Outcomes of Transcatheter Aortic Valve Replacement in Patients With Bicuspid Aortic Valve Disease

Abstract

A bicuspid aortic valve (AV) is the most common congenital cardiac anomaly with an estimated incidence of 0.9% to 2.0% in the general population. 1,2 Patients with bicuspid aortic valves may present with AV stenosis, regurgitation, or a combination of the 2. Patients with bicuspid AV stenosis often present at a younger age than those with trileaflet AV stenosis; however , a small proportion of patients with bicuspid AV may not present until advanced age. According to an analysis from the Society of Thoracic Surgeons (STS) database, ≈4.5% of AV replacements performed for bicuspid AV disease in 2013 were in patients ≥80 years old. In another cohort of octogenarians and nonagenarians undergoing isolated surgical AV replacement, as many as 28% were found to have bicuspid AVs during pathological examination. 3 Because of a higher risk of surgical complications related to age, frailty, and other comorbidities, many of these older patients with severe bicuspid AV ste-nosis may be treated with transcatheter AV replacement (TAVR). Nevertheless, bicuspid AV anatomy (large annu-lar size, bulky and asymmetric leaflet calcification, associated ascending aortic dilatation, and horizontal aorta) poses challenges to treatment with TAVR that may impact procedural outcomes. Current-generation devices have been designed to reduce perivalvular leaks through the use of sealing skirts and facilitated repositioning. Although there is a growing body of evidence worldwide on TAVR performance in patients with bicuspid AV, most of these studies are at a single center, involve a small cohort of patients, or only evaluate short-term outcomes. In GARY (the German Aortic Valve Registry), there was an increased incidence of residual 2+ aortic insufficiency in bicuspid AV cases, in comparison with tricuspid AV cases, when treated with TAVR. 4 More recently , an analysis of a propensity-matched cohort of patients undergoing TAVR for bicuspid AV versus tri-cuspid AV stenosis reported a significantly lower incidence of device success in patients with bicuspid AV. 5 Contrary to this result, an industry-led analysis of a subset of TVT (Transcatheter Valve Therapy) Registry data that included only third-generation balloon-expandable Sapien 3 devices, found a 30-day and 1-year mortality that were not different for bicuspid versus tricuspid TAVR procedures, but a higher 30-day risk of stroke. 6 In this analysis, we included a broad cohort of patients from the TVT Registry with all available data from both self-expanding and balloon-expandable TAVR prostheses to evaluate TAVR outcomes for patients with bicuspid versus tricuspid anatomy. Furthermore, we compared the incidence of procedural success and the incidence of moderate or severe aortic insufficiency across self-expanding versus balloon-expandable TAVR prostheses. Using the complete STS/American College of Cardiology (ACC) TVT Registry data set, we determined whether or not: (1) TAVR for bicuspid AV was associated with an increased incidence of valve-related complications or paravalvular leak in comparison with TAVR for tricuspid AV disease; (2) this trend persisted with newer-generation devices; and (3) 1-year outcomes differed between patients with bicuspid versus tricuspid AV treated with TAVR. • With current-generation transcatheter aortic valve replacement devices, the incidence of device success (96.3% versus 97.4%; P<0.001) was only slightly lower for patients with bicuspid versus tricuspid aortic valve (AV), and residual 2+ aor-tic insufficiency (2.7% versus 2.1%; P=0.006) remained slightly higher for patients with bicuspid versus tricuspid AV. • There was no difference in adjusted 1-year hazard of stroke (hazard ratio, 1.14 [95% CI, 0.94-1.39]) in patients with bicuspid versus tricuspid valves, but the adjusted 1-year hazard of mortality was lower among patients with bicuspid AV (hazard ratio, 0.88 [95% CI, 0.78-0.99]). What Are the Clinical Implications? • Using current-generation technology, transcatheter AV replacement is both safe and effective for the treatment of bicuspid AV stenosis, although there remains a low incidence of moderate or greater aortic insufficiency among both patients with bicuspid and tricuspid AV (2.7% and 2.1%).