Clinical Research
Cardiac Imaging
Diagnosis of Ischemia-Causing Coronary Stenoses by Noninvasive Fractional Flow Reserve Computed From Coronary Computed Tomographic Angiograms: Results From the Prospective Multicenter DISCOVER-FLOW (Diagnosis of Ischemia-Causing Stenoses Obtained Via Noninvasive Fractional Flow Reserve) Study

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Objectives

The aim of this study was to determine the diagnostic performance of a new method for quantifying fractional flow reserve (FFR) with computational fluid dynamics (CFD) applied to coronary computed tomography angiography (CCTA) data in patients with suspected or known coronary artery disease (CAD).

Background

Measurement of FFR during invasive coronary angiography is the gold standard for identifying coronary artery lesions that cause ischemia and improves clinical decision-making for revascularization. Computation of FFR from CCTA data (FFRCT) provides a noninvasive method for identifying ischemia-causing stenosis; however, the diagnostic performance of this new method is unknown.

Methods

Computation of FFR from CCTA data was performed on 159 vessels in 103 patients undergoing CCTA, invasive coronary angiography, and FFR. Independent core laboratories determined FFRCT and CAD stenosis severity by CCTA. Ischemia was defined by an FFRCT and FFR ≤0.80, and anatomically obstructive CAD was defined as a CCTA with stenosis ≥50%. Diagnostic performance of FFRCT and CCTA stenosis was assessed with invasive FFR as the reference standard.

Results

Fifty-six percent of patients had ≥1 vessel with FFR ≤0.80. On a per-vessel basis, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 84.3%, 87.9%, 82.2%, 73.9%, 92.2%, respectively, for FFRCT and were 58.5%, 91.4%, 39.6%, 46.5%, 88.9%, respectively, for CCTA stenosis. The area under the receiver-operator characteristics curve was 0.90 for FFRCT and 0.75 for CCTA (p = 0.001). The FFRCT and FFR were well correlated (r = 0.717, p < 0.001) with a slight underestimation by FFRCT (0.022 ± 0.116, p = 0.016).

Conclusions

Noninvasive FFR derived from CCTA is a novel method with high diagnostic performance for the detection and exclusion of coronary lesions that cause ischemia. (The Diagnosis of ISChemia-Causing Stenoses Obtained Via NoninvasivE FRactional FLOW Reserve; NCT01189331)

Key Words

computational fluid dynamics
coronary CT angiography
fractional flow reserve

Abbreviations and Acronyms

AUC
area under the receiver-operator characteristics curve
CABG
coronary artery bypass surgery
CAD
coronary artery disease
CCTA
coronary computed tomographic angiography
CFD
computational fluid dynamics
FFR
fractional flow reserve
FFRCT
computation of fractional flow reserve from coronary computed tomographic angiography data
ICA
invasive coronary angiography

Cited by (0)

Dr. DeFrance is on the Speaker's Bureau of Toshiba Medical Systems. Dr. Leipsic is on the Speaker's Bureau and medical advisory board of GE Healthcare. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.