[Risk stratification and role for additional diagnostic testing in patients with acute chest pain and normal high-sensitivity cardiac troponin levels].

BACKGROUND

Normal high sensitivity cardiac troponin (hs-cTn) assays rule out acute myocardial infarction (AMI) with great accuracy, but additional non-invasive testing is frequently ordered. This observational study evaluates whether clinical characteristics can contribute to risk stratification and could guide referral for additional testing.

METHODS

This observational study included 918 patients with acute chest pain and normal hs-cTnT values. Major adverse cardiac events (MACE) and non-invasive test results were assessed during one-year follow-up. Patients were classified as low and high risk based on clinical characteristics.

RESULTS

In total, 6,4% of patients experienced MACE during follow-up and mainly comprised revascularisations (86%). Absence of both recent abnormal stress test and suspicious history identified 86% of patients. These patients were at very low risk for MACE (0,4% in 30-days). Despite this, the majority (287/345=83%) of additional tests were performed in low risk patients, with 8% abnormal test findings (positive predictive value for MACE was 17%). The diagnostic yield was significantly higher in the remaining higher risk patients, 40% abnormal test findings and a positive predictive value of 70% for MACE.

CONCLUSION

Clinical characteristics can be used to identify low risk patients with acute chest pain and normal hs-cTnT levels. Current strategies in the emergency department result in numerous additional tests, which are mostly ordered in patients at very low risk and have a low diagnostic yield.