ACC/AHA Appropriate Use Criteria recommend performing stress myocardial perfusion imaging (MPI) for intermediate‐ to high‐risk patients presenting with syncope (level A7), but not for low‐risk patients (level I3). However, there are limited data to support this recommendation. We investigated the yield and diagnostic utility of stress MPI for patients without a diagnosis of coronary artery disease (CAD) presenting with syncope.
From the Cleveland Clinic institutional review board–approved MPI database, we identified consecutive patients without known CAD who had undergone stress MPI between 2006 and 2012 for diagnostic workup of syncope. The left ventricular ejection fraction (EF), volumes, perfusion defects, and overall impression of test results were retrieved. For patients with abnormal MPI, left heart angiograms (LHCs) were reviewed if performed. All‐cause death was determined using the Social Security Death Index master file.
There were 700 patients (mean age, 62 ± 15 years; 55% female) who had undergone stress MPI, 659 (94%) with normal perfusion. Of the 41 patients with abnormal MPI, 18 had subsequent LHCs, with 9 true‐positives (overall yield, 1.3%). Assuming that those who did not have LHCs (n = 23) had true‐positive stress tests, the yield would be 4.6% (likely an overestimation). Among those with EF ≥ 50% (n = 647), the diagnostic yield ranged from 0.9% to 2.5%. In low‐risk patients such as those age < 65 years (n = 374) and nondiabetics (n = 560), there were only 1 and 5 patients with confirmed CAD, respectively. Over a 2.6‐year median follow‐up time, 45 patients (5 with abnormal MPI) died. There was no difference in outcomes between those who underwent LHC versus those who did not (2 of 18 vs. 3 of 23, log‐rank P = 0.9). Also, there was no significant difference in annual mortality between those with normal and abnormal MPI (2.3% vs. 3.3%, respectively; log‐rank P = 0.3).
Stress MPI for low‐risk patients who are evaluated for syncope, has a low yield and is indeed inappropriate. For those who are more intermediate to high risk (such as elderly, diabetic), the stress test yield is still relatively low (compared with 33% of all stress MPIs performed at our center) and with a high false‐positive rate. Revision of the appropriateness criteria might be in order.
To cite this abstract:Alraies M. Yield and Diagnostic Value of Stress Myocardial Perfusion Imaging in Patients with Syncope. Abstract published at Hospital Medicine 2013, May 16-19, National Harbor, Md. Abstract 521. Journal of Hospital Medicine. 2013; 8 (suppl 2). https://www.shmabstracts.com/abstract/yield-and-diagnostic-value-of-stress-myocardial-perfusion-imaging-in-patients-with-syncope/. Accessed July 23, 2019.