title: Cardiovascular risks associated with abacavir and tenofovir exposure in HIV-infected persons.
abstract: OBJECTIVE
  Abacavir use has been associated with cardiovascular risk, but it is unknown whether this association may be partly explained by patients with kidney disease being preferentially treated with abacavir to avoid tenofovir. Our objective was to compare associations of abacavir and tenofovir with cardiovascular risks in HIV-infected veterans.
  
  
  METHODS
  Cohort study of 10 931 HIV-infected patients initiating antiretroviral therapy in the Veterans Health Administration from 1997 to 2007, using proportional hazards survival regression.
  
  
  METHODS
  Primary predictors were exposure to abacavir or tenofovir within the past 6 months, compared with no exposure to these drugs, respectively. Outcomes were time to first atherosclerotic cardiovascular event, defined as coronary, cerebrovascular, or peripheral arterial disease; and time to incident heart failure.
  
  
  RESULTS
  Over 60 588 person-years of observation, there were 501 cardiovascular and 194 heart failure events. Age-standardized event rates among abacavir and tenofovir users were 12.5 versus 8.2 per 1000 person-years for cardiovascular disease, and 3.9 and 3.7 per 1000 person-years for heart failure, respectively. In multivariate-adjusted models, including time-updated measurements of kidney function, recent abacavir use was significantly associated with incident cardiovascular disease [hazard ratio 1.48, 95% confidence interval (CI) 1.08-2.04]; the association was similar but nonsignificant for heart failure (1.45, 0.85-2.47). In contrast, recent tenofovir use was significantly associated with heart failure (1.82, 1.02-3.24), but not with cardiovascular events (0.78, 0.52-1.16).
  
  
  CONCLUSIONS
  Recent abacavir exposure was independently associated with increased risk for cardiovascular events. We also observed an association between recent tenofovir exposure and heart failure, which needs to be confirmed in future studies.
authors.affiliation: Department of Medicine, San Francisco VA Medical Center, California, USA.
authors.forename: Andy I
authors.initials: AI
authors.lastname: Choi
authors.forename: Eric
authors.initials: E
authors.lastname: Vittinghoff
authors.forename: Steven G
authors.initials: SG
authors.lastname: Deeks
authors.forename: Cristin C
authors.initials: CC
authors.lastname: Weekley
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Li
authors.forename: Michael G
authors.initials: MG
authors.lastname: Shlipak
mesh_terms: D000225:Adenine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology; D044966:Anti-Retroviral Agents / Q000009:adverse effects* / Q000494:pharmacology; D054316:Biomarkers, Pharmacological / Q000378:metabolism; D018791:CD4 Lymphocyte Count; D002318:Cardiovascular Diseases / Q000139:chemically induced*; D015331:Cohort Studies; D015224:Dideoxynucleosides / Q000009:adverse effects* / Q000494:pharmacology; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000378:metabolism* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D063065:Organophosphonates / Q000009:adverse effects* / Q000494:pharmacology; D012307:Risk Factors; D000068698:Tenofovir; D014481:United States; D014728:Veterans; D019562:Viral Load; D000099227:Abacavir
chemical_list: D000225:Adenine; D044966:Anti-Retroviral Agents; D054316:Biomarkers, Pharmacological; D015224:Dideoxynucleosides; D063065:Organophosphonates; D000068698:Tenofovir; D000099227:Abacavir