Author + information
- Roberto Scarsini1,
- Gabriele Pesarini2,
- Carlo Zivelonghi3,
- Anna Piccoli1,
- Alessia Gambaro4,
- Corrado Vassanelli5 and
- Flavio Ribichini6
- 1Division of Cardiology, University of Verona, Verona, Italy
- 2Ospedale Civile Maggiore Borgo Trento, Verona, Italy
- 3Azienda ospedaliera universitaria di Verona, Verona, Venice, Italy
- 4Azienda ospedaliera Verona, Verona, Venice, Italy
- 5Division of Cardiology, University of Verona, Verona, Venice, Italy
- 6Università di Verona, Verona, Italy
Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) have not been extensively investigated in patients with severe aortic valve stenosis(AVS) and concomitant coronary artery disease(CAD). The aim of this study was to compare FFR and iFR measurements in patients with severe symptomatic AVS and in patients without AVS, and to correlate these findings with angiographic quantitative coronary analysis (QCA).
FFR and iFR were prospectively measured in the major coronary artery branches of patients undergoing diagnostic coronary angiography as part of the workout for TAVI. Quantitative Coronary Angiography(QCA) was blinded of the FFR-iFR results. These were compared with a matched control group of CAD patients without any valve disease. An FFR value ≤0.80 was considered pathologic while an FFR value >0.80 was considered ‘negative’. ROC curve analysis was performed in order to find the diagnostic accuracy and the optimal diagnostic cut-off value of iFR in predicting postive FFR (≤0.80) in the AVS and in the CAD population.
One-hundred-sixty-six patients (54 AVS and 112 CAD) with 393 lesions (131 AVS and 262 CAD) were enrolled. Correlation between FFR-iFR and QCA parameters was modest but remained constant in patients with AVS. FFR-iFR correlation was maintained in AVS compared with CAD patients, and the iFR accuracy for predicting FFR≤0.8 was similar between the two groups (AUC:0.94 vs 0.96, p=0.45). Using the current cut-off point of iFR≤0.9 for predicting a positive FFR, the false positive rate was 22.6% in the AVS group compared to 16.5% in the CAD group (p=0.27), with a positive predictive value of 41% and 71.7% for AVS and CAD patients respectively. At ROC curve analysis the best cut-off of iFR predicting FFR≤0.8 was lower in patients with AVS compared with CAD patients: 0.84 (J=0.82) vs 0.88 (J=0.81).
AVS may influence functional assessment of concomitant CAD. FFR-iFR correlation in AVS resulted poorer compared with CAD patients. The 0.90 iFR cut-off value to match 0.80 FFR cut-off may defer in AVS patients and deserves further comparative studies.
IMAGING: FFR and Physiologic Lesion Assessment