Prognostic influence of paravalvular leak following TAVI: is aortic regurgitation an active incremental risk factor or just a mere indicator?

Computational study of transcatheter aortic valve replacement based on patient-specific models-rapid surgical planning for self-expanding valves

Transcatheter aortic valve replacement (TAVR) is a minimally invasive interventional solution for treating aortic stenosis. The complex post-TAVR complications are associated with the type of valve implanted and the position of the implantation. The study aimed to establish a rapid numerical research method for TAVR to assess the performance differences of self-expanding valves released at various positions. It also aimed to calculate the risks of postoperative paravalvular leak and atrioventricular conduction block, comparing these risks to clinical outcomes to verify the method's effectiveness and accuracy. Based on medical images, six cases were established, including the aortic wall, native valve and calcification; one with a bicuspid aortic valve and five with tricuspid aortic valves. The parameters for the stent materials used by the patients were customized. High strain in the contact area between the stent and the valve annulus may lead to atrioventricular conduction block. Postoperatively, the self-expanding valve maintained a circular cross-section, reducing the risk of paravalvular leak and demonstrating favorable hemodynamic characteristics, consistent with clinical observations. The outcomes of the six simulations showed no significant difference in valve frame morphology or paravalvular leak risk compared to clinical results, thereby validating the numerical simulation process proposed for quickly selecting valve models and optimal release positions, aiding in TAVR preoperative planning based on patients'geometric characteristics.

Feasibility and outcome of third-generation transcatheter aortic valve implantation in patients with extra-large aortic annulus

BACKGROUND

Many patients in need for transcatheter aortic valve implantation (TAVI) present with an aortic annulus size larger than recommended by the manufacturer's instructions for use (IFU).

AIMS

To investigate procedural and short-term safety and efficacy of TAVI in patients with extra-large annuli (ELA).

METHODS

30-day clinical outcome and valve performance as defined by VARC 3 of 144 patients with an aortic annulus size exceeding the permitted range were compared to a propensity-score matched control cohort of patients with an aortic annulus size consistent with the IFU.

RESULTS

Area and perimeter was 730.4 ± 53.9 mm2 and 96.7 ± 6.5 mm in the ELA group. Technical (96.5% vs. 94.4%) and device success (82.3% vs. 84.5%) were comparable in patients with ELA (annulus area 730.4 ± 53.9 mm2) and matched controls (annulus area 586.0 ± 48.2 mm2). There was no significant difference in 30-day mortality rate, major intraprocedural complications, type 3 or 4 bleedings, major vascular complications, or stroke. Moderate paravalvular leakage (PVL) occurred more frequent in the ELA group (8.9% vs 2.2%; p = 0.02). The rate of new pacemaker implantation was 7.0% in the ELA cohort and 15.0% in the control cohort, respectively (p = 0.05).

CONCLUSION

Treatment of ELA patients with third-generation TAVI prostheses is feasible and safe, providing similar device success and complication rates as in matched controls with regular-sized aortic annulus. Post-interventional pacemaker implantation rates were low compared to the control group, yet incidence of moderate PVL remains problematic in ELA patients.

One-year clinical outcomes of transcatheter aortic valve implantation with the latest iteration of self-expanding or balloonexpandable devices: insights from the OPERA-TAVI registry

BACKGROUND

Midterm comparative analyses of the latest iterations of the most used Evolut and SAPIEN platforms for transcatheter aortic valve implantation (TAVI) are lacking.

AIMS

We aimed to compare 1-year clinical outcomes of TAVI patients receiving Evolut PRO/PRO+ (PRO) or SAPIEN 3 Ultra (ULTRA) devices in current real-world practice.

METHODS

Among patients enrolled in the OPERA-TAVI registry, patients with complete 1-year follow-up were considered for the purpose of this analysis. One-to-one propensity score matching was used to compare TAVI patients receiving PRO or ULTRA devices. The primary endpoint was a composite of 1-year all-cause death, disabling stroke and rehospitalisation for heart failure. Five prespecified subgroups of patients were considered according to leaflet and left ventricular outflow tract calcifications, annulus dimensions and angulation, and leaflet morphology.

RESULTS

Among a total of 1,897 patients, 587 matched pairs of patients with similar clinical and anatomical characteristics were compared. The primary composite endpoint did not differ between patients receiving PRO or ULTRA devices (Kaplan-Meier [KM] estimates 14.0% vs 11.9%; log-rank p=0.27). Patients receiving PRO devices had higher rates of 1-year disabling stroke (KM estimates 2.6% vs 0.4%; log-rank p=0.001), predominantly occurring within 30 days after TAVI (1.4% vs 0.0%; p=0.004). Outcomes were consistent across all the prespecified subsets of anatomical scenarios (all pinteraction>0.10).

CONCLUSIONS

One-year clinical outcomes of patients undergoing transfemoral TAVI and receiving PRO or ULTRA devices in the current clinical practice were similar, but PRO patients had higher rates of disabling stroke. Outcomes did not differ across the different anatomical subsets of the aortic root.

The native aortic valve reduces paravalvular leak in TAVR patients

Background: Paravalvular leak (PVL) is a frequent TAVR complication. Prospective identification of patients who are likely to develop PVL after TAVR would likely lead to improved outcomes. Prior studies have used geometric characteristics to predict the likelihood of PVL development, but prediction and quantification has not been done. One of the reasons is that it is difficult to predict the mechanical deformation of the native diseased aortic valve prior to implantation of the prosthetic valve, as existing calcifications likely contribute to the seal between the prosthetic valve and the aortic annulus. However, the relatively amount the native valve plays in preventing PVL is unknown.

Methods: A retrospective chart review was conducted identifying patients with mild or greater PVL. One patient who had substantial PVL was identified and a 3D printed (pre-TAVR) aortic root was created. Balloon-expandable TAVR stent frames were implanted within the 3D printed root and a new model was created. Using this geometry, computational fluid dynamics (CFD) simulations were done to quantify PVL. The PVL flow path was iteratively decreased to simulate the space occupied by a crushed native aortic valve and PVL was quantified.

Results: PVL was found to decrease as the space occupying the PVL area increased, demonstrating that the native aortic valve contributes to reducing regurgitation. CFD simulations demonstrated that within the patient analyzed, the native valve occupies between 3–40% of the PVL pathway.

Conclusion:A priori techniques that predict the development of post TAVR PVL should account for the native diseased valve as our simulations demonstrate that it plays a role in reducing PVL.

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.

Comparison of Balloon-Expandable Valve and Self-Expandable Valve in Transcatheter Aortic Valve Replacement: A Patient-Specific Numerical Study

Transcatheter aortic valve replacement (TAVR) is a minimally invasive strategy for the treatment of aortic stenosis. The complex post-operative complications of TAVR were related to the type of implanted prosthetic valve, and the deep mechanism of this relationship may guide the clinical pre-operative planning. The purpose of this study was to develop a numerical method of TAVR to compare the outcome difference between balloon-expandable valve and self-expandable valve and predict the post-operative results. A complete patient-specific aortic model was reconstructed. Two prosthetic valves (balloon-expandable valve and self-expandable valve) were introduced to simulate the implantation procedure, and post-procedural function was studied with fluid-structure interaction method, respectively. Results showed similar stress distribution for two valves, but higher peak stress for balloon-expandable valve model. Compared with the self-expandable valve, the balloon-expandable valve was associated with a better circular cross-section and smaller paravalvular gaps area. Hemodynamic parameters like cardiac output, mean transvalvular pressure difference and effective orifice area (EOA) of the balloon-expandable valve model were better than those of the self-expandable valve model. Significant outcome difference was found for two prosthetic valves. Balloon-expandable valve may effectively decrease the risk and degree of post-operative paravalvular leak, while self-expandable valve was conducive to lower stroke risk due to lower aortic stress. The numerical TAVR simulation process may become an assistant tool for prosthesis selection in pre-operative planning and post-operative prediction.

Transcatheter versus Isolated Surgical Aortic Valve Replacement in Young High-Risk Patients: A Propensity Score-Matched Analysis

Background: Younger patients with severe symptomatic aortic stenosis are a particularly challenging collective with regard to the choice of intervention. High-risk patients younger than 75 years of age are often eligible for both the transcatheter aortic valve replacement (TAVR) and the isolated surgical aortic valve replacement (iSAVR). Data on the outcomes of both interventions in this set of patients are scarce. Methods: One hundred and forty-four propensity score-matched patients aged 75 years or less who underwent TAVR or iSAVR at the Hietzing Heart Center in Vienna, Austria, were included in the study. The mean age was 68.9 years (TAVR 68.7 vs. SAVR 67.6 years; p = 0.190) and the average EuroSCORE II was 5.4% (TAVR 4.3 [3.2%] vs. iSAVR 6.4 (4.3%); p = 0.194). Results: Postprocedural adverse event data showed higher rates of newly acquired atrial fibrillation (6.9% vs. 19.4%; p = 0.049), prolonged ventilation (2.8% vs. 25.0%; p < 0.001) and multi-organ failure (0% vs. 6.9%) in the surgical cohort. The in-hospital and 30-day mortality was significantly higher for iSAVR (1.4% vs. 13.9%; p = 0.012; 12.5% vs. 2.8%; p = 0.009, respectively). The long-term survival (median follow-up 5.0 years (2.2–14.1 years)) of patients treated with the surgical approach was superior to that of patients undergoing TAVR (p < 0.001). Conclusion: Although the survival analysis revealed a higher in-hospital and 30-day survival rate for high-risk patients aged ≤75 years who underwent TAVR, iSAVR was associated with a significantly higher long-term survival rate.

Post transcatheter aortic valve replacement ejection fraction response is predictor of survival among patients with whole range of systolic dysfunction

AIMS

The objective of this study is to assess the prognostic effects of T ranscatheter aortic valve replacement (TAVR) on the patients with different degrees of left ventricular systolic (LVS) function and severe symptomatic aortic stenosis. Also examines the prognostic association of LV remodelling after TAVR.

METHODS AND RESULTS

Patients stratified into four subgroups with respect to baseline LV ejection fraction (LVEF) (LVEF > 25%, LVEF 25%-40%, LVEF 41%-49% and LVEF ≥ 50%). We compared the baseline characteristics and temporal changes in echocardiographic parameters of the patients after TAVR, and determined all-cause mortality (ACM) in a follow-up period of mean 20.7 ± 15.8 months (up to 84). There were 495 patients at 8 centres. ACM was similar in all groups (28.1%, 29.5%, 22.5% and 24.1% respectively; p = .44). Immediately after TAVR, there was an improvement in LVEF (from 38.7 ± 9.4 to 44.9% ± 10.9%, p < .001). The percent change in LVEF (pDelta-EF) immediately after TAVR was more prominent in the patients with LVEF < 25% (48.1 ± 49.6, 21.9 ± 29.6), (8.4% ± 15.2%) and (2.1 ± 7)) (p < .01). Importantly, a 12% increase in absolute Delta-EF was observed in patients with LVEF< 25% with 100% sensitivity and 42.5% specificity for the prediction of ACM.

CONCLUSION

This study shows that TAVR is beneficial in the whole range of LVS function, irrespective of the baseline EF. Early recovery in LVEF after TAVR is critical for survival, however, it seems to be more eye catching in the patients with advanced heart failure with reduced EF.

Performance of high conformability vs. high radial force devices in the virtual treatment of TAVI patients with bicuspid aortic valve

OBJECTIVE

Transcatheter Aortic Valve Implantation (TAVI) is a consolidated procedure showing a low operative risk and excellent long-term outcomes in patients with aortic stenosis. Patients presenting a bicuspid aortic valve (BAV) often require valve replacement due to the highly calcific nature of the aortic leaflets. However, BAV patients have usually been contraindicated for TAVI due to their complex valve anatomy. The aim of this work was to compare the performance of devices featuring high conformability (HC) against those with high radial force (HRF).

METHODS

Four BAV patients undergoing TAVI were retrospectively selected. The aortic roots including the native leaflets and calcifications were reconstructed from pre-operative Computed Tomography scans. In each patient, both HC and HRF devices were virtually implanted using Finite Element Analysis simulations. After implantation, paravalvular orifice area, von Mises stress distribution, root contact area, and device eccentricity were calculated.

RESULTS

Simulations showed good agreement with intraoperative imaging. In 3 out of 4 patients, the HRF device resulted in a lower paravalvular area than the HC. Stress distribution was also more homogeneously distributed in the HRF group as compared with the HC group. Despite their lower adaptability, HRF devices showed consistently higher stent-root contact area.

CONCLUSION

HRF devices showed improved results with respect to HC valves after being deployed in BAV anatomies. We hypothesize that the ability to reshape the annulus is the major determinant of success in this subgroup of patients featuring highly calcified leaflets.

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.

Insights into permanent pacemaker implantation following TAVR in a real-world cohort

BACKGROUND

Permanent pacemaker implantation (PPI) following TAVR is a frequent post interventional complication and its management remains controversial.

OBJECTIVE

We sought to elucidate the electrophysiological, procedural, and clinical baseline parameters that are associated with and perhaps predict the need for PPI after TAVR in a heterogeneous-valve-type real-world cohort.

METHODS

Overall, 494 patients receiving TAVR at our center from April 2009 to August 2015 were screened. ECG analyses and clinical parameters were collected prospectively.

RESULTS

Overall, 401 patients in this all-comers real-world TAVR cohort with a PPI rate of 16% were included. The mean age was 82 years, and the mean duration to PPI was 5.5 days. A large proportion of Edwards SAPIEN valves (81%), DirectFlow, CoreValve, and Portico were implanted. The main indications for PPI were atrioventricular (AV) block III, AV-block Mobitz type II, bradycardic atrial fibrillation and persistent sinus bradycardia. Between groups with and without PPI, significant differences were noted in the prevalence of post TAVR balloon dilatation, resting heart rate, QRS interval, PR interval with a cut-off of >178 ms, left anterior fascicular block and RBBB in univariate analyses. In the subsequent multiple regression analysis, post TAVR balloon dilatation and a PR interval with a cut-off of >178 ms were significant predictors of PPI.

CONCLUSION

This real-world cohort differs from others in its size and heterogeneous valve selection, and indicates for the first time that patients with post balloon dilatation or prolonged PR interval are at a higher risk for pacemaker dependency after TAVR.

Transcatheter Aortic Valve Replacements: Current Trends and Future Directions

Since the 1960s when the first aortic surgical aortic valve replacement (SAVR) was performed, continuous growth in the field of valvular technology has occurred. Although SAVR remains a lifesaving procedure, minimally invasive transcatheter aortic valve replacement has revolutionized and expanded aortic valve replacement to patients who were not previously SAVR candidates, increasing their quality of life and survival. Since its introduction in the United States in 2011, the technology and practice have rapidly expanded. Hybrid techniques have been developed that combine surgical access to the vasculature with valvular deployment over transcatheter systems. This literature review aims to describe the differences between the current available valve technologies, review approaches to surgical technique, discuss anesthetic considerations, and look forward to future directions, trends, and challenges.

Transcatheter aortic valve implantation: a revolution in the therapy of elderly and high-risk patients with severe aortic stenosis

Transcatheter aortic valve implantation (TAVI) represents a real revolution in the field of interventional cardiology for the treatment of elderly or high-risk surgical patients with severe symptomatic aortic valve stenosis. Today, TAVI seems to play a key and a reliable role in the treatment of intermediate and maybe low-risk patients with severe aortic stenosis. TAVI has also evolved from a complex and hazardous procedure into an effective and safe therapy by the development of new generation devices. This article aims to review the background and future of TAVI, clinical trials and registries with old and new generation TAVI devices and to focus on some open issues related to post-procedural outcomes.

[Interventional therapy of aortic valve stenosis in Germany]

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has gained importance in recent years for the treatment of symptomatic aortic stenosis in Germany.

OBJECTIVE

This article discusses the indications, the procedure itself and safety issues in TAVI.

MATERIAL AND METHODS

Randomized controlled trials, registry studies, guidelines and expert recommendations are discussed.

RESULTS

Inoperable patients as well as patients ≥ 75 years with a high perioperative risk and patients ≥ 85 years should primarily be treated by TAVI. The decision must be made following discussions in a heart team. If no contraindications are detected the TAVI procedure should be performed via the transfemoral approach with the patient under conscious sedation. In recent years there has been a significant reduction in complication rates.

CONCLUSION

In Germany TAVI is the standard of care for surgical high-risk and inoperable patients with aortic valve stenosis.

The future of transcatheter aortic valve implantation

Since the introduction of transcatheter aortic valve implantation (TAVI) into clinical practice, the treatment of aortic stenosis has changed dramatically. In the past, medical therapy with or without balloon aortic valvuloplasty was the only option for inoperable patients. More recently, TAVI has become the treatment of choice for these patients and the preferred alternative for high-risk operable patients. Surgical aortic valve replacement (SAVR) currently remains the gold standard for patients at low or intermediate operative risk. As randomized trials have demonstrated comparable results between TAVI and SAVR in the high-risk population, there is now a clear trend towards performing TAVI even in intermediate-risk patients while awaiting the results of randomized trials in that population. Nevertheless, there are still questions regarding TAVI involving paravalvular leak (PVL), stroke, pacemaker requirements, and durability that remain to be more definitively answered before TAVI can routinely be performed in a broader, lower risk population. Improvements in patient selection, imaging, and second and third generation devices have decreased the incidence of PVLs and vascular complications that followed the earliest TAVI procedures, but the rates of perioperative stroke and permanent pacemaker implantation must still be addressed. Furthermore, the long-term durability of TAVI devices and a role for post-procedure antithrombotic management remain unanswered. Until these questions are more clearly answered, it is the Heart Team's task to determine the optimal treatment for each patient based on risk scores, frailty metrics, comorbidities, patient preference, and potential for improvement in quality of life.