Long-Term Clinical Outcomes 15 Years After Aortic Valve Replacement With the Freestyle Stentless Aortic Bioprosthesis

Ten-year Durability, Hemodynamic Performance, and Clinical Outcomes after Transcatheter Aortic Valve Implantation Using a Self-expanding Device

INTRODUCTION

The expansion of transcatheter aortic valve implantation (TAVI) to low-risk and younger patients has increased the relevance of the long-term durability of transcatheter heart valves (THV). The present study aims to assess the 10-year durability, hemodynamic performance, and clinical outcomes after TAVI using the CoreValve system.

METHODS

An analysis from a prospective registry with predefined clinical and echocardiographic follow-up included 302 patients who underwent TAVI with the CoreValve system between 2007 and 2015. Bioprosthetic valve failure (BVF) was defined as any bioprosthetic valve dysfunction-related death, re-intervention, or severe hemodynamic valve deterioration.

RESULTS

At the time of TAVI, the mean age was 80.41 ± 7.01 years, and the Society of Thoracic Surgeons (STS) score was 6.13 ± 5.23%. At latest follow-up (median [IQR]: 5 [2-7] years), cumulative all-cause mortality rates at 3, 5, 7, and 10 years was 23.7%, 40%, 65.8%, and 89.8%, respectively. Mean aortic valve area and transvalvular gradient post-TAVI and at 5, 7, and 10 years were 1.94, 1.87, 1.69, and 1.98 cm2 (p = 0.236) and 8.3, 9.0, 8.2, and 10.1 mmHg (p = 0.796), respectively. Overall, 11 patients had BVF, of whom six had structural valve deterioration (SVD). The 10-year actual and actuarial freedom from BVF was 96.1% and 78.8%, and from SVD was 97.9% and 80.9%, respectively. Three patients developed significant non-SVD due to severe paravalvular leakage, and two patients were diagnosed with infective endocarditis.

CONCLUSION

Using an early-generation self-expanding bioprosthesis, we documented durable hemodynamic performance and low rates of BVF and SVD up to 10 years after TAVI.

Recent Advances in the Modification and Improvement of Bioprosthetic Heart Valves

Valvular heart disease (VHD) has become a burden and a growing public health problem in humans, causing significant morbidity and mortality worldwide. An increasing number of patients with severe VHD need to undergo heart valve replacement surgery, and artificial heart valves are in high demand. However, allogeneic valves from donors are lacking and cannot meet clinical practice needs. A mechanical heart valve can activate the coagulation pathway after contact with blood after implantation in the cardiovascular system, leading to thrombosis. Therefore, bioprosthetic heart valves (BHVs) are still a promising way to solve this problem. However, there are still challenges in the use of BHVs. For example, their longevity is still unsatisfactory due to the defects, such as thrombosis, structural valve degeneration, calcification, insufficient re-endothelialization, and the inflammatory response. Therefore, strategies and methods are needed to effectively improve the biocompatibility and longevity of BHVs. This review describes the recent research advances in BHVs and strategies to improve their biocompatibility and longevity.

Interventional versus Surgical Treatment of Degenerated Freestyle Prosthesis

BACKGROUND

 Bioprosthetic stentless aortic valves may degenerate over time and will require replacement. This study aimed to evaluate early- and mid-term outcomes after isolated surgical redo aortic valve replacement (redo-SAVR) and transcatheter valve-in-valve implantation (TAVI-VIV) for degenerated stentless Freestyle bioprostheses.

METHODS

 We reviewed records of 56 patients at a single center. Overall, 37 patients (66.1%) received TAVI-VIV and 19 (33.9%) received redo-SAVR.

RESULTS

 Thirty-day survival was similar in both groups (100%). One-year survival was comparable between groups (97.3% in TAVI-VIV and 100% in redo-SAVR, p = 1.0). The difference in mid-term survival after adjusting for age and EuroScore II was not significant (p = 0.41). The incidence of pacemaker implantation after TAVI-VIV was higher than after redo-SAVR (19.4% vs. 0%, p = 0.08).

CONCLUSION

 The 30-day and 1-year survival rates after both procedures were outstanding, irrespective of baseline characteristics. Isolated redo-SAVR should be favored in young patients, as the pacemaker implantation rate is lower. TAVI-VIV for degenerated Freestyle prosthesis can be a method of choice in elderly patients and those with high operative risk.

Aortic root pseudoaneurysm: a case report and literature review

Pseudoaneurysms of the aortic root are rare. A case of prosthetic aortic valve infection progressing from a confined intramural abscess to a ruptured abscess communicating with the aorta and forming a large pseudoaneurysm is described. Additionally, data from all cases and case series, published between 2000 and 2021, was analyzed. A PUBMED search for the keywords "aortic root mycotic aneurysm," "aortic root abscess AND infective endocarditis," and "aortic root mycotic aneurysm AND infective endocarditis" yielded 152 publications (with 157 cases described): Aortic pseudoaneurysm is more common in males (80.9%, n = 127). Mean age is 51 years (4 months-84 years). The most common symptom is fever (68.5%, n = 102). Mean time until diagnosis is 27.2 days. Embolic complications are present in 17.8% (n = 28) at diagnosis. Most cases are due to valvular infections (n = 72 cases, 45.9%). Prior cardiac surgery is documented in 49.0% (n = 77). The mean time interval for developing aortic root abscess following heart surgery is 32.2 months. 22.3% (n = 35) are immunocompromised. Aetiological agents were Staphylococcus sp. (34.1%, n = 47) and Streptococcus sp. (23.2%, n = 32). Mean antimicrobial therapy lasts 58.5 days. Outcome with surgery is superior to medical treatment: overall inpatient mortality 18.5% (n = 27); with surgery 12.2% (n = 15 out of 123 patients), with only medical management 47.8% (n = 11 out of 23 patients). In conclusion, aortic root pseudoaneurysm occurs most commonly in middle-aged male patients. History of prior aortic procedures is commonly present. Correct diagnosis hinges on detailed history, transoesophageal echocardiography, and computed tomography (CT) aorta. Surgery is the preferred therapeutic option.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01580-x.

Intermediate-term Outcomes Following a Case Series of Reoperations for Medtronic Freestyle Stentless Aortic Valves

Background

Data are limited on long-term outcomes in patients who have undergone a reoperation following failure of a stentless aortic valve.

Methods

Between 2006 and 2016, a retrospective analysis was performed on 24 patients who underwent open aortic valve replacement surgery for a failed stentless aortic valve prosthesis at Health Sciences North, Sudbury, Ontario, Canada. The primary outcome was a low mortality rate from cardiac-related deaths after 5 years.

Results

All patients underwent insertion of a Medtronic Freestyle bioprosthesis (Minneapolis, MN) implanted using the modified subcoronary technique for their initial operation. The interval from the first operation to the stentless redo surgery ranged from 6 to 13 years. Aortic valve reoperation was performed for structural valve deterioration in 96% (n = 23) of the cases. Reoperations involved a removal of the stented valve leaflets and standard aortic valve replacement within the stentless casing in 20% (n = 5) of the cases, with the remaining cases requiring complete removal of the stentless prosthesis and aortic valve replacement. In those in whom a complete removal of the stentless valve was possible (n = 19), no disruption of the native aortic root occurred, with a 0% rate of conversion to a Bentall procedure. No intraoperative mortality occurred. The 30-day and 10-year operative mortality rates were 4% and 16%, respectively.

Conclusions

Redo surgery for failing stentless valves can be done with relatively low risk and with acceptable long-term outcomes without resorting to root-replacement techniques.

Early and Long-Term Clinical and Echocardiographic Outcomes of Sutureless vs. Sutured Bioprosthesis for Aortic Valve Replacement

Objective: The goal of this manuscript is to compare clinical and echocardiographic outcomes of patients undergoing aortic valve replacement (AVR) with Perceval sutureless bioprosthesis (SU-AVR) and sutured bioprosthesis (SB). Methods: Following the PRISMA statement, data were extracted from studies published after August 2022 and found in PubMed/MEDLINE, EMBASE, CENTRAL/CCTR, ClinicalTrials.gov, SciELO, LILACS, and Google Scholar. The primary outcome of interest was post-procedural permanent pacemaker implantation, and the secondary outcomes were new left bundle branch block (LBBB), moderate/severe paravalvular leak (PVL), valve dislocation (pop-out), need for a second transcatheter heart valve, 30-day mortality, stroke, and echocardiographic outcomes. Results: Twenty-one studies were included in the analysis. When SU-AVR was compared to other SB, mortality ranged from 0 to 6.4% for Perceval and 0 to 5.9% for SB. Incidence of PVL (Perceval 1-19.4% vs. SB 0-1%), PPI (Perceval 2-10.7% vs. SB 1.8-8.5%), and MI (Perceval 0-7.8% vs. SB 0-4.3%) were comparable. In addition, the stroke rate was lower in the SU-AVR group when compared to SB (Perceval 0-3.7% vs. SB 1.8-7.3%). In patients with a bicuspid aortic valve, the mortality rate was 0-4% and PVL incidence was 0-2.3%. Long-term survival ranged between 96.7 and 98.6%. Valve cost analysis was lower for the Perceval valve and higher for sutured bioprosthesis. Conclusions: Compared to SB valves, Perceval bioprosthesis has proved to be a reliable prosthesis for surgical aortic valve replacement due to its non-inferior hemodynamics, implantation speed, reduced cardiopulmonary bypass time, reduced aortic cross-clamp time, and shorter length of stay.

Structural abnormalities after aortic root replacement with stentless xenograft

OBJECTIVE

In complex and high-risk aortic root disease, the porcine Freestyle stentless bioprosthesis (Medtronic Inc, Minneapolis, Minn) is an important surgical treatment option. We aimed to determine prevalence and clinical effect of structural and functional abnormalities after full-root Freestyle implantation.

METHODS

Our cross-sectional 2-center study combined with clinical follow-up included 253 patients with full-root Freestyle bioprostheses implanted from 1999 to 2017. Patients underwent transthoracic echocardiography (TTE) and contrast-enhanced, electrocardiogram-gated 4-dimensional cardiac computed tomography (4DCT) at median age 70 (interquartile range, 62-75) years. After 4DCT, clinical follow-up continued throughout 2018. Median follow-up was 3.3 years before 4DCT and 1.4 years after.

RESULTS

We identified abnormalities in 46% of patients, including pseudoaneurysms (n = 32; 13%), moderate or severe coronary ostial stenosis (n = 54; 21%), and moderate-severe leaflet thickening or reduced leaflet motion (n = 51; 20%). TTE only identified 1 patient with pseudoaneurysm. After 4DCT, the unadjusted hazard ratio for surgical reintervention among patients with abnormal 4DCT was 4.2 (95% confidence interval, 1.2-15.3), in all, 10% required a reintervention. 4DCT abnormalities were associated with a statistically nonsignificant increased risk of death, stroke, or myocardial infarction (hazard ratio obtained using Cox proportional hazards regression analysis, 2.4; 95% confidence interval, 0.7-7.6). In all, 4.0% died, 3.6% had a myocardial infarction, and 2.0% had a stroke.

CONCLUSIONS

Structural and functional abnormalities of the aortic root are frequent after Freestyle implantation and TTE appears to be insufficient for follow-up. Abnormalities might be associated with increased risk of reintervention and potentially adverse clinical outcomes. Longer follow-up and larger study populations are needed to further clarify the clinical implications of abnormalities identified with 4DCT.

Transcatheter Aortic Valve Implantation: Long-Term Outcomes and Durability

Transcatheter aortic valve implantation (TAVI) has become the standard of care in symptomatic older patients with severe aortic stenosis regardless of surgical risk. With the development of newer generation transcatheter bioprostheses, improved delivery systems, better preprocedure planning with imaging guidance, increased operator experience, shorter hospital length of stay, and low short- and mid-term complication rates, TAVI is gaining popularity among younger patients at low or intermediate surgical risk. Long-term outcomes and durability of transcatheter heart valves have become substantially important for this younger population due to their longer life expectancy. The lack of standardized definitions of bioprosthetic valve dysfunction and disagreement about how to account for the competing risks made comparison of transcatheter heart valves with surgical bioprostheses challenging until recently. In this review, the authors discuss the mid- to long-term (≥ 5 years) clinical outcomes observed in the landmark TAVI trials and analyze the available long-term durability data emphasizing the importance of using standardized definitions of bioprosthetic valve dysfunction.

Prosthetic cardiac valves: history and review of cardiac prostheses clinically available in Japan

Recently developed prosthetic valves are reliable and essential for the treatment of valvular heart disease. The mechanical valve evolved remarkably following the introduction of pyrolite carbon material, which enabled the creation of a bileaflet form incorporated with a pivot mechanism. The improved durability of the biological valve is attributed mainly to the development of a tissue fixation process and anti-calcification treatments. However, optimal antithrombogenicity and durability have not yet been achieved for either prosthetic valve type. To select the most suitable prosthetic valve for each individual patient from among the many clinically available prosthetic valves, it is necessary to have a thorough understanding of the characteristics of each valve.

A case of freestyle valve reoperation 23 years after the first operation

We present a case of redo stentless valve operation in a 73-year-old man who underwent aortic valve replacement via the subcoronary approach with a freestyle aortic bioprosthesis 23 years ago at our institution. He was referred for surgery because an echocardiogram showed severe aortic regurgitation due to structural valve deterioration, and aortic valve replacement was planned. Severe circumferential calcification and adhesion were noted during the surgery between the freestyle and native roots. Redo-aortic valve replacement was successful despite the technical difficulty. In stentless valve reoperations following aortic valve replacement via the subcoronary method, the planning of valve-in-valve transcatheter aortic valve implantation and sutureless valve implantation may be a practical and safe strategy.

Outcomes after transcatheter valve-in-valve implantation using a balloon-expandable Edwards Sapien valve in patients with degenerated Freestyle aortic bioprosthesis

Background

Transcatheter aortic valve-in-valve implantation (ViV TAVI) in degenerated Medtronic Freestyle aortic bioprosthesis (FSB) has been reported as being technically challenging. This study sought to evaluate procedural data and outcomes after ViV TAVI using a balloon-expandable Edwards valve in patients with failed FSB.

Methods

Between August 2014 and December 2020, twenty-seven consecutive patients underwent ViV TAVI for symptomatic FSB failure at our institution using a Sapien XT (n=1) and Sapien 3 (n=26) valve, respectively. Endpoints were defined according to the Valve Academic Research Consortium-2 (VARC-2) criteria and were retrospectively analyzed.

Results

Mean patient age was 75.7±8.2 years (female n=5, male n=22); Society of Thoracic Surgeons Predicted Risk of Mortality score was 7.3%±6.2%. ViV implantation with correct positioning of the Edwards Sapien valve within the FSB was successful in all cases. Intraprocedural transesophageal echocardiography revealed none/trace paravalvular regurgitation in twenty-five patients (92.6%), mild paravalvular regurgitation was present in two patients (7.4%). Neither of the patients had a mean gradient ≥20.0 mmHg excluding significant patient-prosthesis mismatch. Three early deaths (≤thirty days) occurred resulting in a device success rate of 88.8%. One-year and three-year survival rates for patients alive beyond day thirty after ViV TAVI were 95.8% and 70.0%, respectively.

Conclusions

ViV TAVI with Edwards Sapien valves lead to acceptable functional results in high-risk patients with degenerated FSB but early complications must be considered particularly during hospital stay.

A systematic review on durability and structural valve deterioration in TAVR and surgical AVR

Mechanical valves and bioprosthetic heart valves are widely used for aortic valve replacement (AVR). Mechanical valves are associated with risk of bleeding because of oral anticoagulation, while the durability and structural valve deterioration (SVD) represent the main limitation of the bioprosthetic heart valves. The implantation of bioprosthetic heart valves is increasing precipitously due aging population, and the widespread use of transcatheter aortic valve replacement (TAVR). TAVR has become the standard treatment for intermediate or high surgical risk patients and a reasonable alternative to surgery for low risk patients with symptomatic severe aortic stenosis. Moreover, TAVR is increasingly being used for younger and lower-risk patients with longer life expectancy; therefore it is important to ensure the valve durability for long-term transcatheter aortic valves. Although the results of mid-term durability of the transcatheter heart valves are encouraging, their long-term durability remains largely unknown. This review summarises the definitions, mechanisms, risk factors and assessment of SVD; overviews available data on surgical bioprosthetic and transcatheter heart valves durability.

Serial echocardiographic evaluation of the Perimount Magna Ease prosthesis

Background

The Carpentier-Edwards Perimount Magna Ease prosthesis (PME) represents the latest generation of stented bioprostheses used for surgical aortic valve replacement (SAVR). The aim of our study was to evaluate the long-term clinical outcome and hemodynamic performance of the prosthesis with a focus on the incidence and course of structural valve deterioration (SVD) by serial echocardiographic examinations.

Methods

SAVR with the PME was performed in 58 consecutive patients between 2007 and 2008. Transthoracic echocardiography was performed preoperatively, at discharge and annually during a 10-year follow-up at the German Heart Center Munich.

Results

Mean age at surgery was 62±14 years. At discharge (n=57), the overall mean pressure gradient (MPG) and effective orifice area (EOA) were 15.8±4.1 mmHg and 1.8±0.4 cm², respectively. Moderate patient-prosthesis mismatch (PPM) was present in 18 patients (32%) and severe PPM in 6 patients (11%) at discharge. Ten years following SAVR (n=33), the overall MPG was 16.6±7.3 mmHg and EOA was 1.3±0.4 cm².Thirty-day and late mortality was 2% (n=1) and 21% (n=12), respectively. Survival at 1, 5, and 10 years was 94.7%±3.3%, 91.1%±4.1%, and 77.3%±5.9%, respectively. Freedom from reoperation at 10 years was 88.8%±4.7%. Ten years after PME implantation the cumulative incidence of any SVD, severe SVD, and bioprosthetic valve failure (BVF) was 25%±6%, 14%±5%, and 16%±5%, respectively.

Conclusions

The PME shows an excellent hemodynamic performance over the course of 10 years with development of clinically relevant SVD as late as 6 years post implant, and a 10-year incidence of severe SVD of 14%.

Geometric changes in aortic root replacement using Freestyle prosthesis

Background

The Medtronic Freestyle prosthesis has proven to be a promising recourse for aortic root replacement in various indications. The present study aims to evaluate clinical outcomes and geometric changes of the aorta after Freestyle implantation.

Methods

Between October 2005 and November 2020, the computed tomography angiography (CTA) data of 32 patients were analyzed in a cohort of 68 patients that underwent aortic root replacement using Freestyle prosthesis. The minimum and maximum diameters and areas of the aortic annulus, aortic root, ascending aorta, and the proximal aortic arch were measured at a plane perpendicular to the long axis of the aorta using 3D multiplanar reconstruction in both the preoperative (n = 32) and postoperative (n = 10) CTAs. Moreover, volumetric changes of the aortic root and ascending aorta were quantified.

Results

Mean age was 64.6 ± 10.6 years. Indications for surgery using Freestyle prosthesis were combined aortic valve pathologies, aortic aneurysm or dissection, and endocarditis, with concomitant surgery occurring in 28 out of 32 patients. In-hospital mortality was 18.6%.

Preoperative diameter and area measurements of the aortic annulus strongly correlated with the implanted valve size (p < 0.001). Bicuspid valve was present in 28.1% of the patients. Diameter and areas of the aortic root decreased after freestyle implantation, resulting in a reduction of the aortic root volume (45.6 ± 26.3 cm³ to 18.7 ± 4.5 cm³, p = 0.029). Volume of the aortic root and the ascending aorta decreased from 137.3 ± 65.2 cm³ to 54.5 ± 21.1 cm³ after Freestyle implantation (p = 0.023).

Conclusion

Implantation of the Freestyle prosthesis presents excellent results in restoring the aortic geometry. Preoperative CTA measurements are beneficial to the surgical procedure and valve selection and therefore, if available, should be considered in pre-operative planning.

Survival after aortic root replacement with a stentless xenograft is determined by patient characteristics

OBJECTIVES

Our objective was to examine intermediate-term survival and reinterventions in unselected patients, stratified according to indication, who received a Freestyle (Medtronic Inc, Minneapolis, Minn) bioprosthesis as a full aortic root replacement.

METHODS

Data from medical records were retrospectively collected for patients who had aortic root replacement using Freestyle bioprostheses between 1999 and 2018 at 6 North-Atlantic centers. Survival status was extracted from national registries and results stratified according to indication for surgery.

RESULTS

We included 1030 implantations in 1008 patients with elective indications for surgery: aneurysm (39.8%), small root (8.3%), and other (13.8%), and urgent/emergent indications: endocarditis (26.7%) and Stanford type A aortic dissection (11.4%). Across indications, 46.3% were nonelective cases and 34.0% were reoperations. Median age was 66.0 (interquartile range, 58.0-71.8) years and median follow-up was 5.0 (interquartile range, 2.6-7.9) years. Thirty-day mortality varied from 2.9% to 27.4% depending on indication. Intermediate survival for 90-day survivors with elective indications were not different from the general population standardized for age and sex (P = .95, .83, and .16 for aneurysms, small roots, and other, respectively). In contrast, patients with endocarditis and type A dissection had excess mortality (P < .001). Freedom from valve reinterventions was 95.0% and 94.4% at 5 and 8 years, respectively. In all, 52 patients (5.2%) underwent reinterventions, most because of endocarditis.

CONCLUSIONS

At intermediate term follow-up this retrospective study provides further support for the use of the Freestyle bioprosthesis in the real-world setting of diverse, complex, and often high-risk aortic root replacement and suggests that outcome is determined by patient and disease, rather than by prosthesis, characteristics.

Bioprosthetic valve fracture: Predictors of outcome and follow-up. Results from a multicenter study

OBJECTIVES

To evaluate outcome and its predictors of bioprosthetic valve fracture (BVF) in patients undergoing valve-in-valve transcatheter aortic valve replacement (VIV-TAVR).

BACKGROUND

BVF is feasible and reduces transvalvular gradients in VIV-TAVR-procedures, but follow-up-data and information on factors influencing the outcome are missing.

METHODS

The 81 cases of BVF-VIV-TAVR were collected from 14 international centers.

RESULTS

Predominantly transcatheter heart valve (THV) was implanted first, followed by BVF. VARC-2 defined device success was 93%, most failures were attributed to residual high gradients. Mean gradients decreased from 37 ± 13 mmHg to 10.8 ± 5.9 mmHg (p < 0.001). BVF reduced the gradient by 16 mmHg. During follow-up (FU, 281 ± 164 days) mean gradient remained stable (10.8 ± 5.9 mmHg at discharge, 12.4 ± 6.3 mmHg at FU, p = ns). In-hospital major adverse events occurred in 3.7%. Event-free survival at 276 ± 237.6 days was 95.4%. The linear mixed model identified balloon-expandable valves (BEV), Mitroflow surgical valve, stenotic surgical bioprostheses and balloon only 1 mm larger than the true internal diameter of the surgical valve as predictors for higher gradients.

CONCLUSIONS

BVF is safe and can significantly reduce gradients, which remain stable at FU. BEV, Mitroflow surgical valve, stenotic bioprostheses and balloon larger than the true internal diameter of the surgical valve of only 1 mm are predictors for higher final gradients.

Current Therapeutic Options in Aortic Stenosis

Aortic stenosis is the most common valvular disease requiring valve replacement. Valve replacement therapies have undergone progressive evolution since the 1960s. Over the last 20 years, transcatheter aortic valve replacement has radically transformed the care of aortic stenosis, such that it is now the treatment of choice for many, particularly elderly, patients. This review provides an overview of the pathophysiology, presentation, diagnosis, indications for intervention, and current therapeutic options for aortic stenosis.

Two-year outcomes from the PARTNER 3 trial: where do we stand?

PURPOSE OF REVIEW

The PARTNER 3 trial was conducted to compare outcomes after transcatheter aortic valve replacement (TAVR) with a balloon-expandable valve and surgical aortic valve replacement (SAVR) in individuals at low surgical risk with aortic stenosis. Recently reported rates of death, stoke and valve thrombosis in the TAVR arm have raised concerns about the longevity of this intervention in low-risk individuals. It is incumbent on all members of the Heart Team to understand the potential consequences of these findings.

RECENT FINDINGS

TAVR was initially superior to SAVR at 1 year for a primary composite endpoint of death, stroke and rehospitalization. Results at 2 years now indicate noninferiority. Potential causative factors, comparisons with other transcatheter valves and implications for patients, providers and trainees are explored. Recommendations are additionally provided regarding TAVR and SAVR in individuals with aortic stenosis.

SUMMARY

Concerns regarding the longevity of TAVR in low-risk individuals notwithstanding, results from PARTNER 3 indicate that TAVR is at least noninferior to SAVR out to 2 years. Longer follow-up will be required to determine whether these newly founded concerns are justifiable.

Assessment of long-term outcomes: aortic valve reimplantation versus aortic valve and root replacement with biological valved conduit in aortic root aneurysm with tricuspid valve

OBJECTIVES

We compared the long-term outcomes between aortic valve reimplantation [David V (DV)] and aortic valve and root replacement with biological valved conduit [Bentall-De Bono (BD)] for the patients with aortic root aneurysm with tricuspid valve.

METHODS

Among 876 patients who underwent aortic root replacement in our institution between 2005 and 2018, 371 patients who underwent DV (n = 199) or BD (n = 172) for aortic root aneurysm with tricuspid valve were retrospectively reviewed. Exclusion criteria included aortic stenosis, infective endocarditis, previous prosthetic aortic valve, bicuspid aortic valve, aortic dissection and mechanical Bentall procedure. Propensity score matching was performed based on the patient characteristics, matching 90 patients in each group. The primary end point was all-cause mortality. Secondary end points were reoperation for any cause and specifically for aortic valve-related cause.

RESULTS

After propensity score matching, DV and BD groups each had 1 in-hospital mortality (1.1%). Survival at 10 years was 95.3% [95% confidence interval (CI) 85.8-98.5] in DV and 98.6% (95% CI 90.8-99.8) in BD (P = 0.345). The cumulative incidences of reoperation at 10 years in DV versus BD were 3.9% (95% CI 0.7-11.8) vs 18.1% (95% CI 6.9-33.4) for any cause (P = 0.046) and 1.9% (95% CI 0.1-8.8) vs 15.9% (95% CI 5.5-31.4) for aortic valve-related causes (P = 0.032). The reasons for valve-related reoperation were aortic insufficiency (3/5 in DV vs 5/10 in BD), aortic stenosis (0/5 vs 2/10) and infective endocarditis (2/5 vs 3/10).

CONCLUSIONS

Both DV and BD procedures for patients with aortic root aneurysm with tricuspid valve resulted in excellent 10-year survival. All-cause and aortic valve-related reoperations were significantly less frequent with valve-sparing root replacement, suggesting an advantage of DV over biological BD.

Transcatheter valve-in-valve implantation versus surgical redo aortic root replacement in patients with degenerated freestyle aortic bioprosthesis

BACKGROUND

Transcatheter aortic valve-in-valve implantation (ViV TAVI) represents a new treatment option for patients with degenerated aortic bioprosthesis. Comparative data to redo surgical aortic valve replacement (redo SAVR) are limited.

OBJECTIVE

We investigated feasibility and outcome of ViV TAVI versus redo SAVR in patients with symptomatic degenerated Medtronic Freestyle aortic bioprosthesis (FSB).

METHODS

Between January 2002 and February 2020, 25 patients with failed FSB underwent ViV TAVI and 10 patients with failed FSB underwent redo SAVR. Endpoints were defined according to the Valve Academic Research Consortium-2 (VARC-2) criteria.

RESULTS

Age and logistic EuroSCORE II were higher in patients with ViV TAVI (75.4 ± 1.7 vs. 62.9 ± 5.1 years, p = .019; 11.5 ± 1.6 vs. 5.6 ± 5.6%, p = .007). Valve implantation was successful in all cases. Mean transvalvular pressure gradients were significantly lower in patients with redo SAVR than ViV TAVI (7.6 ± 1.0 vs. 10.3 ± 0.8 mmHg, p = .037). Aortic valve regurgitation was absent in 91% and 100% of patients with ViV TAVI and redo SAVR, respectively. Thirty-day mortality rates were 12% in the ViV TAVI cohort versus 0% in the redo SAVR cohort (p = .542). Within the first year after hospital discharge, one patient after ViV TAVI had redo surgical intervention.

CONCLUSIONS

ViV TAVI and redo SAVR lead to excellent functional results in patients with degenerated FSB. Post-procedural early complications must be considered particularly in patients with ViV TAVI because of higher clinical risk profiles.

Long-term survival after xenograft versus homograft aortic root replacement: Results from a prospective randomized trial

OBJECTIVE

The study objective was to investigate the long-term survival of patients undergoing xenograft versus homograft full root aortic valve replacement.

METHODS

A total of 166 patients requiring aortic valve surgery were randomized to undergo the Freestyle (Medtronic Inc, Minneapolis, Minn) bioprosthesis (N = 90) or a homograft (N = 76) full root aortic valve replacement between 1997 and 2005 in a single institution. Six patients randomly assigned to the homograft crossed over to the Freestyle bioprosthesis because of the unavailability of suitably sized homografts. All surgeons were required to adhere to the standard surgical technique for homograft root implantation previously described. Follow-up was 98.5% complete.

RESULTS

The mean age of the study population was 65 ± 8 years. Coronary artery bypass grafting was associated with root aortic valve replacement in 76 of 166 patients (46%, P = not significant between groups), and overall hospital mortality was 4.8% (8/166, P = not significant between groups). Median follow-up was 13.8 years (range, 0-21.8 years; 2033 patient-years). The Kaplan-Meier survival analysis showed that there was no significant difference in overall survival between the 2 arms at 5, 10, and 15 years. Twenty-year survival was 28.3% ± 5% for the Freestyle group versus 25.1% ± 5.7% for the homograft group (P = .90), which was comparable to the age- and sex-matched UK general population. The freedom from aortic valve reoperation at 20 years was comparable for the Freestyle group versus the homograft group (67.9% ± 8.8% vs 67.2% ± 10.3%, respectively; P = .74).

CONCLUSIONS

This is the first study to investigate the long-term survival of xenograft versus homograft full root aortic valve replacement from a prospective randomized trial. The observed 20-year overall survival and freedom from aortic valve reoperation serve as a benchmark for future studies on interventions for aortic valve disease in the elderly.

Repeat Pregnancy after Prior Aortic Valve-in-Valve Replacement: A Cautionary Tale

Transcatheter aortic valve replacement (TAVR) within a severely stenotic native aortic valve or previously placed surgical biologic aortic valve replacement (SAVR) is a rare occurrence in pregnant patients. The short- and long-term procedural outcomes for future pregnancies in these women or any woman of child bearing age who have received prior TAVR or TAVR in SAVR, are unknown. We describe the first result of a repeat pregnancy outcome in a woman with a history of prior TAVR in SAVR. Both maternal and fetal outcomes were favorable, but maternal cardiac complications observed in the third trimester emphasize our concerns regarding risk for cardiac complications in subsequent pregnancies in patients with a prior TAVR in SAVR. Despite the maternal complications that occurred during repeat pregnancy in this patient, a successful pregnancy outcome reaffirms our recommendation to utilize a multidisciplinary team for pregnancy management in patients with prior TAVR or TAVR in SAVR and to help in the management of any cardiac complications that may occur during or shortly after pregnancy.

Midterm outcomes of subcoronary stentless porcine valve versus stented aortic valve replacement

INTRODUCTION

Stentless porcine xenografts are versatile bioprosthetic valves with the advantage of improved hemodynamics that mimic the function of the native aortic valve. However, these bioprostheses are challenging to implant in the subcoronary position.

METHODS

All consecutive patients who underwent a bioprosthetic aortic valve replacement (AVR) were included from our institutional database. Cox regression analysis was preformed to determine significant predictors for mid term mortality as well as all cause, cardiac, and heart failure readmission.

RESULTS

Patients in the subcoronary stentless group were older and more likely to be female and were likely to have a higher Society of Thoracic Surgery risk of mortality. Survival was superior in the stented AVR cohort at 30-days (96.4% vs 90.5%; P < .001), 1-year (90.5% vs 71.6%; P < .001), and 5-year (74.5% vs 56.9%; P < .001) follow up. Acute kidney injury (16.22% vs 5.22%; P < .001) and blood product transfusion (70.27% vs 44.0%; P < .001) were higher in the stentless group. Multivariable analysis revealed subcoronary stentless implantation as a significant independent risk factor for mortality (hazards ratio: 1.92 [1.35,2.72]; P < .001).

CONCLUSION

Stentless porcine xenograft implantation with the Freestyle bioprosthetic in the subcoronary position can be successfully performed in select patients, but its use is associated with increased perioperative morbidity and mortality affecting midterm outcomes. Individual patient selection and surgeon experience are important to ensure favorable outcomes.

Long-term clinical outcomes of the Toronto stentless porcine valve: 15-year results from dual centers

BACKGROUND AND AIM OF THE STUDY

The purpose of this study is to examine the long-term durability of the Toronto stentless porcine valve (SPV) in the aortic position (St Jude Medical, Minneapolis, MN).

METHODS

We assessed the long-term clinical outcomes of 515 patients with aortic valve replacement (AVR) with the Toronto SPV from 1987 to 2001 at two centers, excluding early (<30 days) death. Median follow-up was 11.5 years (maximum 19.0 years).

RESULTS

Average age was 64.2 ± 10.8 years, and females were 34% (173/515). The incidence of prosthesis-patient mismatch was low, 10.9%. Overall survival was 90.7 ± 1.3%, 75.4 ± 2.0%, and 56.8 ± 3.2% at 5, 10, and 15 years, respectively after surgery. Over the follow-up duration, 116 patients (23%) underwent repeated AVR: 90 for structural valve deterioration (SVD), 12 for endocarditis, 10 nonstructural valve dysfunction (10 aortic regurgitation due to aorta dilatation), and four for other reasons. The cumulative incidence of repeated AVR with death as a competing risk was 1.4% (95% confidence interval [CI], 0.6-2.7), 11.1% (95% CI, 8.4-14.2), and 34.4% (95% CI, 28.8-40.2) at 5, 10, and 15 years, respectively. Reoperative mortality was 5.2% (6/116). In SVD, the regurgitation type was dominant (82%).

CONCLUSIONS

The Toronto SPV is associated with excellent survival and durability during the first decade of follow-up. However, regurgitation type of SVD increases from 10 years after operation with acceptable reoperative mortality. These findings may assist with prosthesis selection and reintervention strategy for failing stentless bioprosthesis.

[Safety of biological valves for aortic valve replacement: A systematic review and meta-analysis]

OBJECTIVE

To provide a comprehensive and contemporary overview of the long-term safety outcomes after aortic valve replacements (AVR) with conventional biological heart valve (stented or stentless).

METHODS

English databases (Medline, Embase, Web of Science, CENTRAL, and ClinicalTrial.gov) and Chinese databases (CNKI, VIP, WanFang, and SinoMed) were searched systemically from January 1, 2000 to January 26, 2019. Eligible randomized controlled trials, non-randomized clinical trials, cohort studies (retrospective or prospective), and unselected case series were included. Strict screening of the obtained literature was conducted to extract relevant data by two reviewers. Other inclusion criteria were studied reporting on outcomes of AVR with biological valves (stented or stentless), with or without coronary artery bypass grafting (CABG) or valve repair procedure, with mean follow-up length equal to or longer than 5 years. We excluded studies that reported only a specific patient group (e.g., patients with renal failure, or pregnancy), without the report of biological valve type, or with study population size less than 100. The meta-analysis was performed using Stata 14.0 software.

RESULTS

In this study, 53 papers (in total 57 study groups) involving 47 803 patients were included. (1) The all-cause mortality was 6.33/100 patient-years (95%CI: 5.85-6.84). Subgroup analysis showed that the mortality rates of porcine and bovine valve prostheses were 5.69/100 patient-years (95%CI: 5.05-6.41) and 7.29/100 patient-years (95%CI: 6.53-8.13), respectively. The all-cause mortality rates for stented and stentless valve were 6.69/100 patient-years (95%CI: 6.12-7.30) and 5.21/100 patient-years (95%CI: 4.43-6.14), respectively. (2) The incidence rate of thromboembolism was 1.16/100 patient-years (95%CI: 0.96-1.40), the incidence rate of permanent pacemaker (PPM) implantation was 1.08/100 patient-years (95%CI: 0.75-1.54), the incidence rate of stroke was 0.74/100 patient-years (95%CI: 0.51-1.06), the incidence rate of structural valve dysfunction (SVD) was 0.73/100 patient-years (95%CI: 0.59-0.91), the incidence rate of major bleeding was 0.52/100 patient-years (95%CI: 0.41-0.65), the incidence rate of endocarditis was 0.38/100 patient-years (95%CI: 0.33-0.44), and the incidence rate of non-structural valve dysfunction (NSVD) was 0.20/100 patient-years (95%CI: 0.13-0.31). The total reoperation rate for biological aortic valve was 0.77/100 patient-years (95%CI: 0.65-0.91), and the SVD related reoperation rate was 0.46/100 patient-years (95%CI: 0.36-0.58).

CONCLUSION

The all-cause mortality for conventional biological AVR was 6.33/100 patient-years. Thromboembolism, PPM implantation, reoperation, stroke, and SVD were major long term complications.

Clinical and Echocardiographic Outcomes After Aortic Valve Repair Surgery

OBJECTIVE

To assess early and late clinical outcomes in patients who underwent aortic valve repair surgery for aortic valve insufficiency, and to investigate predictors for recurrence.

METHODS

Of 151 consecutive patients who underwent aortic valve repair surgery for varying degrees of aortic insufficiency (AI) in our department between 2004 and 2018, 60 (40%) underwent aortic root replacement, 71 (47%) aortic cusp plication, 31 (20%) subcommissural annuloplasty, 29 (19%) circular annuloplasty, and 28 (18%) autologous pericardial patch augmentation.

RESULTS

One patient died in the hospital (0.7%). Mean clinical and echocardiographic follow-up was 62±43 months (range 1 to 159) and 50 ± 40 months (range 1 to 158), respectively. The overall survival rate was 99.3% at 1 year and 98% at 5 years of follow-up. Seventeen patients (11.3%) had recurrent severe AI, and all of them underwent reoperation with a mean duration to reoperation of 35 ± 39 months. Risk factors for the development of recurrent significant AI (≥3) or reoperation, by univariable analysis, were unicuspid or bicuspid aortic valve (AV) (P = 0.018), the use of subcommissural annuloplasty (P = 0.010), the need for cusp repair (P = 0.001), and the use of pericardial patch augmentation (P < 0.001). By multivariable analysis only the use of pericardial patch augmentation emerged as a significant independent predictor for the development of recurrent significant AI (≥3) or reoperation (P = 0.020).

CONCLUSION

AV repair can be performed with low morbidity and mortality, with good early and late clinical outcomes. However, in our experience there was a significant rate of recurrent AI especially in patients who underwent cusp augmentation using glutaraldehyde-treated autologous pericardial patch.

Postimplant biological aortic prosthesis degeneration: challenges in transcatheter valve implants

Surgical aortic valve replacement (SAVR) is highly effective and can be achieved with relatively low risk in patients with severe aortic stenosis. Bioprostheses have been used most frequently during the past 60 years. However, the function of biological valves usually declines after 10-15 years from implant when structural valve degeneration occurs often mandating a reoperation once valve dysfunction becomes haemodynamically significant. Known for many years by surgeons and cardiologists taking care of patients with SAVR, the issue of postimplant structural valve degeneration has been recently highlighted also in patients with transcatheter aortic valve implant (TAVI). There is growing concern that TAVI valves exhibit structural valve degeneration due to inherent challenges of the deployment mode. The impact on postimplant degeneration of TAVI valves compared to SAVR has still to be understood and defined. Based on the ongoing process of expanding TAVI indications, several potential shortcomings and caveats, learned during the last 60 years of SAVR experience, should be taken into consideration to refine this technique.

Reinterventions after freestyle stentless aortic valve replacement: an assessment of procedural risks

OBJECTIVES

Repeat aortic valve interventions after previous stentless aortic valve replacement (AVR) are considered technically challenging with an increased perioperative risk, especially after full-root replacement. We analysed our experience with reinterventions after stentless AVR.

METHODS

A total of 75 patients with previous AVR using a Freestyle stentless bioprosthesis (31 subcoronary, 15 root-inclusion and 29 full-root replacement) underwent reintervention in our centre from 1993 until December 2018. Periprocedural data were retrospectively collected from the department database and follow-up data were prospectively collected.

RESULTS

Median age was 62 years (interquartile range 47-72 years). Indications for reintervention were structural valve deterioration (SVD) in 47, non-SVD in 13 and endocarditis in 15 patients. Urgent surgery was required in 24 (32%) patients. Reinterventions were surgical AVR in 16 (21%), root replacement in 51 (68%) and transcatheter AVR in 8 (11%) patients. Early mortality was 9.3% (n = 7), but decreased to zero in the past decade in 28 patients undergoing elective reoperation. Per indication, early mortality was 9% for SVD, 8% for non-SVD and 13% for endocarditis. Aortic root replacement had the lowest early mortality rate (6%), followed by surgical AVR (13%) and transcatheter AVR (25%, 2 patients with coronary artery obstruction). Pacemaker implantation rate was 7%. Overall survival rate at 10 years was 69% (95% confidence interval 53-81%).

CONCLUSIONS

Repeat aortic valve interventions after stentless AVR carry an increased, but acceptable, early mortality risk. Transcatheter valve-in-valve procedures after stentless AVR require careful consideration of prosthesis leaflet position to prevent obstruction of the coronary arteries.

Pregnancy and transcatheter aortic valve replacement in a severely stenotic Freestyle full aortic root stentless bioprosthesis

Symptomatic degenerative prosthetic aortic valve stenosis during pregnancy represents a significant risk to both mother and fetus, and until recently, surgical aortic valve replacement (SAVR) during pregnancy was often the only choice for women opting to continue pregnancy. However, symptomatic severe stenosis in a pregnant woman with a degenerated full aortic root Freestyle stentless bioprosthesis (FSB) and reimplanted coronary arteries presents additional complexities that require an alternative surgical approach. In this case report, we describe the first successful transcatheter aortic valve replacement (TAVR) in SAVR for a severely stenotic degenerative FSB in a pregnant woman and subsequent delivery of a healthy infant several months later. TAVR in SAVR of a severely stenotic aortic FSB should be considered as a surgical option in symptomatic pregnant women. Short-term and long-term implications for future pregnancy should be discussed by a multidisciplinary team and with the patient.

The Use of Biological Heart Valves

BACKGROUND

Biological heart-valve prostheses have undergone continuous devel- opment up to the present, and technological advances have been made in catheter- assisted valve systems (transcatheter aortic valve implantation, TAVI) and minimally invasive routes of application. These parallel trends have led to major changes in therapeutic strategies, widening the spectrum of patients who are candidates for biological aortic valve implantation.

METHODS

This review is based on pertinent publications retrieved by a systematic search in PubMed employing the search terms "conventional biological aortic pros- thesis," "rapid deployment prosthesis," and "transcatheter aortic valve implantation/ replacement."

RESULTS

Among biological heart-valve prostheses, a distinction is drawn between stented (conventional, rapid-deployment, and catheter-assisted) and non-stented types. The long-term durability of conventional, surgically implantable biological valve protheses is by far the best documented: the reported 5-year reoperation rates range from 13.4% to 36.6%, and the pacemaker implantation rate is ca. 4%. Rapid-deployment prostheses combine the advantages of conventional and ca- theter-assisted techniques and facilitate minimally invasive approaches. The TAVI method is currently recommended for high- and intermediate-risk patients, while conventional valve replacement remains the method of choice for those at low risk. Rapid-deployment and TAVI prostheses is associated with a higher pacemaker im- plantation rate than conventional prostheses: these rates are 8.5-15.3% for TAVI and 6.0-8.8% for rapid-deployment valves. The intermediate-term durability of catheter-assisted and rapid-deployment prostheses appears promising, but their long-term durability is still unclear.

CONCLUSION

The further development of biological heart-valve prostheses in the form of improved conventional, transcatheter, and rapid-deployment prostheses now enables individualized treatment. Before any such procedure is performed, the car- diac team must assess the patient's risk profile and the advantages and disadvan- tages of each type of prosthesis to determine which is best.

Long-term Transcatheter Aortic Valve Durability

Transcatheter aortic valve implantation (TAVI) has become the standard of care for high-risk and inoperable surgical patients and a valid alternative to surgery for low- and intermediate-risk patients with severe, symptomatic aortic stenosis. It is increasingly being used for younger, lower-risk patients, so it is important to ensure the durability for long-term transcatheter aortic valves. The lack of standard definitions of structural valve degeneration (SVD) had made comparison among studies on prosthetic valve durability problematic. The 2017 standardised definitions of SVD by the European Association of Percutaneous Cardiovascular Intervention), the European Society of Cardiology and the European Association for Cardio-Thoracic Surgery, and the 2018 definitions by the Valve In Valve International Data group, has generated an increased uniformity in evaluations. This article examines the potential mechanisms and rates of SVD of transcatheter bioprostheses and the role of redo TAVI as a treatment option.

Open-heart transcatheter aortic valve replacement in complex aortic valve reoperation: about a case series

Introduction

Aortic homograft and stentless aortic root are helpful in acute infective endocarditis of the aortic valve as biological conduit when total root replacement is required. Reoperation for failure of aortic homograft and stentless aortic root remains challenging for the surgeon as the entire root can be heavily calcified.

Case presentation

Here, are reported, three cases of patients successfully treated with open-heart transcatheter aortic valve replacement (TAVR) whereas no other prosthesis was implantable due to a massively calcified homograft or stentless prosthesis.

Discussion

Open-heart TAVR avoided the risk of complete root replacement which is higher than redo aortic valve replacement (AVR). This rescue technique facilitated risky surgical procedure by combining the strengths of both TAVR and conventional AVR.

Morphometrical and biomechanical analyses of a stentless bioprosthetic valve: an implication to avoid potential primary tissue failure

OBJECTIVES

Stentless bioprosthetic valves provide hemodynamic advantages over stented valves as well as excellent durability. However, some primary tissue failures in bioprostheses have been reported. This study was conducted to evaluate the morphometrical and biomechanical properties of the stentless Medtronic Freestyle™ aortic root bioprosthesis, to identify any arising problem areas, and to speculate on a potential solution.

METHODS

The three-dimensional heterogeneity of the stentless bioprosthesis wall was investigated using computed tomography. The ascending aorta and the right, left, and non-coronary sinuses of Valsalva were resected and examined by an indentation test to evaluate their biomechanical properties.

RESULTS

The non-coronary sinus of Valsalva was significantly thinner than the right sinus of Valsalva (p < 0.01). Young's modulus, calculated as an indicator of elasticity, was significantly greater at the non-coronary sinus of Valsalva (430.7 ± 374.2 kPa) than at either the left (190.6 ± 70.6 kPa, p < 0.01) or right sinuses of Valsalva (240.0 ± 56.5 kPa, p < 0.05).

CONCLUSIONS

Based on the morphometrical and biomechanical analyses of the stentless bioprosthesis, we demonstrated that there are differences in wall thickness and elasticity between each sinus of Valsalva. These differences suggest that the non-coronary sinus of Valsalva is the most vulnerable and at greater risk of tissue failure. The exclusion of the non-coronary sinus of Valsalva may be beneficial to mitigate the long-term risks of tissue failure in the stentless bioprosthesis.

Surgery for Active Infective Endocarditis of the Aortic Valve With Infection Extending Beyond the Leaflets

BACKGROUND

The optimal aortic substitute in extensive aortic valve active infective endocarditis (AIE) continues to be debated. To determine the surgical approach in aortic valve AIE with infection extension beyond the leaflets, we evaluated the outcome of reconstructive surgery with various valve substitutes in those patients.

METHODS

During 2000-2013, 168 patients had surgery for extensive aortic valve AIE. Patients were categorised based on aortic valve substitute: Group A: Stented aortic valve replacement (AVR), Group B: Stented AVR with patch support, Group C: Stentless valve, Group D: Aortic allograft, and Group E: Composite valve graft. Outcome parameters were mortality, postoperative cardiogenic or septic shock, stroke, or reinfection.

RESULTS

Stented valves with patch support were more frequently utilised in cases of native valve endocarditis (p<0.001). Postoperative complications were comparable among groups. Concomitant preoperative extension of infection in the mitral valve predicted reinfection (OR 3.6; confidence interval 1.46-8.66; p=0.005). Survival was not affected by operative group (log rank=0.6). Univariable preoperative predictors of mortality were: septic shock (hazard ratio 8.3; 95% confidence interval 3.6-19.2; p<0.001), ejection fraction (hazard ratio 0.96; 95% confidence interval 0.93-0.99; p=0.006), preoperative cardiogenic shock (hazard ratio 1.9; 95%CI 1.1-3.6, p=0.02) and concomitant mitral valve surgery (hazard ratio 1.8; 95% confidence interval 1.2-2.5; p=0.002).

CONCLUSIONS

Surgical treatment of extensive aortic valve infective endocarditis remains a challenge. Outcomes were not affected by the surgical complexity of aortic reconstruction procedure or valve substitute. Surgical approach should be tailored to individual patient's characteristics.

Bioprosthetic aortic valve durability in the era of transcatheter aortic valve implantation

The main limitation of bioprosthetic valves is their limited durability, which exposes the patient to the risk of aortic valve reintervention. Transcatheter aortic valve implantation (TAVI) is considered a reasonable alternative to surgical aortic valve replacement (SAVR) in patients with intermediate or high surgical risk. TAVI is now rapidly expanding towards the lower risk populations. Although the results of midterm durability of the transcatheter bioprostheses are encouraging, their long-term durability remains largely unknown. The objective of this review article is to present the definition, mechanisms, incidence, outcome and management of structural valve deterioration of aortic bioprostheses with specific emphasis on TAVI. The structural valve deterioration can be categorised into three stages: stage 1: morphological abnormalities (fibrocalcific remodelling and tear) of bioprosthesis valve leaflets without hemodynamic valve deterioration; stage 2: morphological abnormalities and moderate hemodynamic deterioration (increase in gradient and/or new onset of transvalvular regurgitation); and stage 3: morphological abnormalities and severe hemodynamic deterioration. Several specifics inherent to the TAVI including valve oversizing, manipulation, delivery, positioning and deployment may cause injuries to the valve leaflets and increase leaflet mechanical stress, which may limit the long-term durability of transcatheter bioprostheses. The selection of the type of aortic valve replacement and bioprosthesis should thus take into account the ratio between the demonstrated durability of the bioprostheses versus the life expectancy of the patient. Pending the publication of robust data on long-term durability of transcatheter bioprostheses, it appears reasonable to select SAVR with a bioprosthesis model that has well-established long-term durability in patients with low surgical risk and long life expectancy.

Aortic Valve Reoperation After Stentless Bioprosthesis: Short- and Long-Term Outcomes

BACKGROUND

Limited data are available regarding outcomes for stentless aortic valve reoperation. The reported reoperative mortality has been unacceptably high.

METHODS

Between 1997 and 2017, a retrospective analysis was performed on 143 patients who underwent open aortic valve reoperations for failed stentless aortic valve bioprostheses. We evaluated both short-term and long-term outcomes on this cohort of patients.

RESULTS

Bicuspid aortic valve was present in 107 of 143 patients (75%) at the time of the initial Freestyle (Medtronic, Minneapolis, MN) procedure, and 120 of 143 patients (84%) underwent a modified inclusion aortic root replacement procedure. The interval from first operation to reoperation was 9 years (range, 5.4 to 11.8), which was significantly shorter for patients with infectious endocarditis (4.1 years; range, 1.8 to 7.1) compared with patients with structural valvular deterioration (10.4 years; range, 8.1 to 12.4, p < 0.001). The median age at the time of reoperation was 59 years (range, 50 to 67). Aortic valve reoperation was performed for structural valve deterioration in 68% cases compared with 32% for infectious prosthetic valve endocarditis. Concomitant surgery included coronary artery bypass (13%), mitral valve surgery (4%), and ascending aorta and arch replacement (42%). The 30-day and inhospital mortality was 1% and 2%, respectively. The composite outcome including myocardial infarction, stroke, new-onset renal failure on hemodialysis, and operative mortality was 4%. The 5-year and 10-year Kaplan-Meier survival after reoperation for failed stentless valve was 83% (95% confidence interval: 73% to 89%) and 57% (95% confidence interval: 36% to 74%).

CONCLUSIONS

Aortic valve reoperation after stentless valve implantation can be performed with low operative mortality and favorable long-term survival.

Biological aortic valve replacement: advantages and optimal indications of stentless compared to stented valve substitutes. A review

Controversy still surrounds the optimal biological valve substitute for aortic valve replacement. In light of the current literature, we review advantages and optimal indications of stentless compared to stented aortic bio-prostheses. Recent meta-analyses, prospective randomized controlled trials and retrospective studies comparing the most frequently used stentless and stented aortic bio-prostheses were analyzed. In the present review, the types and implantation techniques of the bio-prosthesis that are seldom taken into account by most studies and reviews were integrated in the interpretation of the relevant reports. For stentless aortic root bio-prostheses, full-root vs. sub-coronary implantation offered better early transvalvular gradients, effective orifice area and left ventricular mass regression as well as late freedom from structural valve deterioration in retrospective studies. Early mortality and morbidity did not differ between the stentless and stented aortic bio-prostheses. Early transvalvular gradients, effective orifice area and regression of left ventricular hypertrophy were significantly better for stentless, especially as full-root, compared to stented bio-prostheses. The long-term valve-related survival for stentless aortic root and Toronto SPV bio-prosthesis was as good as that for stented pericardial aortic bio-prostheses. For full-root configuration this survival advantage was statistically significant. There seems to be not one but different ideal biological valve substitutes for different subgroups of patients. In patients with small aortic root or exposed to prosthesis-patient mismatch full-root implantation of stentless bio-prostheses may better meet functional needs of individual patients. Longer follow-ups on newer generation of stented bio-prostheses are needed for comparison of their hemodynamic performance with stentless counterparts especially in full-root configuration.

Current indications for stentless aortic bioprostheses

The best aortic prostheses have been debated for decades. The introduction of stentless aortic bioprostheses was aimed at improving hemodynamics and potentially the durability of aortic bioprostheses. Despite the good short- and long-term outcomes after implantation of stentless aortic bioprostheses, their use remains limited owing to the technically demanding implantation techniques. Nevertheless, stentless aortic bioprostheses might be of special benefit in certain indications, where they could be a valuable addition to the surgical armamentarium.

Freestyle stentless bioprosthesis for aortic valve therapy: 17-year clinical results

BACKGROUND

Aortic valve replacement with stentless bioprostheses has been shown to produce lower aortic gradients than stented bioprostheses, thus facilitating left ventricular mass regression and preventing heart failure. We sought to determine the long-term results of stentless biological aortic valve replacement over a 17-year follow-up.

METHODS

Between 1996 and 2012, 2551 patients underwent isolated aortic valve replacement with a stentless prosthesis (Medtronic Freestyle) at a single center. The mean patient age was 72 ± 10 years, 55% were male, 24.1% were in New York Heart Association class I and II, 9.6% had undergone previous surgery, 18.1% had coronary artery disease, and 23.1% had diabetes. For the long-term follow-up, patients were contacted in writing and by telephone; follow-up was 96.3% complete, resulting in 11,546 patient-years.

RESULTS

At 30 days, mortality (5.4%), renal failure (3.9%), myocardial infarction (0.7%), and stroke (1.4%) rates were acceptable. During long-term follow-up of 1-17 years, the bleeding rate (2.9%) was higher than the thromboembolic event rate (0.7%) despite 18.1% of patients being on oral anticoagulants. New pacemaker implantation (4.5%; 0.87 events/100 patient-years), neurological disorders (5%; 0.52 events/100 patient-years), valve insufficiency (0.7%; 0.16 events/100 patient-years), paravalvular leakage (0.4%; 0.09 events/100 patient-years) and reoperation due to valvular complications (0.7%; 0.38 events/100 patient-years) were rare. Long-term survival was 41.8% ± 1.6 after 10 years, 21.3% ± 2.3 after 15 years, and 12.1% ± 3.9 after 17 years.

CONCLUSION

Long-term results after aortic valve replacement with stentless biological prostheses compare favorably with those obtained with stented bioprostheses.