LAUSR

In patients with symptomatic severe aortic stenosis, transcatheter aortic valve replacement (TAVR) has been demonstrated to reduce risk of mortality and stroke for up to 2 years as compared with surgical aortic valve replacement (SAVR).1 TAVR is associated with reduced risk of bleeding complications, acute kidney injury, and onset of atrial fibrillation. However, the risks of pacemaker implantation and major vascular complications are higher with TAVR than SAVR. These are important considerations for the heart team when selecting the appropriate treatment for patients with symptomatic severe aortic stenosis. In patients with low operative risk, who are generally younger and in whom SAVR is associated with excellent outcomes, other factors need to be taken into consideration as well when deciding on treatment. One of those factors in younger patients is the higher frequency of bicuspid aortic valve stenosis, a condition that traditionally has been excluded from randomized clinical trials. In the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry, of 170 959 eligible TAVR procedures, 3.2% were performed in patients with bicuspid aortic valve.2 A modestly higher incidence of moderate and severe paravalvular regurgitation after TAVR has been reported with bicuspid aortic valve as compared with tricuspid aortic valve anatomy (2.7% versus 2.1%; P=0.006). Among patients with tricuspid aortic valve stenosis, residual paravalvular regurgitation remains more common after TAVR than SAVR. Advances in transcatheter valve technology have resulted in reduced incidence of moderate and severe paravalvular regurgitation. In PARTNER 3 (Placement of Aortic Transcatheter Valve Trial) using the SAPIEN 3 valve (Edwards Lifesciences, Irvine, CA),3 there were no differences between TAVR and SAVR in rates of moderate and severe paravalvular regurgitation (0.8% and 0% at 30 days, respectively), although mild paravalvular regurgitation was observed more frequently in TAVR than in SAVR (28.8% versus 2.9%; P<0.001). In contrast to previous studies, the presence of mild paravalvular regurgitation was not associated with increased all-cause mortality. However, the effect of mild paravalvular regurgitation on long-term outcomes needs to be defined carefully, and long-term data on progression of regurgitation will be important. The development of conduction abnormalities and need for permanent pacemaker implantation are additional important factors that should be considered in patients with low surgical risk. The association between permanent pacemaker implantation after TAVR and all-cause death at 1 year remains controversial.4 The development of pacemaker-induced left ventricular systolic dysfunction or leadinduced severe tricuspid regurgitation and right heart failure have been described. Both tricuspid regurgitation and right heart failure have been associated with poor prognosis after TAVR and SAVR.5,6 © 2020 American Heart Association, Inc.