Computational instantaneous wave‐free ratio (IFR) for patient‐specific coronary artery stenoses using 1D network models

Abstract

<jats:title>Abstract</jats:title><jats:p>In this work, we estimate the diagnostic threshold of the instantaneous wave‐free ratio (iFR) through the use of a one‐dimensional haemodynamic framework. To this end, we first compared the computed fractional flow reserve (cFFR) predicted from a 1D computational framework with invasive clinical measurements. The framework shows excellent promise and utilises minimal patient data from a cohort of 52 patients with a total of 66 stenoses. The diagnostic accuracy of the cFFR model was 75.76<jats:italic>%</jats:italic>, with a sensitivity of 71.43<jats:italic>%</jats:italic>, a specificity of 77.78<jats:italic>%</jats:italic>, a positive predictive value of 60<jats:italic>%</jats:italic>, and a negative predictive value of 85.37<jats:italic>%</jats:italic>. The validated model was then used to estimate the diagnostic threshold of iFR. The model determined a quadratic relationship between cFFR and the ciFR. The iFR diagnostic threshold was determined to be 0.8910 from a receiver operating characteristic curve that is in the range of 0.89 to 0.9 that is normally reported in clinical studies.</jats:p>