Accelerated diagnostic pathways for risk stratification of patients presenting to the emergency department with potential acute coronary syndromes may identify very-low-risk patients safe for early discharge to outpatient care.

Patients presenting with potential acute coronary syndrome to the emergency department were prospectively enrolled between November 2007 and April 2010. Patient characteristics in conjunction with 0- and 2-hour biomarkers and electrocardiograms were analyzed according to a 2-hour thrombolysis in myocardial infarction (TIMI) score and 9 other accelerated diagnostic pathways. The primary outcome was acute coronary syndrome by 30 days.

Of 1,000 patients, 362 (36.2%) had a primary outcome. A pathway comprising electrocardiogram, prior ischemic heart disease, 0/2-hour troponin/creatine kinase MB fraction/myoglobin identified the highest proportion (25.0%) as low risk, with 96.1% sensitivity for the primary outcome. A pathway comprising electrocardiogram, history of ischemic heart disease, typical vs atypical symptoms, 0/2-hour troponin was the safest, with 99.7% sensitivity for the primary outcome, but only 9.0% were low risk. A pathway comprising the TIMI score with 0/2-hour troponin and electrocardiograms identified 15.5% as low risk, with a sensitivity of 99.2% for the primary outcome. This compares with standard care in which none were for outpatient care but, 3.3% had a primary outcome postdischarge within 30 days.

In this relatively high-risk population, a 2-hour TIMI score safely identified significant numbers of patients suitable for early discharge to outpatient care.