Self-reported cocaine use is not associated with elevations in high-sensitivity troponin I

OBJECTIVE: High-sensitivity troponin (hsTn) assays detect 10 times lower concentrations of cardiac troponin than conventional assays. We examined the effects of self-reported cocaine use to determine whether those with acute cocaine use being evaluated for ACS are more likely to have elevated hsTnI than those nonusers being evaluated for ACS. METHODS: We conducted a sub-analysis of a prospective cohort of ED patients evaluated for acute coronary syndrome. Recent cocaine use was determined by structured patient interviews. High-sensitivity troponin (Abbott) and conventional troponin I (Abbott, cTnI) were measured on samples drawn at presentation. Urine toxicology screen for cocaine metabolite was obtained at the discretion of treating clinicians. RESULTS: Of 1862 patients enrolled, 444 reported prior cocaine use and 99 reported cocaine use within the preceding month. Median hsTn in patients with last cocaine use within 24 h, 2-7 days, 1 week-1 month, >1 month, and no prior cocaine use were: 9 (IQR: 3-17) ng/L, 6 (IQR: 3-24.3) ng/L, 6 (IQR: 3-89.5) ng/L, 3 (IQR: 3-18.5) ng/L and 3 (IQR: 3-17) ng/L, respectively. Urine toxicology assays (UTox) for cocaine were performed in 640 (34.4%) patients. The median hsTn for those who were UTox+, UTox - and those without a UTox were: 9 ng/L (IQR: 3-48.5), 9 ng/L (IQR: 3-40) and 3 ng/L (IQR: 3-12), respectively. There were no differences in the prevalence of new troponin elevations (hsTn >99th percentile but cTnI <99th percentile) in those with recent cocaine use compared to those without recent cocaine use. CONCLUSIONS: In this first investigation of hsTn in patients with self-reported recent cocaine use, we have determined that hsTn does not lead to an increase in the prevalence of troponin elevation in cocaine users.