Coronary Plaque Progression and Regression in Asymptomatic African American Chronic Cocaine Users With Obstructive Coronary Stenoses: A Preliminary Study.

OBJECTIVE: Although rapid progression of coronary atherosclerosis was observed in chronic cocaine users, it is unknown whether reduced cocaine use retards the progression of atherosclerosis. We investigated whether reduced cocaine use over a 12-month period was associated with coronary plaque regression in cocaine users.
METHODS: Fifteen African American chronic cocaine users with previously coronary computed tomography angiography (CCTA)-confirmed >50% coronary stenosis in Baltimore, Maryland, were enrolled in a study to investigate whether reduced cocaine use is associated with changes in coronary plaque burden over a 12-month period of cash-based incentive intervention, which was implemented to systematically reinforce cocaine abstinence. In addition to previous CCTA (preintervention), CCTA was performed at the intervention baseline and at postintervention. Plaque analyses were performed to determine the trajectory of plaque changes in the absence of intervention by comparing the preintervention with the intervention baseline studies; the trajectory of plaque changes associated with the intervention by comparing the intervention baseline with the postintervention studies; and (3) whether reduced cocaine use was independently associated with changes in coronary plaque burden.
RESULTS: During the 12-month cash-based incentive intervention period, cocaine use in participants was lower. The medians of noncalcified plaque indices were 37.8 (interquartile range [IQR] 29.3-44.0), 43.1 (IQR 38.3-49.0), and 38.7 (IQR 31.2-46.8) mm at preintervention, intervention baseline, and postintervention, respectively. Multivariable generalized estimating equation analysis showed that both total plaque and noncalcified plaque indices at preintervention were significantly lowered as compared with intervention baseline levels; both total plaque and noncalcified plaque indices after intervention were significantly lowered as compared with intervention baseline levels; and reduced cocaine use was independently associated with lower total plaque volume index (P < 0.0001) and noncalcified plaque volume index (P = 0.010).
CONCLUSIONS: Our findings suggest that continued cocaine use may be associated with noncalcified plaque progression, whereas reduced cocaine use may be associated with noncalcified plaque regression. Larger studies are needed to confirm these findings.