A Novel Angiographic Quantification of Aortic Regurgitation After TAVR Provides an Accurate Estimation of Regurgitation Fraction Derived From Cardiac Magnetic Resonance Imaging

Paravalvular Leak in Transcatheter Aortic Valve Implantation: A Review of Current Challenges and Future Directions

Transcatheter aortic valve implantation (TAVI) has emerged as a revolutionary therapeutic modality for the management of severe aortic stenosis (AS), particularly in patients who are at high or prohibitive risk for surgical aortic valve replacement (SAVR). Over the past decade, extensive clinical evidence has expanded the indications for TAVI to include intermediate- and low-risk populations, which usually represent a population of younger age, in which the most common complications of TAVI, including paravalvular leak (PVL) and pacemaker implantation, should be avoided. This review focuses on the incidence and predictors of PVL in various types of TAVI implantation, its clinical implication, and the prevention strategies to tackle this complication.

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.

Paravalvular regurgitation after transcatheter aortic valve replacement: incidence, quantification, and prognostic impact

Transcatheter aortic valve replacement (TAVR) is the standard of care in aortic stenosis with results comparable to surgical aortic valve replacement. However, paravalvular regurgitation (PVR) is more common after TAVR. With the alteration of devices and implantation techniques, the incidence of moderate or more PVR has declined. Mild PVR is still common in around 30% of TAVR patients in low-risk trials. Progression of AS causes myocardial hypertrophy and varying degrees of diastolic dysfunction which may cause heart failure even in combination with small volumes of PVR. Any degree of PVR is associated with an increased risk of overall and cardiovascular mortality. Predictors of PVR are annular eccentricity, severe calcification of the aortic valve, bicuspid aortic valves, and type of prosthesis where balloon-expandable devices are associated with less PVR. PVR is diagnosed using echocardiography, aortic angiogram with or without videodensitometry, haemodynamic parameters, or cardiac magnetic resonance. PVR can be treated using post-dilation, interventional treatment using a vascular plug, or implantation of a second device. Successful post-dilation depends on balloon size which should at least be equal to or >95% of the mean annulus diameter. Implantation of a second device to reduce PVR is successful in ∼90% of cases, either through lengthening of the sealing skirt in case of inadequate position or through further expansion of the index device. Implantation of a vascular plug can successfully reduce PVR and reduce mortality.

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.

Surgical versus Interventional Treatment of Concomitant Aortic Valve Stenosis and Coronary Artery Disease

BACKGROUND

Coronary artery disease (CAD) is frequently diagnosed in patients with aortic valve stenosis. Treatment options include surgical and interventional approaches. We therefore analyzed short-term outcomes of patients undergoing either coronary artery bypass grafting with simultaneous aortic valve replacement (CABG + AVR) or staged percutaneous coronary intervention and transcatheter aortic valve implantation (PCI + TAVI).

METHODS

From all patients treated since 2017, we retrospectively identified 237 patients undergoing TAVI within 6 months after PCI and 241 patients undergoing combined CABG + AVR surgery. Propensity score matching was performed, resulting in 101 matched pairs.

RESULTS

Patients in the CABG + AVR group were younger compared with patients in the PCI + TAVI group (71.9 ± 4.9 vs 81.4 ± 3.6 years; p < 0.001). The overall mortality at 30 days before matching was higher after CABG + AVR than after PCI + TAVI (7.8 vs 2.1%; p = 0.012). The paired cohort was balanced for both groups regarding demographic variables and the risk profile (age: 77.2 ± 3.7 vs78.5 ± 2.7 years; p = 0.141) and EuroSCORE II (6.2 vs 7.6%; p = 0.297). At 30 days, mortality was 4.9% in the CABG + AVR group and 1.0% in the PCI + TAVI group (p = 0.099). Rethoracotomy was necessary in 7.9% in the CABG + AVR, while conversion to open heart surgery was necessary in 2% in the PCI + TAVI group. The need for new pacemaker was lower after CABG + AVR than after PCI + TAVI (4.1 vs 6.9%; p = 0.010). No paravalvular leak (PVL) was noted in the CABG + AVR group, while the incidence of moderate-to-severe PVL after PCI + TAVI was 4.9% (p = 0.027).

CONCLUSION

A staged interventional approach comprises a short-term survival advantage compared with combined surgery for management of CAD and aortic stenosis. However, PCI + TAVI show a significantly higher risk of atrioventricular block and PVL. Further long-term trials are warranted.

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.

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.

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.

Lung-to-finger circulation time can be measured stably with high reproducibility by simple breath holding method in cardiac patients

Lung to finger circulation time (LFCT) has been used to estimate cardiac function. We developed a new LFCT measurement device using a laser sensor at fingertip. We measured LFCT by measuring time from re-breathing after 20 s of breath hold to the nadir of the difference of transmitted red light and infrared light, which corresponds to percutaneous oxygen saturation. Fifty patients with heart failure were enrolled. The intrasubject stability of the measurement was assessed by the intraclass correlation coefficient (ICC). The ICC calculated from 44 cases was 0.85 (95% confidence interval: 0.77–0.91), which means to have “Excellent reliability.” By measuring twice, at least one clear LFCT value was obtained in 89.1% of patients and the overall measurability was 95.7%. We conducted all LFCT measurements safely. High ICCs were obtained even after dividing patients according to age, cardiac index (CI); 0.85 and 0.84 (≥ 75 or < 75 years group, respectively), 0.81 and 0.84 (N = 26, ≥ or < 2.2 L/min/M²). These results show that our new method to measure LFCT is highly stable and feasible for any type of heart failure patients.

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.

Quantitative assessment of aortic regurgitation following transcatheter aortic valve replacement

Introduction: Transcatheter aortic valve replacement (TAVR) is expanding to lower risk and younger patients with severe symptomatic aortic valve disease. Despite clinical and technological improvements, post-procedural aortic regurgitation (AR) remains a limitation of TAVR, particularly when compared to surgical aortic valve replacement. Although several methods for AR quantification after TAVR are currently available, its exact graduation in everyday clinical practice remains challenging.Areas covered: This review describes the currently available evaluation methods of AR after TAVR, with a special emphasis on the quantitative assessment using videodensitometric angiography, echocardiography and cardiac magnetic resonance imaging.Expert opinion: In the majority of clinical scenarios, satisfactory evaluation of post-TAVR AR can be achieved with a combination of post-procedural angiography, hemodynamic indices and transthoracic echocardiography. Nevertheless, some TAVR patients show 'intermediate' forms of post-procedural AR, in which quantitative evaluation is mandatory for prognostic purposes and further decision-making. Notably, interpretation of quantitative measures early post-TAVR is challenging because of the lack of left ventricular enlargement. Video-densitometric angiography is an emerging method that appears to be clinically attractive for immediate post-TAVR assessment, but requires further validation in everyday clinical practice.

Quantitative Angiographic Assessment of Aortic Regurgitation after Transcatheter Aortic Valve Implantation among Three Balloon-Expandable Valves

Objectives:

The aim of the present analysis is to compare the quantitative angiographic aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) among three balloon-expandable valves.

Background:

Quantitative videodensitometric aortography is an objective, accurate, and reproducible tool for adjudication of AR following TAVI.

Methods:

This is a retrospective corelab analysis, independent from industry, of aortograms from patients treated with TAVI using the balloon-expandable Myval transcatheter heart valve (THV) (Meril Life Sciences Pvt. Ltd., India), Sapien 3, and XT THVs (Edwards Lifesciences, Irvine, CA, USA). The study comprised of 108 analyzable aortograms from consecutive patients in a multicenter European registry who underwent Myval THV implantation. The results of quantitative assessment of AR in the Sapien 3 THV (n = 397) and Sapien XT THV (n = 239) were retrieved from a published pooled database.

Results:

The Myval THV had the lowest proportion of patients with moderate or severe angiographic quantitative AR (2.8%) compared to the Sapien 3 THV (8.3%; p = 0.049) and Sapien XT THV (10.9%; p = 0.012). Furthermore, the Myval THV had the lowest mean angiographic quantitative AR (6.3 ± 6.3%), followed by Sapien 3 THV (7.6 ± 7.1%) and Sapien XT THV (8.8 ± 7.5%), and it was significantly lower than that of the Sapien XT THV (p = 0.006), but not significantly different from Sapien 3 THV (p = 0.246).

Conclusion:

The Myval THV, in comparison with other BEV’s analyzed in our database, showed a lower occurrence of moderate or severe AR after TAVI. These results should be confirmed in prospective cohorts of randomized patients with head-to-head THV comparisons.

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).

Current issues in transcatheter aortic valve replacement

Aortic stenosis is the most common valvular disease worldwide. With transcatheter aortic valve replacement (TAVR) being increasingly expanded to lower-risk populations, several challenging issues remain to be solved. The present review aims at discussing modern approaches to such issues as well as the current status of TAVR. TAVR has undergone several developments in the recent years: an increased use of transfemoral access, the development of prostheses in order to adapt to challenging anatomies, improved delivery systems with repositioning features, and outer skirts aiming at reducing paravalvular leak. The indication of TAVR is increasingly being expanded to patients with lower surgical risk. The main clinical trials supporting such expansion are reviewed and the latest data on low-risk patients are discussed. A number of challenges need still to be addressed and are also reviewed in this paper: the need for updated international guidelines including the latest evidence; a reduction of main complications such as permanent pacemaker implantation, paravalvular leak, and stroke (and its potential prevention by using anti-embolic protection devices); the appropriate role of TAVR in patients with concomitant cardiac ischemic disease; and durability of bio-prosthetic implanted valves. Finally, the future perspectives for TAVR use and next device developments are discussed.

Early detection of transcatheter heart valve dysfunction

Introduction: Transcatheter aortic valve implantation therapy is spreading rapidly, representing the standard of care in inoperable and high-risk patients, and a valid alternative in intermediate- and low-risk patients with severe symptomatic aortic stenosis. In this subset, the development and validation of noninvasive, quantitative, in vivo imaging modality, to monitor possible valve dysfunction is mandatory, in order to plan timely therapeutic interventions before the onset of symptoms.Areas covered: The implantation of transcatheter heart valves (THV) is increasing rapidly. As a consequence, THV dysfunction will become a major cause of cardiovascular morbidity after TAVI. Emergency repeat aortic valve replacement surgery is associated with a high rate of mortality compared with elective repeat surgery. In this context, early detection of THV dysfunction is therefore highly desirable. The review aims to examine the different diagnostic method to early detect THV dysfunction.Expert opinion: Most promising innovations in the diagnosis of early detection of THV dysfunction are evaluated, and the future outlook is explored. Waiting for upcoming evidence about the utility of CT, CMR, and PET on early detection of THV dysfunction, tailoring echocardiogram follow-up based on patients' characteristics is the desirable approach.

Ex Vivo Pilot Study of Cardiac Magnetic Resonance Velocity Mapping for Quantification of Aortic Regurgitation in a Porcine Model in the Presence of a Transcatheter Heart Valve

Accuracy of aortic regurgitation (AR) quantification by magnetic resonance (MR) imaging in the presence of a transcatheter heart valve (THV) remains to be established. We evaluated the accuracy of cardiac MR velocity mapping for quantification of antegrade flow (AF) and retrograde flow (RF) across a THV and the optimal slice position to use in cardiac MR imaging. In a systematic and fully controlled laboratory ex vivo setting, two THVs (Edwards SAPIEN XT, Medtronic CoreValve) were tested in a porcine model (n = 1) under steady flow conditions. Results showed a high level of accuracy and precision. For both THVs, AF was best measured at left ventricular outflow tract level, and RF at ascending aorta level. At these levels, MR had an excellent repeatability (ICC > 0.99), with a tendency to overestimate (4.6 ± 2.4% to 9.4 ± 7.0%). Quantification of AR by MR velocity mapping in the presence of a THV was accurate, precise, and repeatable in this pilot study, when corrected for the systematic error and when the best MR slice position was used. Confirmation of these results in future clinical studies would be a step forward in increasing the accuracy of the assessment of paravalvular AR severity.

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.

Paravalvular Regurgitation After Transcatheter Aortic Valve Replacement: Is the Problem Solved?

Paravalvular regurgitation is a frequent complication after transcatheter aortic valve replacement and its association with worse outcomes depends on the degree of its severity. Despite substantial improvement in transcatheter heart valve design, sizing and implantation technique, moderate or severe paravalvular regurgitation still occurs in 2% to 7% of patients and is associated with a more than 2-fold increase in mortality. This review provides a state-of-the-art approach to (i) paravalvular regurgitation prevention by optimizing patient selection, valve sizing, and positioning and (ii) the detection, quantitation and management of paravalvular regurgitation during and after valve implantation.

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.