Outcomes Associated with Introduction of the 5th Generation High-Sensitivity Cardiac Troponin in Patients Presenting with Cardiovascular Disorders.

BACKGROUND:The new high-sensitivity cardiac troponin T (hs-cTnT) is now widely used in the United States. OBJECTIVES:We aimed to examine outcomes associated with the introduction of the new 5th generation hs-cTnT assay among patients presenting to the emergency department (ED) with cardiovascular (CV) disorders. METHODS:The study comprised 5377 patients presenting to the ED with CV disorders between January and September 2018. Outcomes included rates of direct ED discharge, cardiac testing/procedures, and mortality. CV indications for troponin testing were categorized as rule-out acute coronary syndrome (RO-ACS) and other-CV (O-CV). RESULTS:Mean age was 62 ± 17 years, and 47% were female. Demographics and medical history did not differ significantly between the troponin groups. The use of hs-cTnT was associated with increased rates of direct discharge from the ED in the RO-ACS (48% vs. 37%; p < 0.01), but not in the O-CV (25% vs. 25%) cohort. Cardiac tests/procedures were more often performed after hs-cTnT vs. cTnT testing in both cohorts (45% vs. 41% for RO-ACS, and 33% vs. 28% for O-CV; p < 0.05 for both). Multivariate analysis demonstrated that hs-cTnT was not associated with a significant increase in postdischarge mortality in both cohorts (RO-ACS: hazard ratio = 1.47 [p = 0.13], O-CV: hazard ratio = 0.97 [p = 0.87]). CONCLUSIONS:Among patients with RO-ACS, hs-cTnT implementation resulted in increased rates of direct home discharge from the ED, without a significant increase in postdischarge mortality. Among patients presenting with O-CV indication, hs-cTnT implementation resulted in increased rates of cardiac testing procedures without an effect of ED discharge rates or long-term mortality.