High-risk Coronary Plaque Regression in Cash-based Contingency Management Intervention Among Cocaine Users With HIV-associated Subclinical Coronary Atherosclerosis

Background Cocaine use exacerbates human immunodeficiency virus (HIV)-associated subclinical coronary atherosclerosis. We investigated whether cocaine abstinence or reduced use achieved with contingency management (CM) intervention would retard high-risk coronary plaque progression among cocaine users with HIV and subclinical coronary atherosclerosis. Methods Between March 2014 and August 2017, 76 cocaine users with HIV and coronary plaques were enrolled in a study designed to decrease cocaine use and determine whether doing so impacted progression of subclinical coronary atherosclerosis as measured by coronary artery computed tomography examinations. Of the 76, 7 did not complete the study, resulting in 69 participants. A 12-month cash-based CM intervention was implemented to promote cocaine abstinence or reduced cocaine use. Generalized estimating equation approach was used to perform longitudinal data analyses. Findings During the 12-month CM, all 69 participants reduced cocaine use, and of these, 25 (36%; 95% confidence interval, 25%-49%) achieved cocaine abstinence. After adjusting for potential confounding factors, generalized estimating equation analyses showed that (1) endothelin-1 (ET-1) levels, a proinflammatory biomarker for endothelial dysfunction, at the 6-month and 12-month visits were significantly lower compared with baseline ET-1 (P = 0.001 and P < 0.001, respectively), and (2) low-attenuation noncalcified coronary plaque volume, a predictor for myocardial infarction, at 12-month visit was significantly lower compared with baseline low-attenuation noncalcified coronary plaque volume (P < 0.05). Conclusions The findings of this study have not only demonstrated that CM is effective in achieving a sustained reduction in cocaine use, but also provided compelling evidence that reduction in cocaine use leads to quantifiable cardiovascular health benefits, including concurrent decrease in high-risk plaque burden and ET-1, among cocaine users with HIV-associated coronary atherosclerosis.