According to new research, people living with HIV but showing no signs of cardiovascular disease have two to three times as much non-calcified coronary plaque as healthy people.
HIV positive patients are known to have a 1.5 to 2.1 higher risk of heart attack than the general population that does not carry the virus. But data and findings on non-calcified coronary plaque are controversial and unclear to date.
Now, in a study published April 20 in Radiology, researchers at the Center hospitalier de l’Université de Montréal have effectively shown that HIV is in fact associated with an increase in the prevalence of plaque and plaque burden. This knowledge is critical, said the team, led by Carl Chartrand-Lefebvre, MD, M.Sc., clinical professor, because modern advances in antiretroviral medications have changed the life expectancy of people living with the virus.
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“People infected with HIV are now living longer and experiencing more and more age-related illnesses, such as coronary artery disease (CAD),” said the team, noting that the drugs used to treat HIV may contribute to the disease burden.
To determine whether individuals with HIV had different experiences with CAD and different CT characteristics of coronary plaque, the Chartrand-Lefebvre teams conducted a prospective study with 265 participants – 181 people with HIV and 84 healthy volunteers. The mean age of HIV patients and healthy participants was 56 years and 57 years, respectively.
More patients with HIV than healthy cohorts were tobacco smokers (30 percent and 11 percent, respectively), and more patients with HIV were actively using statin therapy (31 percent versus 18 percent, respectively). In addition, 92.3 percent of HIV-positive subjects received antiretroviral therapy for an average of 13.6 years.
For the study, each participant underwent coronary CT angiography with a 256-section CT scanner and 370 mg / ml iopamidol at a rate of 5 ml / sec. The team also performed a non-contrast CT for coronary calcium score. Before analysis, the interpreting radiologists did not know which patients were HIV positive.
Although their analysis did not reveal a difference between the coronary artery calcium score and the overall prevalence of plaque between the two groups, the evaluation did show that the prevalence and volume of non-calcified plaque on CT angiography was two to three times higher were in patients with HIV. after adjustment for cardiovascular risk factors.
“Our study shows that non-calcified coronary plaque increases in people with HIV,” said Lefebvre. “And non-calcified plaque has previously been shown to be associated with worse cardiovascular outcomes than calcified or mixed plaques.”
In addition, the team found that patients with HIV had a 40 percent lower frequency of calcified plaque. While the difference in frequency between groups can probably be attributed to a variety of factors, they emphasized the use of antiretroviral therapy as a likely significant contributor.
“Multiple studies suggest that there is likely an impact of antiretroviral therapy that could increase the risk of coronary artery disease, although it is much more beneficial for people with HIV to receive antiretroviral therapy instead of not taking it,” they say. said.
According to Shenghan Lai, MD, MPH, a professor in the department of epidemiology and the Institute of Human Virology at the University of Maryland School of Medicine, this study outperforms other existing studies examining coronary artery disease in patients with HIV. In an accompanying editorial, he explained that using volume to quantify plaque burden can provide a more complete representation of the plaque.
“This study showed for the first time that HIV infection is associated with an increase in plaque prevalence and plaque volume, and that the latter conclusion is based on a more accurate characterization of plaque burden than some other previous methods,” he said. . “Coronary CT angiography should be considered the non-invasive imaging option of choice in further clinical, prognostic and mechanistic studies of HIV-associated atherosclerosis.”
The Chartrand-Lefebvre team agreed, adding that their results point to a healthier lifestyle that can fight atherosclerosis, especially critical for patients with HIV. The team stressed that it is imperative for the patient group to be aware of the additional risks associated with smoking, diabetes, high blood pressure, obesity and lack of exercise.
In addition, they said, the results also indicate how radiologists can use these scans.
“To radiologists, these results suggest that interpretation of coronary CT angiography in people with HIV should probably include quantification of coronary plaque by subtypes to allow for better stratification of cardiovascular risk,” said Chartrand-Lefebvre.
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