July 13, 2009 - On July 7 the American College of Radiology Imaging Network (ACRIN) started its first cardiovascular trial, ACRIN PA 4005 “Randomized Controlled Study of a Rapid 'Rule Out' Strategy Using CT Coronary Angiography Versus Traditional Care for Low-Risk ED Patients with Potential Acute Coronary Syndromes.”
The trial is led by Harold I. Litt, M.D., Ph.D., chief of cardiovascular imaging at the University of Pennsylvania Health System and Judd Hollander, M.D., professor and clinical research director in the Department of Emergency Medicine at Hospital of the University of Pennsylvania.
A total of 1,365 participants at low-risk (TIMI risk scores between zero and two, ECG without acute ischemia and normal cardiac troponin levels) with potential acute coronary syndromes will be recruited and randomized to either a traditional “rule out” care arm or a CT coronary angiography arm. The investigators seek to determine whether CT coronary angiography can be safely used to discharge low-risk patients to home from the emergency department, decreasing the patient’s length of stay and considerably increasing emergency department efficiency.
Trial funding is made available through the Pennsylvania Department of Health’s Commonwealth Universal Research Enhancement Program with funds from the Tobacco Settlement Act.
For more information: www.acrin.org/4005_protocol.aspx.
March 13, 2026 
