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

BackgroundCocaine 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.MethodsBetween 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.FindingsDuring 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).ConclusionsThe 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.