Why does HIV Pose a Greater Threat to Women’s Hearts?
Cross-posted from NIAID Now Blog
HIV-related heart disease is a leading cause of death among people living with HIV—even when they are on consistent, effective HIV treatment. Researchers are learning that this complication is likely brought on by chronic inflammation from the virus itself and other factors. What is less understood is why HIV seems to take a greater toll on the hearts of women.
While men living with HIV are 1.5 times more likely to have a heart attack than HIV-negative men, that risk doubles when comparing women living with HIV to their HIV-negative counterparts.
NIH-funded scientists are on the case to learn just why this disparity exists and how to ensure women with HIV live longer, healthier lives. New research published in the Journal of Acquired Immune Deficiency Syndromes last month presents vital clues to help close the gender gap. Researchers led by Markella Zanni, M.D., at Massachusetts General Hospital now report that the presence of plaque in the coronary arteries, a common risk factor for heart attacks, manifests itself differently in women living with HIV than in men.
Dr. Zanni’s team compared data from previous studies of Boston-area men and women living with HIV who were not known to have heart disease but who underwent a common imaging technique called coronary computed tomography angiography, or CCTA. CCTA captures the extent and nature of plaque in a person’s arteries and, in doing so, allows clinicians to more precisely assess a patient’s risk of a heart attack. According to the new study, men living with HIV had nearly four times the odds of coronary plaque and a particularly high-risk type of coronary plaque than women living with HIV—even though women have a greater HIV-attributable risk of heart attack. But, why are women still at higher risk?
Studies in HIV-negative populations have also shown that women tend to have less coronary plaque than men, despite worse outcomes from heart disease. The disparity suggests less-studied mechanisms may underlie a woman’s chance of serious cardiovascular events like heart attacks, including plaque hidden in smaller blood vessels feeding the heart. However, without further research, it is not clear whether these observations apply to women living with HIV who have an even greater risk of heart disease.
What researchers can be sure of is that biological sex differences do play a role in the development of HIV-related disease, and as findings from the current study underscore, clinicians should be wary of applying evidence from HIV-related heart disease studies of only male participants to the care of women living with HIV.
Researchers are probing new data to learn how sex differences in heart disease and the progression of HIV infection work together. The REPRIEVE trial, an ongoing study led by Drs. Steven Grinspoon and Pamela Douglas, and supported by the National Institute of Allergy and Infectious Diseases and the National Heart, Lung and Blood Institute, will assess the ability of a statin medication to prevent HIV-related heart disease in both men and women. Within this large, international trial, Dr. Zanni and her colleague Dr. Sara Looby will lead an assessment of how sex differences influence the mechanisms, risk and treatment of heart disease in the context of HIV. Ultimately, physicians may be able to tailor the way they assess and treat the hearts of women living with HIV with evidence specific to both their patient’s sex and HIV status.