A New Improved Accelerated Diagnostic Protocol Safely Identifies Low‐risk Patients With Chest Pain in the Emergency Department

Abstract

To assess whether the accelerated diagnostic protocol (ADP) studied in the Asia Pacific Evaluation of Chest Pain Trial (ASPECT) could be optimized to effectively risk stratify patients with symptoms suggestive of acute coronary syndrome (ACS) and allow early discharge of very-low-risk patients. Patients presenting to the emergency department (ED) with chest pain were prospectively enrolled between November 2007 and April 2010. Blood samples were analyzed at 0 and 2 hours postpresentation with a point-of-care multimarker panel (POC-MMP; troponin I [TnI], creatine kinase myocardial band [CKMB] isoenzyme fraction, and myoglobin) and a high-sensitivity cardiac troponin T assay (hsTnT). Patients received standard care. The original ADP (Thrombolysis in Myocardial Infarction [TIMI] risk score = 0, no ischemic electrocardiogram [ECG] changes, and the multimarker panel negative) was compared with an ADP using the point of care TnI only, hsTnT only, or TIMI risk score = 0 to 1. Primary outcome was ACS within 30 days. Of the 1,000 patients recruited, 362 (36.2%) had ACS. There were 12.3% identified as low risk by the original ADP with a sensitivity for ACS of 99.2% (95% confidence interval [CI] = 97.5% to 99.8%). The ADP with the point of care TnI only or hsTnT had the same sensitivity, but identified more patients for discharge (15.0% vs. 12.3%). Including patients with a TIMI risk score of 1 identified more patients as low risk (19.7%), but with a lower sensitivity (97.0% vs. 99.2%). An ADP consisting of a TIMI risk score of 0, no new ECG changes, and negative troponin at 0 and 2 hours postpresentation safely identifies patients at low risk of ACS, in whom discharge without further evaluation can be considered.