Abstract 19284: Myocardial Perfusion Imaging Has a Higher Rate of False Positivity Compared to CT Angiography in Intermediate Risk Chest Pain Patients Undergoing Catheterization
Introduction: Although noninvasive testing continues to hold an important role in the assessment of chest pain, imprecise categorization of coronary artery disease (CAD) severity may lead to unnecessary invasive procedures. We compared the frequency with which noninvasive tests were falsely positive for severe coronary stenosis in patients hospitalized for intermediate risk chest pain who underwent cardiac catheterization.
Methods: We identified 400 subjects hospitalized with chest pain, who had been randomized to either myocardial perfusion imaging (MPI) [n=200] or coronary CT angiography (CTA) [n=200] as part of a clinical trial. Invasive angiography, performed at the discretion of the treating physicians within one year following noninvasive testing, occurred in 30 subjects assigned to CTA and in 32 assigned to MPI. MPI, CTA and invasive angiogram exams were each interpreted for the presence or absence of severe coronary stenosis (>70% diameter) by the study investigators.
Results: Subjects catheterized were 60 ± 10 years, 52% female, 55% obese, 42% diabetic, 76% hypertensive and 48% smokers. On presentation, chest pain occurred for greater than 15 minutes in 66%, while 78% had an abnormal ECG. Amongst those catheterized, false positivity was common in the MPI group (n=11, 34%) and was rare in the CTA group (n=2, 7%), p< 0.01. The odds for false positivity were increased in those undergoing MPI, odds ratio 6.9 [95% confidence interval: 1.1, 72.1, p = 0.02]. On multivariate analysis, after considering multiple clinical and electrocardiographic potential contributors to false positivity, the presence of slight ST segment depression (< 1mm) on presenting ECG was the only independent predictor of having a false positive MPI exam.
Conclusion: In patients having catheterization for intermediate risk chest pain, the rate of falsely positive noninvasive test was substantially higher in those having MPI compared to those undergoing CTA.
Author Disclosures: S. Mukundan: None. J. Levsky: None. D. Spevack: None. M. Travin: None.
- © 2015 by American Heart Association, Inc.