title: The impact of microvascular resistance on the discordance between anatomical and functional evaluations of intermediate coronary disease.
abstract: OBJECTIVE
  In intermediate coronary artery disease, discordance between anatomical and functional assessments persists and the diagnostic accuracy of an anatomical evaluation is not satisfactory for determining functional significance. We aimed to evaluate the impact of microvascular resistance on "anatomical-functional discordance".
  
  
  RESULTS
  In 97 intermediate coronary lesions of 83 patients, minimum lumen area (MLA), fractional flow reserve (FFR), Δ(Pd/Pa-FFR), and hyperaemic microvascular resistance index (hMVRI) were measured using intravascular ultrasound and an intracoronary dual pressure and Doppler sensor-tipped guidewire. hMVRI correlated with FFR and Δ(Pd/Pa-FFR) (r=0.611, p<0.001; r=-0.509, p<0.001; respectively). After the lesions were categorised into four groups based on functional significance (FFR 0.8) and the MLA cut-off for that (2.5 mm2), hMVRI was higher with a lower Δ(Pd/Pa-FFR) regardless of the MLA group in lesions with FFR >0.8, compared with those in lesions with FFR ≤0.8. hMVRI was independently associated with FFR and Δ(Pd/Pa-FFR) (β=0.443, p<0.001; β=-0.389, p<0.001; respectively).
  
  
  CONCLUSIONS
  Coronary microvascular resistance is associated with anatomical-functional discordance and the ischaemic potential of intermediate epicardial stenosis. In determining a treatment strategy, anatomy alone is insufficient and an integrated physiologic approach is important.
authors.affiliation: Department of Cardiology, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Kyoung-Woo
authors.initials: KW
authors.lastname: Seo
authors.forename: Hong-Seok
authors.initials: HS
authors.lastname: Lim
authors.forename: Myeong-Ho
authors.initials: MH
authors.lastname: Yoon
authors.forename: Seung-Jea
authors.initials: SJ
authors.lastname: Tahk
authors.forename: So-Yeon
authors.initials: SY
authors.lastname: Choi
authors.forename: Byoung-Joo
authors.initials: BJ
authors.lastname: Choi
authors.forename: Hyoung-Mo
authors.initials: HM
authors.lastname: Yang
authors.forename: Joon-Han
authors.initials: JH
authors.lastname: Shin
authors.forename: Gyo-Seung
authors.initials: GS
authors.lastname: Hwang
authors.forename: Jin-Sun
authors.initials: JS
authors.lastname: Park
authors.forename: XiongJie
authors.initials: X
authors.lastname: Jin
mesh_terms: D000368:Aged; D019540:Area Under Curve; D006328:Cardiac Catheterization; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015150:Echocardiography, Doppler; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional; D014655:Vascular Resistance