Incidence and clinical outcome of prosthesis-patient mismatch after transcatheter aortic valve implantation with the CoreValve prosthesis

Biomechanics of Transcatheter Aortic Valve Replacement Complications and Computational Predictive Modeling

Transcatheter aortic valve replacement (TAVR) is a rapidly growing field enabling replacement of diseased aortic valves without the need for open heart surgery. However, due to the nature of the procedure and nonremoval of the diseased tissue, there are rates of complications ranging from tissue rupture and coronary obstruction to paravalvular leak, valve thrombosis, and permanent pacemaker implantation. In recent years, computational modeling has shown a great deal of promise in its capabilities to understand the biomechanical implications of TAVR as well as help preoperatively predict risks inherent to device-patient-specific anatomy biomechanical interaction. This includes intricate replication of stent and leaflet designs and tested and validated simulated deployments with structural and fluid mechanical simulations. This review outlines current biomechanical understanding of device-related complications from TAVR and related predictive strategies using computational modeling. An outlook on future modeling strategies highlighting reduced order modeling which could significantly reduce the high time and cost that are required for computational prediction of TAVR outcomes is presented in this review paper. A summary of current commercial/in-development software is presented in the final section.

Patient Prosthesis Mismatch After SAVR and TAVR

Patient-prosthesis mismatch (PPM) remains one out of many factors to be considered during decision-making for the treatment of aortic valve pathologies. The idea of adequate sizing of a prosthetic heart valve was established by Rahimtoola already in 1978. In this article, the author described the phenomenon that the orifice area of a prosthetic heart valve may be too small for the individual patient. PPM is assessed by measurement or projection of the prosthetic effective orifice area indexed to body surface area (iEOA), while it is recommended to use different cut point values for non-obese and obese patients for the categorization of moderate and severe PPM. Several factors influence the accuracy of both the projected and the measured iEOA for PPM assessment, which leads to a certain number of false assignments to the PPM or no PPM group. Despite divergent findings on the impact of PPM on clinical outcomes, there is consensus that PPM should be avoided to prevent sequelae of increased prosthetic gradients after aortic valve replacement. To prevent PPM, it is required to anticipate the iEOA of the prosthesis prior to the procedure. The use of adequate reference tables, derived from echocardiographically measured mean effective orifice area (EOA) values from preferably large numbers of patients, is most appropriate to predict the iEOA. Such tables should be used also for transcatheter heart valves in the future. During the decision-making process, all available options should be taken into account for the individual patient. If the predicted size and type of a surgical prosthesis cannot be implanted, additional surgical procedures, such as annular enlargement with the Manougian technique, or alternative procedures, such as transcatheter aortic valve implantation (TAVI) can prevent PPM. PPM prevention for TAVI patients is a new field of interest and includes anticipation of the iEOA, prosthesis selection, and procedural strategies.

Prevalence and Significance of Patient Prosthesis Mismatch Following Edwards SAPIEN XT and SAPIEN 3 Transcatheter Aortic Valve Replacement

Background

Severe patient prosthesis mismatch (sPPM) after surgical aortic valve replacement is associated with worse outcomes. Limited data exists on the impact of sPPM on outcomes after transcatheter aortic valve replacement (TAVR), especially regarding the newer generation valves. The aim of this study was to evaluate the incidence, determinants, and outcomes of sPPM in patients undergoing TAVR with Edwards SAPIEN XT (ES XT) and Edwards SAPIEN 3 (ES3) valves (Edwards Lifesciences, Irvine, CA, USA).

Methods

We retrospectively reviewed 366 patients who underwent TAVR with ES XT (n = 114) or ES3 (n = 252) valves between July 2012 and June 2018. sPPM was defined as indexed effective orifice area (iEOA) <0.65 cm²/m². Kaplan-Meier survival estimates were used to determine outcomes.

Results

Multivariate linear regression analysis was utilized to determine potential independent effects of PPM on outcomes. sPPM was present in 40 (11%) of the patients [8 (7%) ES XT and 32 (13%) ES3] and was associated with female sex, smaller left ventricular outflow tract (LVOT) diameter and aortic valve annular area, absence of prior coronary artery bypass graft (CABG) surgery, shorter height, higher body mass index, and smaller pre-TAVR valve area (all p < 0.05). Among those with ES3 valves, the incidence of sPPM was inversely proportional to the valve size (50%, 25%, 5% and 3% for 20-, 23-, 26- and 29-mm valve sizes, respectively; p < 0.001). At a mean follow-up period of 3.5 ± 1.5 years, there was no difference in all-cause mortality (22.5% vs. 25.6%, p = 0.89) or a composite endpoint of heart failure, arrhythmias, stroke, and myocardial infarction (30% vs. 34%, p = 0.24) in those with or without sPPM.

Conclusion

ES3 was associated with a higher incidence of sPPM, particularly with smaller valve sizes. However, the presence of sPPM as defined by iEOA was not an independent predictor of adverse outcomes in patients undergoing TAVR within an intermediate follow-up period.

Transcatheter Aortic Valve Replacement in Patients With a Small Annulus - From the Japanese Nationwide Registry (J-TVT)

BACKGROUND

The details and consequences of a small aortic annulus among transcatheter aortic valve replacement (TAVR) patients remain uncertain. This study investigated the short-term outcomes in patients with small annular size and compared the 30-day outcome between intra- and supra-annular devices, with similar outer casing diameter in this subgroup.Methods and Results:Cases registered in the Japanese national TAVR registry between August 2013 and December 2017 were analyzed. Among a total of 5,870 registered patients, 647 (11.0%) had small annulus (area ≤314 mm²) measured by multi-detector computed tomography. Patients with a small annulus had a significantly smaller indexed effective orifice area (iEOA, 1.10 cm²/m²[0.92-1.35] vs. 1.16 cm²/m²[0.96-1.39], P<0.001) and higher mean pressure gradient (mPG, 10.0 mmHg [6.9-14.2] vs. 8.5 mmHg [6.0-11.5], P<0.001) compared with a normal-sized annulus. Among patients with a small annulus, those receiving a 20 mm intra-annular device had a smaller iEOA (0.94 cm²/m²[0.78-1.06] vs. 1.07 cm²/m²[0.8-1.24], P=0.001) and higher mPG (14.0 mmHg [10.0-18.5] vs. 11.0 [7.0-14.0], P<0.001) compared with those receiving a 23-mm supra-annular device, although the incidence of paravalvular leakage (≥moderate) was similar (14.4% vs. 16.5%, P=0.69).

CONCLUSIONS

Patients with a small annulus were associated with less hemodynamic improvement. A supra-annular device is associated with better echocardiographic improvement in patients with a small annulus, without increasing paravalvular leakage.

Effective Orifice Area of Balloon-Expandable and Self-Expandable Transcatheter Aortic Valve Prostheses: An Echo Doppler Comparative Study

Published data on the size-specific effective orifice area (EOA) of transcatheter heart valves (THVs) remain scarce. Here, we sought to investigate the intra-individual changes in EOA and mean transvalvular aortic gradient (MG) of the Sapien 3 (S3), CoreValve (CV), and Evolut R (EVR) prostheses both at short-term and at 1-year follow-up. The study sample consisted of 260 consecutive patients with severe aortic stenosis who underwent transcatheter aortic valve implantation (TAVI). EOAs and MGs were measured with Doppler echocardiography for the following prostheses: S3 23 mm (n = 74; 28.5%), S3 26 mm (n = 67; 25.8%), S3 29 mm (n = 20; 7.7%), CV 23 mm (n = 2; 0.8%), CV 26 mm (n = 15; 5.8%), CV 29 mm (n = 24; 9.2%), CV 31 mm (n = 9; 3.5%), EVR 26 mm (n = 22; 8.5%), and EVR 29 mm (n = 27; 10.4%). Values were obtained at discharge, 1 month, 6 months, and 1 year from implantation. At discharge, EOAs were larger and MGs lower for larger-size prostheses, regardless of being balloon-expandable or self-expandable. In patients with small aortic annulus size, the hemodynamic performances of CV and EVR prostheses were superior to those of S3. However, we did not observe significant differences in terms of all-cause mortality according to THV type or size. Both balloon-expandable and self-expandable new-generation THVs show excellent hemodynamic performances without evidence of very early valve degeneration.

Impact of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Replacement on Changes in Cardiac Sympathetic Nervous Function

The impact of prosthesis-patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR) on changes in cardiac sympathetic nervous (CSN) function remains unclear. Using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, we investigated the impact of PPM after TAVR on CSN activity.We enrolled 44 of 117 patients with severe aortic stenosis who underwent TAVR for analysis in the present study. We conducted 123I-MIBG scintigraphy at baseline and at about 9 months after TAVR. Differences between baseline and post-TAVR 123I-MIBG parameters were compared between cases with and without PPM.There were 17 and 27 patients with and without PPM, respectively. Those without PPM exhibited significantly decreased left ventricular mass index (122 ± 36 g/m² versus 108 ± 30 g/m², P < 0.001) following TAVR, whereas those with PPM did not (117 ± 21 g/m² versus 110 ± 17 g/m², P = 0.09). Significant improvements in delayed heart-to-mediastinum (H/M) ratio (2.8 ± 0.4 versus 3.0 ± 0.4, P = 0.004) and washout rate (WR) (33% ± 10% versus 24% ± 12%, P < 0.001) were observed after TAVR in patients without PPM but not in those with PPM. Multivariable linear regression analysis revealed PPM to be a negative predictor of improvements in delayed H/M ratio and WR.Delayed H/M ratio and WR improve significantly after TAVR in the absence of PPM, whereas these improvements are not observed in patients with PPM. Hence, the presence of PPM is a negative predictor of improvements in delayed H/M ratio and WR in patients undergoing TAVR.

Incidence, predictors, and outcome of prosthesis-patient mismatch after transcatheter aortic valve replacement: A meta-analysis

BACKGROUND

Prosthesis-patient mismatch (PPM) following transcatheter aortic valve replacement (TAVR) is common, but the incidence, predictors and outcome of PPM are still controversial.

METHODS

A total of 18 articles incorporating 72,016 patients were identified form PubMed and Embase online database.

RESULTS

The pooled incidences of overall, and severe PPM following TAVR were 32.0% and 10.0% separately. Comparing to surgical aortic valve replacement (SAVR), TAVR had lower incidence of overall (OR, 0.31, 95% CI, 0.20-0.50) and severe PPM (OR, 0.38, 95% CI, 0.28-0.52). PPM was associated with a larger body surface area (BSA), larger body mass index (BMI) and previous myocardial infarction in comparison with those patients without PPM. Although PPM was not rare after TAVR, no significant differences were observed both in short- and mid-term all-cause mortality (30 day: OR: 1.51, 95% CI, 0.79-2.87, 1 year: OR: 1.02, 95% CI, 0.96-1.08, and 2 years: OR: 0.99, 95% CI, 0.79-1.24) between patients with PPM and those without PPM.

CONCLUSIONS

Despite the fact that the incidence of PPM was lower than that of SAVR, PPM was not seen to have an impact on short- and mid-term survival.

Imaging for Predicting and Assessing Prosthesis-Patient Mismatch After Aortic Valve Replacement

Prosthesis-patient mismatch (PPM) occurs when the effective orifice area (EOA) of the prosthetic valve is too small in relation to a patient's body size, thus resulting in high residual postoperative pressure gradients across the prosthesis. Severe PPM occurs in 2% to 20% of patients undergoing surgical aortic valve replacement (AVR) and is associated with 1.5- to 2.0-fold increase in the risk of mortality and heart failure rehospitalization. The purpose of this article is to present an overview of the role of multimodality imaging in the assessment, prediction, prevention, and management of PPM following AVR. The risk of PPM can be anticipated at the time of AVR by calculating the predicted indexed from the normal reference value of EOA of the selected prosthesis and patient's body surface area. The strategies to prevent PPM at the time of surgical AVR include: 1) implanting a newer generation of prosthetic valve with better hemodynamic; 2) enlarging the aortic root or annulus to accommodate a larger prosthetic valve; or 3) performing TAVR rather than surgical AVR. The identification and quantitation of PPM as well as its distinction versus prosthetic valve stenosis is primarily based on transthoracic echocardiography, but important information may be obtained from other imaging modalities such as transesophageal echocardiography and multidetector computed tomography. PPM is characterized by high transprosthetic velocity and gradients, normal EOA, small indexed EOA, and normal leaflet morphology and mobility. Transesophageal echocardiography and multidetector computed tomography are particularly helpful to assess prosthetic valve leaflet morphology and mobility, which is a cornerstone of the differential diagnosis between PPM and pathologic valve obstruction. Severe symptomatic PPM following AVR with a bioprosthetic valve may be treated by redo surgery or the transcatheter valve-in-valve procedure with fracturing of the surgical valve stent.

Impact of Prosthesis-Patient Mismatch on 1-Year Outcomes after Transcatheter Aortic Valve Implantation: Meta-analysis of 71,106 Patients

OBJECTIVES

This study sought to evaluate the impact of prosthesis-patient mismatch (PPM) on the risk of early-term mortality after transcatheter aortic valve implantation (TAVI).

METHODS

Databases (Medical Literature Analysis and Retrieval System Online [MEDLINE], Excerpta Medica dataBASE [EMBASE], Cochrane Controlled Trials Register [CENTRAL/CCTR], ClinicalTrials.gov, Scientific Electronic Library Online [SciELO], Latin American and Caribbean Literature on Health Sciences [LILACS], and Google Scholar) were searched for studies published until February 2019. PPM after TAVI was defined as moderate if the indexed effective orifice area (iEOA) was between 0.85 cm2/m2 and 0.65 cm2/m2 and as severe if iEOA ≤ 0.65 cm2/m2.

RESULTS

The search yielded 1,092 studies for inclusion. Of these, 18 articles were analyzed, and their data extracted. The total number of patients included who underwent TAVI was 71,106. The incidence of PPM after TAVI was 36.3% (25,846 with PPM and 45,260 without PPM). One-year mortality was not increased in patients with any PPM (odds ratio [OR] 1.021, 95% confidence interval [CI] 0.979-1.065, P=0.338) neither in those with moderate PPM (OR 0.980, 95% CI 0.933-1.029, P=0.423). Severe PPM was separately associated with high risk (OR 1.109, 95% CI 1.041-1.181, P=0.001).

CONCLUSION

The presence of severe PPM after TAVI increased early-term mortality. Although moderate PPM seemed harmless, the findings of this study cannot not rule out the possibility of it being detrimental, since there are other registries that did not address this issue yet.

Patient-prosthesis mismatch in patients treated with transcatheter aortic valve implantation - predictors, incidence and impact on clinical efficacy. A preliminary study

Introduction

Patient-prosthesis mismatch (PPM) is relatively frequent after surgical aortic valve replacement (SAVR) and negatively impacts prognosis.

Aim

We sought to determine the frequency and clinical effects of PPM after transcatheter aortic valve implantation (TAVI).

Material and methods

Overall, 238 patients who underwent TAVI were screened. Moderate PPM was defined as indexed effective orifice area (EOAi) between 0.65 and 0.85 cm²/m², and severe PPM as < 0.65 cm²/m². All-cause mortality and the Valve Academic Research Consortium 2 (VARC-2) defined composite of clinical efficacy at 1 year were the primary endpoints.

Results

Finally, 201 patients were included (mean age: 79.6 ±7.4 years, 52% females). The femoral artery served as the delivery route in 79% and most of the prostheses were self-expanding (68%). Any PPM was present in 48 (24%) subjects, and only 7 (3.5%) had severe PPM. Body surface area (BSA) independently predicted any PPM (OR = 16.9, p < 0.001) whereas post-dilation tended to protect against PPM (OR = 0.46, p = 0.09). All-cause mortality was similar in patients with moderate or severe PPM as compared to those with no PPM (14.6% vs. 14.3% vs. 13.1%, respectively, log-rank p = 0.98). Neither moderate (OR = 1.6, 95% CI: 0.8-3.2, p = 0.16) nor severe PPM (OR = 1.67, 95% CI: 0.36-7.7, p = 0.51) had a significant impact on composite endpoint, or its elements, with the exception of transvalvular pressure gradient > 20 mm Hg.

Conclusions

Severe PPM after TAVI is rare, can be predicted by larger BSA and does not seem to affect mid-term mortality or composite clinical outcome. Larger studies are needed to find different independent predictors of PPM and elucidate its impact in terms of device durability and long-term clinical efficacy.

Incidence, Predictors and Outcome of Prosthesis-Patient Mismatch after Transcatheter Aortic Valve Replacement: a Systematic Review and Meta-analysis

The aim of this study was to investigate the incidence, predictors and outcome of prosthesis-patient mismatch (PPM) following transcatheter aortic valve replacement (TAVR). A total of 30 articles incorporating 4,691 patients were identified. The pooled incidences of overall, moderate and severe PPM following TAVR were 33.0%, 25.0% and 11.0% respectively. Medtronic CoreValve (MCV) had lower incidence of overall (32% vs: 40%, P < 0.0001) and moderate (23% vs 32%, P < 0.0001) than Edwards Sapien (ESV). PPM was associated with a younger age, smaller annulus diameter and lower left ventricular ejection fraction in comparison with those patients without PPM. Post-dilation (OR, 0.51, 95% CI, 0.38 to 0.68, p < 0.001) during TAVR would decrease the incidence of PPM. Although PPM was common after TAVR, no significant differences were observed both in short- and mid-term all-cause mortality (30 day: OR: 1.1, 95% CI, 0.70 to 1.73 and 2 year: OR: 1.01, 95% CI, 0.74 to 1.38) between patients with PPM and those without PPM. In conclusion, despite being common after TAVR, the incidence of PPM was lower than that of surgical aortic valve replacement (SAVR) and decreased with the experience accumulating, and PPM was not seen to impact on short- and mid-term survival, regardless of its magnitude.

Prosthesis-patient mismatch in aortic stenosis

BACKGROUND

The clinical impacts of prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR) have been debated since Rahimtoola first reported PPM in 1978. Many reports discussing several aspects of PPM have been published to date, but the definitive clinical impacts of PPM have not yet been clarified.

PURPOSE

The purpose of this review is to evaluate recent articles regarding PPM and discuss the latest findings.

RESULTS

Moderate PPM (indexed effective orifice area ≤ 0.85 cm(2)/m(2)) did not affect the surgical outcomes in several papers, but severe PPM (indexed effective orifice area ≤ 0.65 cm(2)/m(2)) affected early and late mortality in almost of the all papers in which it was reported. PPM had a greater effect on younger patients and patients with left ventricular dysfunction than it did on elderly patients and patients with preserved left ventricular function.

CONCLUSION

Based on recent findings, it is difficult to define the impact of PPM after AVR. To some degree, PPM affects the clinical outcomes after AVR; therefore, it is important to avoid PPM, especially severe PPM.