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

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.

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.

Validation of Prosthetic Mitral Regurgitation Quantification Using Novel Angiographic Platform by Mock Circulation

OBJECTIVES

This study aimed to validate a dedicated software for quantitative videodensitometric angiographic assessment of mitral regurgitation (QMR).

BACKGROUND

Quantitative videodensitometric aortography of aortic regurgitation using the time-density principle is a well-documented technique, but the angiographic assessment of mitral regurgitation (MR) remains at best semi-quantitative and operator dependent.

METHODS

Fourteen sheep underwent surgical mitral valve replacement using 2 different prostheses. Pre-sacrifice left ventriculograms were used to assess MR fraction (MRF) using QMR and MR volume (MRV). In an independent core lab, the CAAS QMR 0.1 was used for QMR analysis. In vitro MRF and MRV were assessed in a mock circulation at a comparable cardiac output to the in vivo one by thermodilution. The correlations and agreements of in vitro and in vivo MRF, MRV, and interobserver reproducibility for QMR analysis were assessed using the averaged cardiac cycles (CCs).

RESULTS

In vivo derived MRF by QMR strongly correlated with in vitro derived MRF, regardless of the number of the CCs analyzed (best correlation: 3 CCs y = 0.446 + 0.994x; R = 0.784; p =0.002). The mean absolute difference between in vitro derived MRF and in vivo derived MRF from 3 CCs was 0.01 ± 4.2% on Bland-Altman analysis. In vitro MRV and in vivo MRV from 3 CCs were very strongly correlated (y = 0.196 + 1.255x; R = 0.839; p < 0.001). The mean absolute difference between in vitro MRV and in vivo MRV from 3 CCs was -1.4 ± 1.9 ml. There were very strong correlations of in vivo MRF between 2 independent analysts, regardless of the number of the CCs.

CONCLUSIONS

In vivo MRF using the novel software is feasible, accurate, and highly reproducible. These promising results have led us to initiate the first human feasibility study comprising patients undergoing percutaneous mitral valve edge-to-edge repair.

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).