Background: The High-STEACS (High-Sensitivity Troponin in the Evaluation of Patients With Acute Coronary Syndrome) pathway risk stratifies emergency department patients with possible acute coronary syndrome. This study aims to determine if the High-STEACS hs-cTnT (high-sensitivity cardiac troponin T) pathway can achieve the ≥99% negative predictive value (NPV) safety threshold for 30-day cardiac death or myocardial infarction (CDMI) in a multisite US cohort of patients with and without known coronary artery disease (CAD).
Methods: A secondary analysis of the STOP-CP (High-Sensitivity Cardiac Troponin T [Gen 5 STAT Assay] to Optimize Chest Pain Risk Stratification) cohort, which enrolled adult emergency department patients with possible acute coronary syndrome at 8 US sites (January 25, 2017-September 6, 2018). Participants were classified into outpatient and admission dispositions using the High-STEACS hs-cTnT pathway. Known CAD was defined as prior MI, coronary revascularization, or ≥70% coronary stenosis. Outcomes included 30-day CDMI and efficacy, defined as the proportion identified for outpatient disposition. NPVs and negative likelihood ratios for 30-day CDMI were calculated. NPVs were compared between CAD subgroups using a Fisher exact test.
Results: Among 1351 patients, 53.2% (719/1351) were male, 31.4% (424/1351) had known CAD, and the mean age was 57.4±12.8 years. At 30 days, CDMI occurred in 13.8% (187/1351). High-STEACS classified 63.4% (857/1351) to outpatient disposition, of which 2.0% (17/857) had 30-day CDMI, corresponding to an NPV of 98.0% (95% CI, 96.8-98.8) and negative likelihood ratio of 0.13 (95% CI, 0.08-0.20). In patients with CAD, 46.9% (199/424) were classified to outpatient disposition, of which 4.0% (8/199) had 30-day CDMI. Among patients without CAD, 71.0% (658/927) were classified to outpatient disposition with 1.4% (9/658) having 30-day CDMI. The NPV for 30-day CDMI was 96.0% (95% CI, 92.2-98.2) in patients with CAD versus 98.6% (95% CI, 97.4-99.4) among patients without CAD (P=0.04). The negative likelihood ratio for 30-day CDMI among patients with CAD was 0.16 (95% CI, 0.08-0.31) and 0.12 (95% CI, 0.06-0.22) among patients without CAD.
Conclusions: The High-STEACS hs-cTnT pathway had high efficacy but was unable to achieve the ≥99% NPV safety threshold for 30-day CDMI.
Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02984436.
Keywords: United States; acute coronary syndrome; coronary artery disease; myocardial infarction; troponin.