Objective: To evaluate the feasibility of dipyridamole-induced reversible ischemia on myocardial perfusion positron emission tomography (PET) imaging using Rubidium-82 (Rb-82 PET) to predict the presence of acute coronary syndrome (ACS) in emergency department (ED) chest pain patients at low risk who were admitted to an observation unit.
Methods: Retrospective cross-sectional study of electronic medical records after computerized record retrieval. We matched all ED chest pain visits to a database of all scans read by cardiology between January 1, 2004 and January 1, 2006. A PET scan was performed at the ED physician's discretion after a negative observation unit workup, including serial cardiac biomarkers and ECGs. Data were collected on a standardized abstraction instrument.
Results: There were 7,691 ED visits for chest pain. Among these patients, 1177 had an Rb-82 PET. Fifty four (4.6%) of these patients had an abnormal or probably abnormal scan. Of these, 28 had catheter-proven significant coronary disease, requiring either revascularization or intensive medical management; 22 patients had ACS by clinical assessment but did not undergo catheterization. Four had no coronary artery disease on catheterization.
Conclusion: In a low-risk chest pain population, cardiac PET imaging had true-positive cardiac catheterization rates which were comparable to prior studies of SPECT sestimibi imaging and coronary CTA imaging. With the rapid dissemination of PET technology, and superior performance compared to current imaging methods, myocardial perfusion PET is a feasible alternative to traditional provocative testing in an ED observation unit.