Prospective Comparison of FFR Derived From Coronary CT Angiography With SPECT Perfusion Imaging in Stable Coronary Artery Disease: The ReASSESS Study

Abstract

Objectives: This study sought to compare the per-patient diagnostic performance of coronary computed tomography angiography (CTA)-derived fractional flow reserve (FFR_CT) with that of single-photon emission computed tomography (SPECT), using a fractional flow reserve (FFR) value of ≤0.80 as the reference for diagnosing at least 1 hemodynamically significant stenosis in a head-to-head comparison of patients with intermediate coronary stenosis as determined by coronary CTA.

Background: No previous study has prospectively compared the diagnostic performance of FFR_CT and myocardial perfusion imaging by SPECT in symptomatic patients with intermediate range coronary artery disease (CAD).

Methods: This study was conducted at a single-center as a prospective study in patients with stable angina pectoris (N = 143). FFR_CT and SPECT analyses were performed by core laboratories and were blinded for the personnel responsible for downstream patient management. FFR_CT ≤0.80 distally in at least 1 coronary artery with a diameter ≥2 mm classified patients as having ischemia. Ischemia by SPECT was encountered if a reversible perfusion defect (summed difference score ≥2) or transitory ischemic dilation of the left ventricle (ratio >1.19) were found.

Results: The per-patient diagnostic performance for identifying ischemia (95% confidence interval [CI]), FFR_CT versus SPECT, were sensitivity of 91% (95% CI: 81% to 97%) versus 41% (95% CI: 29% to 55%; p < 0.001); specificity of 55% (95% CI: 44% to 66%) versus 86% (95% CI: 77% to 93%; p < 0.001); negative predictive value of 90% (95% CI: 82% to 98%) versus 68% (95% CI: 59% to 77%; p = 0.001); positive predictive value of 58% (95% CI: 48% to 68%) versus 67% (95% CI: 51% to 82%; p = NS); and accuracy of 70% (95% CI: 62% to 77%) versus 68% (95% CI: 60% to 75%; p = NS) respectively.

Conclusions: In patients with stable chest pain and CAD as determined by coronary CTA, the overall diagnostic accuracy levels of FFR_CT and SPECT were identical in assessing hemodynamically significant stenosis. However, FFR_CT demonstrated a significantly higher diagnostic sensitivity than SPECT.

Keywords: FFR(CT); SPECT myocardial perfusion imaging; coronary CTA; stable angina.