Unstable angina and MI are more common in HIV-infected patients undergoing a first coronary artery catheterization for chest pain or suspected coronary artery disease (CAD) compared with randomly selected patients of similar sex, age, and socioeconomic background who are HIV-negative, a new study suggests.

Speaking at a news conference here at the 2012 Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), senior author Dr Charles Hicks (Duke University Medical Center, Durham, NC) reported that among 96 HIV-positive patients, 54% of urgent catheterizations were done for unstable angina or MI vs 34% among the 41 HIV-negative patients (p=0.04).

All patients in this retrospective analysis of medical records were being seen at Duke or at the University of North Carolina at Chapel Hill. None had a diagnosis of CAD prior to the catheterization.

The HIV-infected patients had significantly more end-stage renal disease (15%) than the HIV-negative cohort (5%; p=0.01) but less prevalence of diabetes (23% vs 42%; p=0.04). Most (87%) of the HIV-infected patients were on highly active antiretroviral therapy (HAART) with a median CD4 cell count of 420/mL. Both groups were largely male and African American.

"A significantly higher proportion of those cared for in the HIV clinic at the time of catheterization either were having a myocardial infarction or having unstable angina," Hicks said, "suggesting that opportunities perhaps to diagnose chest pain, to start the diagnostic algorithm, were not being taken advantage of by the specialty providers."

He added that once the diagnosis was made upon catheterization, "patients were managed in an exactly equivalent way" regardless of HIV status. Approximately 70% in each group underwent stenting or bypass surgery (p=0.90).

All patients had been in care for at least three consecutive visits prior to catheterization. "So we didn't think it was really an access-to-care issue so much as it was perhaps a failure to recognize maybe the promontory signs or the risk factors" in the HIV-infected patients until coronary events were imminent or were under way. The outcome measure of significant CAD was defined as a 50% or greater lesion in one or more major vessels.

Difficult to find appropriate controls

The HIV-infected patients in this study experienced significant CAD despite their relatively young median age of 49 years. Hicks said finding controls of similar age (median 50 years) undergoing cardiac catheterization was difficult, which may help to explain the finding that there was no significant difference in the prevalence of significant CAD between the HIV-positive cohort (63%) and the HIV-negative cohort (54%; p=0.35).

"I think it's a sample size issue," Hicks speculated. "It's not a statistically significant difference, but it's tantalizing" to think that CAD could be picked up earlier in the HIV-infected population with greater awareness by physicians of the heightened risk.

Possible reasons for the increased risk are HIV infection itself, HAART medications, more smoking among the HIV-infected cohort, or other lifestyle issues.

Need for greater awareness

Improved survival of people infected with HIV on HAART has unmasked other clinical conditions, including CAD, hyperlipidemia, and hypertension, that warrant attention from healthcare providers.

Lead author Dr Christy Kaiser (Washington Hospital Center in Washington, DC) said in an interview that infectious-disease specialists caring for HIV-infected patients need to decide whether they will also act as primary-care providers "and to systematically do the preventive medicine—check for hypertension, cholesterol, smoking, weight loss"—or to make it a practice to refer their patients to a primary-care provider for the usual preventive medical screenings and treatment of comorbidities as they arise.

"You actually have a great opportunity with these patients because they are plugged into healthcare early," she said, "and so you can catch them even earlier than a lot of the non-HIV patients who are in the same demographic."

Dr Jean-Michel Molina (University of Paris, France), who was not involved in the study, agreed that physicians need to pay special attention to cardiac risk factors in HIV patients at a younger age "and maybe to send all patients with a number of cardiovascular risk factors to get an expert opinion by a cardiologist."

In an interview, he said that patients often expect their HIV specialist to act as a general practitioner as well. "As these patients get older and since their HIV infection is usually well-controlled now, we should pay attention to all their comorbidities and in particular those that can be associated with death, like cardiovascular disease and cancer, and we should be able to get a checkup by other specialists, in particular cardiologists."

He said usually the same risk factors for cardiovascular disease are found in HIV-infected patients as in the general population, such as family history, history of cardiovascular disease, smoking, and elevated blood lipid levels.

In addition, long-term use of some drugs like boosted protease inhibitors may increase risk. "But this risk is minor in comparison with the risk of the other [traditional] risk factors," Molina noted. "So I think we shouldn't be focused on drugs but rather be sure that we have taken into account the other risk factors that are modifiable, in particular lipids or smoking cessation."