The role of intravascular ultrasound and quantitative angiography in the functional assessment of intermediate coronary lesions: correlation with fractional flow reserve.
BACKGROUND
The correlation between fractional flow reserve (FFR) and intravascular ultrasound (IVUS) metrics including minimal lumen area (MLA), plaque burden and morphology remain a matter of debate.


METHODS
Between June 2008 and May 2013, 132 intermediate stenoses in 109 patients were assessed by FFR, IVUS and quantitative angiography. Receiver-operating characteristic (ROC) curve analyses were used to identify MLA/lesion length/plaque burden cut-off values predictive of FFR <0.80.


RESULTS
FFR <0.80 was observed in 39 lesions. In the entire cohort, MLA value <2.70mm(2) had 79.5% sensitivity, 76.3% specificity, 0.822 area under curve (AUC), 58.5% positive predictive value, 89.9% negative predictive value and 77.3% accuracy in predicting a positive FFR. In lesions with reference diameter vessel (RVD) ≥3.0mm, the MLA cut-off value was 2.84mm(2) (sensitivity 72.2%, specificity 83.0%, AUC 0.842) whereas in lesions with RVD <3.0mm, 2.59mm(2) (sensitivity 90.5%, specificity 69.6%, AUC 0.823). A moderate correlation was observed between MLA and FFR (r=0.429, p<0.001). The cut-off lesion length predictive of FFR <0.80 was 11.0mm with a weak correlation between the two (r=-0.348, p<0.001). Plaque morphology did not significantly affect FFR (p=0.485). On multivariable analysis, MLA (OR: 0.15; 95% CI: 0.05-0.40; p<0.001) and plaque burden (OR: 1.11; 95% CI: 1.04-1.20; p<0.003) were independent predictors of FFR <0.80.


CONCLUSIONS
A modest, yet significant correlation was observed between MLA and FFR. The high negative predictive value of large MLAs (using afore-mentioned cut-off values) may provide some degree of confidence that the lesion in question is not functionally significant.
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy; Interventional Cardiology Unit, New Tokyo Hospital, Chiba, Japan.
Toru
T
Naganuma
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
Azeem
A
Latib
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
Charis
C
Costopoulos
Interventional Cardiology Unit, New Tokyo Hospital, Chiba, Japan.
Kensuke
K
Takagi
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy.
Charbel
C
Naim
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
Katsumasa
K
Sato
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
Tadashi
T
Miyazaki
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
Masanori
M
Kawaguchi
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy; National Heart and Lung Institute, Imperial College London, London, UK.
Vasileios F
VF
Panoulas
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
Sandeep
S
Basavarajaiah
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy.
Filippo
F
Figini
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy.
Alaide
A
Chieffo
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy.
Matteo
M
Montorfano
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy.
Mauro
M
Carlino
Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Italy; Interventional Cardiology Unit, EMO-GVM Centro Cuore Columbus, Milan, Italy. Electronic address: info@emocolumbus.it.
Antonio
A
Colombo
D000368:Aged; D019540:Area Under Curve; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D007558:Italy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional
Fractional flow reserve; Intermediate lesions; Intravascular ultrasound; Plaque morphology; Quantitative coronary angiography