Abstract 18257: Use of the TIMI Risk Score in the Emergency Department Discriminates Acute Coronary Syndrome Among Chest Pain Patients With Known Coronary Artery Disease

Abstract

Background: Patients with known coronary artery disease (CAD) presenting to the Emergency Department (ED) with chest pain thought to be of ischemic origin are often admitted to the hospital, yet half or fewer are eventually diagnosed with acute coronary syndrome (ACS). We assessed whether the use of the TIMI risk score, developed for UA/NSTEMI prognostication, applied in the ED and modified to eliminate the “known CAD” variable, could discriminate which of these high-risk patients actually do and do not have ACS. Methods and Results: Chart review was performed on a prospectively defined cohort of 111 patients with known CAD (73% prior PCI, 42% prior CABG) presenting to the ED with chest pain thought to be of ischemic origin, all of whom were admitted to the hospital from December 2012 to April 2013. The composite TIMI risk score and its individual variables were assessed with logistic regression models for their association with ACS as determined by the inpatient attending physician at hospital discharge. ACS was eventually diagnosed in 36 (32.4%) of the patients. Non-ACS patients had a 2.8 day average length of stay and $9,290 average inpatient (post-ED) hospital charges, which is $696,773 for the 75 (67.6%) non-ACS patients. The odds of having ACS increased by 207% (p <0.001) per 1 point increase in TIMI score. TIMI score discriminates ACS and non-ACS with an area under ROC curve (AUC) of 0.794. In a multi-variable model with the individual TIMI variables, elevated troponin (OR 8.00, p 0.002) and ST deviation (OR 8.38, p 0.007) in the ED, and 2 or more prior chest pain episodes (OR 3.89, p 0.061), were most predictive; AUC 0.834. In a multi-variable model with the TIMI variables and each of the CAD risk factors, elevated troponin (OR 6.95, p 0.008) and ST deviation (OR 9.54, p 0.007) in the ED, and 2 or more prior chest pain episodes (OR 3.90, p 0.067) remained most predictive, and diabetes was the most predictive risk factor (OR 2.03, p 0.282); AUC 0.850. Conclusions: A modified TIMI risk score is a valuable tool for discriminating between ACS and non-ACS among patients with known CAD presenting to the ED with chest pain. Application of this risk score, along with other clinical factors, may help avoid short, though potentially unnecessary admissions, and reduce associated costs.