Various
recent studies have shown that people with HIV are at higher risk of cardiovascular
disease, which may be related to HIV infection itself or metabolic
complications associated with antiretroviral
therapy.
In the June 15, 2007 issue of Clinical
Infectious Diseases, Danish researchers reported on an analysis of risk for
ischemic heart disease, a condition that involves reduced blood flow in the coronary
arteries that supply the heart muscle. Ischemic heart disease can cause angina
(chest pain during exertion) and may lead to myocardial infarction, or heart attack.
The authors looked at data collected between January 1995 and December 2004 from
3953 HIV positive patients in the nationwide Danish HIV Cohort Study, as well
as a population-based control group of 373,856 HIV negative individuals matched
for age and sex. Data on first hospitalization for ischemic heart disease and
co-morbidity (including heart attacks and coronary artery bypass surgery) were
obtained from the Danish National Hospital Registry for all study participants.
Results
·Patients
with HIV who had not started HAART were slightly more likely to be hospitalized
for the first time with ischemic heart disease than control subjects, but the
difference did not reach statistical significance (adjusted relative risk 1.39;
95% CI 0.81-2.33).
·After HAART
initiation, the increase in risk became “substantially higher” (adjusted relative
risk 2.12; 95% CI 1.62-2.76).
·HIV positive
patients on HAART were also more likely than control subject to die within 30
days of hospitalization for ischemic heart disease (8.8% vs 3.8%).
·However,
the relative risk did not increase further during the first 8 years on HAART.
·Among HIV
positive patients, factors associated with higher risk of ischemic heart disease
were lower CD4 count, higher HIV viral load, and shorter time from diagnosis to
starting treatment.
Conclusion
In
conclusion, the authors wrote, “Compared with the general population, HIV-infected
patients receiving HAART have an increased risk of ischemic heart disease, but
the relative risk is stable up to 8 years after treatment initiation.”
They
estimated that the increase in risk for patients on HAART was equivalent to that
associated with smoking 1-4 cigarettes per day.
Since
the risk of ischemic heart disease did not rise with additional time on HAART
(in contrast with the large ongoing D:A:D study), the researchers suggested that other mechanisms
besides antiretroviral-associated lipid elevation may be at work, for example
inflammation or changes in platelet or endothelial (blood vessel lining) function,
possibly linked to immune reconstitution syndrome.
06/01/07
Reference N Obel, HF Thomsen, G Kronborg, and others. Ischemic heart disease in HIV-infected and HIV-uninfected individuals:
a population-based cohort study. Clinical Infectious Diseases 44(12): 1625-1631.
June 15, 2007.
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