POTENTIAL COST-EFFECTIVENESS OF INITIAL MYOCARDIAL PERFUSION IMAGING FOR ASSESSMENT OF EMERGENCY DEPARTMENT PATIENTS WITH CHEST PAIN

Previous investigations have confirmed the diagnostic and predictive u sefulness of initial single-photon emission computed tomography (SPECT ) myocardial perfusion imaging using technetium-99m sestamibi in the e valuation of emergency department patients with chest pain. Patients w ith a normal SPECT perfusion scan performed during chest pain have an excellent short-term prognosis, and may be candidates for expeditious cardiac evaluation or outpatient management. However, there are limite d data regarding the cost effectiveness of this technique. This analys is models the potential cost effectiveness of this procedure. In the c urrent investigation we compared 2 model strategies for management of emergency department patients with typical chest pain and a normal or nondiagnostic electrocardiogram (EGG). In 1 model strategy, (the techn etium-99m sestamibi SPECT myocardial perfusion imaging [SCAN] strategy ), the decision whether to admit or discharge a patient from the emerg ency department is based on results of initial technetium-99m sestamib i SPECT myocardial imaging. Patients with normal scans are discharged; others are admitted. In the second model strategy, (the NO SCAN strat egy), the decision whether or not to admit a patient is based on a com bination of clinical and electrocardiographic variables. Patients with greater than or equal to 3 cardiac risk factors or an abnormal ECG ar e admitted; others are discharged. Adverse cardiac events were prospec tively defined as cardiac death, nonfatal myocardial infarction, or th e need for acute coronary intervention. Costs were assigned using data derived from 102 patients who underwent SPECT myocardial perfusion im aging and an additional 107 emergency department patients with ongoing chest pain who either underwent or were eligible for initial SPECT my ocardial perfusion imaging. Mean (+/- SE) costs were highest among hos pital admitted patients who experienced an adverse cardiac event ($21, 375 +/- $2,733) and lowest in patients discharged from the emergency d epartment ($715 +/- 71). Mean costs per patient of the SCAN strategy a nd NO SCAN strategy were $5,019 versus $6,051, respectively. These res ults were stable in a sensitivity analysis across a range of costs and predictive values. Thus, the SCAN model strategy for initial manageme nt of emergency department patients with typical ongoing angina and a normal or nondiagnostic ECG using initial myocardial perfusion imaging with technetium-99m sestamibi appears to be safe, accurate, and poten tially cost effective. Validation of these preliminary retrospective o bservations will require further prospective investigation. (C) 1997 b y Excerpta Medica, Inc.