Impact of Annular Oversizing on Paravalvular Regurgitation and Valve Hemodynamics: New Insights From PARTNER 3

Large Field-of-View Intravascular Ultrasound for Mitral and Tricuspid Valve-in-Valve Guidance: A Pilot Study

Background

Actual expansion of a transcatheter heart valve (THV) might differ from nominal, particularly during nonaortic valve-in-valve for a degenerated bioprosthetic surgical heart valve (SHV). This pilot study compared THV expansion measured using large-field-of-view intravascular ultrasound (IVUS) vs. multi-slice computed tomography (MSCT) and assessed the correlation between THV dimensions and transvalvular gradients.

Methods

Fourteen patients were successfully treated with mitral/tricuspid valve-in-valve SAPIEN 3 implantation sized using the true SHV inner diameter; all 14 had baseline MSCT and transvalvular gradients measured at baseline, postprocedure, and at discharge. Periprocedural IVUS (in 6 patients using a Philips 10MHz Vision PV035) was compared with postprocedural MSCT (in 9 patients) with offline measurements performed at 1-mm steps along the THV height. Overall, 190 MSCT and paired 124 IVUS cross-sections were analyzed.

Results

There was very good agreement between IVUS THV dimensions and corresponding MSCT measurements (intraclass correlation coefficient ≥0.986 and p < 0.001). IVUS measured THV expansion (percent of the nominal cross-sectional area) was smaller within the inflow and middle of the THV overlapping the ring (85.9% ± 11.3%, 83.8% ± 11.8%) than within the outflow (98.8% ± 12.7%). The residual mean transvalvular gradient increased from periprocedural to predischarge (3.5 ± 2.0 vs. 6.3 ± 1.7 mmHg, p < 0.001). The only independent predictor of predischarge maximal transvalvular gradient was the smallest minimal inner THV frame diameter (r2 = 0.67), predicted by true SHV internal diameter (Beta = 0.066, 95% CI = 0.015-0.117, r2 = 0.49, p = 0.037).

Conclusions

This pilot study is the first to report the feasibility of a large field-of-view IVUS for periprocedural measurement of actual THV expansion when deployed valve-in-valve. Minimal inner THV stent frame dimensions correlate with increased postprocedural transvalvular gradients.

Outcomes and treatment strategy of transcatheter aortic valve replacement with balloon-expandable valve in borderline-size annulus

BACKGROUND

Candidates for transcatheter aortic valve replacement (TAVR) occasionally have a "borderline-size" aortic annulus between 2 transcatheter heart valve sizes, based on the manufacturer's sizing chart. Data on TAVR outcomes in such patients are limited.

METHODS

We retrospectively reviewed 1816 patients who underwent transfemoral-TAVR with balloon-expandable valve (BEV) at our institution between 2016 and 2020. We divided patients into borderline and non-borderline groups based on computed tomography-derived annular measurements and compared outcomes. Furthermore, we analyzed procedural characteristics and compared outcomes between the smaller- and larger-valve strategies in patients with borderline-size annulus.

RESULTS

During a median follow-up of 23.3 months, there was no significant difference between the borderline (n = 310, 17.0 %) and non-borderline (n = 1506) groups in mortality (17.3 % vs. 19.5 %; hazard ratio [HR] = 0.86 [95% CI = 0.62-1.20], p = 0.39), major adverse cardiac/cerebrovascular events (MACCE: death/myocardial infarction/stroke, 21.2 % vs. 21.5 %; HR = 0.97 [0.71-1.32], p = 0.85), paravalvular leak (PVL: mild 21.8 % vs. 20.6 %, p = 0.81; moderate 0 % vs. 1.2 %; p = 0.37), or mean gradient (12.9 ± 5.8 vs. 12.6 ± 5.2 mmHg, p = 0.69) at 1 year. There was no significant difference between the larger-(n = 113) and smaller-valve(n = 197) subgroups in mortality (23.7 % vs. 15.2 %; HR = 1.57 [0.89-2.77], p = 0.12), MACCE (28.1 % vs. 18.4 %; HR = 1.52 [0.91-2.54], p = 0.11), mild PVL (13.3 % vs. 25.9 %; p = 0.12), or mean gradient (12.3 ± 4.5 vs. 13.6 ± 5.3 mmHg, p = 0.16); however, the rate of permanent pacemaker implantation (PPI) was higher in the larger-valve subgroup (15.9 % vs. 2.6 %, p < 0.001).

CONCLUSION

Borderline-size annulus is not associated with higher risk of adverse outcomes after BEV-TAVR. However, the larger-valve strategy for borderline-size annulus is associated with higher PPI risk, suggesting a greater risk of injury to the conduction system.

Incidence and Outcomes of New-Onset Right Bundle Branch Block Following Transcatheter Aortic Valve Replacement

BACKGROUND

The incidence and prognosis of right bundle branch block (RBBB) following transcatheter aortic valve replacement (TAVR) are unknown. Hence, we sought to characterize the incidence of post-TAVR RBBB and determine associated risks of permanent pacemaker (PPM) implantation and mortality.

METHODS

All patients 18 years and above without preexisting RBBB or PPM who underwent TAVR at US Mayo Clinic sites and Mayo Clinic Health Systems from June 2010 to May 2021 were evaluated. Post-TAVR RBBB was defined as new-onset RBBB in the postimplantation period. The risks of PPM implantation (within 90 days) and mortality following TAVR were compared for patients with and without post-TAVR RBBB using Kaplan-Meier analysis and Cox proportional hazards modeling. The risks of PPM implantation (within 90 days) and mortality following TAVR were compared for patients with and without post-TAVR RBBB using Kaplan-Meier analysis and Cox proportional hazards modeling.

RESULTS

Of 1992 patients, 15 (0.75%) experienced new RBBB post-TAVR. There was a higher degree of valve oversizing among patients with new RBBB post-TAVR versus those without (17.9% versus 10.0%; P=0.034). Ten patients (66.7%) with post-TAVR RBBB experienced high-grade atrioventricular block and underwent PPM implantation (median 1 day; Q1, 0.2 and Q3, 4), compared with 268/1977 (13.6%) without RBBB. Following propensity score adjustment for covariates (age, sex, balloon-expandable valve, annulus diameter, and valve oversizing), post-TAVR RBBB was significantly associated with PPM implantation (hazard ratio, 8.36 [95% CI, 4.19-16.7]; P<0.001). No statistically significant increase in mortality was seen with post-TAVR RBBB (hazard ratio, 0.83 [95% CI, 0.33-2.11]; P=0.69), adjusting for age and sex.

CONCLUSIONS

Although infrequent, post-TAVR RBBB was associated with elevated PPM implantation risk. The mechanisms for its development and its clinical prognosis require further study.

Managing the challenge of a small aortic annulus in patients with severe aortic stenosis

INTRODUCTION

Small aortic annulus (SAA) poses a challenge in the management of patients with severe aortic stenosis requiring aortic valve replacement - both surgical and transcatheter - since it has been associated with worse clinical outcomes.

AREAS COVERED

This review aims to comprehensively summarize the available evidence regarding the management of aortic stenosis in patients with SAA and discuss the current controversies as well as future perspectives in this field.

EXPERT OPINION

It is paramount to agree in a common definition for diagnosing and properly treating SAA patients, and for that purpose, multidetector computer tomography is essential. The results of recent trials led to the expansion of transcatheter aortic valve replacement among patients of all the surgical-risk spectrum, and the choice of treatment (transcatheter, surgical) should be based on patient comorbidities, anatomical characteristics, and patient preferences.

Efficacy of larger valve sizing with underfilling in balloon-expandable transcatheter aortic valve replacement

OBJECTIVES

To investigate the efficacy and safety of larger valve sizing beyond the commercially recommended annular range in transcatheter aortic valve replacement (TAVR) with balloon-expandable transcatheter heart valve (THVs).

BACKGROUND

The clinical implications of larger balloon-expandable THV implantation with underfilling are poorly evaluated.

METHODS

This retrospective study included 692 consecutive patients who underwent TAVR with SAPIEN3. A total of 271 patients who underwent SAPIEN 3 implantation were analyzed based on three border zones (Zone 1: 300-345 mm² , 23 vs. 20 mm; Zone 2: 400-430 mm² , 26 vs. 23 mm; Zone 3: 500-546 mm² , 29 vs. 26 mm). The primary endpoint was the effective orifice area (EOA) assessed by echocardiography at 1 year, and secondary endpoints were a 30-day mortality rate, procedural complications during TAVR, and a composite of death from any cause and heart failure requiring rehospitalization at 1 year.

RESULTS

At 1-year follow-up, the EOA in the larger valve groups was greater than that in the recommended valve group in each zone (Zone 1: 1.45 ± 0.03 vs. 1.06 ± 0.06 cm² , p < 0.001; Zone 2: 1.83 ± 0.05 vs. 1.41 ± 0.05 cm² , p < 0.001; Zone 3: 1.93 ± 0.07 vs. 1.69 ± 0.07 cm² , p = 0.02). No significant difference in the secondary endpoint was observed in any of the zones.

CONCLUSIONS

Implantation of the out-of-range larger SAPIEN 3 THVs with underfilling was associated with greater EOA at the 1-year follow-up and feasible in the selected patients.

Impact of Valve Size on Paravalvular Leak and Valve Hemodynamics in Patients With Borderline Size Aortic Valve Annulus

Background

Transcatheter heart valve (THV) selection for transcatheter aortic valve implantation (TAVI) is crucial to achieve procedural success. Borderline aortic annulus size (BAAS), which allows a choice between two consecutive valve sizes, is a common challenge during device selection. In the present study, we evaluated TAVI outcomes in patients with BAAS according to THV size selection.

Methods

We performed a retrospective study including patients with severe aortic stenosis (AS) and BAAS, measured by multi-detector computed tomography (MDCT), undergoing TAVI with self-expandable (SE) or balloon-expandable (BE) THV from the Israeli multi-center TAVI registry. The aim was to evaluate outcomes of TAVI, mainly paravalvular leak (PVL) and valve hemodynamics, in patients with BAAS (based on MDCT) according to THV sizing selection in between 2 valve sizes. In addition, to investigate the benefit of shifting between different THV types (BE and SE) to avoid valve size selection in BAAS.

Results

Out of 2,352 patients with MDCT measurements, 598 patients with BAAS as defined for at least one THV type were included in the study. In BAAS patients treated with SE-THV, larger THV selection was associated with lower rate of PVL, compared to smaller THV (45.3 vs. 64.5%; pv = 0.0038). Regarding BE-THV, larger valve selection was associated with lower post-procedural transvalvular gradients compared to smaller THV (mean gradient: 9.9 ± 3.7 vs. 12.5 ± 7.2 mmHg; p = 0.019). Of note, rates of mortality, left bundle branch block, permanent pacemaker implantation, stroke, annular rupture, and/or coronary occlusion did not differ between groups.

Conclusion

BAAS is common among patients undergoing TAVI. Selection of a larger THV in these patients is associated with lower rates of PVL and optimized THV hemodynamics with no effect on procedural complications. Additionally, shift from borderline THV to non-borderline THV modified both THV hemodynamics and post-dilatation rates.

Haemodynamic differences between two generations of a balloon-expandable transcatheter heart valve

OBJECTIVES

This study aimed to investigate early haemodynamic and clinical performance of the SAPIEN 3 Ultra (S3 Ultra) transcatheter heart valve (THV) system in comparison to its precursor, the SAPIEN 3 (S3). Previous studies have indicated potential haemodynamic differences between the S3 Ultra and S3. Such differences may impact clinical outcome after transcatheter aortic valve implantation (TAVI).

METHODS

Postprocedural haemodynamic performance and 30-day clinical outcome were compared in patients who underwent TAVI receiving either the S3 or the new S3 Ultra prostheses. Multivariable analysis and propensity score matching (PSM) were used to identify factors associated with higher mean transvalvular gradients.

RESULTS

We included 697 patients (S3 Ultra: n=314, S3: n=383) from the multicentre RhineHeart TAVI Registry. Patients receiving the S3 Ultra prosthesis showed significantly higher postprocedural mean transvalvular gradients (14.2±4.8 vs 10.2±4.4 mm Hg; p<0.01). Multivariable logistic regression analyses and additional PSM revealed the use of the S3 Ultra to be associated with higher postprocedural mean transvalvular gradients (p<0.01). 30-day clinical outcomes, such as mortality, myocardial infarction, permanent pacemaker implantation and vascular complications were comparable between the groups.

CONCLUSIONS

The new S3 Ultra THV was associated with a higher postprocedural mean transvalvular gradient compared with the S3 system, while there was no difference in mortality or adverse clinical outcomes at 30 days. These echocardiographic differences will require long-term studies to assess the clinical relevance of this finding.