Management of complications after valvular interventions

Transcatheter valve interventions have transformed the outcomes of patients with valvular heart disease who are at high risk for surgery. With the increasing utilisation and expansion of transcatheter valve interventions, it is of utmost importance to be familiar with their potential complications and their subsequent management, especially given the relative infrequency of many of these issues in contemporary practice. Herein, we present a state-of-the-art review article focusing on the complications, their prevention, and treatment following transcatheter aortic valve implantation, mitral transcatheter edge-to-edge repair, and transcatheter mitral valve replacement.

Benchtop Flow Stasis Quantification: In Vitro Methods and In Vivo Possibilities

PURPOSE

Neo-sinus flow stasis has ben correlated with transcatheter heart valve (THV) thrombosis severity and occurrence. Standard benchtop flow field quantification techniques require optical access or modified prosthesis models that may not reflect the true nature of the original valve. En face and fluoroscopic videodensitometry enable visualization of washout in regions otherwise unviewable.

METHODS

This study compares two in vitro methods of assessing flow stasis in scenarios with insufficient optical access for traditional techniques such as particle image velocimetry (PIV). A series of seven paired experiments were conducted using a previously described laser-enhanced video densitometry (LEVD) and fluoroscopic video densitometry (FVD). Both sets of experiments were analyzed to calculate washout time as a measure of flow stasis. A novel flow stasis measure termed contrast attenuation ratio (CAR) is proposed as a viable single measure of flow stasis obtainable from only a small number of cardiac cycles of in vitro or in vivo fluoroscopic data. Retrospective fluoroscopic datasets (n = 72) were analyzed to assess the feasibility of obtaining this metric from routine clinical practice and its ability to stratify results.

RESULTS

Neo-sinus flow stasis calculated from in vitro fluoroscopy was well correlated with LEVD (r2 = 0.77, p = 0.009). The newly proposed CAR metric showed good agreement with the commonly used "washout time" measure of flow stasis (r2 = 0.91, p < 0.001) while allowing for assessment with incomplete or truncated data. As a proof of concept, CAR was measured in 72 consecutive retrospective fluoroscopic datasets. CAR averaged 10.6 ± 4.6% with a range of 1.5-20.3% in these patients.

CONCLUSIONS

This study demonstrates two in vitro methods that can be used to assess relative flow stasis in otherwise optically inaccessible regions surrounding cardiac or vascular implants. In addition, the fluoroscopic benchtop technique was used to validate a metric that allows for extension to routine clinical fluoroscopy. This contrast attenuation ratio (CAR) metric was found to be both accurate and clinically obtainable, and potentially offers a new method for valve thrombosis risk stratification.

Periprocedural Assessment of Paravalvular Regurgitation After Transcatheter Aortic Valve Replacement Using Diastolic Delta and Videodensitometry

BACKGROUND

Paravalvular regurgitation (PVR) is a common complication after transcatheter aortic valve replacement, posing an increased risk of heart failure and mortality. Accurate intraprocedural quantification of PVR is challenging. Both hemodynamic indices and videodensitometry can be used for intraprocedural assessment of PVR. We compared the predictive value of the isolated versus combined use of the hemodynamic index diastolic delta (DD) and videodensitometry for the incidence of relevant PVR 1 month after transcatheter aortic valve replacement.

METHODS AND RESULTS

In this prospective cohort study, patients underwent periprocedural PVR assessment by DD and videodensitometry (using left ventricular outflow tract-aortic regurgitation [LVOT-AR]). Cardiac magnetic resonance served as reference modality for PVR assessment. Relevant PVR was defined as cardiac magnetic resonance-regurgitant fraction >20%. Fifty-one patients were enrolled in this study. Mean age was 80.6±5.2 years and 45.1% of patients were men. Mean LVOT-AR and cardiac magnetic resonance-regurgitant fraction were 8.2%±7.8% and 11.7%±9.6%, respectively. The correlation between DD and LVOT-AR was weak (r=-0.36). DD and LVOT-AR showed a comparable accuracy to predict relevant PVR (area under the curve 0.82, 95% CI: 0.69-0.95 versus area area under the time-density curve 0.80, 95% CI: 0.62-0.99). The combination of DD and LVOT-AR improved the prediction of relevant PVR (area under the time-density curve, 0.90, 95% CI: 0.81-0.99), and resulted in an increased concordance (86.3%) and positive predictive value (75%) compared with DD alone (76.5% and 40%, respectively), or LVOT-AR alone (82.3% and 50%, respectively).

CONCLUSIONS

DD and videodensitometry are both accurate and feasible modalities for the assessment of PVR after transcatheter aortic valve replacement. The synergistic use of both techniques increases the predictive value for relevant PVR after transcatheter aortic valve replacement.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04281771.

Assessment of paravalvular regurgitation after transcatheter aortic valve replacement using 2D multi-velocity encoding and 4D flow cardiac magnetic resonance

AIMS

To compare the novel 2D multi-velocity encoding (venc) and 4D flow acquisitions with the standard 2D flow acquisition for the assessment of paravalvular regurgitation (PVR) after transcatheter aortic valve replacement (TAVR) using cardiac magnetic resonance (CMR)-derived regurgitant fraction (RF).

METHODS AND RESULTS

In this prospective study, patients underwent CMR 1 month after TAVR for the assessment of PVR, for which 2D multi-venc and 4D flow were used, in addition to standard 2D flow. Scatterplots and Bland-Altman plots were used to assess correlation and visualize agreement between techniques. Reproducibility of measurements was assessed with intraclass correlation coefficients. The study included 21 patients (mean age ± SD 80 ± 5 years, 9 men). The mean RF was 11.7 ± 10.0% when standard 2D flow was used, 10.6 ± 7.0% when 2D multi-venc flow was used, and 9.6 ± 7.3% when 4D flow was used. There was a very strong correlation between the RFs assessed with 2D multi-venc and standard 2D flow (r = 0.88, P < 0.001), and a strong correlation between the RFs assessed with 4D flow and standard 2D flow (r = 0.74, P < 0.001). Bland-Altman plots revealed no substantial bias between the RFs (2D multi-venc: 1.3%; 4D flow: 0.3%). Intra-observer and inter-observer reproducibility for 2D multi-venc flow were 0.98 and 0.97, respectively, and 0.92 and 0.90 for 4D flow, respectively.

CONCLUSION

Two-dimensional multi-venc and 4D flow produce an accurate quantification of PVR after TAVR. The fast acquisition of the 2D multi-venc sequence and the free-breathing acquisition with retrospective plane selection of the 4D flow sequence provide useful advantages in clinical practice, especially in the frail TAVR population.

Emergent Conversion to Open Heart Surgery during Transcatheter Aortic Valve Implantation: The Presence of a Rescue Team Improves Outcomes

OBJECTIVE

Transcatheter aortic valve implant (TAVI) is the gold standard for the high-surgical-risk group of patients with aortic valve disease and it is an alternative to surgery in patients at intermediate risk. Lethal complications can occur, and many of these are manageable only with emergent conversion to open heart surgery. We retrospectively evaluate the outcome of all patients undergoing TAVI in our departments and the impact of a complete cardiac rescue team to reduce 30-day mortality.

METHODS

Data from all patients undergoing TAVI between January 2020 and August 2023 in our center were analyzed. An expert complete rescue was present in catheter laboratory. Primary outcomes were in-hospital and at 30-day mortality and evaluation of all cases needed for emergent conversion to open heart surgery.

RESULTS

825 patients were enrolled. The total mortality was 19/825 (2.3%). Eleven of the total patients (1.3%) required emergent conversion to open heart surgery. Among them, eight were alive (73%), with a theoretical decrease of 0.98% in overall mortality.

CONCLUSIONS

surgical treatment is rare during TAVI. The presence of an expert complete rescue team as support means an increase in survival. Surgery must be used only to restore circulatory and to treat complication while percutaneous approaches should complete the procedure.

Quantitative aortography for assessment of aortic regurgitation in the era of percutaneous aortic valve replacement

Paravalvular leak (PVL) is a shortcoming that can erode the clinical benefits of transcatheter valve replacement (TAVR) and therefore a readily applicable method (aortography) to quantitate PVL objectively and accurately in the interventional suite is appealing to all operators. The ratio between the areas of the time-density curves in the aorta and left ventricular outflow tract (LVOT-AR) defines the regurgitation fraction (RF). This technique has been validated in a mock circulation; a single injection in diastole was further tested in porcine and ovine models. In the clinical setting, LVOT-AR was compared with trans-thoracic and trans-oesophageal echocardiography and cardiac magnetic resonance imaging. LVOT-AR > 17% discriminates mild from moderate aortic regurgitation on echocardiography and confers a poor prognosis in multiple registries, and justifies balloon post-dilatation. The LVOT-AR differentiates the individual performances of many old and novel devices and is being used in ongoing randomized trials and registries.

Biomechanics of Transcatheter Aortic Valve Implant

Transcatheter aortic valve implantation (TAVI) has grown exponentially within the cardiology and cardiac surgical spheres. It has now become a routine approach for treating aortic stenosis. Several concerns have been raised about TAVI in comparison to conventional surgical aortic valve replacement (SAVR). The primary concerns regard the longevity of the valves. Several factors have been identified which may predict poor outcomes following TAVI. To this end, the lesser-used finite element analysis (FEA) was used to quantify the properties of calcifications which affect TAVI valves. This method can also be used in conjunction with other integrated software to ascertain the functionality of these valves. Other imaging modalities such as multi-detector row computed tomography (MDCT) are now widely available, which can accurately size aortic valve annuli. This may help reduce the incidence of paravalvular leaks and regurgitation which may necessitate further intervention. Structural valve degeneration (SVD) remains a key factor, with varying results from current studies. The true incidence of SVD in TAVI compared to SAVR remains unclear due to the lack of long-term data. It is now widely accepted that both are part of the armamentarium and are not mutually exclusive. Decision making in terms of appropriate interventions should be undertaken via shared decision making involving heart teams.

Quantitative Angiographic Assessment of Aortic Regurgitation Following 11 TAVR Devices: An Update of a Multicenter Pooled Analysis

Background

Aortic regurgitation (AR) following transcatheter aortic valve replacement (TAVR) is a major predictor of short- and long-term survival. Thus far, no independent quantitative comparison of AR among commercially available transcatheter heart valves (THVs) has been performed.

Objectives

We sought to assess and compare the degree of acute AR following TAVR between 11 commercially available THVs and update our previous multicenter, pooled analysis.

Methods

Analyses were performed by an independent academic core lab using quantitative videodensitometry, a technique relying solely on the aortogram acquired after TAVR. The pooled analysis (n = 2665) included data from the initial cohort of 7 valves (Lotus [n = 546], Evolut PRO [n = 95], SAPIEN 3 [n = 397], Evolut R [n = 295], SAPIEN XT [n = 239], ACURATE neo [n = 120], and CoreValve [n = 532]) to which data from 4 new valves were added (ACURATE neo2 [n = 120], Myval [n = 108], VitaFlow [n = 105], and Venus-A [n = 113]).

Results

The Lotus valve had the lowest mean AR (3.5% ± 4.4%) followed by ACURATE neo2 (4.4% ± 4.8%), VitaFlow (6.1% ± 6.4%), Myval (6.3% ​± ​6.3%), Evolut PRO (7.4% ± 6.5%), SAPIEN 3 (7.6% ± 7.1%), Evolut R (7.9% ± 7.4%), SAPIEN XT (8.8% ± 7.5%), Venus-A (8.9% ​± ​10%), ACURATE neo (9.6% ± 9.2%), and CoreValve (13.7% ± 10.7%, analysis of variance P-value < .001). The only valves that statistically differed from all their counterparts were Lotus, with the lowest regurgitation in comparison to other valves except ACURATE neo2, which had less regurgitation compared with SAPIEN 3, Evolut R, SAPIEN XT, Venus-A, ACURATE neo, and CoreValve. CoreValve had the highest mean of AR, with the rates of moderate/severe AR: ACURATE neo2 (1.7%), Lotus (2.2%), Myval (2.8%), VitaFlow (4.7%), Evolut PRO (5.3%), SAPIEN 3 (8.3%), Evolut R (8.8%), SAPIEN XT (10.9%), ACURATE neo (11.3%), Venus-A (14.2%), and CoreValve (30.1%)-χ2 P-value < .001.

Conclusions

In this updated pooled analysis, the Lotus valve had the lowest mean AR, while ACURATE neo2 had the lowest rate of moderate/severe AR. Myval, VitaFlow, and Venus-A THVs showed promising results.

Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021

BACKGROUND

 Transcatheter aortic valve implantation (TAVI) has gained worldwide acceptance and implementation as an alternative therapeutic option in patients with severe aortic valve stenosis unable to safely undergo surgical aortic valve replacement. This transformative technique places the radiologist in a key position in the pre-procedural assessment of potential candidates for this technique, delivering key anatomical information necessary for patient eligibility and procedural safety. Recent trials also provide encouraging results to potentially extend the indication to patients with safer risk profiles.

METHOD

 The review is based on a PubMed literature search using the search terms "transcatheter heart valve", "TAVI", "TAVR", "CT", "imaging", "MR" over a period from 2010-2020, combined with personal comments based on the author's experience.

RESULTS AND CONCLUSION

 CT plays a prominent role in the pre-procedural workup, delivering as a true 3D imaging modality optimal visualization of the complex anatomy of the aortic root with simultaneous evaluation of the patency of the different access routes. As such, the contribution of CT is key for the determination of patient eligibility and procedural safety. This input is supplementary to the contributions of other imaging modalities and forms an important element in the discussions of the Heart Valve Team. Knowledge of the procedure and its characteristics is necessary in order to provide a comprehensive and complete report. While the role of CT in the pre-procedural evaluation is well established, the contribution of CT and MR and the clinical significance of their findings in the routine follow-up after the intervention are less clear and currently the subject of intense investigation. Important issues remain, including the occurrence and significance of subclinical leaflet thrombosis, prosthetic heart valve endocarditis, and long-term structural valve degeneration.

KEY POINTS

  · CT plays a crucial role in evaluating transcatheter heart valve candidates. · Evaluation must include the dimensions of the aortic root and access paths. · The exact post-procedural role of CT and MRI has not yet been determined..

CITATION FORMAT

· Salgado R, El Addouli H, Budde RP. Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021. Fortschr Röntgenstr 2021; 193: 1411 - 1425.

Aortic valve function post-replacement of severe aortic stenosis by transcatheter procedure versus surgery: a systematic review and metanalysis

Transcatheter aortic valve replacement (TAVR) has shown to reduce mortality compared to surgical aortic valve replacement (sAVR). However, it is unknown which procedure is associated with better post-procedural valvular function. We conducted a meta-analysis of randomized clinical trials that compared TAVR to sAVR for at least 2 years. The primary outcome was post-procedural patient-prosthesis-mismatch (PPM). Secondary outcomes were post-procedural and 2-year: effective orifice area (EOA), paravalvular gradient (PVG) and moderate/severe paravalvular leak (PVL). We identified 6 trials with a total of 7022 participants with severe aortic stenosis. TAVR was associated with 37% (95% CI [0.51–0.78) mean RR reduction of post-procedural PPM, a decrease that was not affected by the surgical risk at inclusion, neither by the transcatheter heart valve system. Postprocedural changes in gradient and EOA were also in favor of TAVR as there was a pooled mean difference decrease of 0.56 (95% CI [0.73–0.38]) in gradient and an increase of 0.47 (95% CI [0.38–0.56]) in EOA. Additionally, self-expandable valves were associated with a higher decrease in gradient than balloon ones (beta = 0.38; 95% CI [0.12–0.64]). However, TAVR was associated with a higher risk of moderate/severe PVL (pooled RR: 9.54, 95% CI [5.53–16.46]). All results were sustainable at 2 years.

Grading of aortic regurgitation by cardiovascular magnetic resonance and pulsed Doppler of the left subclavian artery: harmonizing grading scales between imaging modalities

Transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) are current standard for assessing aortic regurgitation (AR). Regurgitant fraction (RF) can also be estimated by Doppler examination of the left subclavian artery (LSA-Doppler). However, a comparison of AR grading scales using these methods and a TTE multiparametric approach as reference is lacking. We evaluated the severity of AR in 73 patients (58 ± 15 years; 57 men), with a wide spectrum of AR of the native valve. Using a recommended TTE multiparametric approach the AR was divided in none/trace (n = 12), mild (n = 23), moderate (n = 12), and severe (n = 26). RF was evaluated by LSA-Doppler (ratio between diastolic and systolic velocity–time integrals) and by CMR phase-contrast imaging (performed in the aorta 1 cm above the aortic valve); the grading scales were then calculated. There were a good correlation between all methods, but mean RF values were greater with TTE compared with LSA-Doppler and CMR (39 ± 16% vs. 35 ± 18% vs. 32 ± 20%, respectively; p < 0.037). Mean differences in RF values between methods were significant in the groups with mild and moderate AR. Grading scales that best defined the TTE derived AR severity using CMR were: mild, < 21%; moderate, 22 to 41%; and severe, > 42%; and using LSA-Doppler: mild, < 29%; moderate, 30 to 44%; and severe, > 45%. RF values for AR grading using TTE, LSA-Doppler and CMR correlate well but differ in groups with mild and moderate AR when using a recognized multiparametric echocardiographic approach. Clinical prospective studies should validate these proposed modality adjusted grading scales.

Randomised comparison of a balloon-expandable and self-expandable valve with quantitative assessment of aortic regurgitation using magnetic resonance imaging

Introduction

Transcatheter aortic valve implantation (TAVI) is a safe and effective treatment for inoperable, intermediate- or high-risk patients with severe symptomatic aortic stenosis and has been associated with excellent clinical outcomes. A clinically relevant remaining problem is aortic regurgitation (AR) post-TAVI, which is associated with increased mortality. Therefore, we conducted a prospective randomised trial to assess the safety and efficacy of a first-generation self-expandable valve (SEV; CoreValve) and a third-generation balloon-expandable valve (BEV; Sapien 3) with respect to clinical outcomes and AR as determined quantitatively by magnetic resonance imaging (MRI).

Methods

The ELECT study was an investigator-initiated, single-centre trial involving patients with severe symptomatic aortic stenosis and with a clinical indication for transfemoral TAVI. Fifty-six patients were randomly assigned to the BEV or SEV group.

Results

AR determined quantitatively by MRI was lower in the BEV than in the SEV group [regurgitant fraction: 1.1% (0–8.0) vs 8.7% (3.0–14.8) for SEV; p = 0.01]. Secondary endpoints according to the criteria of the Second Valve Academic Research Consortium (VARC-2) showed BEV to have better early safety [0 (0%) vs 8 (30%); p = 0.002] at 30 days and a lower risk of stroke [0 (0%) vs 5 (21%); p = 0.01], major adverse cardiac and cerebrovascular events [0 (0%) vs 10 (38%); p < 0.001] or death [0 (0%) vs 5 (19%); p = 0.02] in the 1st year compared with SEV.

Conclusions

The use of the latest generation of BEV was associated with less AR as quantitatively assessed by MRI. Although the use of MRI to quantify AR is not feasible in daily clinical practice, it should be considered as a surrogate endpoint for clinical outcomes in comparative studies of valves for TAVI.

ClinicalTrials.gov number NCT01982032.

Comparison of newer generation self-expandable vs. balloon-expandable valves in transcatheter aortic valve implantation: the randomized SOLVE-TAVI trial

Aims

Transcatheter aortic valve implantation (TAVI) has emerged as established treatment option in patients with symptomatic aortic stenosis. Technical developments in valve design have addressed previous limitations such as suboptimal deployment, conduction disturbances, and paravalvular leakage. However, there are only limited data available for the comparison of newer generation self-expandable valve (SEV) and balloon-expandable valve (BEV).

Methods and results

SOLVE-TAVI is a multicentre, open-label, 2 × 2 factorial, randomized trial of 447 patients with aortic stenosis undergoing transfemoral TAVI comparing SEV (Evolut R, Medtronic Inc., Minneapolis, MN, USA) with BEV (Sapien 3, Edwards Lifesciences, Irvine, CA, USA). The primary efficacy composite endpoint of all-cause mortality, stroke, moderate/severe prosthetic valve regurgitation, and permanent pacemaker implantation at 30 days was powered for equivalence (equivalence margin 10% with significance level 0.05). The primary composite endpoint occurred in 28.4% of SEV patients and 26.1% of BEV patients meeting the prespecified criteria of equivalence [rate difference −2.39 (90% confidence interval, CI −9.45 to 4.66); Pequivalence = 0.04]. Event rates for the individual components were as follows: all-cause mortality 3.2% vs. 2.3% [rate difference −0.93 (90% CI −4.78 to 2.92); Pequivalence &lt; 0.001], stroke 0.5% vs. 4.7% [rate difference 4.20 (90% CI 0.12 to 8.27); Pequivalence = 0.003], moderate/severe paravalvular leak 3.4% vs. 1.5% [rate difference −1.89 (90% CI −5.86 to 2.08); Pequivalence = 0.0001], and permanent pacemaker implantation 23.0% vs. 19.2% [rate difference −3.85 (90% CI −10.41 to 2.72) in SEV vs. BEV patients; Pequivalence = 0.06].

Conclusion

In patients with aortic stenosis undergoing transfemoral TAVI, newer generation SEV and BEV are equivalent for the primary valve-related efficacy endpoint. These findings support the safe application of these newer generation percutaneous valves in the majority of patients with some specific preferences based on individual valve anatomy.

Plugging Paravalvular Leak in Transcatheter Aortic Valves

Paravalvular leak can complicate transcatheter aortic valve replacement with important prognostic implications. Correction of defects requires complex planning and execution. Multiple or irregular lesions, calcified annulus, and high sealing skirts on self-expandable devices are especially challenging. Such defects may be approximated using malleable vascular closure devices. (Level of Difficulty: Intermediate.)

Association of Paravalvular Regurgitation With 1-Year Outcomes After Transcatheter Aortic Valve Replacement With the SAPIEN 3 Valve

Importance

Moderate/severe and even mild paravalvular regurgitation (PVR) are associated with increased mortality following transcatheter aortic valve replacement (TAVR) with first and second generations of transcatheter valves.

Objective

To examine the incidence, evolution, and effect on 1-year outcomes of PVR following TAVR with a third-generation balloon-expandable transcatheter heart valve.

Design, Setting, and Participants

Prespecified analysis of PVR in the Placement of Aortic Transcatheter Valves (PARTNER) II SAPIEN 3 trial, conducted between October 1, 2013, and September 3, 2014. Multicenter, nonrandomized registry of 1661 patients at intermediate or high surgical risk undergoing TAVR with the SAPIEN 3. Patients with severe, symptomatic aortic stenosis and high/intermediate surgical risk were enrolled in the registry at 51 sites in the United States and Canada.

Interventions

Transcatheter aortic valve replacement with the SAPIEN 3 valve.

Main Outcomes and Measures

Paravalvular regurgitation was assessed in a core laboratory at 30 days and 1 year according to a 5-class scheme: 0, none or trace; 1, mild; 2, mild to moderate; 3, moderate; 4, moderate to severe; and 5, severe. We assessed the effect of PVR on 1-year mortality and heart failure rehospitalization.

Results

Among the 1661 included in the registry, 1592 received a SAPIEN 3 valve and had assessment of PVR. Of these patients, 55.7% had none-trace PVR, 32.6% had mild, 8.2% had mild to moderate, and 3.5% had at least moderate PVR at 30 days. At 1 year, 9.3% of patients had died and 14.2% had been rehospitalized. Only patients with at least moderate PVR had higher 1-year mortality (hazard ratio [HR], 2.40; 95% CI, 1.30-4.43; P = .005) and composite of mortality/rehospitalization (HR, 2.35; 95% CI, 1.52-3.62; P < .001). In a paired comparison including 1213 patients, 73% of the patients with at least moderate PVR at 30 days showed a reduction in PVR severity of at least 1 PVR class at 1 year.

Conclusions and Relevance

In this series of patients undergoing TAVR with the SAPIEN 3 valve, at least moderate PVR was rare but associated with increased risk of death and heart failure rehospitalization at 1 year. Even the upper range of the mild class in the 3-class grading scheme (ie, mild to moderate in the 5-class scheme) had no significant effect on short-term mortality or rehospitalization. Most patients with at least moderate PVR at 30 days showed a decrease of PVR severity grade at 1 year.

Trial Registration

clinicaltrials.gov Identifier: NCT01314313.

Patient-specific simulation of transcatheter aortic valve replacement: impact of deployment options on paravalvular leakage

Transcatheter aortic valve replacement (TAVR) has emerged as an effective alternative to conventional surgical valve replacement in high-risk patients afflicted by severe aortic stenosis. Despite newer-generation devices enhancements, post-procedural complications such as paravalvular leakage (PVL) and related thromboembolic events have been hindering TAVR expansion into lower-risk patients. Computational methods can be used to build and simulate patient-specific deployment of transcatheter aortic valves (TAVs) and help predict the occurrence and degree of PVL. In this study finite element analysis and computational fluid dynamics were used to investigate the influence of procedural parameters on post-deployment hemodynamics on three retrospective clinical cases affected by PVL. Specifically, TAV implantation depth and balloon inflation volume effects on stent anchorage, degree of paravalvular regurgitation and thrombogenic potential were analyzed for cases in which Edwards SAPIEN and Medtronic CoreValve were employed. CFD results were in good agreement with corresponding echocardiography data measured in patients in terms of the PVL jets locations and overall PVL degree. Furthermore, parametric analyses demonstrated that positioning and balloon over-expansion may have a direct impact on the post-deployment TAVR performance, achieving as high as 47% in PVL volume reduction. While the model predicted very well clinical data, further validation on a larger cohort of patients is needed to verify the level of the model's predictions in various patient-specific conditions. This study demonstrated that rigorous and realistic patient-specific numerical models could potentially serve as a valuable tool to assist physicians in pre-operative TAVR planning and TAV selection to ultimately reduce the risk of clinical complications.

Inter-Technique Consistency and Prognostic Value of Intra-Procedural Angiographic and Echocardiographic Assessment of Aortic Regurgitation After Transcatheter Aortic Valve Implantation

BACKGROUND

We investigated the relationship between intraprocedural angiographic and echocardiographic AR severity after TAVI, and the clinical robustness of angiographic assessment.

METHODS AND RESULTS

In 74 consecutive patients, the echocardiographic circumferential extent (CE) of the paravalvular regurgitant jet was retrospectively measured and graded based on the VARC-2 cut-points; and angiographic post-TAVI AR was retrospectively quantified using contrast videodensitometry (VD) software that calculates the ratio of the contrast time-density integral in the LV outflow tract to that in the ascending aorta (LVOT-AR). Seventy-four echocardiograms immediately after TAVI were analyzable, while 51 aortograms were analyzable for VD. These 51 echocardiograms and VD were evaluated. Median LVOT-AR across the echocardiographic AR grades was as follows: none-trace, 0.07 (IQR, 0.05-0.11); mild, 0.12 (IQR, 0.09-0.15); and moderate, 0.17 (IQR, 0.15-0.22; P<0.05 for none-trace vs. mild, and mild vs. moderate). LVOT-AR strongly correlated with %CE (r=0.72, P<0.0001). At 1 year, the rate of the composite end-point of all-cause death or HF re-hospitalization was significantly higher in >mild AR patients compared with no-mild AR on intra-procedural echocardiography (41.5% vs. 12.4%, P=0.03) as well as in patients with LVOT-AR >0.17 compared with LVOT-AR ≤0.17 (59.5% vs. 16.6%, P=0.03).

CONCLUSIONS

VD (LVOT-AR) has good intra-procedural inter-technique consistency and clinical robustness. Greater than mild post-TAVI AR, but not mild post-TAVI AR, is associated with late mortality.

A novel synchronised diastolic injection method to reduce contrast volume during aortography for aortic regurgitation assessment: in vitro experiment of a transcatheter heart valve model

AIMS

In the minimalist transcatheter aortic valve implantation (TAVI) era, the usage of transoesophageal echocardiography has become restricted. Conversely, aortography has gained clinical ground in quantifying prosthetic valve regurgitation (PVR) during the procedure. In a mock circulation system, we sought to compare the contrast volume required and the accuracy of aortographic videodensitometric PVR assessment using a synchronised diastolic and standard (non-synchronised) injection aortography.

METHODS AND RESULTS

Synchronised diastolic injection triggered by the signal stemming from the mock circulation was compared with standard non-synchronised injection. A transcatheter heart valve was implanted and was deformed step by step by advancing a screw perpendicularly to the cage of the valve in order to create increasing PVR. Quantitative measurement of PVR was derived from time-density curves of both a reference area (aortic root) and a region of interest (left ventricle) developed by a videodensitometric software. The volume of contrast required for the synchronised diastolic injection was significantly less than in the non-synchronised injection (8.1 [7.9-8.5] ml vs. 19.4 [19.2-19.9] ml, p<0.001). The correlation between the two methods was substantial (Spearman's coefficient rho ranging from 0.991 to 0.968). Intraobserver intra-class correlation coefficient for both methods of injection was 0.999 (95% CI: 0.996-1.000) for the synchronised diastolic and 0.999 (95% CI: 0.996-1.000) for the non-synchronised injection group. The mean difference in the rating was 0.17% and limits of agreement were ±1.64% for both groups.

CONCLUSIONS

A short synchronised diastolic injection enables contrast volume reduction during aortography without compromising the accuracy of the quantitative assessment of PVR using videodensitometry.

Role of Computed Tomography in Planning the Appropriate X-Ray Gantry for Quantitative Aortography of Post-transcatheter Aortic Valve Implantation Regurgitation

BACKGROUND

The clinical robustness of contrast-videodensitometric (VD) assessment of aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) has been demonstrated. Correct acquisition of aortic root angiography for VD assessment, however, is hampered by the opacified descending aorta and by individual anatomic peculiarities. The aim of this study was to use preprocedural multi-slice computed tomography (MSCT) to optimize the angiographic projection in order to improve the feasibility of VD assessment.

METHODS AND RESULTS

In 92 consecutive patients, post-TAVI AR (i.e., left ventricular outflow tract [LVOT] AR) was assessed on aortic root angiograms using VD software. The patients were divided into 2 groups: The first group of 54 patients was investigated prior to the introduction of the standardized acquisition protocol; the second group of 38 consecutive patients after implementation of the standardized acquisition protocol, involving MSCT planning of the optimal angiographic projection. Optimal projection planning has dramatically improved the feasibility of VD assessment from 57.4% prior to the standardized acquisition protocol, to 100% after the protocol was implemented. In 69 analyzable aortograms (69/92; 75%), LVOT-AR ranged from 3% to 28% with a median of 12%. Inter-observer agreement was high (mean difference±SD, 1±2%), and the 2 observers' measurements were highly correlated (r=0.94, P<0.0001).

CONCLUSIONS

Introduction of computed tomography-guided angiographic image acquisition has significantly improved the analyzability of the angiographic VD assessment of post-TAVI AR.

Effect of Mechanically Expanded vs Self-Expanding Transcatheter Aortic Valve Replacement on Mortality and Major Adverse Clinical Events in High-Risk Patients With Aortic Stenosis: The REPRISE III Randomized Clinical Trial

IMPORTANCE

Transcatheter aortic valve replacement (TAVR) is established for selected patients with severe aortic stenosis. However, limitations such as suboptimal deployment, conduction disturbances, and paravalvular leak occur.

OBJECTIVE

To evaluate if a mechanically expanded valve (MEV) is noninferior to an approved self-expanding valve (SEV) in high-risk patients with aortic stenosis undergoing TAVR.

DESIGN, SETTING, AND PARTICIPANTS

The REPRISE III trial was conducted in 912 patients with high or extreme risk and severe, symptomatic aortic stenosis at 55 centers in North America, Europe, and Australia between September 22, 2014, and December 24, 2015, with final follow-up on March 8, 2017.

INTERVENTIONS

Participants were randomized in a 2:1 ratio to receive either an MEV (n = 607) or an SEV (n = 305).

MAIN OUTCOMES AND MEASURES

The primary safety end point was the 30-day composite of all-cause mortality, stroke, life-threatening or major bleeding, stage 2/3 acute kidney injury, and major vascular complications tested for noninferiority (margin, 10.5%). The primary effectiveness end point was the 1-year composite of all-cause mortality, disabling stroke, and moderate or greater paravalvular leak tested for noninferiority (margin, 9.5%). If noninferiority criteria were met, the secondary end point of 1-year moderate or greater paravalvular leak was tested for superiority in the full analysis data set.

RESULTS

Among 912 randomized patients (mean age, 82.8 [SD, 7.3] years; 463 [51%] women; predicted risk of mortality, 6.8%), 874 (96%) were evaluable at 1 year. The primary safety composite end point at 30 days occurred in 20.3% of MEV patients and 17.2% of SEV patients (difference, 3.1%; Farrington-Manning 97.5% CI, -∞ to 8.3%; P = .003 for noninferiority). At 1 year, the primary effectiveness composite end point occurred in 15.4% with the MEV and 25.5% with the SEV (difference, -10.1%; Farrington-Manning 97.5% CI, -∞ to -4.4%; P<.001 for noninferiority). The 1-year rates of moderate or severe paravalvular leak were 0.9% for the MEV and 6.8% for the SEV (difference, -6.1%; 95% CI, -9.6% to -2.6%; P < .001). The superiority analysis for primary effectiveness was statistically significant (difference, -10.2%; 95% CI, -16.3% to -4.0%; P < .001). The MEV had higher rates of new pacemaker implants (35.5% vs 19.6%; P < .001) and valve thrombosis (1.5% vs 0%) but lower rates of repeat procedures (0.2% vs 2.0%), valve-in-valve deployments (0% vs 3.7%), and valve malpositioning (0% vs 2.7%).

CONCLUSIONS AND RELEVANCE

Among high-risk patients with aortic stenosis, use of the MEV compared with the SEV did not result in inferior outcomes for the primary safety end point or the primary effectiveness end point. These findings suggest that the MEV may be a useful addition for TAVR in high-risk patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02202434.

The role of echocardiography and CT angiography in transcatheter aortic valve implantation patients

The transcatheter aortic valve implantation (TAVI) consist an alternative treatment in patients with severe aortic stenosis. Multimodality imaging using transthoracic echocardiography (TTE) or transesophageal echocardiography (TOE) and multislice CT (MSCT) constitute cornerstone techniques for the pre-operative management, peri-procedural guidance, follow up and recognition of possible transcatheter valve related complications. CT angiography is much more accurate regarding the total definition of aortic annulus diameter and circumferential area. Two-dimensional (2D) echocardiography, underestimates the aortic valve annulus diameter compared to 3D imaging techniques (MSCT, MRI and 3D TOE). Three-dimensional TOE imaging provides measurements of the aortic valve annulus similar to those delivered by MSCT. The pre-procedural MSCT constitutes the gold standard modality minimizing the presence of paravalvular aortic regurgitation, one of the most frequent complications. TOE/TTE and MSCT performance could predict the possibility of pacemaker implantation post-procedural. The presence of a new transient or persisting MR can be assessed well by TOE. Both TTE and TOE, consist initially the basic examination for post TAVI evaluation. In case of transcatheter heart valve failure, the MSCT could be used as additional imaging technique.