Tong KL et al. (2005) Myocardial contrast echocardiography versus Thrombolysis in Myocardial Infarction score in patients presenting to the emergency department with chest pain and a nondiagnostic electrocardiogram. JACC 46: 920–927

When patients present to an emergency department with cardiac chest pain and a nondiagnostic electrocardiogram, it can be difficult to distinguish between those who can be discharged safely and those with a high risk of an adverse outcome. Although Thrombolysis in Myocardial Infarction (TIMI) scores are useful for risk stratification, troponin levels are not always known at presentation.

Tong et al. compared the diagnostic and prognostic accuracy of regional function and myocardial perfusion on contrast echocardiography with that of TIMI scores for 957 individuals with suspected cardiac chest pain and no ST-segment elevation on the electrocardiogram. All patients underwent myocardial contrast echocardiography within 12 h of symptom onset. Modified TIMI risk scores were initially calculated from six clinical variables, but were adjusted later to incorporate troponin levels.

Participants were followed up for primary (death and myocardial infarction) or secondary (unstable angina and revascularization) events at three time points—early (within 24 h), intermediate (up to 30 days), and late (more than 30 days).

Data analysis revealed that contrast echocardiography classified patients as at high or low risk of adverse events more accurately than modified TIMI scores. A model that incorporated assessment of regional function and myocardial perfusion, together with initial clinical variables, provided the best prognostic information and was not improved further with the addition of troponin data.

According to the authors, implementation of this approach in the emergency department could improve risk assessment of patients with cardiac chest pain, and reduce hospital costs.