Resource utilization and outcome among patients with selective versus nonselective troponin testing

In patients with suspected acute coronary syndrome (ACS), troponin testing is effective for diagnosis and prognosis. Troponin testing has now expanded to include patients without suspected ACS. This nonselective troponin testing has unknown consequences for resource utilization and outcome. Therefore, we examined selective versus nonselective troponin testing with respect to patient characteristics, resource utilization, and outcome. This retrospective 1-year study included all patients with troponin testing at a U.S. emergency department. Testing was classified as selective (ACS) or nonselective (non-ACS) based on admission ICD-9 codes. Troponin upper reference limit (URL) was ≥99th percentile. Among 47,053 patients, troponin was measured in 9109 (19%) of whom 5764 were hospitalized. Admission diagnosis was non-ACS in 4427 (77%) and ACS in 1337 (23%). Non-ACS patients were older, 71±17 versus 65±16 years, with longer hospital stay, 77 versus 32 h, and greater 1-year mortality 22% versus 6.7%; P