Structural valve deterioration in the Mitroflow biological heart valve prosthesis

Size of Self-Expandable Transcatheter Heart Valve and Mid-Term Adverse Events After Transcatheter Aortic Valve Replacement

The hemodynamic performance of self-expandable valves (SEVs) is a preferable choice for small aortic annuli in transcatheter aortic valve replacement (TAVR). However, no data are, so far, available regarding the relation between the size of SEVs and clinical outcomes. This study aimed to evaluate the impact of prosthesis size on adverse events after TAVR using SEVs. We retrospectively analyzed 1,400 patients (23-mm SEV: 13.6%) who underwent TAVR using SEVs at 12 centers. The impact of SEV size on all-cause death and heart failure (HF) after TAVR was evaluated by multivariate Cox regression and propensity score (PS) matching analysis. During the follow-up period (median 511 days), 201 all-cause deaths and 87 HF rehospitalizations were observed. The incidence of all-cause death was comparable between small- (23-mm SEV) and larger-sized (26- or 29-mm SEV) (16.8% vs 13.9%, log-rank p = 0.29). The size of SEV was not associated with a higher incidence of all-cause death (hazard ratio [HR] 1.21, 95% confidence interval [CI] 0.79 to 1.86 in Cox regression; HR 1.31, 95% CI 0.77 to 2.23 in PS matching) and HF after TAVR (subdistribution HR 0.79, 95% CI 0.37 to 1.72 in Cox regression; subdistribution HR 1.00, 95% CI 0.44 to 2.30 in PS matching). The multivariate model including postprocedural prosthesis-patient mismatch showed consistent results. In conclusion, small SEVs had comparable midterm clinical outcomes to larger-sized SEVs, even if the prosthesis-patient mismatch was observed after TAVR.

Research on fatigue optimization simulation of polymeric heart valve based on the iterative sub-regional thickened method

Prosthetic polymeric heart valves (PHVs) have the potential to overcome the inherent material and design limitations of traditional valves in the treatment of valvular heart disease; however, their durability remains limited. Optimal design of the valve structure is necessary to improve their durability. This study aimed to enhance the fatigue resistance of PHVs by improving the stress distribution. Iterative subregional thickening of the leaflets was used, and the mechanical stress distribution and hemodynamics of these polymeric tri-leaflet valves were characterized using a fluid-structure interaction approach. Subregional thickening led to a reduction in stress concentration on the leaflet, with the effective orifice area still meeting ISO 5840-3 and the regurgitant volume achieving a similar value to those in previous studies. The maximum stress in the final iteration was reduced by 28% compared with that of the prototype. The proposed method shows potential for analyzing the stress distribution and hemodynamic performance of subregional thickened valves and can further improve the durability of PHVs.

Excess Reintervention With Mitroflow Prosthesis for Aortic Valve Replacement: Ten-Year Outcomes of a Randomized Trial

BACKGROUND

Current bioprostheses are considered to have improved durability and better hemodynamic performance compared with previous designs, but there are limited comparative data on late outcomes.

METHODS

From 2009 through 2011, 300 adults with severe aortic valve stenosis undergoing aortic valve replacement (AVR) were randomly assigned to receive Edwards Magna, St Jude Epic, or Sorin Mitroflow bioprostheses (n = 100, n = 101, n = 99, respectively). Overall survival was analyzed using Kaplan-Meier and Cox proportional hazards methods, whereas competing risk analysis was used for all time-to-event outcomes. Serial echocardiographic data were fitted with longitudinal models stratified by implant valve size.

RESULTS

During median follow-up of 9.8 years (interquartile range, 8.7-10.2), 10-year survival was 50% for the Magna group, 42% for the Epic group, and 41% for the Mitroflow group (P = .415). Cumulative risk of stroke was 9% at 10 years, and rates were comparable for the three groups. Indexed aortic valve area and mean gradients were similar among the three groups receiving 19 mm and 21 mm valves, but in larger (23 mm or more) prostheses, gradients were lower (P < .001) and indexed aortic valve areas were higher in the Magna group (P < .001). The 10-year risk of endocarditis differed by group (P = .033), with higher incidence in the Mitroflow vs the Magna group (7% vs 0%, P = .019). Late risk of reinterventions in the Mitroflow group was 22%, compared with 0% in the Magna group (P < .001) and 5% in the Epic group (P = .008).

CONCLUSIONS

The Magna valve had the lowest gradients and largest indexed aortic valve area with larger implant sizes. The Mitroflow bioprosthesis is associated with an increased rate of reintervention and possible increased risk of infection compared with Magna and Epic valves.

Review of bioprosthetic structural valve deterioration: Patient or valve?

BACKGROUND

With guidelines progressively recommending bioprosthetic aortic valves in younger patients, a greater emphasis is placed on structural valve deterioration (SVD) as an important clinical endpoint for both transcatheter and surgically implanted valves. However, SVD of bioprosthetic valves is a complex entity with varying definitions in the literature and a multifaceted pathogenesis.

AIM

This review first aims to establish the most updated definitions of SVD as per the literature. We then explore the patient- and valve-related factors that play the greatest roles in facilitating early SVD.

METHODS

A PubMed literature review was conducted to identify the relevant research in this field within the past two decades.

CONCLUSION

Increasing rates of obesity and metabolic syndrome pose a significant risk to the longevity of bioprosthetic valves. Additionally, externally mounted valves have proven to sacrifice durability for superior haemodynamics. Bioprosthetic SVD continues to be a multifactorial issue that will require various patient- and valve-related factors to be addressed.

Comparison of Long-term Performance of Bioprosthetic Aortic Valves in Sweden From 2003 to 2018

IMPORTANCE

The performance of bioprosthetic aortic valves is usually assessed in single valve models or head-to-head comparisons. National databases or registries offer the opportunity to investigate all available valve models in the population and allows for a comparative assessment of their performance.

OBJECTIVE

To analyze the long-term rates of reintervention, all-cause mortality, and heart failure hospitalization associated with commonly used bioprosthetic aortic valves and to identify valve model groups with deviation in clinical performance.

DESIGN, SETTING, AND PARTICIPANTS

This population-based, nationwide cohort study included all adult patients who underwent surgical aortic valve replacement (with or without concomitant coronary artery bypass surgery or ascending aortic surgery) in Sweden between January 1, 2003, and December 31, 2018. Patients were identified from the SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry. Patients with concomitant valve surgery, previous cardiac surgery, and previous transcatheter valve replacement were excluded. Follow-up was complete for all participants. Data were analyzed from March 9, 2020, to October 12, 2021.

EXPOSURES

Primary surgical aortic valve replacement with the Perimount, Mosaic/Hancock, Biocor/Epic, Mitroflow/Crown, Soprano, and Trifecta valve models.

MAIN OUTCOMES AND MEASURES

The primary outcome was cumulative incidence of reintervention, defined as a subsequent aortic valve operation or transcatheter valve replacement. Secondary outcomes were all-cause mortality and heart failure hospitalization. Regression standardization and flexible parametric survival models were used to account for intergroup differences. Mean follow-up time was 7.1 years, and maximum follow-up time was 16.0 years.

RESULTS

A total of 16 983 patients (mean [SD] age, 72.6 [8.5] years; 10 685 men [62.9%]) were included in the analysis. The Perimount valve model group had the lowest and the Mitroflow/Crown valve model group had the highest cumulative incidence of reintervention. The estimated cumulative incidence of reintervention at 10 years was 3.6% (95% CI, 3.1%-4.2%) in the Perimount valve model group and 12.2% (95% CI, 9.8%-15.1%) in the Mitroflow/Crown valve model group. The estimated incidence of reintervention at 10 years was 9.3% (95% CI, 7.3%-11.3%) in the Soprano valve model group.

CONCLUSIONS AND RELEVANCE

Results of this study showed that the Perimount valve was the most commonly used and had the lowest incidence of reintervention, all-cause mortality, and heart failure hospitalization, whereas the Mitroflow/Crown valve had the highest rates. These findings highlight the need for clinical vigilance in patients who receive either a Soprano or Mitroflow/Crown aortic bioprosthesis.

Long-term results of modified bentall procedures: 18-year experience of the flanged technique

OBJECTIVES

To evaluate the early and late outcomes of the modified Bentall procedure with the flanged technique.

METHODS

We reviewed the medical records of 63 patients who had undergone root replacement by the modified Bentall procedure at our institute between January 2001 and December 2018. In most cases, we adopted a composite graft constructed with a mechanical valve or bioprosthesis and a Dacron graft by the flanged technique. Since 2011, we have used Valsalva grafts.

RESULTS

Mean age 57 ± 16 years, range 16-80, male 43 cases. The mean follow-up was 75 ± 56 months (range 0-216). Through April 1, 2020, we could follow up on 61 cases (97%) within a six-month period. Hospital mortality was 7.9% (4.8% in elective cases). In late follow-up, eight deaths were observed. In the bio-Bentall group (n=26), no deaths or major adverse valve-related events (MARVEs) occurred. In the mechanical Bentall group (n=37), seven cases of MARVEs, including two cerebral hemorrhages and one cerebral embolism, were observed. All patients were free from MARVEs at 5 years post procedure in the bio-Bentall group, and 93.8% and 76.8% were event-free at 5 years and 10 years, respectively, in the mechanical Bentall group.

CONCLUSIONS

The 18-year results of the modified Bentall procedure were acceptable, providing excellent outcomes in the bio-Bentall group. The flanged technique enabled the use of a larger prosthesis, which may have resulted in good durability with the bio-Bentall procedure.

Fully coupled dynamic simulations of bioprosthetic aortic valves based on an embedded strategy for fluid-structure interaction with contact

AIMS

This work aims at presenting a fully coupled approach for the numerical solution of contact problems between multiple elastic structures immersed in a fluid flow. The key features of the computational model are (i) a fully coupled fluid-structure interaction with contact, (ii) the use of a fibre-reinforced material for the leaflets, (iii) a stent, and (iv) a compliant aortic root.

METHODS AND RESULTS

The computational model takes inspiration from the immersed boundary techniques and allows the numerical simulation of the blood-tissue interaction of bioprosthetic heart valves (BHVs) as well as the contact among the leaflets. First, we present pure mechanical simulations, where blood is neglected, to assess the performance of different material properties and valve designs. Secondly, fully coupled fluid-structure interaction simulations are employed to analyse the combination of haemodynamic and mechanical characteristics. The isotropic leaflet tissue experiences high-stress values compared to the fibre-reinforced material model. Moreover, elongated leaflets show a stress concentration close to the base of the stent. We observe a fully developed flow at the systolic stage of the heartbeat. On the other hand, flow recirculation appears along the aortic wall during diastole.

CONCLUSION

The presented FSI approach can be used for analysing the mechanical and haemodynamic performance of a BHV. Our study suggests that stresses concentrate in the regions where leaflets are attached to the stent and in the portion of the aortic root where the BHV is placed. The results from this study may inspire new BHV designs that can provide a better stress distribution.

Severe Aortic Regurgitation of Early Degenerated Mitroflow Bioprosthesis: From Echocardiographic Diagnosis to Treatment with Valve-in-Valve Transcatheter Aortic Valve Implantation

Valve-in-Valve transcatheter aortic valve implantation (ViV TAVI) is emerging as an effective therapeutic option for bioprosthetic valve failure. Recently, concern has been raised for early valve deterioration of Mitroflow (Sorin) aortic bioprosthesis, with the development of prevalent stenosis. We report cases of pure severe aortic regurgitation (AR) due to early and mid-term prosthesis degeneration. From June 2018 to October 2019, three patients were treated in our division for the new appearance of severe intraprosthetic regurgitation. Patient 1 (man, 85-year-old) and patient 3 (woman, 83-year-old) had a Mitroflow n. 25 and n. 21 implanted, respectively, in 2012 and 2013 for severe aortic stenosis. Patient 2, a 67-year-old woman with Marfan syndrome underwent a Mitroflow n. 25 implant in 2008 for severe AR and presented chronic type-B aortic dissection. Patient 1 was diagnosed with severe AR in the ambulatory setting, while the other patients presented acute heart failure, requiring inotrope support and high doses intravenous diuretics, and in case 3, temporary extracorporeal ultrafiltration. All patients appeared at high surgical risk and were successfully treated with ViV TAVI, through the right axillary artery in patient 2, and through the femoral artery in patients 1 and 3. Results were good at short- and mid-term follow-up. In conclusion, early and midterm bioprosthesis degeneration with the development of severe AR is a possible complication of the Mitroflow aortic valve. ViV TAVI has been confirmed as a safe and effective therapeutic option in our cases.

Long-term survival after Carpentier-Edwards Perimount aortic valve replacement in Western Denmark: a multi-centre observational study

Background

This study describes the long-term survival, risk of reoperation and clinical outcomes of patients undergoing solitary surgical aortic valve replacement (SAVR) with a Carpentier-Edwards Perimount (CE-P) bioprosthetic in Western Denmark. The renewed interest in SAVR is based on the questioning regarding the long-term survival since new aortic replacement technique such as transcatheter aortic-valve replacement (TAVR) probably have shorter durability, why assessment of long-term survival could be a key issue for patients.

Methods

From November 1999 to November 2013 a cohort of a total of 1604 patients with a median age of 73 years (IQR: 69–78) undergoing solitary SAVR with CE-P in Western Denmark was obtained November 2018 from the Western Danish Heart Registry (WDHR). The primary endpoint was long-term survival from all-cause mortality. Secondary endpoints were survival free from major adverse cardiovascular and cerebral events (MACCE), risk of reoperation, cause of late death, patient-prothesis mismatch, risk of AMI, stroke, pacemaker or ICD implantation and postoperative atrial fibrillation (POAF). Time-to-event analysis was performed with Kaplan-Meier curve, cumulative incidence function was performed with Nelson-Aalen cumulative hazard estimates. Cox regression was applied to detect risk factors for death and reoperation.

Results

In-hospital mortality was 2.7% and 30-day mortality at 3.4%. The 5-, 10- and 15-year survival from all-cause mortality was 77, 52 and 24%, respectively. Survival without MACCE was 80% after 10 years. Significant risk factors of mortality were small valves, smoking and EuroSCORE II ≥4%. The risk of reoperation was < 5% after 7.5 years and significant risk factors were valve prosthesis-patient mismatch and EuroSCORE II ≥4%.

Conclusions

Patients undergoing aortic valve replacement with a Carpentier-Edwards Perimount valve shows a very satisfying long-term survival. Future research should aim to investigate biological valves long-term durability for comparison of different SAVR to different TAVR in long perspective.

Redo aortic valve intervention after transcatheter aortic valve replacement: Analysis of the nationwide readmission database

BACKGROUND

Outcomes of redo aortic valve intervention (AVI) following transcatheter aortic valve replacement (TAVR) have not been well described. We thought to investigate the incidence, predictors, and outcomes of redo AVI after TAVR.

METHODS

The Nationwide Readmission Database (from 2012 to 2017) was queried to identify admissions for TAVR. Redo AVI was defined as readmissions that required either TAVR or balloon aortic valvuloplasty (BAV) or surgical aortic valve replacement (SAVR). A multivariable regression model was used to identify independent predictors of redo AVI. In-hospital outcomes of redo TAVR or BAV and redo SAVR were compared in the unadjusted model.

RESULTS

A total of weighted 148,200 (unweighted redo AVI 297, no redo AVI 73,804) index TAVRs were identified. A weighted 593 (435 TAVR or BAV and 158 SAVR) redo AVI was included with an incidence of 1.0 per 100 person-year during a median of 105 (interquartile range 41-195) days follow-up. Predictors of redo AVI were female, heart failure, obesity, atrial fibrillation, transapical approach, oral anticoagulant use, and acute kidney injury. In-hospital mortality of redo AVI was 7.6% (5.3% for redo TAVR or BAV vs. 13.8% for redo SAVR, unadjusted p = 0.10). Stroke, myocardial infarction, bleeding requiring transfusion, new pacemaker, and acute kidney injury rates were 4.7%, 2.6%, 9.3%, 10.0%, and 31.2%, respectively in redo AVI. Length of stay and hospital cost was 4.8 days and 55,826 U.S. dollars, respectively.

CONCLUSIONS

The incidence of redo AVI was low following TAVR but was associated with high mortality and morbidities.

An in vitro comparison of internally versus externally mounted leaflets in surgical aortic bioprostheses

OBJECTIVES

To improve haemodynamic performance, design modifications of prosthetic valves have been proposed with each new generation of valves. These different designs also impact the amount of mechanical wear, because mechanical stresses are distributed differently. Because long-term evidence for new prosthetic valves is lacking, this in vitro study compared hydrodynamic performance and durability among 3 currently available bioprosthetic valves with internally (IMLV) or externally mounted leaflets (EMLV).

METHODS

Prostheses of the internally mounted Medtronic Avalus and Carpentier-Edwards Perimount Magna Ease valves were compared to prostheses of the externally mounted Abbott Trifecta valve. For each labelled size (e.g. 19, 21 and 23) of the 3 types, 3 valves underwent accelerated wear testing for up to 600 million cycles, corresponding to ∼15 years of simulated wear. The valves underwent hydrodynamic testing and visual inspection.

RESULTS

EMLV had the largest effective orifice area and lowest pressure gradient for each labelled size at baseline and 600 million cycles; the effective orifice area and the pressure gradient were equivalent for the 2 types of IMLV. Five of 9 EMLVs had at least 1 hole or tear in the leaflet tissue around the stent posts, which resulted in severe regurgitation at 500 million cycles in 2 cases. All IMLVs were intact at 600 million cycles with minimal tissue wear.

CONCLUSIONS

EMLV showed superior hydrodynamic performance but inferior mechanical durability compared to IMLV after 600 million cycles of testing. The primary failures were because of significant mechanical abrasion in the commissural region, which may warrant close monitoring of EMLV during long-term follow-up.

New-Generation Transcatheter Aortic Valves in Patients With Small Aortic Annuli - Comparison of Balloon- and Self-Expandable Valves in Asian Patients

BACKGROUND

Asian patients have smaller aortic annuli. Although 20-mm balloon-expandable (BE) transcatheter heart valves (THV) are manufactured for transcatheter aortic valve implantation (TAVI) in these cases, the supra-annular design of self-expandable (SE) THV is considered more suitable; however, real-world comparative data are scarce.Methods and Results:Consecutive TAVI cases (n=330) in a single Japanese center were reviewed. Based on the cutoff for the new-generation 20-/23-mm BE-THV, a small aortic annulus was defined as <330 mm². A considerable number of patients had small annuli: 49/302 (16%). Of these, 33 BE-THV and 13 SE-THV using new-generation valves were compared. Although the SE-THV group had smaller annulus area (median 297 (interquartile range, 280-313) vs. 309 (303-323) mm²(P=0.022)), it had more favorable post-procedural parameters; for SE-THV and BE-THV, respectively, effective orifice area (EOA), 1.5 (1.3-1.6) vs. 1.1 cm²(0.9-1.3) (P=0.002); mean pressure gradient, 7.6 (5.6-11.0) vs. 14.2 mmHg (11.2-18.8) (P=0.001); and peak velocity, 1.8 (1.6-2.4) vs. 2.7 m/s (2.3-3.1) (P=0.001). Although new left bundle branch block was higher with SE-THV (24% and 62%, P=0.02), patient-prosthesis mismatch (PPM) ≥ moderate (indexed EOA <0.85 cm²/m²) was significantly less with SE-THV than with BE-THV (8% vs. 55%; P=0.04). Hemodynamic findings were consistent up to 1 year.

CONCLUSIONS

Small annuli are often seen in Asian patients, for whom SE-THV implantation results in favorable hemodynamics with less PPM.

Aortic root morphology can cause early bioprosthetic valve failure of externally mounted pericardial bioprosthesis

A 73-year-old woman with a narrow aortic root had undergone aortic valve replacement with a 19-mm Mitroflow valve. Aortic annular enlargement with Manouguian's technique was performed, and the bioprosthesis had been implanted on the tilt in a supra-annular position. Four years after the implantation, echocardiography showed a significant de novo aortic regurgitation, which had not been detected 1 year earlier. In the reoperation, the left coronary leaflet of the bioprosthesis had attached and fused to the wall of the sinus of Valsalva, causing deformation of the valve leaflet and a commissural gap between the left and right coronary leaflets, which appeared to have caused the de novo aortic regurgitation. We assessed the cause of early valve deterioration by focusing on the morphology of the aortic root. Preoperative understanding of the aortic root morphology would help to avoid early valve dysfunction for aortic valve replacement with an externally mounted bioprosthesis.

Reintervention After Aortic Valve Replacement: Comparison of 3 Aortic Bioprostheses

BACKGROUND

The decision to implant a biological valve prosthesis is influenced by the issue of durability. We investigated the rate and the cause of reintervention in 3 different aortic valve bioprostheses.

METHODS

The study included all patients who underwent aortic valve replacement with a biological valve prosthesis between October 2009 and December 2018. Three different bioprostheses were compared: Carpentier-Edwards (CE) Magna Ease (Edwards Lifesciences, Irvine, CA), Trifecta (St. Jude Medical, St Paul, MN), and Mitroflow (LivaNova, London, United Kingdom). The primary end point was the rate of explantation. The degree of event-free survival and possible predictors for reintervention were also analyzed using Cox regression analysis.

RESULTS

In total, 2004 biological aortic valves were implanted, including 923 CE, 719 Trifecta, and 362 Mitroflow bioprostheses. The CE group had a significantly higher degree of event-free survival (917 [99.3%]) compared with the Trifecta (685 [95.3%]) and Mitroflow (340 [93.9%]) groups (P < .0001). The only cause of reintervention in the CE group was prosthetic valve endocarditis (6 [100%]), whereas structural valve deterioration was the most common cause of reintervention in the Trifecta (14 [41.2%]) and Mitroflow (14 [63.6%]) groups. Cox regression analysis revealed that age (hazard ratio [HR] 0.9; 95% confidence interval [CI], 0.9-0.9; P < .0001) and type of prosthesis (Trifecta: HR, 6.3; 95% CI, 2.6-15.2; P < .0001; Mitroflow: HR, 6.0, 95% CI, 2.4-15.1; P < .0001) were associated with lower event-free survival.

CONCLUSIONS

The freedom from reintervention after implantation of the CE bioprosthesis is significantly greater than that of the Trifecta and Mitroflow bioprostheses. Further investigations with larger patient populations and long-term follow-up are required to establish their durability and long-term efficacy.

How to treat severe symptomatic structural valve deterioration of aortic surgical bioprosthesis: transcatheter valve-in-valve implantation or redo valve surgery?

The optimal management of aortic surgical bioprosthesis presenting with severe symptomatic structural valve deterioration is currently a matter of debate. Over the past 20 years, the number of implanted bioprostheses worldwide has been rapidly increasing at the expense of mechanical prostheses. A large proportion of patients, however, will require intervention for bioprosthesis structural valve deterioration. Current options for older patients who often have severe comorbidities include either transcatheter valve-in-valve (TVIV) implantation or redo valve surgery. The emergence of TVIV implantation, which is perceived to be less invasive than redo valve surgery, offers an effective alternative to surgery for these patients with proven safety and efficacy in high-risk patient groups including elderly and frail patients. A potential caveat to this strategy is that results of long-term follow-up after TVIV implantation are limited. Redo surgery is sometimes preferable, especially for young patients with a smaller-sized aortic bioprosthesis. With the emergence of TVIV implantation and the long experience of redo valve surgery, we currently have 2 complementary treatment modalities, allowing a tailor-made and patient-orientated intervention. In the heart team, the decision-making should be based on several factors including type of bioprosthesis failure, age, comorbidities, operative risk, anatomical factors, anticipated risks and benefits of each alternative, patient's choice and local experience. The aim of this review is to provide a framework for individualized optimal treatment strategies in patients with failed aortic surgical bioprosthesis.