Management of Elevated Blood Lipids May Be Less Successful in HIV Patients with High Cardiovascular Risk

By Liz Highleyman

Cardiovascular disease is a growing concern as people with HIV live longer. While the association between HIV infection itself, antiretroviral drugs, and cardiovascular events is not yet fully understood, experts agree that managing controllable cardiovascular risk factors is desirable across the board.

The International Disease Society of America (IDSA) and the AIDS Clinical Trials Group (ACTG) have developed guidelines -- based on those of the National Cholesterol Education Program (NCEP) -- for managing cardiovascular risk in HIV positive individuals, including target blood lipid levels.

At the XVII International AIDS Conference last month in Mexico City, investigators with the HIV Outpatient Study (HOPS) presented a poster describing a study of cardiovascular risk management in this cohort.

The researchers analyzed 1697 participants with sufficient data (at least 2 office visits, at least 2 blood pressure readings, and at least 1 lipid panel measured within one year of the first visit after January 1, 2002). Patients were categorized into 4 strata of 10-year cardiovascular disease risk as defined in the NCEP guidelines.

Myocardial infarction

The investigators followed patients until June 30, 2007, death, or their last office visit. They calculated rates of incident (new) cardiovascular events, defined as myocardial infarction, coronary artery disease, peripheral vascular disease, transient ischemic attack, angina, aortic aneurysm, coronary artery bypass, or angioplasty. They also examined trends in the proportion of guideline-eligible patients treated for dyslipidemia (abnormal blood lipids) and hypertension.

Results

• Among the 1697 patients with sufficient data, 557 (32.8%) had < 2 cardiovascular disease risk factors and were considered low risk.

• Among participants with > 2 risk factors:

• 470 patients (27.7%) had a 10-year cardiovascular risk < 10% (moderate risk);
• 322 (19.0%) had a 10%-20% risk (moderately high risk);
• 348 (20.5%) had a risk > 20% (high risk).

• Traditional cardiovascular risk factors -- older age, male sex, hypertension, diabetes, metabolic syndrome -- were more common at each successive higher risk level.

• Rates of incidence cardiovascular disease were 0.37 per 100 person-years in the low risk group, 1.01 in the moderate risk group, 2.24 in the moderately high risk group, and 3.79 in the high risk group.

• For participants in each risk category, the percentage of individuals with low density lipoprotein (LDL)/non-high density lipoprotein (non-HDL) cholesterol, triglycerides, and hypertension that exceeded goals, or HDL below the goal, increased with each successive higher risk category.

• More than half the patients in all groups received lipid-lowering therapy.

• Compliance with NCEP treatment guidelines increased with increasing risk level.

• However, among patients treated according to the guidelines, a decreasing percentage achieved target LDL goals in each successive higher risk category.

• 86.0% in the low risk group;
• 62.0% in the moderate risk group;
• 52.5% in the moderately high risk group;
• 36.4% in the high risk group.

• For the HDL, triglycerides, and hypertension goals, there was no significant difference between the risk groups.

"At least one-fifth of contemporary HOPS patients have a 10-year cardiovascular risk > 20%," the investigators concluded.

"Despite a high frequency of clinical encounters and higher compliance with NCEP guidelines with increasing cardiovascular risk, achievement of treatment goals fell with successively higher cardiovascular risk," they continued. "These findings highlight the challenge clinicians and patients face modifying major cardiovascular disease risk factors in the HIV-infected population."

National Jewish Health, Denver, CO; Cerner Corporation, Vienna, VA; Temple University, Philadelphia, PA; Northwestern University, Chicago, IL; Centers for Disease Control and Prevention, Atlanta, GA.

9/09/08

Reference
KA Lichtenstein, K Buckner, C Armon, and others. Adherence to U.S. National Cholesterol Education Program (NCEP)-based IDSA/ACTG guidelines for management of cardiovascular risk in the U.S. HIV outpatient study (HOPS). XVII International AIDS Conference (AIDS 2008). Mexico City. August 3-8, 2008. Abstract THPE0229.