Utility of stress myocardial perfusion imaging in hospitalized patients with chest pain and normal or nondiagnostic electrocardiograms

The diagnosis of myocardial ischemic events in hospitalized patients with chest pain and a nondiagnostic electrocardiogram is problematic. An accurate, safe, and fast risk stratification protocol is needed to prevent prolonged hospital stays and unnecessary medical therapy. In the present study, the authors sought to determine the utility of stress myocardial perfusion imaging with thallium-201 in predicting the short- and long-term outcomes of this population. On pain cessation, 109 hospitalized patients (mean age, 61±14 years) with chest pain and a normal or nondiagnostic electrocardiogram underwent stress myocardial perfusion single-photon emission computed tomography (SPECT) with thallium-201. At 12±5 months of follow-up, the occurrence of nonfatal myocardial infarction or cardiac death was recorded. Patients with a history of myocardial infarction or coronary revascularization procedures were excluded from the study. A normal SPECT was found in 84 (77%) patients; their hospital stay was significantly shorter than that of patients with abnormal SPECT (1±2 vs. 7±3 days; p<0.0001). During follow-up, only one (1.2%) compared to seven (28%) cardiac events (six myocardial infarctions, one cardiac death) occurred in patients with normal and abnormal scans, respectively (p<0.0001). Coronary angiography was performed on 11 (14%) and 14 (56%) patients with normal and abnormal scans, respectively. No patients with normal scans, compared to eight patients with abnormal scans, required a revascularization procedure. Multivariate regression analysis identified an abnormal SPECT as the only independent predictor of adverse cardiac events (p=0.0016; odds ratio=32). Stress SPECT applied to hospitalized patients with chest pain and a normal or nondiagnostic electrocardiogram is a safe, highly-accurate, and cost-effective method for distinguishing between low- and high-risk patients.