Effect of transcatheter aortic valve replacement on bicuspid coronary hemodynamics:A numerical study

To investigate the effects of transcatheter heart valve(THV)poses and bicuspid aortic valve(BAV)subtypes on coronary hemodynamics after transcatheter aortic valve replacement(TAVR).The computational models for BAV included left-right fusion(LR),non-coronary-left fusion(LN)and non-coronary-right fusion(RN).THV deployment height is defined as the distance below the aortic annulus of the lowest point of the stent,H_(1)=2mm,H_(2)=5mm and H_(3)=8mm,Orientations include O_(1)(one commissure is aligned with the raphe)and O_(2)(one commissure is aligned with the axis of non-fused leaflet symmetry).The maximum flow velocity(Vmax),mean wall shear stress(mWSS)and coronary perfusion pressure(CPP)of coronary were obtained by computational fluid dynamics(CFD)simulation.The CPP was 59%in left coronary and 82%in right coronary higher than that before deployment.At O_(1),the CPP of the LN left coronary and the RN right coronary was 74%and 79%higher than that before deployment.At O_(2),the CPP of the LN right coronary and the RN left coronary was 83%and 82%higher than that before deployment.When the THV deployment height is less than 2​mm,Vmax and CPP of coronary arteries do not return to healthy TAV levels or changed weakly.The overlap of the THV commissure with the coronary ostium makes the coronary CPP so large that it exceeds the level of a healthy TAV.