Risk of Venous and Arterial Thrombosis in HIV-infected Patients: A Narrative Review

Introduction

Currently, human immunodeficiency virus type 1 (HIV-1) infection has a prevalence of 0.8% worldwide [1]. Due to more availability of the antiretroviral therapy (ART), there are presently more people living with HIV infection than in the past (from 29.5 million in 2001 to 33.2 million in 2007). The annual incidence of new HIV-1 infections declined from 3.0 to 2.7 million in 2001 and 2007, respectively. In 2007, two million people died of HIV-related diseases, a declining number since 2005. Finally, people in developing countries on antiretroviral treatment increased from 300,000 in 2001 to 3.0 million in 2007 [2].

Abstract

With the increasing number of patients living with HIV-infection who are successfully treated with antiretroviral therapy (ART), mortality has declined drastically. Either through this prolonged survival or by the introduction of ART, other underlying diseases or risks for such diseases could become clinically relevant such as venous and arterial thrombosis. Prothrombotic abnormalities have consistently been noted amongst HIV-infected patients, who are at a 4- to 6-fold increased risk to develop venous or arterial thrombosis compared to the normal population. This risk is partially due to HIV-infection itself, as prothrombotic abnormalities and thrombotic risk increase when patients develop AIDS. The use of ART, and in particular the use of protease inhibitors (PI), seems to contribute to this risk as well. Nevertheless, even if ART contributes to this risk, this does not outweigh the benefits of ART (ie, reducing mortality and increasing AIDS-free survival). As interruption of ART seems to increase the risk of death from cardiovascular disease or any other cause, as compared with continuous ART use, this implies that once a patient starts with ART it should not be discontinued.

Keywords

AIDS, antiretroviral therapy, arterial thrombosis, cardiovascular disease, HIV, human immunodeficiency virus, risk factors, venous thrombosis