HIV-positive cocaine users have higher rates of coronary calcification

Infection with HIV and concurrent cocaine use may contribute to the early stages of the hardening of the heart’s arteries, according to a study conducted in the US and published in the March 28^th edition of the Archives of Internal Medicine. The investigators from Baltimore found that being HIV-positive, use of cocaine, and being HIV-positive and using cocaine were significantly associated with subclinical coronary calcification.

Cocaine has been shown to cause arterial damage and it has been postulated that infection with HIV can contribute to cardiovascular disease through inflammatory responses to the virus.

Investigators from Baltimore wished to examine the association of HIV infection, cocaine use, and a combination of HIV infection and cocaine use with coronary calcification, a marker of subclinical atherosclerosis.

A total of 224 black individuals aged between 25 and 45 were recruited to the study between Spring 2000 and Spring 2003. Both HIV-positive and HIV-negative individuals were recruited to the study. Individuals were excluded if they had a diagnosis of heart disease, symptoms suggestive of heart disease, or were pregnant.

Sociodemographic details and drug use information were obtained using a questionnaire. Fasting blood lipids and blood pressure were also measured and individuals underwent a computed tomographic (CT) scan to determine coronary calcium.

Cocaine was used by 153 individuals (68%) and a total of 124 individuals (55%) were HIV-positive. Mean age was 38 years, however HIV-positive cocaine users were significantly younger (mean 27 years p < 0 .001). HIV-positive cocaine users were also significantly more likely to smoke, and had a significantly lower body mass index

A total of 192 individuals underwent a CT scan and were included in the investigators’ analysis. The proportion of HIV-positive patients who used cocaine with coronary calcification was significantly higher than that in HIV-negative individuals with no cocaine use. The highest rate of coronary calcification was seen in HIV-positive cocaine users (38%), followed by HIV-negative cocaine users (30%), HIV-negative individuals who did not use cocaine (29%), and HIV-positive non-cocaine users (18%).

However, in further analysis, the investigators also noted that amongst non-users of cocaine, HIV-positive individuals had more calcified lesions, a larger calcified area (p < 0.01), a higher calcification total volume score (p < 0.01), and a higher calcification score (p < 0.01) than HIV-negative individuals. What’s more, calcification scores were similar for HIV-positive individuals, regardless of cocaine use (p < 0.05).

In multiple regression analysis, the investigators established that individuals who were HIV-positive (p = 0.05), individuals who were HIV-positive and used cocaine (p = 0.003), and HIV-negative cocaine users (p = 0.02) had higher total calcification scores.

Because 75% of HIV-positive individuals were taking a protease inhibitor, a class of antiretrovirals which has been associated with accelerated atherosclerosis, the investigators conducted further analysis. This compared HIV-negative non-users of cocaine with HIV-positive non-users of cocaine who were not taking a protease inhibitor. When body mass index was accounted for, the investigators still found that being HIV-positive was significantly associated with coronary calcification (p = 0.02).

“This study in young adults demonstrates a positive association of HIV infection, cocaine use, and both with coronary artery calcification. These findings suggest that HIV infection and cocaine use may be involved in the development of subclinical atherosclerosis”, write the investigators.

The investigators do, however, caution that their study had a cross-sectional design “and the results from this study need to be explained with caution.”

Nevetheless they conclude, “this study suggests that HIV infection, cocaine use, or both may contribute to early subclinical atherosclerotic cardiovascular disease. Studies with a larger sample size are needed to test the interaction between HIV infection and cocaine use, and clinical trials are needed to examine whether reduction in cocaine use is an effective means of preventing atherosclerosis and, thus, ameliorating the burden of coronary disease.”