Background:  HIV appears to increase the risk of cardiovascular disease, and chronic inflammation may be one potential mechanism mediating this risk. Maraviroc (MVC) is a CCR5 antagonist that potently inhibits HIV replication and is known to have immunomodulatory effects in vivo that are independent of its effect on HIV replication. We assessed the effect of MVC intensification on vascular function by flow-mediated vasodilation (FMD) of the brachial artery in treated and suppressed HIV⁺ individuals.

Methods:  We conducted a randomized double-blind placebo-controlled trial of 52 HIV⁺ individuals with plasma HIV RNA levels <40 copies/mL for at least 1 year on ART. Subjects were randomized to add MVC or placebo to their background regimen for 24 weeks, followed by 12 weeks of observation on ART alone. The primary endpoint was the change in FMD at week 24, with additional FMD measures at weeks 4 and 36. The influence of treatment group (MVC vs placebo) on FMD changes was assessed with linear mixed models.

Results:  We randomized 26 subjects to MVC and 26 to placebo. Most (98%) were men. The median baseline values were:  age, 52 years; duration of HIV diagnosis, 17 years; CD4⁺ T cell count, 304 cells/mm³; nadir CD4 count, 147 cells/mm³; and FMD, 4.8%; with no statistically significant differences between arms. FMD tended to increase from baseline to week 24 in the MVC-treated individuals (mean±SD 0.57±2.1%, p = 0.17), but not in placebo-treated subjects (–0.05±2.1%, p = 0.90), but there were no statistically significant differences between groups at any time-point (p = 0.52 overall). Based on observed data, we were powered to detect a difference in the week-24 change in FMD as small as 1.5% between groups. By 12 weeks after study medication discontinuation, the change from week 24 was +0.19±2.0% in the MVC arm (p = 0.63) and +0.46±2.0% (p = 0.29) in the placebo arm.

Conclusions:  Among HIV⁺ individuals maintaining ART-mediated viral suppression, we found little evidence for a clinically relevant effect of MVC intensification on vascular function as assessed by FMD; however, smaller effects cannot be excluded. Additional studies will be needed to ascertain whether MVC treatment has any effect on cardiovascular risk.