The modified accelerated diagnostic protocol (ADP) to assess patients with chest pain symptoms using troponin as the only biomarker (mADAPT), the History, ECG, Age, Risk factors, and Troponin (HEART) pathway, and the Emergency Department Assessment of Chest Pain Rule (EDACS)-ADP, are the three most well-known ADPs for patients with chest pain. These ADPs define major adverse cardiac event (MACE) as components of acute myocardial infarction, revascularization, and death; unstable angina is not included as an endpoint.

We performed a single-center prospective observational study comparing the performance of these 3 ADPs for patients with 30-day MACE with and without unstable angina. We hypothesized that these ADPs will have high sensitivities for MACE without unstable angina, a definition used for score derivation studies. However, when unstable angina is included in the MACE, their performances would be lower than the acceptable rate of >99% sensitivity.

A total of 1,214 patients were included in the analysis. When unstable angina was not included in the endpoint, sensitivities for MACE were 99.1% (95% confidence interval [CI]: 96.7–99.9%), 99.5% (95% CI: 97.4–100%), and 100% (95% CI: 98.3–100%) for mADAPT, EDACS-ADP, and HEART pathway, respectively. The HEART pathway had the highest proportion of patients classified as low risk (39.2%, 95% CI: 35.8–42.9%), followed by EDACS-ADP (31.3%, 95% CI: 28.2–34.6%) and mADAPT (29.3%, 95% CI: 26.4–32.5%). However, when unstable angina was included in the MACE, sensitivities were 96.6% (95% CI: 94.4–98.1%) for mADAPT, 97.3% (95% CI: 95.3–98.6%) for EDACS-ADP, and 97.3% (95% CI: 95.3–98.6%) for the HEART pathway, respectively. There were 15 false-negative cases with mADAPT, and 12 false-negative cases each for EDACS-ADP and HEART pathway.

All three ADPs—mADAPT, EDACS-ADP, and HEART pathway—were similarly accurate in their discriminatory performance for the risk stratification of ED patients presenting with possible ACS when unstable angina was not included in the endpoint. The HEART pathway showed the best combination of sensitivity and proportion of patients that can be classified as safe for early discharge. However, when unstable angina was added to the endpoint, all three ADPs did not show appropriate safety levels and their performances were lower than the acceptable risk of MACE.