title: The influence of artery wall curvature on the anatomical assessment of stenosis severity derived from fractional flow reserve: a computational fluid dynamics study.
abstract: This study aims to investigate the influence of artery wall curvature on the anatomical assessment of stenosis severity and to identify a region of misinterpretation in the assessment of per cent area stenosis (AS) for functionally significant stenosis using fractional flow reserve (FFR) as standard. Five artery models of different per cent AS severity (70, 75, 80, 85 and 90%) were considered. For each per cent AS severity, the angle of curvature of the arterial wall varied from straight to an increasingly curved model (0°, 30°, 60°, 90° and 120°). Computational fluid dynamics was performed under transient physiologic hyperemic flow conditions to investigate the influence of artery wall curvature on the pressure drop and the FFR. The findings in this study may be useful in in vitro anatomical assessment of functionally significant stenosis. The FFR decreased with increasing stenosis severity for a given curvature of the artery wall. Moreover, a significant decrease in FFR was found between straight and curved models discussed for a given severity condition. These findings indicate that the curvature effect was included in the FFR assessment in contrast to minimum lumen area (MLA) or per cent AS assessment. The MLA or per cent AS assessment may lead to underestimation of stenosis severity. From this numerical study, an uncertainty region could be evaluated using the clinical FFR cutoff value of 0.8. This value was observed at 81.98 and 79.10% AS for arteries with curvature angles of 0° and 120° respectively. In conclusion, the curvature of the artery should not be neglected in in vitro anatomical assessment.
authors.affiliation: a Centre for Engineering Programs , HELP College of Arts and Technology , Kuala Lumpur , Malaysia.
authors.forename: Kalimuthu
authors.initials: K
authors.lastname: Govindaraju
authors.affiliation: b Cardiology department , Derriford Hospital , Plymouth , UK.|c Institute of Cellular Medicine , Newcastle University , Newcastle upon Tyne , UK.
authors.forename: Girish N
authors.initials: GN
authors.lastname: Viswanathan
authors.affiliation: d Department of Mechanical Engineering , University of Malaya , Kuala Lumpur , Malaysia.
authors.forename: Irfan Anjum
authors.initials: IA
authors.lastname: Badruddin
authors.affiliation: d Department of Mechanical Engineering , University of Malaya , Kuala Lumpur , Malaysia.
authors.forename: Sarfaraz
authors.initials: S
authors.lastname: Kamangar
authors.affiliation: e Center for Energy Sciences, Department of Mechanical Engineering , University of Malaya , Kuala Lumpur , Malaysia.
authors.forename: N J
authors.initials: NJ
authors.lastname: Salman Ahmed
authors.affiliation: f Department of Automotive and Marine Engineering Technology , College of Technological Studies, The Public Authority for Applied Education and Training , Kuwait city , Kuwait.
authors.forename: Abdullah A A A
authors.initials: AA
authors.lastname: Al-Rashed
mesh_terms: D003198:Computer Simulation; D023921:Coronary Stenosis / Q000473:pathology* / Q000503:physiopathology*; D003331:Coronary Vessels / Q000503:physiopathology*; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D057446:Hydrodynamics; D008955:Models, Cardiovascular; D011312:Pressure
keywords: Straight and curved arteries; anatomical assessment; computational fluid dynamics; fractional flow reserve