Association between three-year mortality after transcatheter aortic valve implantation and paravalvular regurgitation graded by videodensitometry in comparison with visual grading

BACKGROUND

Estimation of regurgitant fraction by videodensitometry (VD-AR) of aortic root angiograms is a new tool for objective grading of paravalvular regurgitation (PVR) after transcatheter aortic valve implantation (TAVI). Stratification with boundaries at 6% and 17% has been proposed to reflect "none/trace", "mild" and "moderate or higher" PVR.

OBJECTIVE

We sought to investigate the association of strata of VD-AR with 3-year mortality and to compare VD-AR with visual grading of angiograms.

METHODS

We interrogated our database for patients undergoing transfemoral TAVI from 2008 to 2018. Vital status of the patients was obtained from population registers. To test differences in survival and estimate adjusted hazard ratios (HRs) we fitted Cox models.

RESULTS

Our retrospective study included 699 patients with evaluable angiograms at completion of the TAVI procedure. Cumulative 3-year mortality was 35.0% in 261 (37.3%) patients with VD-AR < 6%, 33.9% in 325 (46.5%) patients with VD-AR between 6 and 17% (HR [95% confidence interval] 1.06 [0.80-1.42]; P = 0.684) and 47.2% in 113 (16.2%) patients with VD-AR > 17% (HR 1.57 [1.11-2.22]; P = 0.011). Visually, PVR was graded as "none/trace" in 470 (67.2%) patients, as "mild" in 219 (31.3%) and as "moderate" in 10 (1.4%). Both mild PVR and moderate PVR on visual grading were significantly associated with mortality (HRs 1.31 [1.12-1.54]; P = 0.001 and 1.92 [1.13-3.24]; P = 0.015; respectively).

CONCLUSIONS

VD-AR > 17%, but not VD-AR 6-17%, was independently associated with mortality. Compared with subjective visual evaluation, VD-AR resulted in a smaller proportion of patients with PVR classified as prognostically relevant.

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.

Angiographic quantification of aortic regurgitation following myval octacor implantation; independent core lab adjudication

BACKGROUND

The balloon expandable Myval transcatheter heart valve (THV) showed encouraging results regarding residual aortic regurgitation (AR) from multiple observational studies. The newly designed Myval Octacor has been introduced recently, aiming for a reduction in AR and improved performance.

OBJECTIVES

The focus of this study is to report the incidence of AR using the validated quantitative Videodensitometry angiography technology (qLVOT-AR%) in the first in human use of the Myval Octacor THV system.

METHODOLOGY

We report on the first in human use of the Myval Octacor THV system in 125 patients in 18 Indian centres. Independent retrospective analysis of the final aortograms following implantation of the Myval Octacor was performed using the CAAS-A-Valve software. AR is reported as a regurgitation fraction. The previously validated cutoff values have been used to identify ≥moderate AR (RF% >17%), mild (6% < RF% ≤17%), and none or trace AR (RF% ≤ 6%).

RESULTS

Final aortogram was analysable for 103 patients (84.4%) among the 122 available aortograms. 64 (62%) patients, had tricuspid aortic valve (TAV), 38 (37%) with bicuspid AV (BAV), and one with unicuspid AV. The median absolute RF% was 2% [1, 6], moderate or more AR incidence was 1.9%, mild AR in 20.4%, and none or trace AR in 77.7%. The two cases with RF% >17% were in the BAV group.

CONCLUSION

The initial results of Myval Octacor using quantitative angiography-derived regurgitation fraction demonstrated a favourable outcome regarding residual AR, possibly due to improved device design. Results must be confirmed in a larger randomised study, including other imaging modalities.

Comparative Quantitative Aortographic Assessment of Regurgitation in Patients Treated With VitaFlow Transcatheter Heart Valve vs. Other Self-Expanding Systems

Objectives

To compare the quantitative angiographic aortic regurgitation (AR) of six self-expanding valves after transcatheter aortic valve replacement (TAVR).

Background

Quantitative videodensitometric aortography (LVOT-AR) is an accurate and reproducible tool for assessment of AR following TAVR.

Methods

This is a retrospective central core-lab analysis of 1,257 consecutive cine aortograms performed post-TAVR. The study included 107 final aortograms of consecutive patients who underwent TAVR with first-generation VitaFlow in four Chinese centers and 1,150 aortograms with five other transcatheter aortic valves (Evolut Pro, Evolut R, CoreValve, Venus A-Valve, and Acurate Neo). LVOT-AR analyses of these five valves were retrieved from a previously published pooled database.

Results

Among 172 aortograms of patients treated with VitaFlow, 107 final aortograms (62.2%) were analyzable by LVOT-AR. In this first in man eight cases necessitated a procedural valve in valve due to inappropriate TAVR positioning and severe aortic paravalvular regurgitation. In the VitaFlow group, the mean LVOT-AR of the intermediate aortograms was 7.3 ± 7.8% and the incidence of LVOT-AR >17% was 8.6%. The mean LVOT-AR of the final aortogram was 6.1 ± 6.4% in the VitaFlow group, followed by Evolut Pro (7.3 ± 6.5%), Evolut R (7.9 ± 7.4%), Venus A-valve (8.9 ± 10.0%), Acurate Neo (9.6 ± 9.2%), and lastly CoreValve (13.7 ± 10.7%) (analysis of variance p < 0.001). Post hoc 2-by-2 testing showed that CoreValve had significantly higher LVOT-AR compared with each of the other five THVs. No statistical difference in LVOT-AR was observed between VitaFlow, Evolut Pro, Evolut R, Acurate Neo, and Venus A-valves. The VitaFlow system had the lowest proportion of patients with LVOT-AR >17% (4.7%) (AR after the final aortograms), followed by Evolut Pro (5.3%), Evolut R (8.8%), Acurate Neo (11.3%), Venus A-valve (14.2%), and CoreValve (30.1%) (chi-square p < 0.001).

Conclusion

Compared to other commercially available self-expanding valves, VitaFlow seems to have a low degree of AR and a low proportion of patients with ≥moderate/severe AR as assessed by quantitative videodensitometric angiography. Once the learning phase is completed, comparisons of AR between different transcatheter heart valves should be attempted in a prospective randomized trial.

Paravalvular Aortic Regurgitation Severity Assessed by Quantitative Aortography: ACURATE neo2 versus ACURATE neo Transcatheter Aortic Valve Implantation

The new-generation ACURATE neo2 system was commercially released in September 2020. In this study, we sought to compare the aortic regurgitation (AR) severity of the ACURATE neo2 versus the ACURATE neo transcatheter heart valve, using quantitative videodensitometric angiography (qAR). This is a retrospective, Corelab analysis of final post-transcatheter aortic valve implantation (TAVI) aortograms of patients treated with the ACURATE neo2 and ACURATE neo systems. The ACURATE neo2 cohort comprised consecutive patients treated between September 2020 and January 2021 at two centers. The ACURATE neo cohort included consecutive patients treated before September 2020. Our primary objective was to compare AR severity on qAR following TAVI with ACURATE neo2 and ACURATE neo. Out of 401 aortograms, 228 (56.9%) were analyzable, with 120 in the ACURATE neo2 cohort, and 108 in the ACURATE neo cohort. The mean AR fraction was 4.4 ± 4.8% in the neo2 cohort, and 9.9 ± 8.2% in the neo cohort (p < 0.001). Furthermore, moderate or severe AR (qAR > 17%) was detected in 2 aortograms (1.7%) in the neo2 cohort and 15 aortograms (13.9%) in the neo cohort (p < 0.001). Quantitative aortography shows a lower rate of moderate or severe paravalvular AR in what is the first European experience of the new-generation, self-expanding ACURATE neo2 when compared to the first-generation ACURATE neo. Moreover, aortographic data need to be correlated and compared to Core Laboratory-adjudicated 30-day echocardiographic data.

Quantitative Angiographic Assessment of Aortic Regurgitation After Transcatheter Implantation of the Venus A-valve: Comparison with Other Self-Expanding Valves and Impact of a Learning Curve in a Single Chinese Center

Objectives

We aimed to compare the quantitative angiographic aortic regurgitation (AR) into the left ventricular out flow tract (LVOT-AR) of five different types of transcatheter self-expanding valves and to investigate the impact of the learning curve on post-TAVR AR.

Background

Quantitative video densitometric aortography is an objective, accurate, and reproducible tool for assessment of AR following TAVR.

Methods and results

This retrospective academic core-lab analysis, analyzed 1150 consecutive cine aortograms performed immediately post-TAVR. Quantitative angiographic AR of post-procedural aortography in 181 consecutive patients, who underwent TAVR with the Venus A-valve in a single Chinese center, were compared to the results of Evolut Pro, Evolut R, CoreValve, (Medtronic, Dublin, Ireland) and Acurate Neo (Boston Scientific, Massachusetts, US) transcatheter heart valves (THVs), from a previously published pooled database. Among the 181 aortograms of patients treated with the Venus A-Valve, 113 (62.4%) were analyzable for quantitative assessment of AR. The mean LVOT-AR was 8.9% ± 10.0% with 14.2% of patients having moderate or severe AR in the Venus A-valve group. No significant difference in mean LVOT-AR was observed between Evolut Pro, Evolut R, Acurate Neo, and Venus A-valve. The incidence of LVOT-AR >17%, which correlates with echocardiographic derived ≥ moderate AR, with the Evolut Pro was lower than with the Venus A-valve (5.3% vs. 14.2%, p = 0.034), but was not different from the Evolut R (5.3% vs. 8.8%, p = 0.612), or the Acurate Neo (5.3% vs. 11.3% p = 0.16) systems. A landmark analysis after recruitment of the first half of patients treated with the Venus A valve (N = 56), showed a significantly lower mean LVOT-AR in the second half of the series (11.3% ± 11.9% vs. 6.5% ± 7.1%, p = 0.011). The incidence of LVOT-AR >17% in the latest 57 cases was also numerically lower (7.0% vs. 21.4%, p = 0.857) and compared favorably with the best in class of the self-expanding valves.

Conclusion

The Venus A-valve has comparable mean LVOT-AR to other self-expanding valves but has a higher rate of moderate or severe AR than the Evolut Pro THV. However, after completion of a learning phase, results improved and compared favorably with the best in class of the commercially available self-expanding valves. These findings should be confirmed in prospective randomized comparisons of AR between different THVs.

Online Quantitative Aortographic Assessment of Aortic Regurgitation After TAVR: Results of the OVAL Study

OBJECTIVES

The aim of this study was to investigate the online assessment feasibility of aortography using videodensitometry in the catheterization laboratory during transcatheter aortic valve replacement (TAVR).

BACKGROUND

Quantitative assessment of regurgitation after TAVR through aortography using videodensitometry is simple, reproducible, and validated in vitro, in vivo, in clinical trials, and in "real-world" patients. However, thus far the assessment has been done offline.

METHODS

This was a single center, prospective, proof-of-principle, feasibility study. One hundred consecutive patients with aortic stenosis and indications to undergo TAVR were enrolled. All final aortograms were analyzed immediately after acquisition in the catheterization laboratory and were also sent to an independent core laboratory for blinded offline assessment. The primary endpoint of the study was the feasibility of the online assessment of regurgitation (percentage of analyzable cases). The secondary endpoint was the reproducibility of results between the online assessment and the offline analysis by the core laboratory.

RESULTS

Patients' mean age was 81 ± 7 years, and 56% were men. The implanted valves were either SAPIEN 3 (97%) or SAPIEN 3 Ultra (3%). The primary endpoint of online feasibility of analysis was 92% (95% confidence interval [CI]: 86% to 97%) which was the same feasibility encountered by the core laboratory (92%; 95% CI: 86% to 97%). Reproducibility assessment showed a high correlation between online and core laboratory evaluations (R² = 0.87, p < 0.001), with an intraclass correlation coefficient of 0.962 (95% CI: 0.942 to 0.975; p < 0.001).

CONCLUSIONS

This study showed high feasibility of online quantitative assessment of regurgitation and high agreement between the online examiner and core laboratory. These results may pave the way for the application of videodensitometry in the catheterization laboratory after TAVR. (Online Videodensitometric Assessment of Aortic Regurgitation in the Cath-Lab [OVAL]; NCT04047082).

On the Modeling of Patient-Specific Transcatheter Aortic Valve Replacement: A Fluid-Structure Interaction Approach

PURPOSE

Transcatheter aortic valve replacement (TAVR) is a minimally invasive treatment for high-risk patients with aortic diseases. Despite its increasing use, many influential factors are still to be understood and require continuous investigation. The best numerical approach capable of reproducing both the valves mechanics and the hemodynamics is the fluid-structure interaction (FSI) modeling. The aim of this work is the development of a patient-specific FSI methodology able to model the implantation phase as well as the valve working conditions during cardiac cycles.

METHODS

The patient-specific domain, which included the aortic root, native valve and calcifications, was reconstructed from CT images, while the CAD model of the device, metallic frame and pericardium, was drawn from literature data. Ventricular and aortic pressure waveforms, derived from the patient's data, were used as boundary conditions. The proposed method was applied to two real clinical cases, which presented different outcomes in terms of paravalvular leakage (PVL), the main complication after TAVR.

RESULTS

The results confirmed the clinical prognosis of mild and moderate PVL with coherent values of regurgitant volume and effective regurgitant orifice area. Moreover, the final release configuration of the device and the velocity field were compared with postoperative CT scans and Doppler traces showing a good qualitative and quantitative matching.

CONCLUSION

In conclusion, the development of realistic and accurate FSI patient-specific models can be used as a support for clinical decisions before the implantation.

Feasibility study of a synchronized diastolic injection with low contrast volume for proper quantitative assessment of aortic regurgitation in porcine models

OBJECTIVES

To evaluate the in vivo feasibility of aortography with one accurately timed diastolic low-volume contrast injection for quantitative assessment of aortic regurgitation (AR) post transcatheter aortic valve replacement (TAVR).

BACKGROUND

With the rise of a minimalistic approach for TAVR, aortography (re)emerges as a pragmatic tool for AR assessment. In a mock circulation system, we have validated the accuracy of a single diastolic injection triggered by electrocardiogram (ECG) with low-contrast volume.

METHODS

Two-phase experiment: first, a series of aortograms were performed in a porcine model, with 8 mL of contrast using the synchronized (SYNC) and the conventional non-synchronized (NS) injections. In a second phase, we developed a model of AR by inserting partially unsheathed Wallstents of 6-10 mm of diameter across the pig's aortic valve, performing SYNC injections with 8 mL of contrast and NS injections with 8 mL and 15 mL (rate: 20 mL/sec). Respective accuracies of SYNC vs. NS were assessed using Passing-Bablock regression. An angiography core laboratory performed quantitative AR assessment with videodensitometry (VD-AR).

RESULTS

The SYNC injections produced higher opacification of the aortic root compared with NS injections (P = 0.04 for density). In the second phase, a regression line for predicting VD-AR based on the SYNC injection resulted in a lower intercept and a slope closer to the line of identity (y = 11.9 + 0.79x, P < 0.001, r²  = 0.94) with the NS-8 mL than with the NS-15 mL injection (y = 26.5 + 0.55x, P < 0.001, r²  = 0.81).

CONCLUSION

Synchronized diastolic injection with low contrast volume produced denser images in the aortic root and more accurate than the conventional injection; thus, may be an appealing alternative for assessment of AR post TAVR.