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CROI 2013: Heart Disease Rises Only Slighter Faster with Age for People with HIV

The risk of cardiovascular disease among HIV positive men in D:A:D rose from age 40-45 to 60-65, but only slightly more rapidly than in the general population,researchers reported at the 20th Conference on Retroviruses and Opportunistic Infections (CROI 2013) last week in Atlanta. A related analysis found that the likelihood of death after a heart attack has fallen over time.

Several presentations at CROI provided additional information on cardiovascular disease in people with HIV, including current epidemiology, pathogenesis, prediction of risk, and outcome monitoring.

Heart disease is one of the non-AIDS conditions of increasing concern as HIV positive people grow older. Over the years it has been challenging to accurately characterize just how bad heart disease is in people with HIV, as the methods and time it takes to collect the necessary information have been difficult to accomplish.

One study presented at CROI showed that the risk of heart disease among people with HIV is slightly higher according to age compared with the general population.

D:A:D (Data Collection on Adverse Events of Anti-HIV Drugs) is a large, ongoing prospective cohort study that assesses adverse event rates and risks among HIV positive people in the Europe, the U.S., and Australia.

Kathy Petoumenosfrom the University of New South Walesand colleagues set out to see whether the risk of cardiovascular disease increases faster with age among people with HIV. Their analysis focused on HIV positive men in D:A:D who had no prior cardiovascular disease and had all heart disease risk data available, including family history, smoking, diabetes, and laboratory values. The researchers analyzed 139,115 person-years of follow-up data from 24,323 men.

The researchers adjusted their analysis for cardiovascular risk factors including family history, smoking, cumulative lopinavir/ritonavir (Kaletra) and indinavir (Crixivan) use, use of abacavir (Ziagen, also in the Epzicom coformulation) within 6 months, diabetes, total cholesterol, HDL ("good") cholesterol, and systolic blood pressure (the top number). They then compared their results to general population cardiovascular risk cohorts including the Framingham Heart Study, CUORE (an study of Italian men), and ASSIGN (a Scottish cohort).

Results

• The researchers identified 474 myocardial infarctions (MIs) or heart attacks, 683 cases of coronary heart disease (CHD), and 884 cases of cardiovascular disease overall.
• As expected, crude event rates for heart attacks, CHD, and cardiovascular disease were higher at age 60 to 65 than at age 40 to 45.
• Heart disease incidence at age 40 to 45 vs 60 to 65 in D:A:D men was as follows:

o   MI incidence: 2.29 vs 6.53 per 1000 person-years;

o   CHD incidence: 3.11 vs 11.91 per 1000 person-years;

o   Cardiovascular disease: 3.65 vs 15.89 per 1000 person-years.

• The relative risk curves for the risk of CHD in men ages 40 to 65 were somewhat greater that those for the 3 general population studies.
• Cardiovascular disease relative risk for HIV positive men increased slightly faster after the age of 40 compared with the general population models.
• However, the relative risk of MI in HIV positive men with increasing age after 40 was similar to the Framingham general population model.
• Stopping smoking had the biggest impact as an intervention in people over 50 years old.
• Lowering cholesterol by 1 mmol/L and blood pressure by 10 mmHg had less of an impact.

The absolute risk of cardiovascular disease associated with HIV is still unknown. However, this analysis concluded that cardiovascular disease increased with age in the D:A:D cohort, but "only slightly faster" than seen in the general population, the researchers concluded.

They noted that, "the additional multiplicative risk of HIV infection is not unlike other risk factors such as smoking." These results suggest that working to lower cardiovascular disease risk in younger people with HIV would reduce the longer-term risks at older ages.

In a related D:A:D analysis,Caroline Sabin from University College London and colleagues found that mortality following myocardial infarction in people with HIV had decreased over time from 1999 to 2011. Looking at 844 cases of MI, they found that most people (91%) who had heart attacks were men, almost all (96%) had used antiretroviral therapy (ART), the median CD4 count was approximately 440 cells/mm³, and just over half were smokers.

One-tenth of people who had had a heart attack had another MI and one-third died during follow-up. A majority of deaths (61%) occurred during the first month after an MI. While cardiovascular causes were responsible for about 90% of deaths during the first month, it then became a less important factor, accounting for about 40% of deaths thereafter. The proportion of people who died within 1 month after an MI fell from 26% during 1999-2002 to 20% during 2005-2006 to 8% during 2009-2011 -- a decrease of 12% per year.

The researchers found that reduced post-MI mortality was attributable to greater use of cardiovascular medications (such as lipid-lowering and blood pressure drugs) and surgical procedures, but cautioned that a considerable proportion of D:A:D participants were still not receiving appropriate cardiovascular care.

3/15/13

References

K Petoumenos, W El-Sadr, A d’Arminio Monforte, et al. Increased Risk of Cardiovascular Disease with Age in Men: A Comparison of D:A:D with HIV^– Cardiovascular Disease Risk Equations. 20th Conference on Retroviruses and Opportunistic Infections (CROI 2013). Atlanta, March 3-6, 2013. Abstract 61.

C Sabin, L Ryom, M Law, et al. Improvements in short-term mortality following myocardial infarction: the Data Collection on Adverse Events of Anti-HIV Drugs Study. 20th Conference on Retroviruses and Opportunistic Infections (CROI 2013). Atlanta, March 3-6, 2013. Abstract 748.