Comparison of performance of self-expanding and balloon-expandable transcatheter aortic valves

Comparison of invasive and non-invasive gradients before and after TAVI and their implications on clinical outcomes

Transcatheter aortic valve implantation (TAVI) is recommended for treatment of high-risk aortic stenosis patients. While measuring mean transaortic valve gradient (MG) is crucial in evaluating procedural success, echocardiographic measurements often overestimate direct invasive measurements. This study aimed to examine the discordance between echocardiographic and invasive MGs in TAVI patients and assess their prognostic value on long-term outcomes. This prospective registry included consecutive TAVI patients at a tertiary university hospital. Transthoracic or transoesophageal echocardiography was performed pre-TAVI, at discharge, 1 month, 1, and 5 years with invasive MG measurements obtained peri-procedurally. The primary endpoints were 5-year all-cause mortality and major adverse cardiac events. Among 1353 patients from 2011 to 2023, non-invasive MGs exceeded invasive MGs pre- and post-implantation (43 [36, 52] mmHg vs. 40 [30, 50] mmHg, p < 0.001; 9 [6, 12] mmHg vs. 4 [2, 7] mmHg, p < 0.001) Pre-procedural MGs correlated better than post-procedural MGs (r = 0.70, p < 0.001 vs. r = 0.23, p < 0.001), particularly in self-expandable valves and smaller sinus of Valsalva diameter (SOVd) (r = 0.33, p < 0.001; r = 0.46, p < 0.001 vs R = 0.06, p = 0.701). Non-invasive MG remained stable from discharge (9 [6, 12] mmHg) to 5 years (9 [7, 12] mmHg). While structural valve deterioration and patient-prosthesis mismatch showed no impact, extreme invasive MGs (< 3 or > 6 mmHg) predicted worse outcomes (mortality hazard: 1.25 [1.06, 1.88] and 0.85 [0.8, 0.95], respectively), unlike non-invasive measurements. In conclusion, invasive as compared with non-invasive MGs correlated better before than after valve implantation, whereas invasive MGs were always lower than non-invasive MGs. Lower invasive MGs after TAVI appeared to be associated with favourable long-term outcomes.

Guidelines for the Evaluation of Prosthetic Valve Function With Cardiovascular Imaging: A Report From the American Society of Echocardiography Developed in Collaboration With the Society for Cardiovascular Magnetic Resonance and the Society of Cardiovascular Computed Tomography

In patients with significant cardiac valvular disease, intervention with either valve repair or valve replacement may be inevitable. Although valve repair is frequently performed, especially for mitral and tricuspid regurgitation, valve replacement remains common, particularly in adults. Diagnostic methods are often needed to assess the function of the prosthesis. Echocardiography is the first-line method for noninvasive evaluation of prosthetic valve function. The transthoracic approach is complemented with two-dimensional and three-dimensional transesophageal echocardiography for further refinement of valve morphology and function when needed. More recently, advances in computed tomography and cardiac magnetic resonance have enhanced their roles in evaluating valvular heart disease. This document offers a review of the echocardiographic techniques used and provides recommendations and general guidelines for evaluation of prosthetic valve function on the basis of the scientific literature and consensus of a panel of experts. This guideline discusses the role of advanced imaging with transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance in evaluating prosthetic valve structure, function, and regurgitation. It replaces the 2009 American Society of Echocardiography guideline on prosthetic valves and complements the 2019 guideline on the evaluation of valvular regurgitation after percutaneous valve repair or replacement.

Comparison of a novel self-expanding transcatheter heart valve with two established devices for treatment of degenerated surgical aortic bioprostheses

AIMS

This study was performed to compare haemodynamic properties of a novel transcatheter heart valve (THV) with two established valve technologies for treatment of failing surgical aortic bioprosthetic valves (SAV). The ALLEGRA THV has been recently described with a proven safety and performance profile.

METHODS AND RESULTS

The study was designed as a retrospective, single-centre study investigating 112 patients (77.7 ± 7.1 years, 53.8% female, STS score 6.8 ± 5.8% and logEuroSCORE I 27.4 ± 16.1%) with failing SAV. Patients were treated with the ALLEGRA THV (NVT, n = 24), the CoreValve/EvolutR (MTD, n = 64) or the Edwards Sapien/Sapien XT/Sapien 3 (EDW, n = 24). Adverse events, haemodynamic outcomes and patient safety were analysed according to VARC-3 definitions. Overall procedural success was high (94.6%), even though 58.9% of the treated SAV were classified as small (true inner diameter < 21 mm). After treatment, the mean pressure gradient was significantly reduced (baseline: 33.7 ± 16.5 mmHg, discharge: 18.0 ± 7.1 mmHg), with a corresponding increase in effective orifice area (EOA). The complication rates did not differ in between groups. There was a trend to lower mean transvalvular gradients after implantation of self-expanding THV with supra-annular valve function, despite a higher frequency of smaller SAVs in the NVT and MTD group. Additionally, comparison between NVT and MTD revealed statistically lower transvalvular gradients (NVT 14.9 ± 5.0 mmHg, MTD 18.7 ± 7.5 mmHg, p = 0.0295) in a subgroup analysis.

CONCLUSIONS

Valve-in-valve (ViV) treatment of failing SAV with supra-annular design like the ALLEGRA THV resulted in favourable haemodynamic outcomes with similar low clinical event rates and may therefore be an interesting alternative for VIV TAVI.

Differences in blood flow dynamics between balloon- and self-expandable valves in patients with aortic stenosis undergoing transcatheter aortic valve replacement

BACKGROUND

The differences in pre- and early post-procedural blood flow dynamics between the two major types of bioprosthetic valves, the balloon-expandable valve (BEV) and self-expandable valve (SEV), in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR), have not been investigated. We aimed to investigate the differences in blood flow dynamics between the BEV and SEV using four-dimensional flow cardiovascular magnetic resonance (4D flow CMR).

METHODS

We prospectively examined 98 consecutive patients with severe AS who underwent TAVR between May 2018 and November 2021 (58 BEV and 40 SEV) after excluding those without CMR because of a contraindication, inadequate imaging from the analyses, or patients' refusal. CMR was performed in all participants before (median interval, 22 [interquartile range (IQR) 4-39] days) and after (median interval, 6 [IQR 3-6] days) TAVR. We compared the changes in blood flow patterns, wall shear stress (WSS), and energy loss (EL) in the ascending aorta (AAo) between the BEV and SEV using 4D flow CMR.

RESULTS

The absolute reductions in helical flow and flow eccentricity were significantly higher in the SEV group compared in the BEV group after TAVR (BEV: - 0.22 ± 0.86 vs. SEV: - 0.85 ± 0.80, P < 0.001 and BEV: - 0.11 ± 0.79 vs. SEV: - 0.50 ± 0.88, P = 0.037, respectively); there were no significant differences in vortical flow between the groups. The absolute reduction of average WSS was significantly higher in the SEV group compared to the BEV group after TAVR (BEV: - 0.6 [- 2.1 to 0.5] Pa vs. SEV: - 1.8 [- 3.5 to - 0.8] Pa, P = 0.006). The systolic EL in the AAo significantly decreased after TAVR in both the groups, while the absolute reduction was comparable between the groups.

CONCLUSIONS

Helical flow, flow eccentricity, and average WSS in the AAo were significantly decreased after SEV implantation compared to BEV implantation, providing functional insights for valve selection in patients with AS undergoing TAVR. Our findings offer valuable insights into blood flow dynamics, aiding in the selection of valves for patients with AS undergoing TAVR. Further larger-scale studies are warranted to confirm the prognostic significance of hemodynamic changes in these patients.

Comparison of self- and balloon-expandable valves in patients with dilatated ascending aorta undergoing transcatheter aortic valve replacement

Background

Limited studies have focused on the performance of self-expandable valves (SEVs) and balloon-expandable valves (BEVs) in patients with dilatated ascending aorta (AA) undergoing transcatheter aortic valve replacement (TAVR). The present study compared the performance of widely used Edwards BEVs and domestic SEVs in patients with dilatated AA among Chinese population.

Methods

We identified and reviewed 207 patients who had baseline AA diameter ≥40 mm and underwent transfemoral TAVR. Patients were divided into two groups: SEV and BEV. The SEVs were locally manufactured valves that have received Chinese regulatory approval (Venus-A, Taurus One, and VitaFlow), while the BEVs were Edwards Sapien XT and Sapien3. Procedural device success and post-procedural changes of AA diameters were compared.

Results

The sample size of SEV group was larger than that of BEV group because BEVs were not available in China in the early clinical practice. The overall device success was slightly lower in SEV group compared with BEV group (84.2% vs. 95.8%, P=0.213). However, in the univariable and multivariable logistic regression analyses, only bicuspid aortic valve (BAV) was found to be an independent risk factor for device failure (OR: 2.632, CI: 1.107-6.257, P=0.029). During the median follow-up of 21 months, no statistical difference was found between the two groups regarding the overall survival (83.1%±4.7% vs. 95.8%±4.1%, P=0.533), and no aortic dissection nor rupture was observed. In a subgroup of patients who had follow-up CTs ≥12-month intervals, the AA diameter appeared to remain stable in SEV group with an aortic expansion rate of 0 (-0.4 to 0.8) mm (P=0.102), while it slightly enlarged in BEV group with an aortic expansion rate of 0.4 (-0.4 to 0.6) mm/y (P=0.038). In addition, the AA diameter also slightly enlarged in patients with BAV [0.2 (0 to 1.0) mm/y, P=0.015], while it remained stable in patients with tricuspid aortic valve (TAV) [0 (-0.8 to 0.6) mm/y, P=0.640].

Conclusions

In patients with dilatated AA who underwent TAVR, the type of THVs did not affect the procedural device success. BAV appeared to be a risk factor for both device failure and higher aortic expansion rate in these patients.

Effect of aortic curvature on bioprosthetic aortic valve performance

Transvalvular pressure gradient (ΔP) after aortic valve replacement is an important surrogate of aortic bioprostheses performance. Invasive ΔP is often measured after transcatheter aortic valve replacement to exclude patient-prosthetic mismatch. However, invasive aortic pressures are usually recorded in the pressure recovery (PR) zone downstream of the valve, potentially resulting in ΔP underestimation compared to noninvasive measurements. PR was extensively studied in straight ascending aortas. However, the impact of various aortic arch configurations on ΔP has not been explored. PR was assessed in a pulse duplicating simulator at various cardiac conditions of cardiac output, heart rates and pressures. Three different aortic geometries with identical root dimensions but with different aortic arches were used: (1) curvature 1, (2) curvature 2, and (3) straight aortic models. Instantaneous pressure and peak ΔP measurements were recorded incrementally along the models for each cardiac condition. The models with aortic arches produced two distinct PR zones (after the valve and after the aortic arch), whereas the model without an aortic arch produced only one PR zone (after the valve). The trend of the pressure and ΔP curves for each model was independent of the cardiac condition used, but the individually measured pressure magnitudes did change with different conditions. In this study, we illustrated the differences in PR between distinct aortic curvatures and straight aorta. PR affects pressure and ΔP measurements. These effects are clear when recording aortic pressures by catheterization and echocardiography.