Diffusion of troponin testing in unstable angina patients: adoption prior to guideline release

We examined diffusion of troponin testing in Medicare patients with unstable angina before the release of year 2000 American College of Cardiology/American Heart Association guidelines recommending measurement in all patients with acute coronary syndromes. We identified unstable angina admissions from Medicare administrative files for 22 Alabama hospitals over two time periods: 03/1997–02/1998 and 01/99–12/1999. Data were obtained from chart abstraction. Patients not confirmed for unstable angina by a clinical algorithm were eliminated. For 1997–1998, 1116 (87.7%) of all identified cases were clinically confirmed for unstable angina, and 1176 (90.3%) were confirmed for 1999. In 1997–1998, 235 (21%) of unstable angina patients had troponin measured, compared to 822 (70%) in 1999. From 1999, patients with troponin measurement, vs. those without, more likely had typical angina (50.9%, 37.4%), chest pain on arrival (72.8%, 57.1%), and chest pain at rest (45.4%, 37.2%) and more often received EKG within 20 min of presentation (46.3%, 27.9%) ( P