Although 75-85% of patients presenting to the emergency department with chest pain ultimately do not receive a diagnosis of acute coronary syndrome, a lengthy assessment process is still mandatory as patients with a missed diagnosis of myocardial infarction are at increased risk for a cardiovascular event.  Than et al. prospectively validated the safety of a predefined accelerated diagnostic protocol (ADP) aimed at assessing chest pain patients within two hours.

The study took place in 14 emergency departments across the Asia-Pacific region.  The ADP developed utilised a structured pre-test probability scoring method including Thrombolysis in Myocardial Infarction [TIMI] score, electrocardiography, and point-of-care biomarker panel of troponin, creatine kinase MB, and myoglobin. The primary endpoint was major adverse cardiac events within 30 days after initial presentation (including initial hospital attendance).

During the course of the study 3582 consecutive patients were recruited and completed follow-up, of which 421 (11·8%) patients had a major adverse cardiac event (see breakdown in figure). The ADP classified 352 (9·8%) of all patients as low risk and potentially suitable for early discharge. A major adverse cardiac event occurred in only three (0·9%) of these patients, giving the ADP a sensitivity of 99·3% (95% CI 97·9–99·8), a negative predictive value of 99·1% (97·3–99·8), and a specificity of 11·0% (10·0–12·2).

Conclusions:

A novel accelerated diagnostic protocol can be used to identify emergency department patients who are at low-risk of cardiovascular events in the short term.  Although longer-term follow-up is needed, this protocol may allow a more efficient assessment of chest pain in the emergency department.

• Than M, Cullen L, Reid CM, et al.  A 2-h diagnostic protocol to assess patients with chest pain symptoms in the Asia-Pacific region (ASPECT): a prospective observational validation study.  Lancet 2011; 377:1077-84.