The team at King's Thrombosis Exemplar Centre have published numerous articles and features on thrombosis care, listed below.
Future Trends
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VTE prevention
VTE: a key patient safety issue
British Journal of Healthcare Management 2009 Volume 15 Number 2
This article provides an update on the Department of Health’s integrated National VTE Prevention Programme.
Preventing venous thromboembolism through risk assessment approaches (Visit website)
British Journal of Nursing 2008 Volume 17 Number 12
VTE is a significant cause of morbidity and mortality in hospitalised patients. Careful selection of a suitable VTE risk assessment approach is required to improve the chance of its successful implementation in-hospital.
Multidisciplinary team approach to VTE prevention and treatment (View PDF)
Pharmacy Focus 2008 Issue 3
A large proportion of in-patients remain at risk for VTE. Hospital-wide strategies to assess risk and implement measures for appropriate prophylaxis should be a priority and are a multidisciplinary issue. This article outlines the roles of the anticoagulation pharmacist and thrombosis nurse specialist in the thrombosis team.
NPSA actions can make anticoagulant therapy safer (View PDF)
Pharmacy Factors 2007 Issue 13
The National Patient Safety Agency safety alert 18 on anticoagulation was published in 2007 and required action from Trusts to address safety issues with anticoagulation. This article discusses progress taken at King's Thrombosis Centre towards implementing the required actions and outlines the team's challenges and successes.
Preventing VTE: how to implement the CMO's recommendations (View PDF)
Pharmacy Focus 2007 Issue 2
In this article, Dr Roopen Arya offers his views on implementing the Chief Medical Officer's (CMO) report of the independent expert working group on the prevention of venous thromboembolism (VTE) in hospitalised patients.
Preventing VTE: putting guidance into practice (View PDF)
Pharmacy Factors 2007 Issue 12
This article considers the issues facing the Implementation Working Group (IWG) in providing leadership for national roll-out of the CMO recommendations for VTE prevention.
Prevention of VTE in hospitalised patients – the CMO’s report (Visit website)
Thrombus 2007 Volume 11 Number 2
The Chief Medical Officer (CMO) for England, Sir Liam Donaldson, recently published the report of the independent expert working group on the prevention of venous thromboembolism (VTE) in hospitalised patients. This is the culmination of a political process initiated in March 2005 by the publication of the House of Commons Health Committee report that concluded that much more needed to be done to prevent avoidable deaths from VTE.
VTE and ethnicity
Venous thromboembolism and ethnicity (Visit Website)
British Journal of Haematology 2009;146:369-383
Venous thromboembolism (VTE) has long been considered a disease that affects predominantly white populations, a misconception resulting from a paucity of epidemiological data from non-Western countries, and the low incidence of hereditary thrombophilia in those of non-Caucasian background. Over the last decade, interest has grown in this area with the emergence of evidence that VTE is as prevalent, if not more so, in the black population and is also common in Asian groups. Much is still to be learned, as our current knowledge of hereditary thrombophilia and acquired risk factors do not fully explain the risk of VTE in non-Caucasian groups. This review summarises the current understanding of ethnic variation in VTE and highlights the need for further research in this area.
Venous thromboembolism – racial and ethnic influences (Visit website)
Therapy 2008 Volume 5 Number 2
The epidemiology and risk factors for venous thromboembolism are well described in European populations, but such data is scarce in other ethnic groups. Venous thrombosis has traditionally been perceived as affecting only Europeans; this erroneous belief is reinforced by the low incidence of the common hereditary thrombophilias outside Europe, together with the lack of general perception and poor availability of diagnostic services in developing countries. It is now evident that venous thrombosis is prevalent across a number of different racial groups. Furthermore, conventional thrombophilia testing has been shown to be uninformative in most non-Europeans and laboratory reference ranges for these tests may be inappropriate for some non-European populations. Further research is needed to characterize the nature of venous thromboembolism in non-Europeans.
Ethnic communities and venous thrombosis (Visit website)
Thrombus 2005 Volume 8 Number 4
In populations of European origin, the epidemiology and risk factors for venous thromboembolism (VTE) are well characterised but such data are scanty for other ethnic groups. Traditionally, venous thrombosis has been recognised as a condition confined to the populations of Europe, this has been strengthened by the lack of diagnostic services in developing countries and the low incidence of known hereditary prothrombotic mutations in non-Europeans.
Coagulation factor levels and venous thrombosis in the black population (Visit website)
Thrombosis and Haemostasis 2004 Volume 91
This study evaluated the relationship between D-dimer, FVIII:C, fibrinogen and DVT in 125 patients and volunteers.
Venous thromboembolism in the black population (Visit website)
Archives of Internal Medicine 2004 Volume 164
Data on venous-thromboembolism (VTE) in black populations is scarce and many contend that VTE mainly affects those of European origin. King's College Hospital in South London has an ethnically diverse local population with 25% of West African or Caribbean origin.
Tests for Hereditary Thrombophilia Are of Limited Value in the Black Population (Visit website)
Stroke 2003 Volume 34
The Camberwell Thrombophilia Study is a population-based study investigating thrombophilia in the black population. FVIII and fibrinogen are thrombophilic markers in blacks that should be considered when assessing risk factors for both venous and arterial thrombosis.
Risk factors for venous thrombosis in the black population (Visit website)
Thrombosis and Haemostasis 2003 Volume 90
This study suggests that raised FVIII:C is a major risk factor for VTE in black subjects with prevalence and odds ratio exceeding those reported for white subjects.
JAK2 mutation
Recurrent refractory arterial thromboembolism associated with the Janus kinase 2 V617F mutation (Visit Website)
Journal of Vascular Surgery 2009;49:211-213
We report two patients with peripheral vascular disease requiring multiple bilateral radiologic and surgical interventions, and whose disease was unresponsive to conventional anticoagulation and antiplatelet therapy. Although thrombocytosis was only intermittent, analysis of the Janus kinase 2 (JAK2) gene revealed a V617F mutation, thus confirming the presence of an underlying occult myeloproliferative disorder. We propose that JAK2 mutation analysis be considered in patients with recurrent, unexplained arterial events to identify those with occult myeloproliferative disorders.
Recurrent refractory arterial thromboembolism associated with the JAK2 V617F mutation
Journal of Vascular Surgery 2008 (In press)
Role of the JAK2 mutation in abdominal vein thrombosis (Visit website)
Thrombus 2007 Volume 11 Number 3
Venous thrombosis in the portal, mesenteric and hepatic veins are rare but severe conditions often affecting young patients. Thrombosis of the hepatic veins results in Budd–Chiari syndrome (BCS), which has a heterogeneous clinical presentation. Portal vein thrombosis (PVT) presents with complications of portal hypertension.
Prevalence of the activating JAK2 tyrosine kinase mutation V617F in the Budd-Chiari syndrome (Visit website)
Gastroenterology 2006 Volume 130
JAK2V617F occurs in a high proportion of patients with BCS. Latent MPD was missed in a substantial number of our subjects when using standard techniques. Such cases should be carefully observed for the subsequent development of overt MPD and possibly screened for JAK2V617F if the index of suspicion is high.
Various
Frequency, demographics and risk (according to tumour type or site) of cancer-associated thrombosis among patients seen at outpatient DVT clinics (Visit website)
Thrombosis and Haemostasis 2010; 103:338-343
Venous thromboembolism is a clinically important complication for both hospitalised and ambulatory cancer patients. In the current study, the frequency, demographics and risk (according to tumour site) of VTE were examined among patients seen at outpatient DVT (deep-vein thrombosis) clinics. The study shows that outpatients have a similar rate of cancer-associated VTE as VTE patient populations previously reported, that cancer-associated VTE occurs in an older age group and earlier in females and that outpatients exhibit distinct tumour site-specific risk from that described among hospitalised cancer patients.
Haemostasis and thrombosis in liver disease (Visit website)
British Journal of Haematology 2010; In press
Liver disease impacts on both primary and secondary haemostatic mechanisms and historically these changes were thought to underpin the bleeding diathesis. However, bleeding complications in patients with liver disease are unpredictable, with the majority of haemorrhagic episodes occurring as a result of porto-systemic varices. Thrombosis is an increasingly recognised complication and systemic hypercoagulability may contribute to the development of parenchymal extinction and accelerated hepatic fibrosis. Routine laboratory tests do not reliably predict the risk of haemorrhage and the optimal management strategy to avert potential bleeding complications is yet to be established. There may be a future role for global coagulation assays, such as thrombelastograpy and thrombin generation, in both stratifying the risk of bleeding and guiding management of these patients.
Stroke prevention in the young child with sickle cell anaemia (Visit website)
Annals of Hematology 2009 Oct;88(10):943-6
Cerebrovascular disease resulting in stroke is a serious and preventable complication of sickle cell anaemia (SCA). Children at high risk of preventable stroke can be identified by transcranial Doppler ultrasound (TCD). Current guidelines in the UK recommend annual TCD screening from 3 years, although studies suggest an earlier peak incidence, between 2 and 5 years. A single centre retrospective review was undertaken to identify the prevalence of stroke and success of TCD screening in young children. We report five episodes of stroke in under 3s and outcome of TCD screening in children under 3, compared to over 3. TCD analysis was as successful in the 2-3-year age group as in the 3-4-year group. We therefore propose that all children with SCA should be offered TCD screening from the age of 2 years. Furthermore, infants with high risk features of SCA should undergo a first attempt at TCD screening even earlier.
New anticoagulants for prevention and treatment of venous thromboembolism (Visit Website)
Current Vascular Pharmacology 2010 In Press
There is a clear need for new anticoagulants with predictable pharmacokinetics and anticoagulant effect. To this end, 2 new agents; dabigatran and rivaroxaban, have recently been licensed for use in orthopaedic thromboprophylaxis. This review discusses the limitations of traditional anticoagulants, and summarises the development and clinical studies pertaining to the use of 3 new targeted anticoagulants: idraparinux, rivaroxaban and dabigatran in VTE, in addition to the limitations of these novel agents.
Late onset hypogonadism: an alternate cause for night sweats in the haematology clinic (Visit Website)
British Journal of Haematology 2009;145:435-437
Virchow and his triad: a question of attribution (Visit Website)
British Journal of Haematology 2009;143:180-190
Virchow's triad describes three factors that contribute to the development of venous thrombosis: hypercoagulability, stasis and endothelial injury. Yet, extensive review of the historical literature casts doubt on the existence of a triad described by Virchow in the form it is currently quoted throughout contemporary medical literature. Certainly his work involved extensive study of venous thrombosis and pulmonary embolism, with these two terms being coined by Virchow, but a triad of factors relating to the development of venous thrombosis is elusive. Interestingly, Virchow only began to be routinely credited with this triad one hundred years after publication of his work on venous thrombosis. This acknowledgement coincided with the accumulation of experimental evidence for the role these factors play in thrombogenesis. Controversial as the origins of Virchow's triad might be, it is apt given his substantial contribution to our knowledge of venous thromboembolism, and the fact that the triad continues to be clinically relevant today that a triad pertaining to Virchow should remain.
Ambulatory therapy of patients with free-floating proximal deep vein thrombosis is safe (Visit website)
Thrombosis and Haemostasis 2005 Volume 94
The data presented supports the safety of ambulatory therapy in clinically stable patients with free-floating thrombus treated with LMWH and warfarin. Caval filter insertion should be reserved for patients with contraindication to anticoagulation and those with embolic events occurring despite therapeutic levels of anticoagulation.
Long-haul flights and deep vein thrombosis: a significant risk only when additional factors are also present (Visit website)
British Journal of Haematology 2002 Volume 116
To address the association between travel and deep vein thrombosis (DVT) we examined the risk factors for DVT in 568 consecutive patients with suspected DVT attending King's College Hospital in London. No significant link between DVT and long-haul travel was demonstrable in this cohort, with an odds ratio of 1•3 (CI 0•6–2•8). Risk of DVT was only increased in long-haul travellers if one or more additional risk factors were present, with an odds ratio of 3•0 (CI 1•1–8•2). Such individuals may benefit from prophylactic measures to minimize risk.
