Heart problems escalate in HIV patients using anti-retroviral therapy
Patients with HIV using an anti-retroviral therapy (ART) seem to have an increased risk of atherosclerosis and cardiovascular disease (CVD) risks, according to a scientific poster, “Cardiac Disease in Patients with HIV: Atherogenesis, CT Coronary Calcium Assessment, and Spectrum of Extracardiac Findings,” presented at the 93rd annual meeting of the Radiological Society of North America (RSNA) this week in Chicago.

J.S. Chen, MD, PhD, from department of radiology and medicine at the University of California at San Francisco, told Cardiovascular Business News that “Priscilla Hsue was the referring cardiologist, who runs an HIV/AIDS clinic in San Francisco, began recognizing how common cardiovascular events occur in her HIV patients several years ago.” Hsue started the HIV Cardiology Clinic in March 2004 at the Positive Health Program at Ward 86, which is one of the first subspeciality clinics of its kind in the United States.

Chen is pleased that the study was made available to the radiology community at RSNA 2007 because “as imagers, we have to be aware that there will be linkage in the extracardiac findings in HIV patients.”

Through this study, the researchers were seeking to understand the link between HIV and atherogenesis; to discuss the usage of CT coronary calcium assessment to evaluate coronary artery disease (CAD) in patients with HIV; and to discuss the spectrum of extracardiac findings and appreciated during such imaging.

More than one million in the United States have HIV/AIDS, with 40,000 new cases every year. There are more than four million cases of HIV/AIDS diagnosed globally.

The researchers questioned examined accelerated atherogenesis because there are case reports of severe premature CAD in young men with HIV. The typical patient is a male smoker who is younger than a corresponding non-HIV-infected patient. Also, restenosis rates post-percutaneous transluminal coronary angioplasty (PTCA) appear higher than in HIV population.

Overall, the researchers emphasized that classic coronary risk factors typically manifest their effects over decades before adverse coronary event occurs in non-HIV-infected populations, but these studies are beginning to suggest higher risk of MI over a much briefer span of time, which raises questions about a potentially increased atherogenesis patients with HIV receiving ART.

Chen said that “inherent C-reactive protein (CEP) is being correlated with CAD, and also seems to be correlated with HIV victims, and we now are attempting to find out if its linked to naturally degenerative effects of the HIV virus, or if its related in some way to ART.”

The potential mechanism for the link between accelerated atherogenesis and the HIV infection could be the inherent inflammatory state of HIV infection as well as other concurrent infections and lipodystrophy from active retroviral therapy.

The CT coronary calcium assessment, which noninvasively examines coronary artheroma, sought to detect subclinical CAD. They used non-contrast CT coronary calcium scoring.

The researchers retrospectively reviewed 267 asymptomatic HIV patients from the HIV Cardiology Clinic undergoing CT coronary calcium scoring from 2004 to 2007, and were evaluated for the presence and type of extracardiac findings. Of those patients, there were 231 males with a mean age of 48 years, and 36 Females with a mean age of 56 years.

The researchers separated their findings into three classifications: significant, those who necessitated immediate attention of follow-up imaging; non-critical findings, those of clinical interest, but now imaging follow-up or immediate attention needed; and incidental findings: which are not clinically relevant

The researchers found that 33 percent of the patients had extracardiac findings (87 of 267 studies) and had 8 percent had significant findings (23 of 267).

Nearly a quarter of extracardiac findings (23/87, or 26 percent were significant), which the researchers thought was the most critical finding of the study. The significant findings included pulmonary nodules, active bronchopneumonia, lymphadenopathy, an indeterminate adrenal lesion, indeterminate renal lesion and sclerotic bone lesions.

Chen stressed that even though the percentage of extracardiac findings may seem small, he wanted people to remember that more than 25 percent of those findings were significant, which could indicate serious potential cardiac risk.

The not-critical included right aortic arch, known nodules, known pericardial or pleural effusion, and/or lymphadenopathy. The incidental findings were “not surprisingly” the largest category (63 percent of all extracardiac findings; 55/87) 21 percent overall incidence (55/267), which included hepatic cysts, calcified lymph nodes and calcified granulomata.

Prior to this study, three observational studies have raised links between HIV infection, ART and CVD, but have been limited by low incidence of cardiovascular events, relatively brief duration of therapy, and retrospective design. Nonetheless, cardiac experts “are actively investigating the dyslipidemia and other metabolic changes prevalent in patients with HIV and on antiretroviral regimens and recommending assessment of risk with imaging studies such as coronary calcium scoring and carotid duplex sonography,” the researchers said.

Screening calcium scoring CT scans for HIV patients at increased risk of atherosclerosis as a substantial percentage (33 percent) have extracardiac findings, especially given interest in the use of CT to assess these patients for development of accelerated CAD and potentially to monitor response to intervention.

High prevalence of significant non-cardiac findings (about 10 percent) in CT coronary calcium assessment scans in asymptomatic HIV-positive patients would support the careful review of all extracardiac structures.

Chen said that he and his fellow researchers “are currently taking data to see if there is a distinction between these findings in non-infected HIV patients.”