Background Acute chest pain accounts for a substantial proportion of patients attending the Emergency Department (ED). Initial investigations are frequently inconclusive and many patients thus require admission for further risk stratification. We have previously demonstrated the clinical benefits and cost savings of stress echocardiography (SE) compared to stress ECG for risk stratification of patients admitted with suspected acute coronary syndrome (ACS) but normal ECG and negative 12-h troponin. However, the feasibilty of SE in routine clinical practice and its ability to predict hard cardiac events in this patient population is unknown.
Methods Consecutive patients admitted via the ED with chest pain and who underwent SE within 24 h of admission via our acute chest pain service were assessed for feasibility of SE, time to test and were followed-up for hard cardiac events (cardiac death and acute myocardial infarction—AMI).
Results Of 719 consecutive patients, 674 (94.6%) had diagnostic images at SE and were followed-up over 26 months. The median time to test for all patients was 1 day and median in-hospital length of stay for those with normal SE was also 1 day. There were 17 hard events (14 cardiac deaths and 3 AMI). Annualised hard cardiac event rate in the normal SE group (n=517, 73.6%) was 0.58% compared with 3.5% in the abnormal SE group (p=0.002). Cox regression analysis revealed that among clinical, ECG and SE variables, only abnormal SE [p=0.001, HR 4.02, 95% CI 1.73 to 9.36] and advancing age (10-year increase) [p=0.005, HR 1.70, 95% CI 1.18 to 2.44] were independent predictors of hard events in the multivariate model. Similarly, abnormal SE was also the strongest predictor of cardiac death [p=0.001, HR 4.52, 95% CI 1.81 to 11.3]. At any stage during follow-up, an abnormal SE carried at least a fourfold increased risk of either cardiac death or any hard event over a normal SE result.
Conclusion This is the first study to show that the incorporation of SE into a clinical acute chest pain service has excellent feasibility, provides rapid assessment with early triaging and accurate risk stratification of patients with suspected ACS but non-diagnostic ECG and negative 12-h troponin.
- Stress echocardiography
- acute coronary syndrome
- chest pain