Venous Thrombosis in Blacks

• DOI: 10.1161/circulationaha.111.073098
• Publication Date: 2012-02-13T21:45:16Z
• Authors: Tyler W. Buckner; Nigel S. Key
• Keywords: Adult; Risk; Venous Thrombosis; 2. Zero hunger; Anticoagulants; Thrombophlebitis; Sickle Cell Trait; 3. Good health; Black or African American; Fibrin Fibrinogen Degradation Products; 03 medical and health sciences; 0302 clinical medicine; Humans; Thrombophilia; Female; Genetic Predisposition to Disease; Obesity; Warfarin; Pulmonary Embolism; Case Management; Ultrasonography

Case Presentation: A 42-year-old black woman is diagnosed with idiopathic (unprovoked) lower-extremity deep vein thrombosis (DVT) after presenting with leg swelling. She is treated with anticoagulation for 6 months without major complications and with stable international normalized ratios, and her lower-extremity symptoms completely resolve. She has sickle cell trait but no other chronic conditions. The patient's mother also had an idiopathic DVT at 53 years of age. Physical examination is notable only for obesity (body mass index 33 kg/m2) and absence of lower-extremity swelling, redness, and pain. D-dimer and follow-up lower-extremity Doppler ultrasound testing are negative. Testing for antiphospholipid antibodies was negative at the time the clot was diagnosed; further tests for thrombophilia have not been performed. She wants to know whether she should continue taking warfarin. In 2008, the US Surgeon General issued The Surgeon General's Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism , which highlighted the scope and impact of venous thromboembolism (VTE). In the United States alone, as many as 100 000 to 180 000 deaths occur annually due to DVT and pulmonary embolism (PE).1 Many of these events are preventable by implementation of standard prophylactic measures in certain high-risk populations (eg, hospitalized patients with reduced mobility); however, a large proportion of VTE events occur spontaneously, without clear inciting factors. Identification of novel risk factors for VTE might allow clinicians to better identify at-risk patients and modify both primary and secondary prevention strategies accordingly. The incidence of VTE depends on a complex interaction of inherited and environmental risk factors. The prevalence of inherited risk factors depends on the population being studied. To date, the genetics of VTE has been studied most frequently in patients with European …