Risk Factors for Venous Thromboembolism in Patients with Human Immunodeficiency Virus Infection

Katie L. Kiser, Pharm.D.; Melissa E. Badowski, Pharm.D.


Pharmacotherapy. 2010;30(12):1292-1302. 

In This Article


Available data suggest that there are multiple risk factors and associations with increased risk of VTE in patients with HIV. Risk factors with the strongest association include a diagnosis of AIDS, low CD4+ cell count especially in the presence of clinical AIDS, protein S deficiency, and protein C deficiency. Risk factors that are still controversial as to whether they are associated with VTE in patients with HIV include male sex, protease inhibitor therapy, presence of active opportunistic infections (most commonly reported with PCP and cytomegalovirus infection), and presence of antiphospholipid antibodies, including anticardiolipin antibodies and lupus anticoagulant. There are several gaps in knowledge regarding what VTE risk factors exist in this population. Long-term and prospective studies assessing factors associated with VTE in patients with HIV or AIDS will continue to clarify these issues and facilitate the development of a risk stratification system with appropriate VTE preventive measures, if appropriate.

Although the frequency of VTE in the presence of HIV may decrease with the implementation of the new antiretroviral guidelines, there are still nonadherent individuals who may benefit from VTE prophylaxis. Although some risk factors in the HIV-positive population are modifiable, those with risk factors that cannot be altered should be monitored more closely. Individuals with modifiable factors should be educated on how to minimize their risks. Due to the lack of consensus on monitoring and interpretation of VTE risk factors in patients with HIV, we do not recommend routine monitoring of antiphospholipid antibodies, protein C, or protein S. Those patients possessing additional risk factors for VTE in the presence of HIV should, however, be monitored at each visit for clinical signs and symptoms for VTE.

It is reasonable to compile the data presented and conclude that we should consider many nontraditional risk factors for VTE when assessing patients with HIV or AIDS. These patients may be at an increased risk for VTE despite standard screening tools. Future assessment of VTE risk factors in this population along with the subsequent development of a VTE risk screening tool are needed.


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