Venous thromboembolism (VTE) is a silent disease that is sometimes overlooked by patients and clinicians. Due to a general lack of awareness about VTE, a condition that may include deep vein thrombosis (DVT) and/or pulmonary embolism (PE), patients are not often diagnosed accurately and given timely treatment, resulting in high disease morbidity. Improving the awareness of VTE amongst healthcare professionals and the general public is crucial.

As incoming president of the International Society of Thrombosis and Haemostasis (ISTH), Professor Pantep Angchaisuksiri is uniquely qualified to help address this challenge. In an interview with Lab Insights, he shares thoughts on the prevalence of VTE in Asia and the need to increase VTE awareness.

VTE in Asia: prevalence and diagnostic considerations

VTE is prevalent in Asia and its incidence has risen substantially in recent years. In China, a 5-fold increase in PE was reported from 1997 to 2008 [1]. It was also estimated, through a review focussed on publications from Asia, that post-surgical DVT rates ranged from 0.15% to 1.35% from 1995 to 2016 [2].

Growing incidence of VTE can be attributed in part to the rising awareness of the disease among healthcare professionals in Asia, which could lead to a greater push in ordering screening tests for VTE and thus improving detection rates. Another contributing factor is the greater access to imaging tools like compression ultrasounds and computed tomography scans that provide confirmation to an initial diagnostic test.

VTE is a multifactorial disease, and becauses its signs and symptoms are not well defined, early recognition can only occur if a clinician is actively looking for it. To complicate matters, a clinical diagnosis of VTE isn’t very reliable. Hence, a clinician must be able to identify patients who are at high risk of VTE and consider the appropriate tests when a patient presents with signs and symptoms indicating a potential VTE event. This should be followed by confirmatory methods to formally diagnose a patient with VTE.

The availability of healthcare resources varies between countries in Asia. To avoid unnecessary utilisation of imaging modalities that can be costly, patients who are at low risk of VTE can have a D-dimer test performed. A negative D-dimer test in these patients would indicate a very low probability of VTE, while those with a positive test can be prioritised by the healthcare system.

Expanding VTE knowledge in Asia

VTE affects a wide range of individuals, so educational initiatives about VTE should target clinicians across various specialities. In parallel, focus should also be placed on patient education, which can empower patients to seek a consultation if they have cause to believe they are experiencing symptoms of VTE .

Patients on anticoagulants with a high risk of bleeding can be given VTE prophylaxis using mechanical methods, so clinicians should be encouraged and trained to assess the patient’s bleeding risk using scoring algorithms. The IMPROVE Bleeding Risk Assessment Score was developed in the West, but has been validated for use in the Asian context in a study conducted in China [3]. Even so, not many clinicians are aware of this scoring algorithm, and more research is needed to determine the risk of VTE and anticoagulant-associated bleeding risks amongst Asian patients, as most studies include only a small portion of Asian subjects.

The ISTH undertakes the responsibility to improve the visibility and awareness of VTE by celebrating World Thrombosis Day on Oct 13th. The ISTH is also encouraging engagement with policymakers and payers about VTE, as well as expanding the programmes to involve more developing countries from Asia and around the world.

Next steps for VTE awareness in Asia

We also need more high-quality, prospective research on VTE in Asia. This must include extensive, well-designed clinical studies evaluating the risk of VTE and the appropriate use of thrombo-prophylaxis in different situations for Asian populations.

In addition, local guidelines for the prevention and management of VTE based on data in an Asian population should be developed to help guide clinical management of VTE in Asia.

Resources: 

[1] Yang, Y. et al. (2011) “Pulmonary embolism incidence and fatality trends in Chinese hospitals from 1997 to 2008: A multicenter registration study,” PLoS ONE, 6(11). Available at: https://doi.org/10.1371/journal.pone.0026861.

[2] Lee, L. et al. (2017) “Incidence of venous thromboembolism in Asian populations: A systematic review,” Thrombosis and Haemostasis, 117(12), pp. 2243–2260. Available at: https://doi.org/10.1160/th17-02-0134.

[3] Zhang, Z. et al. (2020) “Validation of the improve bleeding risk score in Chinese medical patients during hospitalization: Findings from the dissolve-2 study,” The Lancet Regional Health – Western Pacific, 4, p. 100054. Available at: https://doi.org/10.1016/j.lanwpc.2020.100054.

Bonus: Angchaisuksiri, P. et al. (2021) “Venous thromboembolism in Asia and worldwide: Emerging insights from Garfield-VTE,” Thrombosis Research, 201, pp. 63–72. Available at: https://doi.org/10.1016/j.thromres.2021.02.024.