Valve Prosthesis–Patient Mismatch, 1978 to 2011

Prosthesis-patient mismatch after transcatheter aortic valve implantation

Prosthesis-patient mismatch (PPM), first described in 1978, occurs when a prosthetic valve functions normally, but has an effective orifice area that is too small relative to the patient's body surface area. It results in residual left ventricular afterload and higher transvalvular pressure gradient, which has been considered to impair prognosis. PPM following surgical aortic replacement is reportedly associated with worse clinical outcomes, such as high mortality. However, the impact of PPM on clinical outcomes after transcatheter aortic valve implantation (TAVI) remains unclear. There is conflicting evidence on the impact of PPM following TAVI due to differences across studies in terms of follow-up period, methods, patient populations, and type of bioprosthetic valve. The present review summarizes the most recent evidence on PPM after TAVI.

Patient Prosthesis Mismatch

Concept of patient prosthesis mismatch came into existence from 1978 onward when Rahimtoola first defined it as “mismatch can be considered to be present when the effective prosthetic valve area, after insertion into the patient, is less than that of a normal human valve.” Patient prosthesis mismatch produces higher than expected pressure gradient through normally functioning valve. Since insertion of first ball caged mechanical valve in descending aorta by Dr. Charles Hufnagel in 1952, prosthetic valve had undergone tremendous improvement in terms of valve design, hemodynamics, durability, and thrombogenicity. Despite these marked changes in valve design, prosthetic valves are still subjected to inherent complications.

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.

Patient–Prosthesis Mismatch in Contemporary Small-Size Mechanical Prostheses Does Not Impact Survival at 10 Years

Background: The effect of PPM in mechanical prostheses on long-term survival is not well-established. Methods: Patients who received a 21 mm or smaller aortic valve between 2000 and 2011 were retrospectively analyzed (n = 416). Propensity matching was used in order to account for baseline differences in patient subgroups (PPM vs. no PPM; severe PPM vs. no severe PPM). Results: Five- and ten-year survival was 78 ± 3.52% and 64.51 ± 4.51% in patients with PPM, versus 83.3 ± 3.12% and 69.37 ± 4.36% in patients without (p = 0.28) when analyzed at 10.39 ± 5.25 years after the primary procedure. Independent risk factors for impaired survival, after matching, were age, serum creatinine, and severe pulmonary hypertension. Five- and ten-year survival in patients with severe PPM was 73.34 ± 6.01% and 61.76 ± 8.17%, respectively, versus 74.72 ± 5.68% and 67.50 ± 7.09% in those without (p = 0.49), at 8.82 ± 5.17 years after SAVR. Age was the only independent variable that influenced long-term survival when severe PPM was added to the model. Conclusions: PPM or severe PPM does not impact long-term survival up to 10 years in mechanical valve recipients when matching for preoperative variables.

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.

Impact of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Replacement in Asian Patients

BACKGROUND

Little is known about the incidence of prosthesis-patient mismatch (PPM) and its impact following transcatheter aortic valve replacement with self-expanding valves in Asian population. We aimed to assess post-procedural effective orifice area with standardized methods and the impact of PPM on mid-term outcomes after CoreValve/Evolut R implantation in Asian population.

METHODS

Among 201 consecutive patients undergoing CoreValve/Evolut R implantation, PPM was assessed at 30 days and defined based on core lab-measured indexed effective orifice area as severe (< 0.65 cm²/m²) or moderate (0.65 to 0.85 cm²/m²). Multivariable regression models were utilized to examine predictors of PPM as well as mortality and rehospitalization for heart failure at mid-term follow-up.

RESULTS

Moderate and severe PPM were observed following self-expanding valves in 37 (18.4%) and 3 (1.5%) patients, respectively. These 40 patients were included in the PPM group. Predictors of PPM included female, larger body surface area, and lower left ventricular ejection fraction. At mid-term (median 30.4 months, interquartile range 17.0 to 57.8 months) follow-up, patients with PPM had an increased risk of all-cause death (adjusted hazard ratio [aHR]: 1.95; 95% CI: 1.08 to 3.53; P = 0.027), cardiovascular mortality (aHR: 3.38; 95% CI: 1.04 to 10.99; P = 0.043), and rehospitalization for heart failure (aHR: 2.40; 95% CI: 1.11 to 5.17; P = 0.025).

CONCLUSIONS

PPM was associated with higher mid-term mortality and rehospitalization for heart failure in Asian population. The expected post-procedural effective orifice area for any given valve size may be helpful in pre-procedural decision-making to avoid PPM.

The fallacy of indexed effective orifice area charts to predict prosthesis-patient mismatch after prosthesis implantation

Aims 

Indexed effective orifice area (EOAi) charts are used to determine the likelihood of prosthesis–patient mismatch (PPM) after aortic valve replacement (AVR). The aim of this study is to validate whether these EOAi charts, based on echocardiographic normal reference values, can accurately predict PPM.

Methods and results 

In the PERIcardial SurGical AOrtic Valve ReplacemeNt (PERIGON) Pivotal Trial, 986 patients with aortic valve stenosis/regurgitation underwent AVR with an Avalus valve. Patients were randomly split (50:50) into training and test sets. The mean measured EOAs for each valve size from the training set were used to create an Avalus EOAi chart. This chart was subsequently used to predict PPM in the test set and measures of diagnostic accuracy (sensitivity, specificity, and negative and positive predictive value) were assessed. PPM was defined by an EOAi ≤0.85 cm²/m^2, and severe PPM was defined as EOAi ≤0.65 cm²/m². The reference values obtained from the training set ranged from 1.27 cm² for size 19 mm up to 1.81 cm² for size 27 mm. The test set had an incidence of 66% of PPM and 24% of severe PPM. The EOAi chart inaccurately predicted PPM in 30% of patients and severe PPM in 22% of patients. For the prediction of PPM, the sensitivity was 87% and the specificity 37%. For the prediction of severe PPM, the sensitivity was 13% and the specificity 98%.

Conclusion 

The use of echocardiographic normal reference values for EOAi charts to predict PPM is unreliable due to the large proportion of misclassifications.

Clinical and Technical Challenges of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Implantation

Prosthesis-patient mismatch (PPM) is present when the effective area of a prosthetic valve inserted into a patient is inferior to that of a normal human valve; the hemodynamic consequence of a valve too small compared with the size of the patient's body is the generation of higher than expected transprosthetic gradients. Despite evidence of increased risk of short- and long-term mortality and of structural valve degeneration in patients with PPM after surgical aortic valve replacement, its clinical impact in patients subject to transcatheter aortic valve implantation (TAVI) is yet unclear. We aim to review and update on the definition and incidence of PPM after TAVI, and its prognostic implications in the overall population and in higher-risk subgroups, such as small aortic annuli or valve-in-valve procedures. Last, we will focus on the armamentarium available in order to reduce risk of PPM when planning a TAVI procedure.

Prosthesis-patient mismatch after surgical aortic valve replacement in patients with aortic stenosis

OBJECTIVES

The issue of prosthesis-patient mismatch (PPM) after surgical aortic valve replacement (SAVR) has been a controversial topic. We sought to evaluate the long-term clinical impacts of PPM in patients undergoing SAVR in an updated, homogeneous cohort.

METHODS

Using the prospective institutional database, we identified 895 adult patients (median age 66, interquartile range 58-72; 45.6% women) who underwent isolated SAVR from January 2000 to March 2016. Those with pure aortic insufficiency and concomitant other cardiac operations were excluded from this study cohort. The presence of a significant PPM was defined as an indexed effective orifice area 0.85 cm2/m2 or less. The outcome of interest was all-cause deaths. Propensity score matching was performed for adjusting bias.

RESULTS

Significant PPM was present in 247 patients (27.6%). During the follow-up period (mean 71.2 ± 51.04 months), 134 patients (15%) died. Survival rates at 10 and 15 years were 78.3% vs 83.8% and 71.3% vs 57.6% in the PPM and non-PPM groups (P = 0.972). Risk factor analysis indicated that developing PPM was not associated with a risk of death. After propensity score matching (1:1), developing PPM was not a risk factor for long-term death as well (P = 0.584).

CONCLUSIONS

Significant PPM was common after SAVR in patients with aortic stenosis. However, there was no significant difference in survival rate between those with and without PPM.

Impact of valve size, predicted effective and indexed effective orifice area after aortic valve replacement

INTRODUCTION

The impact of manufacturer labeled prosthesis size and predicted effective orifice area (EOA) on long-term survival after aortic valve replacement is not clear although indexed effective orifice area (iEOA) has been associated with worse survival.

METHODS

Data was retrospectively collected from Jan 2000-Dec 2019 for prosthesis type, model, and size for isolated aortic valve replacements. Stratified survival was compared between groups and subgroups for labeled valve size, EOA and predicted patient prosthesis mismatch (PPM).

RESULTS

A total of 3444 patients were included. Moderate and severe PPM was 15.6% and 1.6%, respectively. Cumulative lifetime hazard was worse for biological valves (mortality: biological 77.7% vs. mechanical 64.8%, p = .001). Moderate prosthetic aortic stenosis (AS), (EOA = 1-1.5 cm² ) was 12.1% and severe prosthetic AS (EOA ≤ 1 cm² ) was 0.8%, respectively. Survival was 10.5 ± 0.4 years with moderate to severe prosthetic AS (EOA≤1.5 cm² ) versus 12.6 ± 0.2 years with mild to no prosthetic AS (EOA>1.5 cm² ), p = .001. Worse survival in the presence of moderate-severe prosthetic AS was seen with biological valves (9.7 ± 0.4 years vs. 11.2 ± 0.2 years, p = .001 for EOA≤1.5, >1.5 cm² , respectively). Moderate to severe PPM was associated with worse survival (11.1 ± 0.4 years for iEOA ≤ 0.85 cm² /m² vs. 12.5 ± 0.2 years with iEOA > 0.85 cm² /m² , p = .001). Moderate to severe PPM predicted worse long term survival (hazard ratio: 3.56; 95% confidence interval: 1.37-9.25; p = .009).

CONCLUSION

Predicted prosthetic moderate to severe AS and moderate to severe PPM adversely affect long term survival. Smaller valves are associated with reduced survival.

Perceval or Trifecta to Prevent Patient-Prosthesis Mismatch

The Trifecta aortic valve has excellent hemodynamics characteristics. Moreover, the Perceval prosthesis may achieve better hemodynamics than the conventional valves; therefore, it has been proposed to reduce the incidence of patient-prosthesis mismatch. Our aim was to compare the prevalence of this complication between both prostheses. All patients who underwent valve replacement with a Perceval or a Trifecta from 2016 to 2020 at our institution were included. We calculated the prevalence of patient-prosthesis mismatch for each prosthesis and size and performed a multinomial logistic regression model to investigate the impact of choosing one prosthesis over the other. A total of 516 patients were analyzed. Moderate mismatch was present in 33 (8.6%) in the Trifecta group and 28 (21.4%) in the Perceval group, p < 0.001. Severe mismatch was present in 8 (2.1%) patients with Trifecta and 5 (3.8%) patients with Perceval, p = 0.33. Compared with the Perceval, the Trifecta prosthesis was shown to reduce moderate patient-prosthesis mismatch: OR = 0.5 (95% CI 0.3-0.9, p = 0.02). Both prostheses led to a similar risk of severe patient-prosthesis mismatch: OR = 0.9 (95% CI 0.3-2.8, p = 0.79). Both prostheses provide a very low risk of severe patient-prosthesis mismatch. Compared with the Perceval prothesis, the Trifecta prosthesis is able to reduce by 50% the risk of moderate mismatch.

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.

Determinants of Aortic Prosthesis Mismatch in a Brazilian Public Health System Hospital: Big Patients or Small Prosthesis?

Background

Prosthesis-patient mismatch (PPM) is associated with worse outcomes.

Objective

Determine the frequency and evaluate preoperatory variables independently associated with severe PPM in a tertiary hospital focused on Public Health Care.

Methods

A total of 316 patients submitted to aortic valve replacement, who had echocardiography performed within the first 30 days after surgery, were retrospectively analyzed. The indexed effective orifice area (iEOA) of the prosthesis was used to classify the patients into three groups, according to PPM, considering body mass index (BMI): severe PPM (iEOA) < 0.65 cm²/m²), mild to moderate PPM (iEOA, 0.65 cm²/m² - 0.85 cm²/m²) and without PPM (iEOA > 0.85 cm²/m²) for a BMI < 30 kg/m² and severe PPM (iEOA) < 0.55 cm²/m²), mild to moderate (iEOA, 0.55 cm²/m²- 0.70 cm²/m²) and without PPM (iEOA > 0.7 cm²/m²) for a BMI > 30 kg/m². Statistical significance was considered when p < 0.05.

Results

iEOA was obtained in 176 patients. The frequency of severe and moderate PPM was 33.4% and 36.2%, respectively. Severe PPM patients were younger and had larger BMI, but smaller left ventricular outflow tract diameter (LVOTD). The independent variables used to predict severe PPM were male gender, BMI > 25 kg/m², age < 60 years, LVOTD < 21 mm, and rheumatic etiology with an area under the ROC curve of 0.82.

Conclusion

The frequency of severe PPM is high in a Brazilian population representative of the Public Health System, and it is possible to predict PPM from preoperative variables such as rheumatic valvular disease, gender, BMI, age and LVOTD.

Multimodality Imaging of Complications of Cardiac Valve Surgeries

Replacement with a prosthetic heart valve (PHV) remains the definitive surgical procedure for management of severe cardiac valve disease. PHV dysfunction is uncommon but can be a life-threatening condition. The broad hemodynamic and pathophysiologic manifestations of PHV dysfunction are stenosis, regurgitation, and a stuck leaflet. Specific structural abnormalities that cause PHV dysfunction include prosthetic valve-patient mismatch, structural failure, valve calcification, dehiscence, paravalvular leak, infective endocarditis, abscess, pseudoaneurysm, abnormal connections, thrombus, hypoattenuating leaflet thickening, and pannus. Multiple imaging modalities are available for evaluating a PHV and its dysfunction. Transthoracic echocardiography is often the first-line imaging modality, with additional modalities such as transesophageal echocardiography, CT, MRI, cine fluoroscopy, and nuclear medicine used for further characterization and establishing a specific cause. The authors review PHVs and the role of imaging modalities in evaluation of PHV dysfunction and illustrate the imaging appearances of different complications. Online supplemental material is available for this article. ^©RSNA, 2019.

Patient prosthesis mismatch after aortic valve replacement: An Indian perspective

CONTEXT

Perioperative period.

AIMS

Occurrence of PPM after AVR, factors associated with PPM, impact on mortality.

SETTINGS AND DESIGN

Teritary Care Referral Cardiac Centre.

MATERIALS AND METHODS

A retrospective analysis of AVR procedures at a single centre over 4 years was conducted. Demographic, echocardiographic and outcome data were collected from institute database. Rahimtoola criteria of indexed effective orifice area (iEOA) were used to stratify patients into PPM categories. Patients with and without PPM were compared for associated factors.

STATISTICAL ANALYSIS USED

Independent t-test, chi-square test, logistic regression analysis, ROC-AUC, Youden index.

RESULTS

606 patients with complete data were analysed for PPM. The incidence of mild, moderate and severe PPM was 6.1% (37), 2.5% (15) and 0.5% (3) respectively. There was no impact of PPM on all-cause in-hospital mortality. PPM was observed more with Aortic Stenosis (AS) compared to Aortic Regurgitation (AR) as etiology. Aortic annulus indexed to BSA (iAA) had a very good predictive ability for PPM at <16mm/m 2 BSA.

CONCLUSIONS

PPM has lower incidence after AVR in this Indian population and does not increase early mortality. Patients with AS and iAA<16mm/m2BSA should be cautiously dealt with to prevent PPM.

Does patient-prosthesis mismatch after aortic valve replacement affect survival and quality of life in elderly patients?

BACKGROUND

To evaluate the impact of patient-prosthesis mismatch (PPM) on survival, functional status, and quality of life (QoL) after aortic valve replacement (AVR) with small prosthesis size in elderly patients.

METHODS

Between January 2005 and December 2013, 152 patients with pure aortic stenosis, aged at least 75 years, underwent AVR, with a 19 or 21 mm prosthetic heart valve. PPM was defined as an indexed effective orifice area less than 0.85 cm/m. Median age was 82 years (range 75-93 years). Mean follow-up was 56 months (range 1-82 months) and was 98% complete. Late survival rate, New York Heart Association functional class, and QoL (RAND SF-36) were assessed.

RESULTS

Overall, PPM was found in 78 patients (53.8%). Among them, 42 patients (29%) had an indexed effective orifice area less than 0.75 cm/m and 17 less than 0.65 cm/m (11.7%). Overall survival at 5 years was 78 ± 4.5% and was not influenced by PPM (P = NS). The mean New York Heart Association class for long-term survivors with PPM improved from 3.0 to 1.7 (P < 0.001). QoL (physical functioning 45.18 ± 11.35, energy/fatigue 49.36 ± 8.64, emotional well being 58.84 ± 15.44, social functioning 61.29 ± 6.15) was similar to that of no-PPM patients (P = NS).

CONCLUSION

PPM after AVR does not affect survival, functional status, and QoL in patients aged at least 75 years. Surgical procedures, often time-consuming, contemplated to prevent PPM, may therefore be not justified in this patient subgroup.

Patient and procedure selection for the prevention of prosthesis-patient mismatch following aortic valve replacement

Prosthesis-patient mismatch (PPM) is frequent following surgical aortic valve replacement (SAVR) and is associated with an increased risk of morbidity and mortality. Preventive strategies to avoid or minimise PPM should be implemented in patients who are at high risk (i.e., patients with a small aortic annulus or those undergoing a valve-in-valve procedure within a small surgical bioprosthesis) and/or vulnerable to PPM (i.e., depressed left ventricular [LV] systolic function, severe LV hypertrophy, concomitant mitral regurgitation, and paradoxical low-flow, low-gradient aortic stenosis). Recent studies suggest that transcatheter aortic valve replacement (TAVR) may be superior to SAVR for the prevention of PPM and associated adverse cardiac events, particularly in the subset of patients with a small (<21 mm) aortic annulus. However, further randomised studies are needed to confirm the potential superiority of TAVR for this purpose.

Incidence, Timing, and Predictors of Valve Hemodynamic Deterioration After Transcatheter Aortic Valve Replacement: Multicenter Registry

BACKGROUND

Scarce data exist on the incidence of and factors associated with valve hemodynamic deterioration (VHD) after transcatheter aortic valve replacement (TAVR).

OBJECTIVES

This study sought to determine the incidence, timing, and predictors of VHD in a large cohort of patients undergoing TAVR.

METHODS

This multicenter registry included 1,521 patients (48% male; 80 ± 7 years of age) who underwent TAVR. Mean echocardiographic follow-up was 20 ± 13 months (minimum: 6 months). Echocardiographic examinations were performed at discharge, at 6 to 12 months, and yearly thereafter. Annualized changes in mean gradient (mm Hg/year) were calculated by dividing the difference between the mean gradient at last follow-up and the gradient at discharge by the time between examinations. VHD was defined as a ≥10 mm Hg increase in transprosthetic mean gradient during follow-up compared with discharge assessment.

RESULTS

The overall mean annualized rate of transprosthetic gradient progression during follow-up was 0.30 ± 4.99 mm Hg/year. A total of 68 patients met criteria of VHD (incidence: 4.5% during follow-up). The absence of anticoagulation therapy at hospital discharge (p = 0.002), a valve-in-valve (TAVR in a surgical valve) procedure (p = 0.032), the use of a 23-mm valve (p = 0.016), and a greater body mass index (p = 0.001) were independent predictors of VHD.

CONCLUSIONS

There was a mild but significant increase in transvalvular gradients over time after TAVR. The lack of anticoagulation therapy, a valve-in-valve procedure, a greater body mass index, and the use of a 23-mm transcatheter valve were associated with higher rates of VHD post-TAVR. Further prospective studies are required to determine whether a specific antithrombotic therapy post-TAVR may reduce the risk of VHD.

Geometric changes in ventriculoaortic complex after transcatheter aortic valve replacement and its association with post-procedural prosthesis-patient mismatch: an intraprocedural 3D-TEE study

AIMS

Prosthesis-patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR) leads to increased mortality. However, its peri-procedural determinants remain unknown. We investigated geometric changes in aortic annulus (AoA) and left ventricular outflow tract (LVOT) during TAVR by three-dimensional transoesophageal echocardiography (3D-TEE) and its association with post-procedural PPM.

METHODS AND RESULTS

A total of 131 patients with severe aortic stenosis underwent intraprocedural 3D-TEE during balloon-expandable TAVR. The severity of PPM was graded using the indexed effective orifice area calculated by Doppler echocardiography at discharge, with moderate defined as ≥0.65 and ≤0.85 cm²/m² and severe defined as <0.65 cm²/m². 3D planimetered AoA area decreased after TAVR (P< 0.001), whereas the LVOT increased (P= 0.004). The eccentricity of both AoA and LVOT decreased after TAVR (both, P< 0.001). At discharge, the incidence of overall and severe PPM was 44 and 12%, respectively. Patients with PPM had a larger body surface area, smaller aortic valve area, and less frequent balloon dilation (all P< 0.05). Patients with PPM had a lower post-TAVR AoA area/pre-TAVR AoA area (91 ± 8 vs. 95 ± 7%, P= 0.001) than those without PPM. The post-TAVR AoA area/pre-TAVR AoA area was independently associated with overall PPM (odds ratio, 1.80; 95% CI, 1.06-3.05; P= 0.031) and severe PPM (odds ratio, 2.50; 95% CI, 1.05-5.36; P= 0.04). Additionally, a cut-off value of this ratio >86.3% had a sensitivity of 84% and a specificity of 44% for the prevention of severe PPM.

CONCLUSION

3D-TEE can evaluate geometric changes in AoA and LVOT during balloon-expandable TAVR and predicts post-procedural PPM.

Aortic valve prosthesis-patient mismatch and exercise capacity in adult patients with congenital heart disease

OBJECTIVES

To report the prevalence of aortic valve prosthesis-patient mismatch (PPM) in an adult population with congenital heart disease (CHD) and its impact on exercise capacity. Adults with congenital heart disease (ACHD) with a history of aortic valve replacement may outgrow their prosthesis later in life. However, the prevalence and clinical consequences of aortic PPM in ACHD are presently unknown.

METHODS

From the national Dutch Congenital Corvitia (CONCOR) registry, we identified 207 ACHD with an aortic valve prosthesis for this cross-sectional cohort study. Severe PPM was defined as an indexed effective orifice area ≤0.65 cm2/m2 and moderate PPM as an indexed orifice area ≤0.85 cm2/m2 measured using echocardiography. Exercise capacity was reported as percentage of predicted exercise capacity (PPEC).

RESULTS

Of the 207 patients, 68% was male, 71% had a mechanical prosthesis and mean age at inclusion was 43.9 years ±11.4. The prevalence of PPM was 42%, comprising 23% severe PPM and 19% moderate PPM. Prevalence of PPM was higher in patients with mechanical prostheses (p<0.001). PPM was associated with poorer exercise capacity (mean PPEC 84% vs. 92%; p=0.048, mean difference =-8.3%, p=0.047). Mean follow-up was 2.6±1.1 years during which New York Heart Association (NYHA) class remained stable in most patients. PPM showed no significant effect on death or hospitalisation during follow-up (p=0.218).

CONCLUSIONS

In this study we report a high prevalence (42%) of PPM in ACHD with an aortic valve prosthesis and an independent association of PPM with diminished exercise capacity.

Standards for heart valve surgery in a 'Heart Valve Centre of Excellence'

Surgical centres of excellence should include multidisciplinary teams with specialist expertise in imaging, clinical assessment and surgery for patients with heart valve disease. There should be structured training programmes for the staff involved in the periprocedural care of the patient and these should be overseen by national or international professional societies. Good results are usually associated with high individual and centre volumes, but this relationship is complex. Results of surgery should be published by centre and should include rates of residual regurgitation for mitral repairs and reoperation rates matched to the preoperative pathology and risk.

Seventeen-millimeter St. Jude Medical Regent valve in patients with small aortic annulus: dose moderate prosthesis-patient mismatch matter?

Background

The study was designed to evaluate the effects of moderate prosthesis-patient mismatch (defined as 0.65 cm²/m² < indexed effective orifice area ≤ 0.85 cm²/m²) on midterm outcomes after isolated aortic valve replacement with a 17-mm St. Jude Medical Regent valve in a large series of patients, and to determine if these effects are influenced by patient confounding variables.

Methods

One-hundred and six patients with and without moderate prosthesis-patient mismatch early after implantation of a 17-mm Regent valve at aortic position were included. Both clinical and echocardiographic assessments were performed preoperatively, at discharge and during follow-up period (mean follow-up time 52.6 ± 11.9 months).

Results

The prevalence of moderate prosthesis-patient mismatch was documented in 46 patients (43.4%) at discharge. During the follow-up period, no difference in the regression of left ventricular mass, decrease of transvalvular pressure gradients, mortality and prosthesis-related complications was observed between patients with and without moderate prosthesis-patient mismatch. After adjustment for several risk factors, moderate prosthesis-patient mismatch was associated with increased midterm mortality in patients with baseline left ventricular ejection fraction < 50% (HR: 1.80, p = 0.02), but with normal prognosis in those with preserved LV function. Younger age (cut off value = 65 years) was not an independent predictor of increased midterm mortality and valve-related complications in patients with moderate prosthesis-patient mismatch.

Conclusions

Moderate prosthesis-patient mismatch after aortic valve replacement with a small mechanical prosthesis is associated with increased mortality and adverse events in patients with pre-existing left ventricular dysfunction. Selected patients with small aortic annulus can experience satisfactory clinical improvements and midterm survival after aortic valve replacement with a 17-mm Regent valve.

Hemodynamic performance and outcome of percutaneous versus surgical stentless bioprostheses for aortic stenosis with anticipated patient-prosthesis mismatch

OBJECTIVES

We aimed to compare the performance and midterm survival of transcutaneous aortic valve replacement (TAVR) and surgically implanted stentless aortic valve replacement (SAVR) for severe aortic stenosis in patients anticipated to have patient-prosthesis mismatch (PPM).

METHODS

A retrospective analysis was performed of 86 and 49 consecutive TAVR and SAVR patients with severe aortic stenosis and calculated minimal effective orifice area larger than the best projected effective orifice area. Cox hazard analyses were used to assess the effect of TAVR versus SAVR on outcome.

RESULTS

The peak and mean transprosthetic gradient at discharge were lower (P < .001 for both) in the TAVR group. Mild or greater aortic regurgitation was more frequent in the TAVR group (61% vs 7%; P < .0001). At 3 months of follow-up, the mean gradient in the TAVR group was similar to that of the SAVR group but the prevalence of aortic regurgitation was still higher. The unadjusted 3-year survival rate was superior in the SAVR versus TAVR group (91.6% ± 4% vs 67.0% ± 7%; P = .01). Adjustments for both age and comorbidity resulted in loss of the difference in mortality between the 2 groups.

CONCLUSIONS

In patients with anticipated PPM, TAVR offers an immediate lower incidence of PPM than SAVR but a greater prevalence of aortic regurgitation. The differences in transaortic gradients became nonsignificant 3 months postoperatively. The question of whether TAVR is a suitable substitute for SAVR in patients with anticipated PPM, in particular, those who are older and sicker, warrants additional investigation.

Update on aortic valve prosthesis-patient mismatch in Japan

The influence of aortic valve prosthesis-patient mismatch (VP-PM) on the clinical outcome has been an ongoing controversy. The reported prevalence of VP-PM after aortic valve replacement (AVR) ranges widely between 20 and 70 %. The inconsistent impact of VP-PM on short-term and long-term mortality, regression of left ventricular (LV) hypertrophy, and exercise capacity may be explained by differences of the patient populations, the definition of VP-PM, and the use of different prostheses. Moreover, many factors other than the severity of VP-PM should be taken into account when considering its impact on individual patients after AVR. Although the concept of VP-PM is easy to understand, it cannot be applied to the whole patient population. In Japan, the age of the candidates for AVR has increased markedly in recent years, but almost all elderly patients with a small BSA (<1.6 m(2)) have received newer-generation prostheses with a small outer diameter and large effective orifice area. Indeed, previous studies of Japanese patients have demonstrated that VP-PM was no more than moderate in most cases and its impact on clinical outcomes was generally acceptable. Although severe VP-PM is infrequent and its clinical implications are still unproven in elderly Japanese patients, it would seem reasonable to try to prevent severe VP-PM. Thus, VP-PM itself cannot be accepted as an independent risk factor in Japanese patients, but the useful preventive strategies for severe VP-PM in inactive very elderly persons remain controversial. The implantation of newer-generation biological or mechanical prostheses with or without aortic annular enlargement should be considered according to the characteristics of the patient and the risk-benefit ratio for carrying out a particular procedure in an individual patient.