Evaluation and outcomes of patients admitted to a tertiary medical assessment unit with acute chest pain of possible coronary origin
- Rebecca L Sander, MBChB, Senior Medical Registrar; Ian A Scott, MBBS, FRACP, MHA, Director of Internal Medicine and Clinical Epidemiology; Leena Aggarwal, MBBS, MD, FRACP, Director of Medical Assessment and Planning Unit
The study aims to (i) profile clinical characteristics, risk estimates of acute coronary syndrome (ACS), use and yield of non-invasive cardiac testing, discharge diagnosis and 30-day outcomes among patients admitted with acute chest pain of possible coronary origin; and (ii) construct a risk stratification algorithm that informs management decisions.
This is a retrospective cohort study of 130 consecutive patients admitted to a tertiary hospital medical assessment unit between 24 January and 22 March 2012. Estimates of ACS risk were based on Australian guidelines and Thrombolysis in Myocardial Infarction (TIMI) scores.
Patients were of mean age 61 years, 45% had known coronary artery disease (CAD), 58% presented with typical ischaemic pain, 82% had intermediate to high ACS risk and 61% underwent testing. Myocardial ischaemia was cardiologist-confirmed discharge diagnosis in 29% of patients, and was associated with known CAD, typical pain, multiple risk factors and high TIMI risk scores (P < 0.001 for all associations). Of 98 non-invasive investigations, 9% (95% CI, 5–17%) were positive for myocardial ischaemia. Major adverse event rate at 30 days was 0.8% (95% CI, <0.1–6%). An algorithm was constructed that integrates known CAD, ACS risk and TIMI scores in identifying low-risk patients capable of rapid discharge from EDs without further investigation, and classifying the remainder into risk groups that informs choice of investigations and need for telemetry.
In patients with indeterminate chest pain, clinical features and risk scores identify most with myocardial ischaemia. An algorithm is presented that might inform triaging, early discharge, choice of testing and need for telemetry.