Effect of Maraviroc on Endothelial Function in HIV-Infected Patients

Inclusion Criteria: 1. Stable antiretroviral therapy for at least 12 months 2. All plasma HIV RNA levels within the past year must be below level of detection (\< 50 copies RNA/mL), although isolated single values \> 50 but \< 200 copies will be allowed. 3. Screening plasma HIV RNA levels \< 50 copies RNA/mL 4. \>90% adherence to therapy within the preceding 30 days, as determined by self-report 5. Females of childbearing potential must have a negative serum pregnancy test at screening and agree to use a double-barrier method of contraception throughout the study period. Exclusion Criteria: 1. Ongoing or prior use of any integrase inhibitor or R5 inhibitor. 2. Patients who plan to modify existing antiretroviral therapy in the next 24 weeks for any reason 3. Serious illness requiring hospitalization or parental antibiotics within preceding 3 months 4. Concurrent or recent exposure to any immunomodulatory drugs 5. Advanced liver disease or active hepatitis B or C 6. Patients with systolic blood pressure \<100/70 7. Starting or stopping statin therapy during the trial