Transcatheter Heart Valve Deployment Research Articles

Safety and Efficacy of TAVR With a Pressure Sensor and Pacing Guidewire: SAFE-TAVI Trial

BackgroundThe SavvyWire (OpSens Inc) is a 0.035-inch preshaped guidewire with dedicated pacing properties and a distal pressure sensor allowing for continuous hemodynamic pressure monitoring. ObjectivesThis study sought to determine the efficacy and safety of the guidewire during transcatheter aortic valve replacement (TAVR) procedures. MethodsThis prospective, multicenter clinical study included patients with severe aortic stenosis undergoing TAVR in 8 European centers. The primary efficacy endpoint was defined as effective left ventricular rapid pacing runs with the guidewire translating into a significant systemic pressure drop (below 60 mm Hg). The safety outcome included the absence of major procedural complications related to the guidewire. ResultsA total of 121 patients (mean age: 82.2 ± 5.9 years, 50% women) were included in the study, and 119 (98.3%) patients were finally treated with the study device. A balloon-expandable valve was implanted in 45 (37.8%) patients. Predilatation and postdilatation were performed in 89 (74.8%) and 14 (11.8%) patients, respectively. The primary efficacy endpoint was achieved in 116 (98.3%) patients, and the mean aortic systolic arterial pressure achieved during rapid pacing was 46.6 ± 11.3 mm Hg. Hemodynamic assessment with the use of the OptoMonitor 3 (OpSens Inc) without additional catheter exchange was achieved in 117 (99.2%) patients. The safety endpoint was achieved in 117 (99.2%) patients. No procedural mortality, stroke, or ventricular perforation was reported. ConclusionsThe use of the guidewire during TAVR procedures appeared to be efficacious and safe. This device could help minimize interventions during the procedure and improve the clinical decision making after transcatheter heart valve deployment. (SavvyWire Efficacy and Safety in Transcatheter Aortic Valve Implantation Procedures [SAFE-TAVI]; NCT05492383)

Physician-Modified Endograft-Facilitated Transcatheter Pulmonary Valve Replacement in Large Right Ventricular Outflow Tract.

Transcatheter pulmonary valve replacement (TPVR) in patients with a congenital or acquired abnormality resulting in enlarged right ventricular outflow tract (RVOT) is challenging and may preclude treatment with dedicated devices. We describe a technique using a physician-modified endograft to facilitate TPVR. Six patients underwent physician-modified endograft-facilitated TPVR for severe symptomatic pulmonary insufficiency with enlarged RVOT. The fenestration was created in a commercially available endograft before implantation, which was then deployed from the dominant branch pulmonary artery into the RVOT, with the fenestration aligned with the ostium of the nondominant pulmonary artery. A covered stent was placed through the fenestration into the nondominant branch pulmonary artery, and a transcatheter heart valve was deployed within the endograft at the level of the original pulmonary valve. Four patients had tetralogy of Fallot, 1 had pulmonary atresia, and 1 had rheumatic valve disease. The RVOT/main pulmonary artery was severely enlarged (diameter, 44.2 [43.5-50.6] mm). All patients had reduced right ventricular (RV) function and dilated RVs (RV end-diastolic volume, 314 [235-316] mL). Successful endograft, covered stent, and transcatheter heart valve deployment were achieved in all cases without stent/valve embolization, vascular complications, or bleeding complications. At 30 days, 1 patient had mild pulmonary insufficiency, while others had none. The RV size measured by echocardiography was significantly reduced after TPVR (RV area, 34.4 [baseline] versus 29.0 [pre-discharge] versus 25.3 [30 days] cm2; P=0.03). During median follow-up of 221.5 (range, 29-652) days, there were no deaths or need for pulmonary valve reintervention. One patient developed severe tricuspid regurgitation due to entrapment of the anterior tricuspid leaflet by the endograft. The patient underwent successful tricuspid replacement and resection of the offending endograft with preservation of the pulmonary valve prosthesis. Simple fenestration of an off-the-shelf endograft and associated covered stent placement through the fenestration allows TPVR for patients with dysfunctional native or patch-repaired pulmonary valves and RVOT enlargement.

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, H1 ​= ​2 ​mm, H2 ​= ​5 ​mm and H3 ​= ​8 ​mm, Orientations include O1 (one commissure is aligned with the raphe) and O2 (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 O1, the CPP of the LN left coronary and the RN right coronary was 74% and 79% higher than that before deployment. At O2, 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.

Timing of bioprosthetic valve fracture in transcatheter valve-in-valve intervention: impact on valve durability and leaflet integrity.

Bioprosthetic valve fracture (BVF) can be used to improve transcatheter heart valve (THV) haemodynamics following a valve-in-valve (ViV) intervention. However, whether BVF should be performed before or after THV deployment and the implications on durability are unknown. Aims: We sought to assess the impact of BVF timing on long-term THV durability. The impact of BVF timing was assessed using small ACURATE neo (ACn) or 23 mm SAPIEN 3 (S3) THV deployed in 21 mm Mitroflow valves compared to no-BVF controls. Valves underwent accelerated wear testing up to 200 million (M) cycles (equivalent to 5 years). At 200M cycles, THV were evaluated by hydrodynamic testing, second-harmonic generation (SHG) microscopy, scanning electron microscopy (SEM) and histology. At 200M cycles, the regurgitant fraction (RF) and effective orifice area (EOA) for the ACn were 8.03±0.30%/1.74±0.01 cm2 (no BVF), 12.48±0.70%/1.97±0.02 cm2 (BVF before ViV) and 9.29±0.38%/2.21±0.0 cm2 (BVF after ViV), respectively. For the S3 these values were 2.63±0.51%/1.26±0.01 cm2, 2.03±0.42%/1.65±0.01 cm2, and 1.62±0.38%/2.22±0.01 cm2, respectively. Further, SHG and SEM revealed a higher degree of superficial leaflet damage when BVF was performed after ViV for the ACn and S3. However, the histological analysis revealed significantly less damage, as determined by matrix density analysis, through the entire leaflet thickness when BVF was performed after ViV with the S3 and a similar but non-significant trend with the ACn. Conclusions: BVF performed after ViV appears to offer superior long-term EOA without increased RF. Ultrastructure leaflet analysis reveals that the timing of BVF can differentially impact leaflets, with more superficial damage but greater preservation of overall leaflet structure when BVF is performed after ViV.

Impact of left ventricular outflow tract calcium on valve geometry in self-expanding transcatheter aortic-valve replacement.

Evaluate transcatheter heart valve (THV) geometry according to left ventricular outflow tract (LVOT) calcium degree and its impact on hemodynamics and outcomes in patients undergoing transcatheter aortic valve replacement (TAVR) with a contemporary self-expanding THV. LVOT calcium remains challenging for contemporary THVs. LVOT calcium location and degree may affect THV deployment and impact flow patterns and shear stress, accelerating THV degeneration. EPROMPT (CoreValve Evolut Pro Prospective Registry; NCT03423459) is a prospective, investigator-initiated, multicenter registry of patients undergoing TAVR using CoreValve Evolut PRO/PRO + THVs. A total of 107 patients were enrolled in EPROMPT's computed tomography (CT) cohort between January 2018 and October 2021. These patients underwent follow-up CT scan 30 days post-TAVR. We analyzed THV geometry and its interaction with the aortic root following deployment using 30-day post-TAVR CT in patients with none/mild versus moderate/severe LVOT calcium. Thirty-day THV inflows were less eccentric in the short axis in patients with none/mild versus moderate/severe LVOT calcium (1.16 ± 0.09 vs. 1.21 ± 0.12; p = 0.007). THV became more circular and was similar between both cohorts at the THV waist (1.08 ± 0.06 vs. 1.09 ± 0.11; p = 0.551), leaflet tips (1.03 ± 0.04 vs. 1.05 ± 0.09; p = 0.299), and THV outflow (1.04 ± 2.2 vs. 1.03 ± 2.7; p = 0.143). Thirty-day > mild paravalvular leak was low in both cohorts (1.5% vs. 2.4%; p = 0.724); mean gradients were similar (7.7 ± 3.6 vs. 7.7 ± 3.4 mmHg; p = 0.955). Despite inflow deformities observed in patients with moderate/severe LVOT calcium, Evolut PRO/PRO + conforms to elliptical aortic annuli, maintaining circularity and proper function at the leaflets and outflow, even in patients with moderate/severe LVOT calcium.

3D Printing and Computational Modeling for the Evaluation of LVOT obstruction in Transcatheter Mitral Valve Replacement

Transcatheter mitral valve replacement (TMVR) is an emerging alternative treatment for those patients not qualified for surgery. However, TMVR can determine an obstruction of the left ventricular outflow tract (namely, neo-LVOT) induced by the transcatheter heart valve (THV) displacing the native mitral valve leaflet towards the myocardial wall. This condition can lead to haemodynamic impairment and ultimately patient death. We sought to predict the neo-LVOT obstruction by first developing patient-specific simulations of the THV deployment and then comparing predictions with post-TMVR diagnostic images and 3D printed human models. Using pre-TMVR computed-tomography (CT) imaging, patient-specific anatomies of two patients were reconstructed and then meshed with ABAQUS/Explicit solver. The latter was used to simulate the crimping and deployment of SAPIEN 3 THV (Edwards Lifesciences, Irvine, CA) and then simulate the cardiac beating. The neo-LVOT cross sectional area was then computed. For both patients, rigid heart models were printed with SLS rapid prototyping technology while the SAPIEN 3 device was printed with flexible resin to manually positioning the device in the human host.Numerical predictions and 3D printed model measurements of neo-LVOT area agreed well with those obtained by post-TMVR CT imaging. Both computational modelling and 3D printing revealed a comprehensive assessment of the TMVR feasibility, which is not readily conferred by conventional CT imaging. Particularly, the realistic printed models could become an efficient and indispensable tool to help the heart team visualizing the LVOT obstruction to anatomical scale, in a life-size replica of patient-specific cardiac anatomy.

Novel Pressure-Regulated Deployment Strategy for Improving the Safety and Efficacy of Balloon-Expandable Transcatheter Aortic Valves.

The authors propose a novel pressure-regulated method for balloon-expandable transcatheter heart valve (THV) deployment, aimed at optimizing prosthesis-annulus apposition while preventing significant tissue injury. The optimal method for balloon-expandable THV deployment remains debated. Current protocols are volume dependent, relying on under- and overfilling of the deployment apparatus. During deployment, the annular wall tension exerted by the expanding prosthesis is determined by maximal THV diameter and balloon pressure (Laplace's law). Three hundred thirty consecutive patients with severe native aortic stenosis who underwent TAVR with SAPIEN 3 THVs were included. One hundred and six patients were considered at high risk for annular rupture. THVs were deployed until reaching a predetermined balloon pressure. Postdilatation was performed to reduce mild or greater angiographic paravalvular regurgitation (PVR). Using a biomechanical model, annular wall stress was estimated for each case and assessed against rates of postdilatation, mild or greater PVR on transthoracic echocardiography, new permanent pacemaker placement or left bundle branch block, and annular rupture. Patients with wall stress >3 MPa had reduced postdilatation rate (P< 0.001) and reduced final PVR (P=0.014). Annular rupture occurred in 2 of 3 high-risk patients with wall stress >3.5 MPa (3.69 and 3.84 MPa); no rupture occurred in 95 high-risk patients with wall stress≤3.5 MPa. We defined a single target deployment pressure per THV size to ensure deployment within target wall stress levels of 3 to 3.5 MPa: 6.25 atm for 23-mm THVs, 5.5 atm for 26-mm THVs, and 5 atm for 29-mm THVs. Patients within this target range (n=136) had a 10.0% postdilatation rate, 12.7% mild PVR, and no moderate to severe PVR. The relationship between balloon filling volume and associated pressure and wall stress was inconsistent. Pressure-regulated THV deployment is a simple, reproducible, safe, and effective method, regardless of high-risk anatomical complexities.

Novel pressure-regulated deployment strategy for improving the safety and efficacy of balloon-expandable transcatheter aortic valves

Abstract Background The optimal method for balloon-expandable transcatheter heart valve (THV) deployment remains unknown. Current implantation protocols are volume-dependent and rely on ad-hoc filling of the deployment apparatus without accounting for annular wall tension during prosthesis expansion, predisposing patients to inconsistent clinical outcomes. During THV deployment, the annular wall tension exerted by the expanding prosthesis is determined by prosthesis diameter and balloon pressure (Laplace's Law). Objective We proposed and tested a novel method for balloon-expandable THV deployment, aimed at controlling balloon pressure and the resulting annular wall tension to allow optimal prosthesis-annulus apposition while preventing significant tissue injury. Methods 330 consecutive patients with severe native aortic stenosis who underwent balloon-expandable THV implantation between 2015–2020 were included. 106 patients were considered high-risk for annular rupture. THVs were deployed until reaching a pre-determined balloon pressure; 4–4.5atm in earlier cases to establish experience and safety, later increasing to 5–6.5atm in most cases. Post-dilatation was performed to reduce &amp;gt;mild angiographic regurgitation (PVR). Using a biomechanical model, annular wall stress (tension) was estimated for each case and assessed against recorded rates of post-dilatation, ≥mild paravalvular regurgitation (PVR) on TTE, new PPM or LBBB and annular rupture. Results Patients with wall stress &amp;gt;3MPa (n=184) had reduced post-dilatation rate (p&amp;lt;0.001) and final PVR (≥mild, p=0.014). Annular rupture occurred in 2/3 high-risk cases with wall stress &amp;gt;3.5MPa; no rupture occurred in 102 high-risk cases with wall stress ≤3.5MPa. Based on these results, we defined target deployment wall stress levels (3–3.5MPa) and associated deployment pressure per THV size. Patients within this target range (n=136) had 8.1% new PPM, 12.5% new LBBB, 12.7% mild PVR with no cases of ≥moderate PVR. Importantly, there was an inconsistent relationship between deployment balloon volume and resulting annular wall stress. Conclusion Pressure-regulated THV deployment is a simple, easily reproducible, safe and effective method, regardless of high-risk anatomical complexities. Funding Acknowledgement Type of funding sources: None. Annular wall stress and PVRModel, stress vs volume and new strategy

Mechanism of transcatheter heart valve deployment for right ventricular outflow tract insufficiency after surgical reconstruction in childhood as assessed with intravascular ultrasound

Abstract Introduction Transcatheter heart valve (THV) deployment can be used to treat right ventricular outflow tract (RVOT) insufficiency. Purpose To study deployment mechanism of a balloon expandable THV (Melody or Edwards SAPIEN [ES] 3) implanted for pulmonary homograft insufficiency using intravascular ultrasound (IVUS) with Visions PV.035 Digital Catheter (Philips) offering an imaging field of 60mm. Methods Sequential (baseline and post-THV) IVUS was performed in 6 pts (median age 33 [20–44] yrs, 3 ♀, all with Tetralogy of Fallot) who had undergone prior corrective surgery (4 transannular patch, 1 bioprosthetic valve or 1 pulmonary homograft), but who presented with significant RVOT insufficiency. IVUS-visualized homograft cross-sections were perpendicular to its long axis and were obtained along the entire homograft length (Fig. 1). Volumetric measurements included the native pulmonary homograft (inner lumen and outer dimension) and the corresponding inner-stent/inner-THV cross-sections post-THV for a total of 16 evenly spaced cross-sections per analyzed region. Each THV (1 Melody [Ø 22mm, 28mm nominal length] and 5 ES3 [Ø 23mm, 18mm height; 4 Ø 29mm, 22.5mm height]) was implanted after pre-stenting using stents of 36, 39, or 48mm length, deployed on a 24mm (n=1) or 30mm (n=4) balloon-in-balloon catheter. Results Overall, there were 96 paired cross-sections. There was significant increase in average lumen dimension after THV deployment (Δ of 97.5mm2) accompanied by the similar increase in outer pulmonary homograft dimensions (Δ of 84.0mm2) (Table 1). Whereas the maximal lumen diameter was unchanged, the minimal lumen diameter increased significantly resulting in substantial decrease in the ratio of max/min lumen diameter of 1.41±0.20 vs 1.16±0.13 (p&amp;lt;0.001) representing a reduction in lumen eccentricity. Conclusions During balloon-expandable THV implantation to treat RVOT insufficiency, there is a significant increase in baseline lumen dimensions accompanied by a substantial outer RVOT dimension increase to normalize lumen eccentricity. Figure 1. IVUS intraprocedural visualisation Funding Acknowledgement Type of funding source: None

Pre-Operative Modeling of Transcatheter Mitral Valve Replacement in a Surgical Heart Valve Bioprosthesis

Obstruction of the left ventricular outflow tract (LVOT) is a common complication of transcatheter mitral valve replacement (TMVR). This procedure can determine an elongation of an LVOT (namely, the neo-LVOT), ultimately portending hemodynamic impairment and patient death. This study aimed to understand the biomechanical implications of LVOT obstruction in a patient who underwent TMVR using a transcatheter heart valve (THV) to repair a failed bioprosthetic heart valve. We first reconstructed the heart anatomy and the bioprosthetic heart valve to virtually implant a computer-aided-design (CAD) model of THV and evaluate the neo-LVOT area. A numerical simulation of THV deployment was then developed to assess the anchorage of the THV to the bioprosthetic heart valve as well as the resulting Von Mises stress at the mitral annulus and the contract pressure among implanted bioprostheses. Quantification of neo-LVOT and THV deployment may facilitate more accurate predictions of the LVOT obstruction in TMVR and help clinicians in the optimal choice of the THV size.

The Fluid Mechanics of Transcatheter Heart Valve Leaflet Thrombosis in the Neosinus.

Transcatheter heart valve (THV) thrombosis has been increasingly reported. In these studies, thrombus quantification has been based on a 2-dimensional assessment of a 3-dimensional phenomenon. Postprocedural, 4-dimensional, volume-rendered CT data of patients with CoreValve, Evolut R, and SAPIEN 3 transcatheter aortic valve replacement enrolled in the RESOLVE study (Assessment of Transcatheter and Surgical Aortic Bioprosthetic Valve Dysfunction With Multimodality Imaging and Its Treatment with Anticoagulation) were included in this analysis. Patients on anticoagulation were excluded. SAPIEN 3 and CoreValve/Evolut R patients with and without hypoattenuated leaflet thickening were included to study differences between groups. Patients were classified as having THV thrombosis if there was any evidence of hypoattenuated leaflet thickening. Anatomic and THV deployment geometries were analyzed, and thrombus volumes were computed through manual 3-dimensional reconstruction. We aimed to identify and evaluate risk factors that contribute to THV thrombosis through the combination of retrospective clinical data analysis and in vitro imaging in the space between the native and THV leaflets (neosinus). SAPIEN 3 valves with leaflet thrombosis were on average 10% further expanded (by diameter) than those without (95.5±5.2% versus 85.4±3.9%; P<0.001). However, this relationship was not evident with the CoreValve/Evolut R. In CoreValve/Evolut Rs with thrombosis, the thrombus volume increased linearly with implant depth (R2=0.7, P<0.001). This finding was not seen in the SAPIEN 3. The in vitro analysis showed that a supraannular THV deployment resulted in a nearly 7-fold decrease in stagnation zone size (velocities <0.1 m/s) when compared with an intraannular deployment. In addition, the in vitro model indicated that the size of the stagnation zone increased as cardiac output decreased. Although transcatheter aortic valve replacement thrombosis is a multifactorial process involving foreign materials, patient-specific blood chemistry, and complex flow patterns, our study indicates that deployed THV geometry may have implications on the occurrence of thrombosis. In addition, a supraannular neosinus may reduce thrombosis risk because of reduced flow stasis. Although additional prospective studies are needed to further develop strategies for minimizing thrombus burden, these results may help identify patients at higher thrombosis risk and aid in the development of next-generation devices with reduced thrombosis risk.

New expandable mitral annuloplasty ring facilitates transcatheter mitral valve implantation: proof of concept.

Transcatheter mitral valve-in-ring (TMVIR) implantation with transcatheter heart valve (THV) prostheses can be performed in patients with recurrent mitral regurgitation (MR) following annuloplasty. However, an oval configuration and sometimes the rigidity of surgical rings can often lead to suboptimal THV expansion, resulting in considerable paravalvular or central leakage. Therefore, our aim was to develop an annuloplasty ring that fully adjusts to THV implantation. A three-dimensional annuloplasty ring was separated into four pieces at defined locations, the sections were reconnected with heat-shrinkable tubing and rearranged into the original shape. A non-tear stainless steel circular cord of defined length was inserted into the ring's sewing cuff to serve as a limiting structure for THV expansion. We implanted this ring in the mitral position into an isolated pig heart, deployed a THV into the ring, and investigated its function. Fluoroscopy showed that, upon THV deployment, the four breaking points of the ring separated as expected, and the ring expanded in a circular fashion to full expansion of the limiting cord. It securely anchored the THV to the ring, leaving no paravalvular gaps. We developed an expandable mitral ring to which the THV attached without leakage. This may impact on the future design of annuloplasty rings. Further studies should evaluate the safety of increasing the perimeter of a mitral ring and its durability.

Neo-annulus: a reference plane in a surgical heart valve to facilitate a valve-in-valve procedure.

To determine the level of the narrowest plane (neo-annulus) of a surgical heart valve (SHV), which could be used for sizing and securing a transcatheter heart valve (THV) during a valve-in-valve (VIV) procedure and define its relationship with the fluoroscopic markers of the SHV. In the native aortic valve, the aortic annulus is used as a reference plane for sizing and deployment of THV as it provides the narrowest dimension to securely anchor the THV. However, the reference level for different models of SHV that are currently treated by a VIV procedure remains unknown. We studied 13 aortic SHVs from all major heart valve manufacturers (labeled size 21, 22, or 23). A 26cc valvuloplasty balloon was inflated with contrast within each SHV under fluoroscopy to achieve a 'waist'. The level of the 'waist' was compared with the SHV and its fluoroscopic markers to identify the level of the neo-annulus. In all SHVs tested, the balloon 'waist' or 'neo-annulus' was at the level of the sewing ring. When the fluoroscopic marker of the SHV was the sewing ring, the level of the neo-annulus was also at that level, irrespective of supra-annular or intra-annular design. However, when the fluoroscopic marker was the stent frame, the relationship between the fluoroscopic marker and the level of the neo-annulus was different for supra-annular and intra-annular designs. This correlation was not possible in two models of SHV as neither the stent nor the sewing ring was radio-opaque. We have demonstrated that the narrowest portion of all SHVs is at the level of its sewing ring, which can be identified fluoroscopically and should be used as a reference level during a VIV procedure.

Left main occlusion secondary to aortic root rupture following transcatheter aortic valve replacement managed by left main stenting

Acute left main coronary occlusion secondary to a periaortic root hematoma secondary to annular rupture during transcatheter heart valve deployment is reported.