March 4th, 2013
Veterans Study Finds HIV to Be an Independent Risk Factor for MI
Although it has long been suspected that people with the HIV virus are at increased risk for cardiovascular (CV) disease, reliable data has not been available. Now a new study published online in JAMA Internal Medicine provides a much clearer picture of the relationship between CV disease and HIV.
Matthew Freiberg and colleagues analyzed data from 82,459 HIV-positive and matched uninfected veterans enrolled in the Veterans Aging Cohort Study (VACS) Virtual Cohort (VC) and found a significant elevation in myocardial infarction (MI) in the HIV-positive group:
MI event rate per 1,000 person-years in the HIV-positive and the matched uninfected groups:
- age 40-49: 2 versus 1.5
- age 50-59 years: 3.9 versus 2.2
- age 60-69 years: 5 versus 3.3
All the differences achieved statistical significance. Overall, with adjustments for other risk factors, cormorbidities, and substance use, HIV-positive subjects had nearly a 50% elevated risk of MI compared with uninfected subjects (HR 1.48, CI 1.27-1.72). The elevated risk was found even in subjects with low levels of the HIV virus. The results also suggested that recent antiretroviral therapy (ART) may be associated with an increase in the risk of MI.
The findings “suggest that the Framingham risk score may underestimate AMI risk among HIV-positive people and that the addition of HIV and ART to a model of established AMI risk factors may be clinically useful,” the authors wrote.
In an accompanying editorial, Patrick Mallon writes that “the results demonstrate a clear and consistent excess risk of MI (approximately 50% increase) in HIV-positive people across a range of age groups, with the association between HIV status and MI remaining significant when controlled for a number of covariates…” Since the cause of this increased risk is not understood, he argues, “presuming that interventions used in the general population to reduce the risk of MI will translate into similar reductions in MI incidence in HIV-positive populations is arguably naive.”