Daniel M. Keller, PhD

September 10, 2012

September 10, 2012 (San Francisco, California) — Unstable angina and myocardial infarction were more common in HIV-positive patients than in HIV-negative patients undergoing coronary artery catheterization, according to a new study. All patients were undergoing a first catheterization for chest pain or suspected coronary artery disease (CAD).

Urgent catheterizations were performed for unstable angina or myocardial infarction in 54% of the 96 HIV-positive patients and in 34% of the 41 HIV-negative patients (P = .04), senior author Charles Hicks, MD, professor of medicine in the division of infectious diseases at Duke University Medical Center in Durham, North Carolina, reported at a news conference here at the 52nd Interscience Conference on Antimicrobial Agents and Chemotherapy.

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.

Sex, age, and socioeconomic background were similar in the HIV-positive and HIV-negative groups, and both groups were largely male and black.

The HIV-positive patients had significantly more end-stage renal disease than the HIV-negative patients (15% vs 0%; P = .01), but less diabetes (23% vs 42%; P = .04). Most (87%) of the HIV-positive patients were receiving highly active antiretroviral therapy (HAART), and median CD4 cell count was 420 cells/mL.

At the time of catheterization, a significantly higher proportion of patients being cared for in an HIV clinic, compared with a similar group of HIV-negative patients, had a myocardial infarction or unstable angina, Dr. Hicks noted, "suggesting that opportunities 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 at catheterization, "patients were managed in an exactly equivalent way," regardless of HIV status. Approximately 70% of each group underwent stenting or bypass surgery (P = .90).

All patients had been in care for at least 3 consecutive visits prior to catheterization. "So we didn't think it was really an access-to-care issue as much as it was a failure to recognize the promontory signs or the risk factors" in the HIV-positive patients until coronary events were imminent or underway. The outcome measure of significant CAD was defined as a 50% or greater lesion in 1 or more major vessels.

Difficult to Find Appropriate Control Subjects

Despite a relatively young median age (49 years), the HIV-positive patients experienced significant CAD. Dr. Hicks noted that it was difficult to find control subjects of a similar age undergoing cardiac catheterization, which might help explain why there was no significant difference in the prevalence of significant CAD between the HIV-positive and HIV-negative groups (63% vs 54%; P = .35).

"I think it's a sample-size issue," Dr. Hicks speculated. "It's not a statistically significant difference, but it's tantalizing" to think that CAD could be picked up earlier in HIV-positive patients if more physicians were aware of this increased risk.

Among the possible reasons for the increased risk are the HIV infection itself, HAART medications, more smoking by HIV-positive patients, and other lifestyle issues.

Need for Greater Awareness

The prolonged survival of HIV-positive people associated with HAART has unmasked clinical conditions that warrant attention from healthcare providers, such as CAD, hyperlipidemia, and hypertension.

Lead study author Christy Kaiser, MD, formerly of Duke and now a cardiology fellow at Washington Hospital Center in Washington, DC, told Medscape Medical News that infectious disease specialists caring for HIV-positive patients need to decide whether they will act as primary care providers and "systematically do the preventive medicine — check for hypertension, cholesterol, smoking, weight loss" — or whether they will make it a practice to refer patients to a primary care provider for the usual preventive medical screenings and the treatment of comorbidities.

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

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

In an interview with Medscape Medical News, he said that patients often expect their HIV specialist to act as a general practitioner as well. "As these patients get older...we should pay attention to all their comorbidities — in particular those that can be associated with death, like cardiovascular disease and cancer — and we should be able to get a check-up by other specialists, in particular cardiologists."

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

The long-term use of some drugs, such as boosted protease inhibitors, can increase risk, "but this risk is minor in comparison to the risk of the [traditional] risk factors," Dr. Molina noted. "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 and smoking cessation."

There was no commercial funding for the study. Dr. Hicks, Dr. Kaiser, and Dr. Molina have disclosed no relevant financial relationships.

52nd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC): Abstract H-229. Presented September 9, 2012.