Relationship Between Coronary Contrast-Flow Quantitative Flow Ratio and Myocardial Ischemia Assessed by SPECT MPI

Jeff M Smit,Arthur J Scholte,Johan H.C Reiber,Victoria Delgado,J Wouter Jukema,Gerhard Koning,Alexander R Van Rosendael,Petra Dibbets-Schneider,Jeroen J Bax,Bart J Mertens

doi:10.1007/s00259-017-3769-2

Abstract

PurposeA new method has been developed to calculate fractional flow reserve (FFR) from invasive coronary angiography, the so-called “contrast-flow quantitative flow ratio (cQFR)”. Recently, cQFR was compared to invasive FFR in intermediate coronary lesions showing an overall diagnostic accuracy of 85%. The purpose of this study was to investigate the relationship between cQFR and myocardial ischemia assessed by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI).MethodsPatients who underwent SPECT MPI and coronary angiography within 3 months were included. The cQFR computation was performed offline, using dedicated software. The cQFR computation was based on 3-dimensional quantitative coronary angiography (QCA) and computational fluid dynamics. The standard 17-segment model was used to determine the vascular territories. Myocardial ischemia was defined as a summed difference score ≥2 in a vascular territory. A cQFR of ≤0.80 was considered abnormal.ResultsTwo hundred and twenty-four coronary arteries were analysed in 85 patients. Overall accuracy of cQFR to detect ischemia on SPECT MPI was 90%. In multivariable analysis, cQFR was independently associated with ischemia on SPECT MPI (OR per 0.01 decrease of cQFR: 1.10; 95% CI 1.04-1.18, p = 0.002), whereas clinical and QCA parameters were not. Furthermore, cQFR showed incremental value for the detection of ischemia compared to clinical and QCA parameters (global chi square 48.7 to 62.6; p <0.001).ConclusionsA good relationship between cQFR and SPECT MPI was found. cQFR was independently associated with ischemia on SPECT MPI and showed incremental value to detect ischemia compared to clinical and QCA parameters.

Highlights

CQFR analysisFractional flow reserve (FFR) is considered the gold standard to assess the hemodynamic significance of coronary artery stenoses [1]
CQFR was independently associated with ischemia on SPECT MPI (OR per 0.01 decrease of called Bcontrast-flow quantitative flow ratio (cQFR): 1.10; 95% confidence interval (CI) 1.04-1.18, p = 0.002), whereas clinical and quantitative coronary angiography (QCA) parameters were not
A good relationship between cQFR and SPECT MPI was found. cQFR was independently associated with ischemia on SPECT MPI and showed incremental value to detect ischemia compared to clinical and QCA parameters

Summary

Introduction

CQFR analysisFractional flow reserve (FFR) is considered the gold standard to assess the hemodynamic significance of coronary artery stenoses [1]. Despite the supporting evidence for FFR assessment in intermediate coronary artery stenoses, FFR is used in only a minority of the cases (6.1%) [4]. This may be related to some important limitations of FFR, such as the high costs of the pressure-wire and the need for hyperaemia induction. To overcome these limitations, a new method has been developed to calculate FFR from invasive coronary angiography, the so-called Bcontrast-flow quantitative flow ratio (cQFR)^ [5, 6]. CQFR was compared to invasive FFR in intermediate coronary lesions showing an overall diagnostic accuracy of detecting an invasive FFR ≤0.80 of 85% with a sensitivity and specificity of 74% and 91%, respectively [5]

Objectives

Methods

Results

Discussion

Conclusion