.

COMPARATORS

28 patients who declined anticoagulation/were unable to come for follow-up, and six with CP-C received VKA. Overall recanalization rate (RR) on dabigatran was 56 (47.1%); 25 (21%) complete recanalization, 31 (26%) partial recanalization and 63 (52.9%) stable PVT over median follow-up of 32 months. Patients not anticoagulated had a spontaneous RR in 21.4% (28 patients; p = 0.005 compared with dabigatran group) and none recanalized on VKA. On multivariable analysis, predictors of recanalization on dabigatran were Factor VIII Antigen level (FVIII:Ag, HR 0.6; 95% CI 0.3-0.9, p = 0.032), non-occlusive PVT (HR 3.5, 95% CI 1.9-5.6, p = 0.025) and acute PVT (HR 2.1; 95% CI 1.5-3.2, p = 0.003). Mortality was 14 (11.8%).

CONCLUSION

On dabigatran, 47% of 119 patients achieved portal vein recanalization over 32 months of follow-up which was higher than the spontaneous RR (21.4%) in an untreated cohort. High Factor VIII:Ag was a predictor of non-recanalization. Dabigatran was safe in cirrhosis (CP-A and B) while further work is needed in CP-C.

Clinical spectrum and long-term outcomes of non-cirrhotic portal venous system thrombosis in Hispanic population

INTRODUCTION AND OBJECTIVES

Portal venous system thrombosis (PVT) outside the setting of cirrhosis is uncommon with limited information available about the etiological and clinical characteristics across varied racial and ethnic groups.

MATERIALS AND METHODS

This retrospective cohort study examines the long-term outcomes of non-cirrhotic, Hispanic adults diagnosed with PVT at a single center in Mexico City between January 2000 and August 2023. Patients with conditions predisposing to PVT were excluded.

RESULTS

We included 100 Hispanic adults diagnosed with non-cirrhotic PVT. Thrombophilia was identified in 49 %, with antiphospholipid syndrome (APS) being the most prevalent thrombophilia (23 %), followed by JAK2 mutation (18 %). Chronic PVT, observed in 70 % of cases, predominantly affected the portal vein (50 %), followed by porto-mesenteric (41 %) and porto-splenic (9 %) territories. At diagnosis, 55 % had esophageal varices. Anticoagulant therapy was administered to over half of the patients for >12 months. Over a median follow-up of 55 months, the 5-year risk of re-thrombosis was 24 %, and the 5-year risk of variceal bleeding (VB) was 45 %. The 4-year overall survival (OS) was 97 %. Comparative analysis between thrombophilia-associated and idiopathic PVT did not reveal significant differences in VB, re-thrombosis, and OS.

CONCLUSIONS

This study underscores the unique clinical profile of Hispanic patients with non-cirrhotic PVT, highlighting a high prevalence of APS and substantial risks of VB. These findings contribute to a better understanding of PVT in Hispanics and emphasize the importance of tailored management strategies. The generalizability of our results may be limited by the thrombophilia testing approach, the excluded populations, and its retrospective, single center nature.

Splanchnic vein thrombosis: management for the thrombosis specialist

Splanchnic vein thrombosis (SpVT) is an uncommon site of venous thrombosis that is associated with complications including portal hypertension and hepatic dysfunction. The evaluation and management of this patient population has evolved in recent years, but there are limited data from clinical trials to guide management. Given the various acquired and biologic risk factors leading to the development of SpVT and the potential complications that can arise from it, input from a multidisciplinary team can be valuable in managing such patients, including thrombosis specialists or hematologists, gastroenterologists or hepatologists, interventional radiologists, and surgeons. In this article, we present 4 cases that highlight important issues and considerations in the evaluation of SpVT, including initial diagnostic approach in a patient with a new diagnosis of SpVT, considerations for anticoagulant therapy, management of SpVT in patients with myeloproliferative neoplasms, and the role of interventional vascular procedures in the management of SpVT. By reviewing the current literature, we address clinically relevant questions that are posed to clinicians managing patients with SpVT; we also point out gaps in our current knowledge that merit future investigation.

Abdominal surgery in patients with chronic noncirrhotic extrahepatic portal vein obstruction: A multicenter retrospective study

BACKGROUND AND AIMS

In patients with noncirrhotic chronic extrahepatic portal vein obstruction (EHPVO), data on the morbimortality of abdominal surgery are scarce.

APPROACH AND RESULTS

We retrospectively analyzed the charts of 76 patients (78 interventions) with EHPVO undergoing abdominal surgery within the Vascular Disease Interest Group network. Fourteen percent of the patients had ≥1 major bleeding (unrelated to portal hypertension) and 21% had ≥1 Dindo-Clavien grade ≥3 postoperative complications within 1 month after surgery. Fifteen percent had ≥1 portal hypertension-related complication within 3 months after surgery. Three patients died within 12 months after surgery. An unfavorable outcome (ie, ≥1 abovementioned complication or death) occurred in 37% of the patients and was associated with a history of ascites and with nonwall, noncholecystectomy surgical intervention: 17% of the patients with none of these features had an unfavorable outcome, versus 48% and 100% when one or both features were present, respectively. We then compared 63/76 patients with EHPVO with 126 matched (2:1) control patients without EHPVO but with similar surgical interventions. As compared with control patients, the incidence of major bleeding ( p <0.001) and portal hypertension-related complication ( p <0.001) was significantly higher in patients with EHPVO, but not that of grade ≥3 postoperative complications nor of death. The incidence of unfavorable postoperative outcomes was significantly higher in patients with EHPVO than in those without (33% vs. 18%, p =0.01).

CONCLUSIONS

Patients with EHPVO are at high risk of major perioperative or postoperative bleeding and postoperative complications, especially in those with ascites or undergoing surgery other than wall surgery or cholecystectomy.

Anticoagulation for splanchnic vein thrombosis in myeloproliferative neoplasms: a systematic review and meta-analysis

BACKGROUND

Optimal anticoagulation management in patients with myeloproliferative neoplasms (MPN) experiencing splanchnic vein thrombosis (SpVT) requires balancing risks of bleeding and recurrent thrombosis.

OBJECTIVES

We conducted a systematic review and meta-analysis to assess the incidence of bleeding and thrombosis recurrence in patients with MPN-SpVT.

METHODS

We included retrospective or prospective studies in English with ≥10 adult patients with MPN-SpVT. Outcomes included recurrent venous thrombosis (SpVT and non-SpVT), arterial thrombosis, and major bleeding. Pooled rates per 100 patient years with 95% CIs were calculated by DerSimonian-Laird method using random-effects model.

RESULTS

Out of 4624 studies screened, 9 studies with a total of 443 patients were included in the meta-analysis with median follow-up of 3.5 years. In the 364 patients with MPN-SpVT treated with anticoagulation, pooled event rate for major bleeding was 2.8 (95% CI, 1.5-5.1; I2 = 95%), for recurrent venous thrombosis was 1.4 (95% CI, 0.8-2.2; I2 = 72%), and for arterial thrombosis was 1.4 (95% CI, 0.6-3.3; I2 = 92%) per 100 patient years. Among 79 patients (n = 4 studies) who did not receive anticoagulation, pooled event rate for major bleeding was 3.2 (95% CI, 0.7-12.7; I2 = 97%), for recurrent venous thrombosis 3.5 (95% CI, 1.8-6.4; I2 = 88%), and for arterial thrombosis rate 1.6 (95% CI, 0.4-6.6; I2 = 95%) per 100 patient years.

CONCLUSION

Patients with MPN-SpVT treated with anticoagulation have significant risks for both major bleeding and thrombosis recurrence. Further studies are necessary to determine the optimal anticoagulation approach in patients with MPN-SpVT.

Direct Oral Anticoagulants: Quick Primer on When to Use and When to Avoid

Direct oral anticoagulants (DOACs) have transformed the landscape of antithrombotic therapy in the past two decades. However, there is uncertainty about when they should or should not be used for treatment or prevention of thromboembolic events. DOACs have largely replaced warfarin for many patients with atrial fibrillation or venous thromboembolism who require anticoagulant therapy. In addition to noninferior efficacy, fewer drug-drug and food-drug interactions and improved convenience; DOACs have been shown to reduce the risk of intracranial hemorrhage. They have also received new indications compared with warfarin, such as cardiovascular risk reduction in patients with stable atherosclerotic diseases. However, there are some scenarios in which DOACs are associated with inferior efficacy or worse safety compared with standard treatment, such as warfarin. These include patients with mechanical heart valves, thrombotic antiphospholipid syndrome, and others. Although DOACs offer a streamlined and convenient option for the management of many patients with or at risk of thromboembolic events, their use should be avoided in certain high-risk scenarios. This minireview summarizes such conditions and those in which there is uncertainty for use of DOACs for particular diseases or particular patient subgroups.

Recurrent splanchnic and extrasplanchnic thrombotic events in patients with non-cirrhotic portal vein thrombosis associated with local factors

BACKGROUND & AIMS

One-third of non-cirrhotic portal vein thrombosis (NCPVT) cases are associated with local factors. The risk of rethrombosis after anticoagulation withdrawal is unknown. We aimed to determine factors associated with new splanchnic or extrasplanchnic thrombotic events in this setting.

METHODS

We performed a retrospective study including cases of recent NCPVT associated with local factors. High- and low-risk prothrombotic factors, prespecified according to RIPORT study criteria, were assessed. Univariate and multivariate Cox models assessed the influence of different variables on the occurrence of new thrombotic events.

RESULTS

At baseline, 83/154 (53.9%) patients had at least one prothrombotic factor including 50 (32.5%) with a high-risk and 33 (21.4%) with a low-risk prothrombotic factor. Oestrogen-containing contraception was discontinued in all patients. During follow-up, 63/140 (45%) patients had at least one prothrombotic factor, including 47 (33.6%) with a high-risk and 16 (11.4%) with a low-risk prothrombotic factor. Seventeen new thrombotic events occurred after a median follow-up of 52 (IQR 14-62) (min-max 3.0-69.0) months. New thromboses were associated with high-risk factors (hazard ratio [HR] 3.817, 95% CI 1.303-11.180, p = 0.015), but were inversely related to recanalization (HR 0.222, 95% CI 0.078-0.635, p = 0.005) and anticoagulation (HR 0.976, 95% CI 0.956-0.995, p = 0.016). When a high-risk factor was present a new thrombotic event occurred in 7.4%, 14.6%, 14.6% and 28.8% of patients at 1, 3, 5 and 7 years under anticoagulants, respectively, compared to 21.2%, 21.2%, 58% and 58% without anticoagulants, respectively.

CONCLUSIONS

In cases of recent NCPVT associated with local factors, high-risk factors for thrombosis are associated with new thrombotic events. Permanent anticoagulation appears beneficial in this high-risk situation.

IMPACT AND IMPLICATIONS

In non-cirrhotic portal vein thrombosis (NCPVT) associated with local factors, systematic screening for prothrombotic factors is recommended, but the prevalence of the latter is not clearly established, and the risk of recurrent intra or extrasplanchnic thromboembolism is poorly described. Thus, interest in permanent anticoagulation remains. NCPVT associated with local factors is a matter of concern for hepatologists, gastroenterologists and digestive surgeons. Due to a lack of knowledge, practices are heterogeneous. Our findings highlight that systematic screening for prothrombotic factors in NCPVT is needed even when associated with local factors, as it may justify long-term anticoagulation for the prevention of new intra or extrasplanchnic thrombotic events in at least one-third of cases. The interest in long-term anticoagulation should be investigated prospectively in the absence of high-risk prothrombotic factors.

CLINICAL TRIAL NUMBER

NCT0536064.

Portal vein thrombosis: diagnosis, management, and endpoints for future clinical studies

Portal vein thrombosis (PVT) refers to the development of a non-malignant obstruction of the portal vein, its branches, its radicles, or a combination. This Review first provides a comprehensive overview of all aspects of PVT, namely the specifics of the portal venous system, the risk factors for PVT, the pathophysiology of portal hypertension in PVT, the interest in non-invasive tests, as well as therapeutic approaches including the effect of treating risk factors for PVT or cause of cirrhosis, anticoagulation, portal vein recanalisation by interventional radiology, and prevention and management of variceal bleeding in patients with PVT. Specific issues are also addressed including portal cholangiopathy, mesenteric ischaemia and intestinal necrosis, quality of life, fertility, contraception and pregnancy, and PVT in children. This Review will then present endpoints for future clinical studies in PVT, both in patients with and without cirrhosis, agreed by a large panel of experts through a Delphi consensus process. These endpoints include classification of portal vein thrombus extension, classification of PVT evolution, timing of assessment of PVT, and global endpoints for studies on PVT including clinical outcomes. These endpoints will help homogenise studies on PVT and thus facilitate reporting, comparison between studies, and validation of future studies and trials on PVT.

[Coagulation disorders in liver cirrhosis - Diagnostics and management]

Patients with liver cirrhosis often exhibit complex alterations in their hemostatic system that can be associated with both bleeding and thrombotic complications. While prophylactic correction of abnormal coagulation parameters should be avoided, an individualized approach is recommended prior to invasive procedures, whereby specific preventive measures to stabilize hemostasis should be based on the periprocedural bleeding risk. While the haemostatic system of patients with compensated cirrhosis is often in a rebalanced haemostatic state due to a parallel decline in both pro- and anti-haemostatic factors, a decompensation of liver cirrhosis can lead to destabilization of this fragile equilibrium. Since conventional coagulation tests do not adequately capture the complex changes in the hemostatic system in cirrhosis, functional analysis methods such as viscoelastic tests or thrombin generation assays can be used for evaluating the coagulation status. This review describes the underlying pathophysiological changes in the hemostatic system in liver cirrhosis, provides an overview of diagnostic methods and discusses therapeutic measures in case of bleeding and thrombotic complications.

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).

Current concepts in the management of non-cirrhotic non-malignant portal vein thrombosis

Non-cirrhotic non-malignant portal vein thrombosis (NCPVT) is an uncommon condition characterised by thrombosis of the portal vein, with or without extension into other mesenteric veins, in the absence of cirrhosis or intra-abdominal malignancy. Complications can include intestinal infarction, variceal bleeding and portal biliopathy. In this article, we address current concepts in the management of NCPVT including identification of risk factors, classification and treatment, and review the latest evidence on medical and interventional management options.

Essential thrombocythemia: 2024 update on diagnosis, risk stratification, and management

OVERVIEW

Essential thrombocythemia is a Janus kinase 2 (JAK2) mutation-prevalent myeloproliferative neoplasm characterized by clonal thrombocytosis; clinical course is often indolent but might be interrupted by thrombotic or hemorrhagic complications, microcirculatory symptoms (e.g., headaches, lightheadedness, and acral paresthesias), and, less frequently, by disease transformation into myelofibrosis (MF) or acute myeloid leukemia.

DIAGNOSIS

In addition to thrombocytosis (platelets ≥450 × 109 /L), formal diagnosis requires the exclusion of other myeloid neoplasms, including prefibrotic MF, polycythemia vera, chronic myeloid leukemia, and myelodysplastic syndromes with ring sideroblasts and thrombocytosis. Bone marrow morphology typically shows increased number of mature-appearing megakaryocytes distributed in loose clusters.

GENETICS

Approximately 80% of patients express myeloproliferative neoplasm driver mutations (JAK2, CALR, MPL), in a mutually exclusive manner; in addition, about 50% harbor other mutations, the most frequent being TET2 (9%-11%), ASXL1 (7%-20%), DNMT3A (7%), and SF3B1 (5%). Abnormal karyotype is seen in <10% of patients and includes +9/20q-/13q-.

SURVIVAL AND PROGNOSIS

Life expectancy is less than that of the control population. Median survival is approximately 18 years but exceeds >35 years in younger patients. The triple A survival risk model, based on Age, Absolute neutrophil count, and Absolute lymphocyte count, effectively delineates high-, intermediate-1-, intermediate-2-, and low-risk disease with corresponding median survivals of 8, 14, 21, and 47 years.

RISK FACTORS FOR THROMBOSIS

Four risk categories are considered: very low (age ≤60 years, no thrombosis history, JAK2 wild-type), low (same as very low but JAK2 mutation present), intermediate (same as low but age >60 years), and high (thrombosis history or age >60 years with JAK2 mutation).

MUTATIONS AND PROGNOSIS

MPL and CALR-1 mutations have been associated with increased risk of MF transformation; spliceosome with inferior overall and MF-free survival; TP53 with leukemic transformation, and JAK2V617F with thrombosis. Leukemic transformation rate at 10 years is <1% but might be higher in JAK2-mutated patients with extreme thrombocytosis and those with abnormal karyotype.

TREATMENT

The main goal of therapy is to prevent thrombosis. In this regard, once-daily low-dose aspirin is advised for all patients and twice daily for low-risk disease. Cytoreductive therapy is advised for high-risk and optional for intermediate-risk disease. First-line cytoreductive drugs of choice are hydroxyurea and pegylated interferon-α and second-line busulfan.

ADDITIONAL CONTENT

The current review includes specific treatment strategies in the context of extreme thrombocytosis, pregnancy, splanchnic vein thrombosis, perioperative care, and post-essential thrombocythemia MF, as well as new investigational drugs.

When Direct Oral Anticoagulants Should Not Be Standard Treatment: JACC State-of-the-Art Review

For most patients, direct oral anticoagulants (DOACs) are preferred over vitamin K antagonists for stroke prevention in atrial fibrillation and for venous thromboembolism treatment. However, randomized controlled trials suggest that DOACs may not be as efficacious or as safe as the current standard of care in conditions such as mechanical heart valves, thrombotic antiphospholipid syndrome, and atrial fibrillation associated with rheumatic heart disease. DOACs do not provide a net benefit in conditions such as embolic stroke of undetermined source. Their efficacy is uncertain for conditions such as left ventricular thrombus, catheter-associated deep vein thrombosis, cerebral venous sinus thrombosis, and for patients with atrial fibrillation or venous thrombosis who have end-stage renal disease. This paper provides an evidence-based review of randomized controlled trials on DOACs, detailing when they have demonstrated efficacy and safety, when DOACs should not be the standard of care, where their safety and efficacy are uncertain, and areas requiring further research.

[Splanchnic vein thrombosis]

Splanchnic vein thrombosis includes Budd-Chiari syndrome and portal vein thrombosis. These diseases share common features: (i) they are rare diseases and (ii) they can lead to portal hypertension and its complications. Budd-Chiari syndrome and portal vein thrombosis in the absence of underlying liver disease share many risk factors, the most common being myeloproliferative neoplasms. A rapid and comprehensive workup for thrombosis risk factors is necessary in these patients. Long-term anticoagulation is indicated in most patients. Portal vein thrombosis can also develop in patients with cirrhosis, and is associated with a worse course of cirrhosis. Indications for anticoagulation in patients with cirrhosis are increasing. Transjugular intrahepatic portosystemic shunt is a second-line procedure in this setting. Because of the rarity of these diseases, high-level evidence studies are rare. However, collaborative studies have provided a better understanding of their natural history and allowed to improve the management of these patients. This review focuses on the causes, diagnosis, and management of patients with Budd-Chiari syndrome, patients with portal vein thrombosis without underlying liver disease, and patients with cirrhosis and portal vein thrombosis.

How to manage splanchnic vein thrombosis in patients with liver disease

Liver cirrhosis and splanchnic vein thrombosis (SVT) are strictly correlated. Portal vein thrombosis, the most common location of SVT, is frequently diagnosed in liver cirrhosis (pooled incidence 4.6 per 100 patient-years), and liver cirrhosis is a common risk factor for SVT (reported in 24%-28% of SVT patients). In cirrhosis-associated SVT, anticoagulant treatment reduces mortality rates, thrombosis extension, and major bleeding, and increases the rates of recanalization, compared to no treatment. Achieving vessel recanalization improves the prognosis of cirrhotic patients by reducing liver-related complications (such as variceal bleeding, ascites, hepatic encephalopathy). Anticoagulation should be therefore routinely prescribed to cirrhotic patients with acute SVT unless contraindicated by active bleeding associated with hemodynamic impairment or by excessively high bleeding risk. Of note, early treatment is associated with higher probability of achieving vessel recanalization. The standard treatment consists of low-molecular-weight heparin, followed by oral anticoagulants (eg, vitamin K antagonists or direct oral anticoagulants), if not contraindicated by severe liver dysfunction. Cirrhotic patients with SVT should be treated long-term (especially if candidate for liver transplantation) since liver cirrhosis is a persistent risk factor for recurrent thrombosis. In this review, we discuss the management of SVT in patients with liver cirrhosis, with a focus on the anticoagulant treatment in terms of indications, timing, drugs, duration, and particular scenarios, such as gastroesophageal varices and thrombocytopenia.

Clinical outcomes and prognostic factors in non-cirrhotic non-neoplastic patients with portal vein thrombosis: A single-centre experience

INTRODUCTION

The knowledge of natural history and prognostic factors of portal vein thrombosis (PVT) is still based on a limited number of studies.

AIM

To describe our single-center experience with 79 consecutive non-neoplastic non-cirrhotic patients with PVT (15 recent/64 chronic PVT).

RESULTS

Among patients with recent PVT, 7 received anticoagulation alone, 4 systemic thrombolysis, 3 direct thrombolysis through a TIPS and 1 TIPS alone. Portal recanalization was achieved in 11 patients. In patients with chronic PVT, the rate of variceal progression was high (20% at one year and 50% at two years). The thrombotic involvement of splenic and superior mesenteric veins was the only risk factor for variceal enlargement. The cumulative bleeding rates were 10% at one year and 20% at two years. A multisegmental thrombosis and large varices at entry and a previous variceal bleeding were the independent predictors for variceal bleeding. The cumulative rate of new thrombotic events was 14% at one year and 18% at two years. Eight patients died, 2 because of thrombotic events. There were no bleeding-related deaths. Two-year cumulative survival rate was 90%.

CONCLUSIONS

Our study supports the importance of anticoagulation especially when a more extended thrombosis is present. Moreover, in patients with chronic PVT, the timing of follow-up endoscopy should be based on the extension of thrombosis and not, as in cirrhosis, on the size of varices at first endoscopy.

Polycythemia vera: 2024 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Polycythemia vera (PV) is a JAK2-mutated myeloproliferative neoplasm characterized by clonal erythrocytosis; other features include leukocytosis, thrombocytosis, splenomegaly, pruritus, constitutional symptoms, microcirculatory disturbances, and increased risk of thrombosis and progression into myelofibrosis (post-PV MF) or acute myeloid leukemia (AML).

DIAGNOSIS

A working diagnosis is considered in the presence of a JAK2 mutation associated with hemoglobin/hematocrit levels of >16.5 g/dL/49% in men or 16 g/dL/48% in women; morphologic confirmation by bone marrow examination is advised but not mandated.

CYTOGENETICS

Abnormal karyotype is seen in 15%-20% of patients with the most frequent sole abnormalities being +9 (5%), loss of chromosome Y (4%), +8 (3%), and 20q- (3%).

MUTATIONS

Over 50% of patients harbor DNA sequence variants/mutations other than JAK2, with the most frequent being TET2 (18%) and ASXL1 (15%). Prognostically adverse mutations include SRSF2, IDH2, RUNX1, and U2AF1, with a combined incidence of 5%-10%.

SURVIVAL AND PROGNOSIS

Median survival is ⁓15 years but exceeds 35 years for patients aged ≤40 years. Risk factors for survival include older age, leukocytosis, abnormal karyotype, and the presence of adverse mutations. Twenty-year risk for thrombosis, post-PV MF, or AML are ⁓26%, 16% and 4%, respectively.

RISK FACTORS FOR THROMBOSIS

Two risk categories are considered: high (age >60 years or thrombosis history) and low (absence of both risk factors). Additional predictors for arterial thrombosis include cardiovascular risk factors and for venous thrombosis higher absolute neutrophil count and JAK2V617F allele burden.

TREATMENT

Current goal of therapy is to prevent thrombosis. Periodic phlebotomy, with a hematocrit target of <45%, combined with once- or twice-daily aspirin (81 mg) therapy, absent contraindications, is the backbone of treatment in all patients, regardless of risk category. Cytoreductive therapy is reserved for high-risk disease with first-line drugs of choice being hydroxyurea and pegylated interferon-α and second-line busulfan and ruxolitinib. In addition, systemic anticoagulation is advised in patients with venous thrombosis history.

ADDITIONAL TREATMENT CONSIDERATIONS

At the present time, we do not consider a drug-induced reduction in JAK2V617F allele burden, which is often incomplete and seen not only with peg-IFN but also with ruxolitinib and busulfan, as an indicator of disease-modifying activity, unless accompanied by cytogenetic and independently-verified morphologic remission. Accordingly, we do not use the specific parameter to influence treatment choices. The current review also includes specific treatment strategies in the context of pregnancy, splanchnic vein thrombosis, pruritus, perioperative care, and post-PV MF.

Molecular Mechanisms Underlying Vascular Liver Diseases: Focus on Thrombosis

Vascular liver disorders (VLDs) comprise a wide spectrum of clinical-pathological entities that primarily affect the hepatic vascular system of both cirrhotic and non-cirrhotic patients. VLDs more frequently involve the portal and the hepatic veins, as well as liver sinusoids, resulting in an imbalance of liver homeostasis with serious consequences, such as the development of portal hypertension and liver fibrosis. Surprisingly, many VLDs are characterized by a prothrombotic phenotype. The molecular mechanisms that cause thrombosis in VLD are only partially explained by the alteration in the Virchow's triad (hypercoagulability, blood stasis, and endothelial damage) and nowadays their pathogenesis is incompletely described and understood. Studies about this topic have been hampered by the low incidence of VLDs in the general population and by the absence of suitable animal models. Recently, the role of coagulation imbalance in liver disease has been postulated as one of the main mechanisms linked to fibrogenesis, so a novel interest in vascular alterations of the liver has been renewed. This review provides a detailed analysis of the current knowledge of molecular mechanisms of VLD. We also focus on the promising role of anticoagulation as a strategy to prevent liver complications and to improve the outcome of these patients.

Bleeding and Thrombotic Complications in Patients With Cirrhosis: A State-of-the-Art Appraisal

Much has evolved over the past 25 years regarding our understanding of the coagulopathy of liver disease. Paradoxically, this form of coagulopathy is relatively hypercoagulability despite the common clinical impression of a hemorrhagic tendency. The latter is largely driven by portal-mesenteric venous pressure (ie, portal hypertension) and has little to do with hemostatic pathways. It cannot be emphasized enough that the INR does not offer a meaningful measure in this situation and may lead to interventions such as fresh frozen plasma that can actually worsen portal pressure and hence pressure-driven bleeding. With regard to procedure-related bleeding, we point out substantial differences in the definition of high-risk procedures and propose a new operational definition dependent on the applicability of local hemostatic measures, although this requires further investigation. The common occurrence of venous thrombosis in these patients requires careful consideration of hemostatic pathways and overall risk and benefit of intervention. The decision regarding anticoagulation therapy needs to be driven not only by a global assessment including history of non-portal hypertensive-related bleeding, but also by fall risk which can result in head trauma in patients prone to encephalopathy. This is probably best estimated by frailty but has yet to be adequately investigated. In the background of these concerns, several superimposed and complex conditions including infections and renal dysfunction should be taken into account. Inherited forms of thrombophilia in the setting of cirrhosis perhaps do not outweigh the thrombophilia inherent to liver disease but warrant further consideration.

Therapeutic anticoagulation for splanchnic vein thrombosis in acute pancreatitis: A national survey and case-vignette study

BACKGROUND

Splanchnic vein thrombosis (SVT) is a major complication of moderate and severe acute pancreatitis. There is no consensus on whether therapeutic anticoagulation should be started in patients with acute pancreatitis and SVT.

AIM

To gain insight into current opinions and clinical decision making of pancreatologists regarding SVT in acute pancreatitis.

METHODS

A total of 139 pancreatologists of the Dutch Pancreatitis Study Group and Dutch Pancreatic Cancer Group were approached to complete an online survey and case vignette survey. The threshold to assume group agreement was set at 75%.

RESULTS

The response rate was 67% (n = 93). Seventy-one pancreatologists (77%) regularly prescribed therapeutic anticoagulation in case of SVT, and 12 pancreatologists (13%) for narrowing of splanchnic vein lumen. The most common reason to treat SVT was to avoid complications (87%). Acute thrombosis was the most important factor to prescribe therapeutic anticoagulation (90%). Portal vein thrombosis was chosen as the most preferred location to initiate therapeutic anticoagulation (76%) and splenic vein thrombosis as the least preferred location (86%). The preferred initial agent was low molecular weight heparin (LMWH; 87%). In the case vignettes, therapeutic anticoagulation was prescribed for acute portal vein thrombosis, with or without suspected infected necrosis (82% and 90%), and thrombus progression (88%). Agreement was lacking regarding the selection and duration of long-term anticoagulation, the indication for thrombophilia testing and upper endoscopy, and about whether risk of bleeding is a major barrier for therapeutic anticoagulation.

CONCLUSION

In this national survey, the pancreatologists seemed to agree on the use of therapeutic anticoagulation, using LMWH in the acute phase, for acute portal thrombosis and in the case of thrombus progression, irrespective of the presence of infected necrosis.

Myeloproliferative neoplasms and splanchnic vein thrombosis: Contemporary diagnostic and therapeutic strategies

Myeloproliferative neoplasms (MPNs) are the most common etiologies of primary splanchnic vein thrombosis, present in almost forty percent of patients with Budd-Chiari syndrome or portal vein thrombosis. Diagnosis of MPNs can be difficult in these patients because key characteristics, such as elevated blood cell counts and splenomegaly, are confounded by portal hypertension or bleeding complications. In recent years, diagnostic tools have improved to provide more accurate diagnosis and classification of MPNs. Although bone marrow biopsy findings remain a major diagnostic criterion, molecular markers are playing an increasing role not only in diagnosis but also in better estimating prognosis. Therefore, though screening for JAK2V617F mutation should be the starting point of the diagnostic workup performed in all patients with splanchnic vein thrombosis, a multidisciplinary approach is needed to accurately diagnose the subtype of myeloproliferative neoplasm, recommend the useful additional tests (bone marrow biopsy, search for an additional mutation using targeted next-generation sequencing), and suggest the best treatment strategy. Indeed, providing a specific expert care pathway for patients with splanchnic vein thrombosis and underlying myeloproliferative neoplasm is crucial to determine the optimal management to reduce the risk of both hematological and hepatic complications.