There were a number of presentations and posters on HIV and the heart this year at the Conference on Retroviruses and Opportunistic Infections (CROI) in Atlanta. These ranged from studies showing that a common scoring system for heart attack risk may under-estimate risk in people with HIV; studies showing higher rates of heart disease in younger HIV-positive people; data about whether cholesterol-lowering statin drugs can reduce mortality; and the fact that people with HIV aren’t taking aspirin to protect their hearts to the same degree as similar HIV-negative people.
HIV and Cardiovascular Disease (CVD)
One of the most common ways to “score” your risk of having a heart attack comes from the years’ long Framingham heart study. The Framingham Risk Score (FRS) takes into account your weight, blood pressure, cholesterol levels and smoking history among other things. People with a lower score (under 10%) have a lower risk of having a heart attack in the coming 10 years than people with a higher score (usually 20% or more).
Previous studies have found that people with HIV might be more prone to heart attacks than HIV-negative people who have similar heart attack risks and that HIV itself may play a role in this. What hasn’t been known is whether the FRS is adequate at predicting which people with HIV are at the highest risk of a heart attack. There are also concerns that people with hepatitis C virus (HCV) may also be missed by the FRS.
To determine this, researchers looked at data from an archive of male veterans enrolled in a Veterans Affairs study from 2001 through 2009. Veterans with HIV and HCV were more likely to have drug and alcohol abuse histories than those without either disease. They were also less likely to use cholesterol lowering drugs.
In short, researchers found that the FRS was about equally good at predicting heart attack risks in men infected with HCV alone and in non-infected men, but that it under-estimated the risk in men with either HIV alone or those co-infected with both HIV and HCV. This is not the only study to find that the FRS may be underestimating heart attack risks in HIV-positive individuals. To date, a replacement or modification of the FRS specific to people with either HIV or HCV has not been widely validated though some newer scoring systems exist.
A different study among HIV-positive veterans involved in the Veterans Aging Cohort Study (VACS) looked not only at heart attacks, but also end-stage kidney disease and non-AIDS related cancers. As for heart attacks, there was evidence that HIV-positive veterans had an 81% increased risk compared to similar HIV-negative veterans. HIV-positive men also had greater amounts of plaque in their arteries. Researchers associated with the study hypothesized that HIV-related inflammation might be driving the increased risk.
Given a study earlier in the year showing that smoking alone outweighs HIV in terms of risk of death, it is even more critical that people with HIV seek to quit smoking, moderate their alcohol use, eat healthfully and get ongoing exercise.
Statins to Reduce Death Risk?
Though one study at CROI found that statins were effective at reducing markers of immune inflammation, something that should be helpful in reducing the risk of CVD and other illnesses, two larger studies of statin use by HIV-positive individuals did not find a statistically significant improvement in CVD or all-cause mortality from statin use. In both cases, especially with more potent statins such as atorvastatin and rosuvastatin, there was a trend toward lower rates of heart disease, but not quite large enough to be truly meaningful. Other studies, however, have suggested beneficial effects of statins on heart disease in HIV-positive people. In the larger study, from the Veterans cohort, statin therapy there was a trend toward both a decreased risk of non-AIDS cancers and death.
Is HIV More Potent Than Aspirin?
Finally, one study looked into aspirin use and its effects in people living with HIV in a large Boston health system. Although aspirin has well-proven beneficial effects on heart health in HIV-negative people, less is known about its effect in HIV-positive individuals.
Researchers in this study looked at two things. First, they examined how often aspirin was used by study participants. Second, they analyzed whether low-dose aspirin had a beneficial effect on heart attacks. The results moved in opposite directions.
While aspirin use was much lower among HIV-positive men than HIV-negative men or women (HIV-positive women had similar rates to HIV-negative women), there didn’t seem to be any positive influence of aspirin on the risk of having a heart attack. Experts say that what’s needed is a randomized study of aspirin in HIV-positive people at risk of CVD or inclusion of more people with HIV in CVD studies.