Nonspecific chest pain is the second most common reason for presentation to the emergency department, according to the Centers for Disease Control and Prevention (CDC).

Acute coronary syndrome (ACS) identification with appropriate disposition is quite challenging. While most ED patients with undifferentiated chest pain do not have ACS, missing this diagnosis has major morbidity and mortality implications.

Current guidelines recommend risk stratification for ruling out ACS, but performing these investigations can lengthen ED stays, increase admissions, and lead to further testing that does not yield any substantial information. All of these can increase costs and unnecessary hospitalizations.

After excluding the small percentage of patients with obvious evidence of myocardial infarction (MI), identifying the 10 to 20 percent of those remaining with undifferentiated chest pain due to coronary heart disease (CHD) is challenging. Risk factors, clinical findings, and electrocardiographs (ECGs) are not always enough to exclude acute MI with a high level of confidence.

Risk stratification tools help clinicians accurately identify patients at intermediate to high risk of CHD and who warrant further evaluation, and quickly and safely discharge those patients at low risk. There are currently 12 different risk stratification tools for undifferentiated chest pain. The “best” tool remains unclear.

In a first-of-its-kind study, researchers compared the performance of nine different risk scores within the same population presenting to the ED with undifferentiated chest pain.

Comparing the Nine Coronary Risk Scores

Dr. Henry Wamala and colleagues performed a retrospective study comparing the performance of nine risk scores for coronary heart disease (CHD) among patients coming to the ED with undifferentiated chest pain.

The patients included in the study did not have electrocardiographs or troponin results diagnostic of ischemic chest pain (ICP) or acute coronary syndrome upon presentation, nor did they have a clearly evident non-coronary diagnosis. Of the 401 participants, 123 had ICP as a final diagnosis.

The researchers compared the following nine risk scores:

  • The North American Chest Pain Rule (NACPR)
  • History, ECG, Age, Risk Factors, and Troponin (HEART) score
  • Thrombolysis in Myocardial Infarction (TIMI)
  • Modified TIMI (m.TIMI)
  • Accelerated Diagnostic Protocol to Assess Patients with Chest Pain Symptoms Using Contemporary Troponins (ADAPT)
  • Emergency Department Assessment of Chest Pain Score (EDACS)
  • Global Registry of Acute Coronary Events (GRACE)
  • Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT)
  • Florence Prediction Rule (FPR)

The researchers calculated risk scores according to discharge diagnosis of noncardiac chest pain or ICP. The scientists used area under receiver-operator characteristic curves (AUC) and predictive values to compare score performance. In this study, a lower odds ratio (OR) for ICP indicates a lower risk for ischemic chest pain.

In distinguishing low-risk patients from high-risk patients, the team found that NACPR performed best, followed by HEART and TIMI. ADAPT performed worst. The five remaining scores showed intermediate performance. NACPR maximized yield of low-risk patients with the lowest miss rate for ICP. The HEART risk score identified the highest proportion of low-risk patients, but it had a higher miss rate.

The results of this study have practical implications for clinicians involved in caring for ED patients with undifferentiated chest pain.