Feasibility of Redo-Transcatheter Aortic Valve Replacement in Sapien Valves Based on In Vivo Computed Tomography Assessment.

BACKGROUND: Our aim was to assess the feasibility of repeat transcatheter aortic valve (TAV) replacement for degenerated Sapien3 (S3) prostheses by simulating subsequent implantation of S3 or Evolut, using in vivo computed tomography-based sizing and the impact on coronary and patient-prosthesis mismatch risks. METHODS: Computed tomography scans from 356 patients with prior S3 TAV replacement implantation were analyzed. The in vivo sizing for second TAV based on averaged area of 3 levels of outflow, mid (narrowest) and inflow, was compared with in vitro recommendations, that is, same size as index S3 for second S3 and 1 size larger for Evolut. Risks of coronary obstruction and patient-prosthesis mismatch were determined by valve-to-aorta distance and estimated effective orifice area, respectively. RESULTS: Overall, the majority of patients (n=328; 92.1%) had underexpanded index S3 with an expansion area of 94% (91%-97%), leading to significant differences in size selection of the second TAV between in vivo and in vitro sizing strategies. Expansion area <89% served as a threshold, resulting in 1 size smaller than the in vitro recommendations were selected in 45 patients (13%) for S3-in-S3 and 13 (4%) for Evolut-in-S3, while the remaining patients followed in vitro recommendations (P<0.01, in vivo versus in vitro sizing). Overall, 57% of total patients for S3-in-S3 simulation and 60% for Evolut-in-S3 were considered low risk for coronary complications. Deep index S3 implantation (odds ratio, 0.76 [interquartile range, 0.67-0.87]; P<0.001) and selecting Evolut as the second TAV (11% risk reduction in intermediate- or high-risk patients) reduced coronary risk. Estimated moderate or severe patient-prosthesis mismatch risk was 21% for S3-in-S3 and 1% for Evolut-in-S3, assuming optimal expansion of the second TAV. CONCLUSIONS: Redo-TAV replacement with S3-in-S3 and Evolut-in-S3 could be feasible with low risk to coronaries in ≈60% of patients, while the remaining 40% will be at intermediate or high risk. The feasibility of redo-TAV replacement is influenced by sizing strategy, type of second TAV, native annular anatomy, and implant depth.

Deformation of transcatheter heart valves with mitral valve-in-valve.

BACKGROUND: The use of oversizing in mitral valve-in-valve (MViV) procedures can lead to non-uniform expansion of transcatheter heart valves (THV). This may have implications for THV durability. AIMS: The objective of this study was to assess the extent and predictors of THV deformation in MViV procedures. METHODS: We examined 33 patients who underwent MViV with SAPIEN prostheses. The extent of THV deformation (deformation index, eccentricity, neosinus volume, asymmetric leaflet expansion and vertical deformation) and hypoattenuating leaflet thickening (HALT) were assessed using cardiac computed tomography (CT), performed prospectively at 30 days post-procedure. For descriptive purposes, the THV deformation index was calculated, with values >1.00 representing a more hourglass shape. RESULTS: Non-uniform underexpansion of THV was common after MViV implantation, with a median expansion area of 74.0% (interquartile range 68.1-84.1) at the narrowest level and a THV deformation index of 1.21 (1.13-1.29), but circularity was maintained with eccentricity ranging from 0.24 to 0.28. The degree of oversizing was a key factor associated with greater underexpansion and a higher deformation index (ß=-0.634; p<0.001; ß=0.594; p<0.001, respectively). Overall, the incidence of HALT on the 30-day postprocedural CT was 27.3% (9 of 33). Most patients (32 of 33) were on anticoagulation therapy, but the prothrombin time and international normalised ratio (PT-INR) at the time of the CT scan was <2.5 in 23 of 32 patients. Among patients with a PT-INR of <2.5, HALT was predominantly observed with a high THV deformation index of ≥1.18. CONCLUSIONS: THV deformation, i.e., underexpansion and an hourglass shape, commonly occurs after MViV implantation and is negatively affected by excessive oversizing. Optimising THV expansion during MViV could potentially prevent HALT.

Early safety and feasibility of a first-in-class biomimetic transcatheter aortic valve - DurAVR.

BACKGROUND: TAVI is a widely accepted treatment for patients with severe aortic stenosis (AS). Despite the adoption of diverse therapies, opportunities remain to develop technologies tailored to provide optimal acute and potential long-term benefits, particularly around haemodynamics, flow and durability. AIMS: We aimed to evaluate the safety and feasibility of the DurAVR transcatheter heart valve (THV), a first-in-class biomimetic valve, in the treatment of patients with symptomatic severe AS. METHODS: This was a first-in-human (FIH), prospective, non-randomised, single-arm, single-centre study. Patients with severe, symptomatic AS of any surgical risk and who were eligible for the DurAVR THV prosthesis were recruited; they were assessed at baseline, 30 days, 6 months, and 1 year post-procedure for implant success, haemodynamic performance, and safety. RESULTS: Thirteen patients (73.9±6.4 years old, 77% female) were enrolled. The DurAVR THV was successfully implanted in 100% of cases with no device-related complications. One access site complication, one permanent pacemaker implantation, and one case of moderate aortic regurgitation occurred. Otherwise, no deaths, stroke, bleeding, reinterventions, or myocardial infarction were reported during any of the follow-up visits. Despite a mean annulus size of 22.95±1.09 mm, favourable haemodynamic results were observed at 30 days (effective orifice area [EOA] 2.00±0.17 cm2, and mean pressure gradient [MPG] 9.02±2.68 mmHg) and were sustained at 1 year (EOA 1.96±0.11 cm2, MPG 8.82±1.38 mmHg), resulting in zero patients with any degree of prosthesis-patient mismatch. Additionally, new valve performance measures derived from cardiovascular magnetic resonance displayed restoration of laminar flow, consistent with a predisease state, in conjunction with a mean coaptation length of 8.3±1.7 mm. CONCLUSIONS: Preliminary results from the FIH study with DurAVR THV demonstrate a good safety profile with promising haemodynamic performance sustained at 1 year and restoration of near-normal flow dynamics. Further clinical investigation is warranted to evaluate how DurAVR THV may play a role in addressing the challenge of lifetime management in AS patients.

Prospective Evaluation for Hypoattenuated Leaflet Thickening Following Transcatheter Aortic Valve Implantation.

Prospective investigations for the frequency of hypoattenuated leaflet thickening (HALT) and its clinical implications in transcatheter aortic valve implantation (TAVI) patients are limited. We initiated a prospective screening program of TAVI patients for HALT beginning in July 2015. Eligible patients were evaluated with gated, contrast-enhanced multidetector computed tomography within 30 days of TAVI, and examined for HALT and clinical outcomes. During the study period, 287 patients (81 ± 8 years; 53% men) who underwent TAVI with commercially approved devices were examined. Overall, 26 patients (9.1%) had occurrence of HALT, and only one of these patients had detectable hemodynamic changes on echocardiography at diagnosis. Notably, 9 of 26 HALT patients had been receiving warfarin, however, the HALT patients more often had subtherapeutic international normalized ratio whereas using warfarin than patients without HALT on index multidetector computed tomography imaging (p = 0.01). Patients who developed HALT had lower baseline aortic gradient, valvuloarterial impedance, and peak aortic velocity, and more commonly had been treated with balloon-expandable valves (73% of all HALT cases) with a higher incidence among those who received larger prostheses. All patients with HALT were placed on anticoagulation at diagnosis, and valvular function remained unchanged at follow-up. Two patients with HALT (7.7%) experienced ischemic stroke. A statistical trend for more major adverse clinical events was present in HALT patients. In conclusion, HALT was detected in 9% of TAVI cases in this prospective observational cohort, with a greater frequency in patients with large, balloon-expandable prostheses. Prospective screening may be considered as early HALT is reversible by timely therapeutic anticoagulation.