UCLA

Background

 After adjustment for cardiovascular risk factors and despite higher mortality, those with human immunodeficiency virus (HIV+) have a greater risk of acute myocardial infarction (AMI) than uninfected individuals.

Methods

 We included HIV+ individuals who started combination antiretroviral therapy (cART) in the Veterans Aging Cohort Study (VACS) from 1996 to 2012. We fit multivariable proportional hazards models for baseline, time-updated and cumulative measures of HIV-1 RNA, CD4 counts, and the VACS Index. We used the trapezoidal rule to build the following cumulative measures: viremia copy-years, CD4-years, and VACS Index score-years, captured 180 days after cART initiation until AMI, death, last clinic visit, or 30 September 2012. The primary outcomes were incident AMI (Medicaid, Medicare, and Veterans Affairs International Classification of Diseases-9 codes) and death.

Results

 A total of 8168 HIV+ individuals (53 861 person-years) were analyzed with 196 incident AMIs and 1710 deaths. Controlling for known cardiovascular risk factors, 6 of the 9 metrics predicted AMI and all metrics predicted mortality. Time-updated VACS Index had the lowest Akaike information criterion among all models for both outcomes. A time-updated VACS Index score of 55+ was associated with a hazard ratio (HR) of 3.31 (95% confidence interval [CI], 2.11-5.20) for AMI and a HR of 31.77 (95% CI, 26.17-38.57) for mortality.

Conclusions

 Time-updated VACS Index provided better AMI and mortality prediction than CD4 count and HIV-1 RNA, suggesting that current health determines risk more accurately than prior history and that risk assessment can be improved by biomarkers of organ injury.