Cardiovascular Disease Risk

• Do Protease Inhibitors Increase the Risk for Coronary Heart Disease Among HIV-Positive Patients-Follow-Up Through June 2000 (Poster 655)
  Authored by D. Klein, L. Hurley, M. Sorel, and S. Sidney
  View the original abstract

The use of combination antiretroviral medications has clearly increased the life expectancy for those infected with HIV. Long-term survival, therefore, will likely require the long-term administration of medications. The down side to this is the potential for increasing the risk of long-term complications and toxicities. One potential complication is coronary heart disease. It is known that several HIV drugs, particularly protease inhibitors, increase the levels of total cholesterol and LDL (the "bad") cholesterol. Worse yet, HDL levels (the "good") often go down. The net effects of these changes are to increase the cardiac risk ratio (a measure of cholesterol risk). There are varying reports of HIV-infected patients with heart disease. Fortunately, heart disease among generally young populations of people is rare. For researchers, this rarity imposes some difficulty, as patients need to be followed for long periods of time in order to get an accurate assessment of the disease. One way to circumvent this issue is to study large cohorts of people.

Klein and colleagues at the Kaiser Permanente of Northern California conducted this study to evaluate the risk of coronary heart disease (CHD) in persons with HIV. The Kaiser group is uniquely positioned to answer this question as all patients in this HMO plan receive most (if not all) of their health care and medications from providers within the plan. Analysis of this observational cohort of over 4,500 patients (starting in 1996), representing 14,700 patient-years of follow up were presented. Hospital events among HIV-infected persons that led to a coronary heart disease discharge diagnosis were categorized, and compared to random age- and sex-matched individuals. There were 23 coronary heart disease hospitalizations, 15 because of heart attacks. The age-adjusted coronary heart disease event rates were similar among patients who took protease inhibitors and those who did not. The rate for all HIV-positive cases was 1.6 times higher than HIV-negative controls.

The basis for this increased rate of coronary heart disease is unknown. Is it possible that the HIV-infected individuals had high frequencies of other risk factors for coronary heart disease? The authors begin to address this question with a health behavioral survey and from this survey, rates of high blood pressure, elevated cholesterol, diabetes, and tobacco use could be assessed. This data was obtained from 264 HIV-infected and 710 HIV-negative individuals. The rates were generally in keeping with published rates of classic coronary heart disease risk factors in the United States. There was a moderately higher level of hypertension in HIV negatives (compared with HIV positive) and a greater likelihood of hypercholesterolemia in HIV infected. There was no difference in the reporting of diabetes and tobacco use.

These studies are of relevance to the North American treatment community. Long-term survival gives us the luxury of worrying about long-term health risk. For the first time in years, I talk about smoking and high blood pressure with my patients. We do screenings for prostate, breast, and colon cancer. Coronary heart disease risk is a major focus of our preventive medicine strategies. While one would like to see multiple, independent confirmation of increased risk, the Kaiser study provides a basis for further discussions and research. Lacking currently are good outcomes data regarding modifying coronary heart disease interventions in the HIV population. This study reinforces the need to be vigilant about modifiable coronary heart disease risk factors and the management of elevated cholesterol. The need to control HIV and immune depletion must always be paramount, but a balanced assessment of risk is an important element to caring for the total health needs of individuals.