SearchFrom public health scares about the risk of deep vein thrombosis (DVT) on long-distance flights to high rates of pulmonary embolism (PE) in patients recovering from major surgery, venous thromboembolism (VTE) is a well-publicised, serious health issue.1, 2
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Patients undergoing major orthopaedic surgery for total hip or total knee replacement or surgery for fracture of the hip are at particularly high risk of DVT. Undertreatment remains a problem, despite ample evidence that primary preventive therapy effectively reduces the risk of DVT, PE, and fatal PE.3, 57
Thrombosis complications also play a major role in cardiovascular disease. Blood clots in coronary arteries cause acute coronary syndrome, and blood clots that form in the heart are the major cause of stroke in people with atrial fibrillation.4, 5
Understanding Thrombosis
Venous and arterial thrombosis: a major global health concern
Haemostasis and the coagulation cascade
Blood clot formation, or haemostasis, depends on an intricate series of events involving platelets, other cells, and the activation of specific blood proteins, known as coagulation factors.6
Diagnosing thrombosis
Clinical symptoms of DVT and acute coronary syndrome can be associated with other conditions.8, 9 For that reason, objective diagnostic tests may be required for diagnosis.
How thrombosis develops
A thrombus is a blood clot formed when there is an imbalance in the blood coagulation system. A thrombus can block the flow of blood through a vein or artery, and can detach from the vessel wall to become a life-threatening embolus when it lodges in the lungs or other vital organs.6
- 1 - Lapostolle F, Surget V, Borron SW, et al. Severe pulmonary embolism associated with air travel. N Engl J Med. 2001;345(11):779-783.
- 2 - Moll S, Mackman N. Venous thromboembolism: a need for more public awareness and research into mechanisms. Arterioscler Thromb Vasc Biol. 2008;28(3):367-369.
- 3 - Geerts WH, Bergqvist D, Pineo GF, Heit JA, Samama CM, Lassen MR, and Colwell CW. Prevention of Venous Thromboembolism: American College of Chest Physicians (ACCP) Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. Jun 2008: 381S–453S.
- 57 - Cohen AT, Tapson VF, Bergmann JF, et al; ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross-sectional study. Lancet. 2008;371(9610):387-394.
- 4 - Lip GY, Tse HF. Management of atrial fibrillation. Lancet. 2007;370(9587):604-618.
- 5 - Fuster V, Moreno PR, Fayad ZA, Corti R, Badimon JJ. Atherothrombosis and high-risk plaque: part I: evolving concepts. J Am Coll Cardiol. 2005;46(6):937-954.
- 6 - Colman RW, Clowes AW, George JN, Goldhaber SZ, Marder VJ. Overview of hemostasis. In: Colman RW, Clowes AW, George JN, Goldhaber SZ, Marder VJ, eds. Hemostasis and Thrombosis: Basic Principles and Clinical Practice. 5th ed. Philadelphia, PA: Lippincott, Williams & Wilkins; 2006:1-16.
- 8 - Tapson VF. Acute pulmonary embolism. N Engl J Med. 2008;358(10):1037-1052.
- 9 - Miller KL, Pollack CV Jr, Peterson ED. Moving from evidence to practice in the care of patients who have acute coronary syndrome. Cardiol Clin. 2006;24(1):87-102.
- Acute coronary syndrome
- This is an umbrella term used to cover any group of clinical symptoms compatible with acute myocardial ischaemia (chest pain due to insufficient blood supply to the heart muscle that results from coronary artery disease). Acute coronary syndrome covers the spectrum of clinical conditions ranging from unstable angina to STEMI and NSTEMI.
- Venous thromboembolism
- A condition in which a blood clot (thrombus) forms in a vein, which in some cases then breaks free and enters the circulation as an embolus, finally lodging in and completely obstructing a blood vessel, e.g., in lungs causing a PE. The term encompasses both DVT and PE.
- Coagulation factors
- Group of plasma protein substances (Factor I to XIII) contained in the plasma, which act together to bring about blood coagulation.
- Haemostasis
- The prevention of blood loss, either by the physiological properties of vasoconstriction and coagulation or by surgical means.
