Background
Chest pain is the second most common chief complaint in North American Emergency Departments. An estimated six million patients with chest pain are seen annually in the U.S. Data from the U.S. suggest that 2.1% of patients with acute myocardial infarction and 2.3% of patients with unstable angina are misdiagnosed, with slightly higher rates reported in a recent Canadian study (4.6% and 6.4%, respectively). Information obtained from the history, 12-lead ECG, and a single set of cardiac enzymes is unable to identify patients who are safe for early discharge with sufficient sensitivity. 2002 ACC/AHA guidelines for UA/NSTEMI do not identify very low risk patients who can be safely discharged without provocative testing. As a result large numbers of very low risk patients are triaged to chest pain observation units and undergo provocative testing, at significant cost to the healthcare system. Clinical decision rules use clinical findings (history, physical exam, test results) to suggest a diagnostic or therapeutic course of action. Currently no methodologically robust clinical decision rule identifies patients safe for early discharge.

Objectives
The goal of this study is to derive and validate a clinical decision rule which will allow emergency physicians to accurately identify patients with chest pain who are safe for early discharge without provocative testing. The specific aims are to: i) Apply standardized clinical assessments to patients with chest pain, incorporating results of early cardiac testing; ii) Determine the inter-observer reliability of the clinical information; iii) Determine the statistical association between the clinical findings and the diagnosis of acute coronary syndrome; and iv) Use multivariate analysis to develop a highly sensitive clinical decision rule to guide triage decisions.

Methods
The study will utilize a prospective cohort design. Standardized clinical variables will be collected on all patients over the age of 25 complaining of chest pain prior to provocative testing. Variables strongly associated with the outcome of definite acute coronary syndrome will be further analyzed with multivariate analysis to derive the clinical rule.

Importance
The study will develop a highly sensitive clinical decision rule to identify very low risk patients safe for early discharge. This will improve patient care, lower healthcare costs, and decrease the frequency of missed acute coronary syndrome.

February 8, 2008 — Hess et al.'s ED Chest Pain Clinical Decision Rule Protocol has been Published!
The design and methodology paper was accepted for publication in the journal of BMC Emergency Medicine.
Click here to access the article.

OHRI members:

Pam Ladouceur
My-Linh Tran
Sheryl Domingo