Discordance Between Resting and Hyperemic Indices of Coronary Stenosis Severity: The VERIFY 2 Study (A Comparative Study of Resting Coronary Pressure Gradient, Instantaneous Wave-Free Ratio and Fractional Flow Reserve in an Unselected Population Referred for Invasive Angiography).
Distal coronary to aortic pressure ratio (Pd/Pa) and instantaneous wave-free ratio (iFR) are indices of functional significance of a coronary stenosis measured without hyperemia. It has been suggested that iFR has superior diagnostic accuracy to Pd/Pa when compared with fractional flow reserve (FFR).We hypothesized that in comparison with FFR, revascularization decisions based on either binary cutoff values for iFR and Pd/Pa or hybrid strategies incorporating iFR or Pd/Pa will result in similar levels of disagreement.



This is a prospective study in consecutive patients undergoing FFR for clinical indications using proprietary software to calculate iFR. We measured Pd/Pa, iFR, FFR, and hyperemic iFR. Diagnostic accuracy versus FFR ≤0.80 was calculated using binary cutoff values of ≤0.90 for iFR and ≤0.92 for Pd/Pa, and adenosine zones for iFR of 0.86 to 0.93 and Pd/Pa of 0.87 to 0.94 in the hybrid strategy. One hundred ninety-seven patients with 257 stenoses (mean diameter stenosis 48%) were studied. Using binary cutoffs, diagnostic accuracy was similar for iFR and resting Pd/Pa with misclassification rates of 21% versus 20.2% (P=0.85). In the hybrid analysis, 54% of iFR cases and 53% of Pd/Pa cases were outside the adenosine zone and rates of misclassification were 9.4% versus 11.9% (P=0.55).



Binary cutoff values for iFR and Pd/Pa result in misclassification of 1 in 5 lesions. Using a hybrid strategy, approximately half of the patients do not receive adenosine, but 1 in 10 lesions are still misclassified. The use of nonhyperemic indices of stenosis severity cannot be recommended for decision making in the catheterization laboratory.



URL: http://www.clinicaltrials.gov. Unique identifier: NCT02377310.
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.). barryhennigan@physicians.ie.
Barry
B
Hennigan
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Keith G
KG
Oldroyd
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Colin
C
Berry
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Nils
N
Johnson
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
John
J
McClure
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Peter
P
McCartney
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Margaret B
MB
McEntegart
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Hany
H
Eteiba
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Mark C
MC
Petrie
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Paul
P
Rocchiccioli
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Richard
R
Good
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Martin M
MM
Lindsay
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Stuart
S
Hood
From the University of Glasgow, United Kingdom (B.H., K.G.O., C.B., P.M., M.B.M., H.E., M.C.P., P.R., R.G., M.M.L., S.H., S.W.); Cardiology Department, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom (B.H., K.G.O., C.B., J.M.); and The Weatherhead PET Imaging Center, Houston, TX (N.J.).
Stuart
S
Watkins
D000241:Adenosine / Q000008:administration & dosage*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D019540:Area Under Curve; D062186:Arterial Pressure; D006328:Cardiac Catheterization; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012146:Rest; D012720:Severity of Illness Index; D012815:Signal Processing, Computer-Assisted; D012984:Software; D014665:Vasodilator Agents / Q000008:administration & dosage*; D055815:Young Adult
D014665:Vasodilator Agents; D000241:Adenosine
adenosine; coronary stenosis; fractional flow reserve, myocardial; hyperemia; percutaneous coronary intervention