Arq Bras Cardiol: Imagem cardiovasc 2020; 33(3): 1-7

Fractional Flow Reserve by Tomography Diagnostic Performance in the Detection of Coronary Stenoses Hemodynamically Significant

DOI: 10.5935/2318-8219.20200037

Abstract

Background

Coronary computed tomography angiography is a noninvasive anatomic test for the diagnosis of coronary artery disease. The coronary fractional flow reserve is the gold standard method to determine if coronary stenosis is hemodynamically significant but requires an invasive procedure. Fractional flow reserve measurement by tomography is a new method to determine the hemodynamic significance of coronary luminal reduction.

Objective

To compare the accuracy of the invasive fractional flow reserve with the fractional flow reserve measurement by tomography.

Method

Patients submitted to invasive coronary computed tomography angiography and fractional flow reserve were included in the study. Flow-restricted stenosis was defined by fractional flow reserve measurement by tomography and fractional flow reserve ≤ 0.8, and anatomically significant coronary artery disease was defined as stenosis ≥ 50%. Diagnostic performance of fractional flow reserve measurement by tomography and stenosis by coronary computed tomography angiography was accessed with invasive fractional flow reserve as the gold standard.

Results

Among the patients, 33% had fractional flow reserve ≤0.8. There was no significant difference between the fractional flow reserve measurement by tomography and fractional flow reserve averages (0.87 versus 0.84; p = 0.4). The correlation between the values of the methods was r = 0.77, and concordance was moderate (k = 0.54). When fractional flow reserve ≤ 0.75 was analyzed, the concordance between the methods was absolute. The sensitivity, specificity, positive predictive value and negative predictive value of fractional flow reserve measurement by tomography were, respectively, 50%, 100%, 100% and 75%, for the threshold of 0.8. The mean difference between fractional flow reserve and fractional flow reserve measurement by tomography was -0.033 (95%CI -0.072-0.007), with concordance limits between -0.176 and -0.1111.

Conclusion

Fractional flow reserve measurement by tomography is a new method with high diagnostic performance in the detection of hemodynamically significant coronary stenoses and significantly elevates the specificity of the isolated coronary computed tomography angiography.