Early myocardial perfusion gated-SPECT in patients with chest pain and non-diagnostic ECG in the emergency department

OBJECTIVE: To analyze the value of early resting myocardial perfusion gated-SPECT in patients with chest pain and non-diagnostic ECG in the emergency department. PATIENTS AND METHOD: 222 patients (49% women, mean age 61 13] years) with atypical chest pain and with non-diagnostic ECG were randomized into two groups. Group A comprised 111 patients in whom early resting myocardial perfusion gated-SPECT (<6 hours since the end of chest pain) was performed and CK-MB mass and troponin I were determined at 0, 4 and 8 hours. Group B comprised 111 patients with conventional management in the emergency department without gated-SPECT. RESULTS: Myocardial perfusion gated-SPECT was positive in all 8 patients with increased levels of CK-MB mass and troponin I. This corresponded to a sensitivity and a negative predictive value of 100% for the diagnosis of AMI. Specificity was 84% and positive predictive value was 33% when doubtful results were considered as negative. The number of patients admitted (18.4% vs 32.7%, P<.027) and length of stay (13 6] hours vs 15.9 8.6] hours, P<.009) in the emergency department were lower in group A. CONCLUSIONS: In patients with atypical chest pain and non-diagnostic ECG in the emergency department, early resting gated-SPECT was highly sensitive and showed good negative predictive value for the diagnosis of AMI, but positive predictive value was low. This technique may reduce the number of hospitalized patients and length of stay in the emergency department.