Use of an accelerated chest pain assessment protocol in patients at intermediate risk of adverse cardiac events.

OBJECTIVE: To determine the feasibility, safety and effectiveness of a structured clinical pathway for stratification and management of patients presenting with chest pain and classified as having intermediate risk of adverse cardiac outcomes in the subsequent six months.

DESIGN: Prospective clinical audit.

PARTICIPANTS AND SETTING: 630 consecutive patients who presented to the emergency department of a metropolitan tertiary care hospital between January 2000 and June 2001 with chest pain and intermediate-risk features.

INTERVENTION: Use of the Accelerated Chest Pain Assessment Protocol (ACPAP), as advocated by the "Management of unstable angina guidelines--2000" from the National Heart Foundation and the Cardiac Society of Australia and New Zealand.

MAIN OUTCOME MEASURE: Adverse cardiac events during six-month follow-up.

RESULTS: 409 patients (65%) were reclassified as low risk and discharged at a mean of 14 hours after assessment in the chest pain unit. None had missed myocardial infarctions, while three (1%) had cardiac events at six months (all elective revascularisation procedures, with no readmissions with acute coronary syndromes). Another 110 patients (17%) were reclassified as high risk, and 21 (19%) of these had cardiac events (mainly revascularisations) by six months. Patients who were unable to exercise or had non-diagnostic exercise stress test results (equivocal risk) had an intermediate cardiac event rate (8%).

CONCLUSIONS: This study validates use of ACPAP. The protocol eliminated missed myocardial infarction; allowed early, safe discharge of low-risk patients; and led to early identification and management of high-risk patients.