"A 2-Hour Diagnostic Protocol for Possible Cardiac Chest Pain in the Emergency Department"
JAMA IM Nov 1
http://archinte.jamanetwork.com/article.aspx?articleid=1748796 
"Conclusions and Relevance  Using the accelerated diagnostic protocol in the experimental pathway almost doubled the proportion of patients with chest pain discharged early. Clinicians could discharge approximately 1 of 5 patients with chest pain to outpatient follow-up monitoring in less than 6 hours. This diagnostic strategy could be easily replicated in other centers because no extra resources are required."