pressure is associated with an increased risk of heart attack among people
with HIV, a US study published in the online edition of Clinical Infectious Diseases shows. However, investigators from the
Veterans Aging Study Virtual Cohort also found that, in most cases, people living with HIV who had elevated blood pressure had a similar risk of heart attack when
compared with HIV-negative controls with similar elevations in blood pressure.
“HIV status and
blood pressure are associated with AMI [acute myocardial infarction (heart
attack)] risk independently of each other,” comment the authors. “By comparing
all participants to a common referent group…we were better able to assess the
individual and combined effects of HIV status on elevated blood pressure.”
There is now a
large body of research showing that people living with HIV have an increased
risk of heart attack compared to HIV-negative individuals. Elevated blood
pressure – hypertension and prehypertension – are recognised risk factors for
heart attack in the general population. Blood pressure control is as important
for people with HIV as anyone else. Current goals for blood pressure
control are below 140/90 mmgHg (hypertension) or below 130/80 mmHg (prehypertension).
wanted to see if people with HIV who have elevated blood pressure had an
increased risk of heart attack over and above that seen in matched HIV-negative
population comprised 81,000 US veterans who received care after 2003. A third
of participants in the study were living with HIV and each participant was matched with two
HIV-negative controls of the same age and ethnicity.
Blood pressure was
assessed at baseline. In people not taking blood pressure treatment, it was
categorised as normal if between 90-120/60-80 mmHg (16%); prehypertensive when
between 120-139/80-89 mmHg (44%) and hypertensive when 140/100 mmHg or above
(39%). There were similar proportions of people with HIV and HIV-negative people
in each blood pressure category. Mean age ranged from 46 to 53 years.
The participants in the study were
followed for a median of 5.9 years and contributed a total of 406,000
person-years of follow-up. During this time there were 860 heart attacks.
The incidence of
heart attack increased as blood pressure increased, and was 12.9 per
10,000 person-years among people with normal blood pressure compared to 14.5
per 10,000 person-years for people with hypertension.
People living with HIV who had normal blood pressure or prehypertension did not have an increased
risk of heart attack compared to the HIV-negative controls. However, the risk
of heart attack was significantly higher among people living with HIV who were hypertensive compared to control patients with hypertension (aHR = 2.57; 95% CI, 1.76-3.76
vs. aHR = 1.47; 95% CI, 1.02-2.11).
Despite this there
was no significant interaction between elevated blood pressure and HIV status
and the risk of heart attack in a statistical model that considered blood
pressure as a continuous measure.
“We found no
statistical interaction between HIV, elevated blood pressure and AMI risk,” the
investigators write. “This suggests that HIV may not modify the association
between blood pressure and AMI risk.”
HIV-negative individuals with normal blood pressure, people living with HIV who had
prehypertension or hypertension had a significant increase in the risk of heart
Each 10 mmg/Hg
increase in pulse pressure was associated with a small but significant increase
in the risk of heart attack (HR = 1.12; 95% CI, 1.06-1.19). Having HIV did
not modify the association between pulse pressure and heart attack risk.
“Our data suggest
that traditional CVD [cardiovascular disease] risk factors like hypertension
contribute additional AMI risk independently of and in addition to that
contributed by HIV infection,” comment the researchers. They acknowledge a
number of limitations in their study, including its observational design,
statistical power and the possibility of unmeasured confounding, such as family
and hypertensive blood pressure was associated with an increased risk of AMI in
a cohort of HIV infected and uninfected Veterans,” the authors conclude.
“Future studies should prospectively investigate whether HIV interacts with
blood pressure to further increase AMI risk.”