Abstract P15: Prospective validation of a modified TIMI risk score in Emergency Department patients with chest pain

Introduction: Investigators in Manchester, UK derived a modified TIMI risk score that classified chest pain patients with either ischemic ECG changes or cardiac troponin elevations as high risk, optimizing the score for use in ED patients with possible acute coronary syndrome. We prospectively validate this modified risk score to determine if it can be used to identify a low risk group of ED chest pain patients safe for early discharge. Methods: We conducted a prospective cohort study in an urban academic ED over a 9-month period. We enrolled patients over 24 years of age with a primary complaint of chest pain. The primary outcome was AMI, revascularization, or death within 30 days. Results: We enrolled 970 patients with the following characteristics: mean age (S.D.) 59.5 (13.8) years, 39.8% female, 17.6% history of diabetes and 22.9% history of AMI. The modified TIMI risk score outperformed the original risk score in terms of overall diagnostic accuracy (Area under ROC curve 0.87 versus 0.82, p=0.001). Sensitivity and specificity at potential cut-points were: >0: 98.3%, 23.6%; >1: 94.0%, 53.8%; and >2: 90.6%, 73.2%. The lowest cut-point (TIMI/modified TIMI >0) was the only cut-point that predicted adverse cardiac events with sufficient sensitivity to consider early discharge. The sensitivity and specificity of the modified and original TIMI risk scores at this cut-point were identical. Conclusions: The Manchester modified TIMI risk score outperformed the original TIMI risk score with regard to overall diagnostic accuracy. However, it did not improve on the original risk score’s ability to identify patients safe for early ED discharge. Both scores are insufficiently sensitive or specific to be recommended as the sole means of stratifying risk in ED chest pain patients.