Ninety-day follow-up of patients in the emergency department with chest pain who undergo initial single-photon emission computed tomographic perfusion scintigraphy with technetium 99m-labeled sestamibi

Background. Patients in the emergency department with typical chest pain and a normal or nondiagnostic electrocardiogram have a 10% to 20% risk of nonfatal myocardial infarction. These patients can be stratified into groups of very low and very high risk for inpatient adverse cardiac events on the basis of initial Tc-99m-labeled sestamibi single-photon emission computed tomographic (SPECT) perfusion imaging performed during symptoms. However, the intermediate or posthospital discharge prognosis of such patients has not been reported. Methods and Results. Patients (n = 150) with typical chest pain (based on a semiquantitative chest pain questionnaire) and a normal or nondiagnostic electrocardiogram underwent injection of 15 to 45 mCi Tc-99m-labeled sestamibi injected during symptoms. Ninety-day follow-up history (telephone questionnaire and review of medical records) was obtained in 140 patients, and follow-up electrocardiography was performed in 72 patients. Cardiac events (death, nonfatal myocardial infarction, thrombolysis, percutaneous transluminal coronary angioplasty, or coronary artery bypass grafting) occurred before hospital discharge in 33 patients (18%), and these patients were excluded from further analysis. At follow-up, two (8%) of 25 patients with an abnormal initial scintigram and none of 87 patients with a normal scan had cardiac events (p = 0.008). Conclusions. In patients with typical angina and a normal or nondiagnostic electrocardiogram, initial SPECT scintigraphy allows early accurate risk stratification. The previously observed excellent inpatient prognosis of patients with a normal scintigram appears to extend for at least 90 days of follow-up. These observations may provide a rational basis for safe and cost-effective outpatient evaluation of selected patients in the emergency department with typical angina, a normal or nondiagnostic electrocardiogram, and a normal initial Tc-99m-labeled SPECT perfusion scintigram performed during symptoms.