Abstract 13647: Comparison of the HEART and TIMI Risk Scores for Suspected Acute Coronary Syndrome in the Emergency Department

Introduction: The emergency department (ED) evaluation for suspected acute coronary syndrome (ACS) is common, costly, and challenging. Risk scores may facilitate clinical care and screening for research studies. The Thrombolysis in Myocardial Infarction (TIMI) score is perhaps the best known example, but the HEART score demonstrates promise specifically in ED settings. Hypothesis: We tested the null hypothesis that the TIMI and HEART risk scores have equivalent test characteristics in the ED evaluation of suspected ACS. Methods: We analyzed data from the Internet Tracking Registry of Acute Coronary Syndromes (i*trACS) from 9 EDs on patients with suspected ACS, 1999-2001. We excluded patients with an ED diagnosis of ACS, or without sufficient data to calculate TIMI and HEART scores. The primary outcome was 30-day major adverse cardiovascular events (MACE), including all-cause death, acute myocardial infarction, and urgent revascularization. We describe test characteristics of the TIMI and HEART risk scores. Results: The study cohort included 8,255 patients with 508 (6.2%) 30-day MACE. Receiver operating curve analysis favored HEART (c-statistic: 0.75, 95%CI 0.73-0.77) over TIMI (c-statistic: 0.68, 95%CI 0.66-0.70). A HEART score >3 (negative predictive value[NPV] 0.98, 95%CI 0.98-0.99; positive predictive value [PPV] 0.10, 95%CI 0.09-0.11) demonstrates equivalent or superior NPV/PPV compared to TIMI>0 (NPV 0.98, 95%CI;0.97-0.98; PPV 0.08, 95%CI 0.07-0.08) and TIMI>1 (NPV 0.96, 95%CI 0.96-0.97; PPV 0.1, 95%CI 0.09-0.11). Conclusions: The HEART score is more accurate than TIMI and specifically outperforms TIMI at “low-risk” thresholds.