Description:
<jats:title>Abstract</jats:title><jats:sec><jats:title>Objectives and Background</jats:title><jats:p>This study aims to evaluate whether the high correlation and classification agreement of the instantaneous wave‐free ratio (iFR) and the resting distal coronary to aortic pressure ratio (<jats:italic>P</jats:italic><jats:sub>d</jats:sub><jats:italic>/P</jats:italic><jats:sub>a</jats:sub>) with the fractional flow reserve (FFR) can be confirmed in stent‐jailed side branches (J‐SB).</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Consecutive patients (<jats:italic>n</jats:italic> = 49) undergoing provisional stenting were prospectively enrolled and a physiological assessment of the J‐SB (<jats:italic>n</jats:italic> = 51) was performed. FFR, iFR, and <jats:italic>P</jats:italic><jats:sub>d</jats:sub>/<jats:italic>P</jats:italic><jats:sub>a</jats:sub> were measured and the hemodynamic relevance was determined using cutoff values of ≤0.80, ≤0.89, and ≤0.92, respectively.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Both iFR (<jats:italic>r</jats:italic> = 0.75) and <jats:italic>P</jats:italic><jats:sub>d</jats:sub>/<jats:italic>P</jats:italic><jats:sub>a</jats:sub> (<jats:italic>r</jats:italic> = 0.77) correlated closely with FFR. Classification agreement with FFR was 78% for iFR (81% sensitivity, 77% specificity) and 75% for <jats:italic>P</jats:italic><jats:sub>d</jats:sub>/<jats:italic>P</jats:italic><jats:sub>a</jats:sub> (63% sensitivity and 80% specificity). However, angiographic diameter stenosis and pressure indices correlated poorly. For a threshold of ≥70% stenosis, agreement concerning hemodynamic relevance was found in 59% for FFR, 69% for iFR, and 61% for <jats:italic>P</jats:italic><jats:sub>d</jats:sub>/<jats:italic>P</jats:italic><jats:sub>a</jats:sub>.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>As reported for other lesion types, FFR and the adenosine‐independent pressure indices iFR and <jats:italic>P</jats:italic><jats:sub>d</jats:sub>/<jats:italic>P</jats:italic><jats:sub>a</jats:sub> show close correlation and a high classification agreement of approximately 75%–80% in J‐SB. Therefore, iFR can be regarded as a recommendable alternative to FFR for the guidance of provisional stenting in bifurcation lesions.</jats:p></jats:sec>