Classification performance of instantaneous wave-free ratio (iFR) and fractional flow reserve in a clinical population of intermediate coronary stenoses: results of the ADVISE registry.
OBJECTIVE
To evaluate the classification agreement between instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) in patients with angiographic intermediate coronary stenoses.


RESULTS
Three hundred and twelve patients (339 stenoses) with angiographically intermediate stenoses were included in this international clinical registry. The iFR was calculated using fully automated algorithms. The receiver operating characteristic (ROC) curve was used to identify the iFR optimal cut-point corresponding to FFR 0.8. The classification agreement of coronary stenoses as significant or non-significant was established between iFR and FFR and between repeated FFR measurements for each 0.05 quantile of FFR values, from 0.2 to 1. Close agreement was observed between iFR and FFR (area under ROC curve= 86%). The optimal iFR cut-off (for an FFR of 0.80) was 0.89. After adjustment for the intrinsic variability of FFR, the classification agreement (accuracy) between iFR and FFR was 94%. Amongst the stenoses classified as non-significant by iFR (>0.89) and as significant by FFR (≤0.8), 81% had associated FFR values located within the FFR "grey-zone" (0.75-0.8) and 41% within the 0.79-0.80 FFR range.


CONCLUSIONS
In a population of intermediate coronary stenoses, the classification agreement between iFR and FFR is excellent and similar to that of repeated FFR measurements in the same sample. Vasodilator-independent assessment of intermediate stenosis seems applicable and may foster adoption of coronary physiology in the catheterisation laboratory.
International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom. rpetraco@imperial.ac.uk
Ricardo
R
Petraco
Javier
J
Escaned
Sayan
S
Sen
Sukhjinder
S
Nijjer
Kaleab N
KN
Asrress
Mauro
M
Echavarria-Pinto
Tim
T
Lockie
Muhammed Z
MZ
Khawaja
Cecilia
C
Cuevas
Nicolas
N
Foin
Christopher
C
Broyd
Rodney A
RA
Foale
Nearchos
N
Hadjiloizou
Iqbal S
IS
Malik
Ghada W
GW
Mikhail
Amarjit
A
Sethi
Raffi
R
Kaprielian
Christopher S
CS
Baker
David
D
Lefroy
Michael
M
Bellamy
Mahmud
M
Al-Bustami
Masood A
MA
Khan
Alun D
AD
Hughes
Darrel P
DP
Francis
Jamil
J
Mayet
Carlo
C
Di Mario
Simon
S
Redwood
Justin E
JE
Davies
D000368:Aged; D000465:Algorithms; D006328:Cardiac Catheterization; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000145:classification / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D008131:London; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012042:Registries; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013030:Spain