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  Conference on Retroviruses
and Opportunistic Infections
Seattle, Washington
March 4-7, 2019
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Higher risk of recurrent venous thromboembolism with HIV in Dutch national study
  Conference on Retroviruses and Opportunistic Infections (CROI), March 4-7, 2019, Seattle
Mark Mascolini
People with HIV infection had a higher rate of recurrent venous thromboembolism than HIV-negative people, according to results of a national study in the Netherlands [1]. Recurrence risk proved highest in the first year after anticoagulant therapy stopped and in people with lower CD4-cell gains.
People with HIV, even those with antiretroviral-controlled infection, have sticky blood. This procoagulant state boosts their risk of first thromboembolism [2], a clot blocking a blood vessel. How long anticoagulant therapy should last depends on recurrence risk. Because that risk remains unknown in people with HIV, ATHENA cohort researchers compared venous thromboembolism rates in HIV-positive cohort members and the Dutch general population.
The ATHENA team identified everyone in this HIV cohort who had a first venous thromboembolism (either deep venous thrombosis or pulmonary embolism) from 2003 through 2015. From the Dutch MEGA cohort, they selected an HIV-negative control population who had a first thromboembolism between 1999 and 2004. The investigators estimated recurrent thromboembolism incidence by Kaplan Meier analysis accounting for death as a competing risk. They used Cox regression analysis to pinpoint recurrence predictors.
The analysis included 153 first-thromboembolism patients with HIV and 4005 without HIV. The HIV group had a higher proportion of men (82% versus 45%) but was similar in age at first thromboembolism (median 48 and 49 years). Median months of coagulant therapy were 6 in both groups, and both groups had 6 years of follow-up.
Through follow-up thromboembolism recurred in 26% of the HIV group and 16% of the HIV-negative group. Regardless of gender or whether the first thromboembolism was provoked,* the recurrence rate was higher in people with HIV (overall crude incidence 5.2 per 100 person-years versus 3.1 per 100 person-years). Increased recurrence risk with HIV occurred mainly in the first year after anticoagulant therapy stopped. In people with HIV, Cox regression analysis estimated a 20% lower recurrence rate with every 100-cell higher CD4 count between first thromboembolism and anticoagulant withdrawal (adjusted hazard ratio 0.80, 95% confidence interval 0.68 to 0.95).
The ATHENA team proposed that thromboembolism recurrence seems heightened in people with versus without HIV, particularly in the first year after anticoagulants stop and in people with worse CD4-cell recovery during anticoagulant therapy.
*Provoked thromboembolisms are those associated with cancer, surgery, estrogen use, immobilization, or cast use.
1. Rokx C, Howard JB, Smit C, et al. HIV infection and risk of recurrent venous thromboembolism: a national cohort study. Conference on Retroviruses and Opportunistic Infections (CROI). March 4-7, 2019. Seattle. Abstract 636.
2. Howard JB, Rokx C, Smit C et al. Incidence of a first venous thrombotic event in people with HIV in the Netherlands: a retrospective cohort study. Lancet HIV. 2019. https://middleeast.thelancet.com/journals/lanhiv/article/PIIS2352-3018(18)30333-3/fulltext