External Validation of the Vancouver Chest Pain Rule

To study the validity of the Vancouver Chest Pain Rule (JW Emerg Med Mar 14 2006), researchers prospectively evaluated its performance in a convenience sample of 593 consecutive patients aged 25 and older who presented with acute chest pain to an emergency department in Iran in 2009. The primary outcome was development of acute coronary syndrome (ACS; diagnosed according to predefined criteria) within 30 days of presentation.

The rule categorizes patients younger than 40 as low risk for ACS if they have normal initial electrocardiogram (ECG) and no history of ischemic chest pain. Patients aged 40 and older are categorized as low risk if they have normal initial ECG, no history of ischemic chest pain, chest pain that does not radiate and that increases with deep breath or palpation, and either initial CK-MB <3.0 µg/mL or CK-MB ≥3.0 µg/mL along with no ECG change or CK-MB or troponin rise within 2 hours of presentation (see figure).

Use of the rule would have categorized 49.2% of study patients as low risk and eligible for discharge. Four of those patients (1.4%) developed ACS within 30 days; none of them died. The rule had a sensitivity for ACS within 30 days of 95.1%, a specificity of 56.3%, and negative and positive predictive values of 98.6% and 25.9%, respectively. Two of the four patients missed by the rule would have been identified by adding troponin-T measurement to the algorithm.