Heart Disease Risk Varies Among the PIs: Comparing Atazanavir and Nelfinavir

June 3, 2007
John Schieszer

Internal Medicine World Report, February 2006, Volume 0, Issue 0

WASHINGTON, DC?Patients with HIV who are receiving the protease inhibitor (PI) atazanavir (Reyataz) appear to be less likely to develop coronary artery disease (CAD) than those taking the PI nelfinavir (Viracept). And the lower incidence of heart disease with atazanavir appears to be maintained, regardless of smoking status, diabetes, or hypertension, according to new data presented at the 45th annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

Patients with HIV who develop lipid abnormalities as a result of their highly active antiretroviral therapy (HAART) appear to face the same CAD risk as the general population with dyslipidemia. With this in mind, investigators at the University of Connecticut in Storrs compared the 10-year risk for CAD of HIV-infected patients receiving either ata?zanavir or nelfinavir.

Data were obtained from a randomized, controlled study that evaluated the efficacy and safety of atazanavir, 400 mg daily (n = 101), and nelfinavir, 750 mg 3 times daily (n = 100), as part of HAART including didanosine (Videx) and stavudine (Zerit) in treatment-na?ve pa?tie?nts. These data were then incorporated into two, 5000-patient Monte Carlo simulations?a type of study that combines thousands of iterations of data in order to reach a clearer outcome.

Baseline cholesterol levels and percent change in cholesterol levels at 48 weeks after PI administration were used to estimate individual cholesterol profiles, which were then used to model patients' 10-year CAD risk using the Framingham risk equation for men in the presence or absence of additional CAD risk factors.

"We looked at different things that may affect the risk of CAD.... We found that if a person had no risk factors, then atazanavir had significantly less risk of CAD associated with it. We also found that if a patient was a smoker and had diabetes as well as hypertension, that atazanavir was associated with a lower incidence of angina, stroke, vascular disease, myocardial in?farc?tion, and death," said lead investigator Effie Gillespie, PharmD, Pharma?coeconomics and Outcomes Research Fellow at the University of Connec?ticut/ Hartford Hospital.

Dr Gillespie noted that this is an important issue to consider when beginning antiretroviral therapy. In addition, many trials have demonstrated a connection between hyperlipidemia and in?creased mortality.

However, this study has several limitations, including the fact that it only looked at dyslipidemia. The differences between the 2 agents were statistically significant, with the risk being lowered by 33% for patients taking atazanavir compared with nelfinavir, according to Dr Gillepsie.

"When it comes to managing HIV patients, we now know that we need to look at long-term issues and look closely at how HAART regimens are affecting other parts of the body, such as lipid levels," she told IMWR. "These patients are living longer, and they are dying of comorbid conditions such as CAD. We need to start thinking about these issues in the beginning, so they can live even longer than they are currently."