title: Usefulness of combined intravascular ultrasound parameters to predict functional significance of coronary artery stenosis and determinants of mismatch.
abstract: OBJECTIVE
  Efficacy of combined intravascular ultrasound (IVUS) parameters in functional significance prediction and discrepancy between IVUS and fractional flow reserve (FFR) have not been well defined. This study therefore aimed to: 1) evaluate the diagnostic accuracy of combined IVUS parameters, namely minimal lumen area (MLA) and percent plaque burden (%PB), in functional significance prediction of coronary artery stenosis; and 2) define factors that affect the relation between FFR value and IVUS parameters.
  
  
  RESULTS
  At 11 international centres, IVUS and FFR measurements were concurrently performed in 945 major epicardial coronary artery lesions (886 patients). Functional significance was defined as FFR ≤0.8. MLA and FFR correlated weakly (r=0.289, p<0.001). Diagnostic accuracy of MLA ≤4.0 mm2, %PB >70% and their combination were 50%, 47% and 51%, respectively, with similar area under the curve (AUC) of 0.561, 0.511 and 0.516, respectively. The best cut-off values (BCV) were MLA ≤3.0 mm2 and %PB >75%, with accuracy of 60% for MLA, 50% for %PB and 56% for their combination, and AUC of 0.618, 0.511 and 0.533, respectively. MLA BCV ≤3.0 mm2 had higher predictive power than %PB BCV >75% or their combination. Independent predictors of functional significance were male gender (odds ratio 1.76 [95% confidence interval: 1.19-2.62]), left ventricular ejection fraction (LVEF, 0.98 [0.96-0.99]), LAD lesion (2.52 [1.73-3.67]), reference vessel diameter (0.60 [0.41-0.86]), lesion length (1.04 [1.02-1.06]) and MLA (0.79 [0.69-0.92]). False negative lesion incidence was 24.4% in association with race (for Asians, 0.391 [0.219-0.698]), LAD lesion (2.677 [1.709-4.191]) and LVEF (0.977 [0.957-0.997]). False positive lesion incidence was 17.0% in association with non-LAD lesion (2.444 [1.620-3.686]).
  
  
  CONCLUSIONS
  Combined IVUS parameters did not improve the accuracy of functional significance prediction. Discrepancy between IVUS and FFR, which was not rare, should be taken into account in clinical decision making.
authors.affiliation: Keimyung University Dongsan Medical Center, Daegu, Republic of Korea.
authors.forename: Yun-Kyeong
authors.initials: YK
authors.lastname: Cho
authors.forename: Chang-Wook
authors.initials: CW
authors.lastname: Nam
authors.forename: Jung-Kyu
authors.initials: JK
authors.lastname: Han
authors.forename: Bon-Kwon
authors.initials: BK
authors.lastname: Koo
authors.forename: Joon-Hyung
authors.initials: JH
authors.lastname: Doh
authors.forename: Itsik
authors.initials: I
authors.lastname: Ben-Dor
authors.forename: Ron
authors.initials: R
authors.lastname: Waksman
authors.forename: Augusto
authors.initials: A
authors.lastname: Pichard
authors.forename: Naotaka
authors.initials: N
authors.lastname: Murata
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tanaka
authors.forename: Chi-Hang
authors.initials: CH
authors.lastname: Lee
authors.forename: Nieves
authors.initials: N
authors.lastname: Gonzalo
authors.forename: Javier
authors.initials: J
authors.lastname: Escaned
authors.forename: Marco A
authors.initials: MA
authors.lastname: Costa
authors.forename: Takashi
authors.initials: T
authors.lastname: Kubo
authors.forename: Takashi
authors.initials: T
authors.lastname: Akasaka
authors.forename: Xinyang
authors.initials: X
authors.lastname: Hu
authors.forename: Jian-An
authors.initials: JA
authors.lastname: Wang
authors.forename: Hyoung-Mo
authors.initials: HM
authors.lastname: Yang
authors.forename: Myung-Ho
authors.initials: MH
authors.lastname: Yoon
authors.forename: Seung-Jea
authors.initials: SJ
authors.lastname: Tahk
authors.forename: Hyuck-Jun
authors.initials: HJ
authors.lastname: Yoon
authors.forename: In-Sung
authors.initials: IS
authors.lastname: Chung
authors.forename: Seung-Ho
authors.initials: SH
authors.lastname: Hur
authors.forename: Kwon-Bae
authors.initials: KB
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D017023:Coronary Angiography / Q000379:methods; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000502:physiology; D006321:Heart / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional / Q000379:methods