| |
Coronary Artery Walls Thicker in Young Adults With Early-Acquired HIV
|
| |
| |
4th International Workshop on HIV Pediatrics, July 20-21, 2012. Washington, DC
Compared with healthy HIV-negative people, 20 HIV-positive teens and young adults who got infected early in life had significantly thicker coronary vessel walls, an indicator of cardiovascular trouble [1]. This small study from branches of the US National Institutes of Health (NIH) used a novel "black-blood" coronary vessel wall magnetic resonance (MR) imaging technique that may have advantages over MR- or computed tomography (CT) angiography or measurements of carotid intima media thickness (cIMT).
Previous studies establish that HIV infection boosts the risk of myocardial infarction and stroke. Even young HIV-positive adults may bear this heightened risk, as suggested by autopsies of 15 HIV-positive people from 23 to 32 years old that documented coronary intimal thickening and endothelial thickening, and smooth muscle cell proliferation [2].
NIH investigators planned this study of HIV-positive teens and young adults with "black-blood" MR imaging, which shows the blood vessel rather than the lumen (as MR- and CT-angiography do), which is not operator-dependent (as cIMT is), and which does not require radiation.
This prospective study involved 20 HIV-positive teens and young adults and 12 healthy HIV-negative controls who had undergone MR of the proximal right coronary artery. No study participants had active cardiovascular disease or cardiovascular symptoms at the time of their scan.
Age averaged 21.1 years and ranged from 15 to 29 in the HIV group. In the control group, age averaged 29.3 years and ranged from 23 to 47, so they were significantly older than the HIV-positive people (P < 0.001). Ten of the HIV-positive people (50%) were men, compared with 5 (42%) of the HIV-negative controls. Average body mass index was similar in the two groups, 23.2 kg/m2 in HIV-positive people and 23.9 kg/m2 in controls.
Among the 20 people with HIV, 11 (55%) were black, 5 (25%) white, 2 (10%) Native American, and 2 (10%) Hispanic or mixed race. Fourteen people (70%) were using antiretrovirals at the time of their scan for an average 15 years. Eleven of these 14 were taking a protease inhibitor for an average 9 years. No one was taking lipid medication, and 1 was on antihypertensive therapy. Only 8 HIV-positive people had a viral load below 50 copies, current CD4 count averaged 559, and nadir CD4 count averaged 266. No one had a CD4 nadir below 200. Only 2 people (10%) with HIV smoked.
Average right coronary artery wall thickness was significantly greater in the HIV-positive teens and young adults than in the older HIV-negative controls (1.31 +/- 0.21 mm versus 1.07 +/- 0.12 mm, P = 0.0015).
Right coronary artery wall thickness was greater in HIV-positive people with a viral load below 50 copies than in those with a detectable load (1.4 versus 1.2 mm, P = 0.003). And there was a nonsignificant trend for an association between longer time on antiretroviral therapy and increased vessel wall thickness (r = 0.40, P = 0.07). But linear regression analysis found no association between artery wall thickness and duration of HIV infection, current or nadir CD4 count, or levels of total cholesterol, low-density lipoprotein cholesterol, or triglycerides. The researchers suggested, though, that analyses of larger groups may identify such associations.
The NIH investigators believe the significantly greater coronary artery wall thickness in the HIV group is "a likely surrogate marker of generalized vascular disease in a group of young patients who acquired HIV in early life." They believe these preliminary data suggest a relationship between antiretroviral therapy and vessel wall thickness. But they cautioned that the analysis rests on a small sample size and limited clinical data on controls, who were not matched to the HIV group by age.
The researchers called for "future development and validation of noninvasive techniques to accurately evaluate coronary artery vessel wall thickness and progression of atherosclerosis" in young, asymptomatic, at-risk populations.
References
1. Purdy J, Edwards E, Abd-Elmoniem K, et al. Evidence of coronary vessel wall thickening in asymptomatic young HIV positive patients using MR imaging of HIV-associated vasculopathy. 4th International Workshop on HIV Pediatrics. July 20-21, 2012. Washington, DC. Abstract LB_01.
2. Tabib A, Leroux C, Mornex JF, Loire R. Accelerated coronary atherosclerosis and arteriosclerosis in young human-immunodeficiency-virus-positive patients. Coron Artery Dis. 2000;11:41-46.
| |
| |
| |
|
|
|
