Very Long-Term Survival Implications of Heart Valve Replacement With Tissue Versus Mechanical Prostheses in Adults <60 Years of Age

Long-term function of a novel autologous transcatheter pulmonary heart valve implant in an adult animal model

BACKGROUND

Current heart valve implants entail major disadvantages in the treatment for younger patients or those with congenital heart defects.

AIM

Evaluation of novel transcatheter pulmonary valve implant made from autologous pericardium with natural crosslinking agent in an in vitro setup and in vivo animal model METHODS: Valves were tested in a pulse duplicator according to ISO-standard 5840. For in vivo studies computer tomography was performed to measure sheep's native pulmonary valve dimensions. Pericardium was harvested by thoracotomy, personalized implants were manufactured and deployed in pulmonary valve position of the same sheep. Every 3 months implant functionality was evaluated by intracardiac echocardiography, intracardiac pressure measurements and cardiac magnetic resonance imaging (cMRI). Implants were explanted for macroscopic and histological examination.

RESULTS

In vitro experiments showed compliance with regulatory requirements in terms of valve opening and insufficiency. Five sheep successfully received an autologous valve implant. Two animals had to be euthanized due to trauma sustained in the stable. Long-term valve function was excellent in three out of four animals with median implant cMRI regurgitation fraction of 9% (n = 4) at 3 months, 8% (n = 3) at 6, 8% (n = 3) at 9, 12% (n = 3) at 13, 8% (n = 2) at 17% and 8% (n = 2) at 20.5 months after implantation. Despite good adherence to neighboring tissue and endothelization, histological assessment revealed some signs of degeneration.

CONCLUSION

Transcatheter pulmonary valve implants showed promising function for up to 20.5 months encouraging research to further improve this approach.

Aortic Valve Replacement in Adult Patients with Decellularized Homografts: A Single-Center Experience

BACKGROUND

decellularized aortic homografts (DAH) represent a promising alternative for aortic valve replacement in young adults due to their low immunogenicity and thrombogenicity. Herein, we report our midterm, single-center experience in adult patients with non-frozen DAH from corlife.

METHODS

safety, durability, and hemodynamic performance were evaluated according to current guidelines in all consecutive patients who had received a DAH at our center since 03/2016.

RESULTS

seventy-three (mean age 47 ± 11 years, 68.4% (n = 50) male) patients were enrolled. The mean diameter of the implanted DAH was 24 ± 2 mm. Mean follow-up was 36 ± 27 months, with a maximum follow-up of 85 months and cumulative follow-up of 215 years. No cases of stenosis were observed, in four (5.5%) cases moderate aortic regurgitation occurred, but no reintervention was required. No cases of early mortality, non-structural dysfunction, reoperation, valve endocarditis, or thrombosis were observed. Freedom from bleeding and thromboembolic events was 100%; freedom from re-intervention was 100%; survival was 98.6% (n = 72).

CONCLUSIONS

early and mid-term results showed low mortality and 100% freedom from reoperation, thromboembolic events, and bleeding at our center. However, in order for this novel approach to be established as a valid alternative to aortic valve replacement in young patients, long-term data are required.

Impact of different in vitro models on functional performance of the self-expanding transcatheter heart valve

OBJECTIVES

Transcatheter heart valves (THVs) are investigated according to International Organization for Standardization requirements using in vitro heart simulators to evaluate hydrodynamic performance. In contrast to surgical valves, a THV's performance heavily depends on the configuration and shape of the aortic anulus. In International Organization for Standardization regulations, there is no detailed definition for the construction of a compartment in which a THV has to be tested. Therefore, the aim of this in vitro study was to compare different in vitro models for functional testing of THVs.

METHODS

Porcine aortic conduits (23-mm diameter) were implanted in Dacron prostheses and calcified with double-distilled water and calcification buffer at 37°C over 83 million cycles in a Hi-Cycler (durability testing) mimicking nearly 3 patient-years. Hydrodynamic testing of Evolut PRO 26 mm was performed within 3 models (plexiglass, native conduit and calcified conduit; all 23-mm diameter) at a frequency of 64 bpm and different stroke volumes (55-105 ml).

RESULTS

Calcified conduits showed significantly higher mean pressure gradients (MPG) and lower effective orifice areas (EOA) in comparison to native conduits (without THV; P < 0.001). EOA and MPG of Evolut PRO differed depending on the model tested. Calcified conduits resulted in the lowest EOA and highest MPG of the THV compared to plexiglass and the native conduit. Full expansion of the THV was least impaired in the native conduit, while lowest geometric orifice area, lowest minimal internal diameter and highest pin-wheeling index of Evolut PRO were seen in the calcified conduit.

CONCLUSIONS

Full expansion and functional performance of the Evolut PRO THV depends on the configuration of the testing compartment in an in vitro setting.

Aortic valve replacement in patients aged 50 to 69 years: Analysis using Korean National Big Data

BACKGROUND

The aim of this study was to compare the clinical outcomes and long-term survival in patients who underwent isolated aortic valve replacement (AVR) with mechanical versus bioprosthetic valves.

METHODS

Patients aged 50-69 years who had undergone AVR from 2002 to 2018 were identified and their characteristics were collected from Korean National Health Information Database formed by the National Health Insurance Service, Republic of Korea. Of the 5792 patients, 1060 patients were excluded due to missing values on characteristics. Of the 4732 study patients, 1945 patients (41.1%) had received bioprosthetic valves (Group B) and 2787 patients (58.9%) had received mechanical valves (Group M). A propensity score-matched analysis was performed to match 1429 patients in each group. Data on mortality, cardiac mortality, reoperations, cerebrovascular accidents, and bleeding complications were obtained.

RESULTS

The overall survival rates at 5 and 10 years postoperatively were 87.8% and 75.2% in the matched Group B and 91.2% and 76.7% in the matched Group M, respectively (p = .140). Freedom from cardiac death rates at postoperative 5 and 10 years were 95.6% and 92.4% in the matched Group B and 96.0% and 92.1% in the matched Group M, respectively (p = .540). The cumulative incidence of reoperation was higher in the matched Group B than in the matched Group M (p = .007), and the cumulative incidence of major bleeding was higher in the matched Group M than in the matched Group B (p = .039).

CONCLUSION

In patients aged 50-69 years who underwent isolated AVR, the patients who received bioprosthetic valves showed similar cardiac mortality-free survival and long-term survival rates to the patients who received mechanical valves.

Long-Term Outcomes Stratified by Age in Patients with a Mechanical versus Biological Mitral Valve Replacement

Objectives: Balancing anticoagulation and reoperation risks determines prostheses choice (mechanical/biological) for mitral valve replacement. We aimed to re-evaluate the outcomes after biological versus mechanical mitral valve replacement. Methods: We compared long-term benefits and risks of mechanical and biological prostheses in 2056 patients (52% men, 48% women; 65.4 ± 12.1 years) who underwent mitral valve replacements between 1993−2017, in a retrospective single-centre study. Data sources included prospective institutional database, social registry, general practitioner data and follow-up questionnaire. Patients were stratified by age: < = 39 y (n = 82), 40−49 y (n = 164), 50−59 y (n = 335), 60−69 y (n = 593), 70−79 y (n = 743) and > = 80 y (n = 139). Long-term outcomes (mortality, reoperations, bleeding) were analysed. Results: Altogether, 1308 mechanical (53% men, 47% women; 61.5 ± 11.7 years) and 748 biological (50% men, 50% women; 72.3 ± 9.6 years) valves were implanted. The reason for valve replacement was stenosis in 162, insufficiency in 823 and combined in 323 cases for mechanical, while it was 46, 567 and 135 for biological valves, respectively. Overall cumulative survival was higher with mechanical prosthesis (mean: 139 ± 4 vs. 102 ± 5 months, 10 y: 55% vs. 33%, p < 0.0001). Subgroup analysis revealed higher survival among patients receiving mechanical prosthesis up to 60 years (< = 39 y p = 0.047, 40−49 y p < 0.0001, 50−59 y p = 0.001). In patients 60−69 years, overall survival did not differ; however, in survivors beyond 8 years, mechanical prosthesis showed improved survival (p = 0.014). While between 70−79 years survival was nearly identical, for above 80 years, patients had a higher survival with biological prosthesis (p = 0.014). Conclusion: The present data demonstrated a higher survival of mechanical prosthesis in a wide range of patients after mitral valve replacement.

Biofabrication of Sodium Alginate Hydrogel Scaffolds for Heart Valve Tissue Engineering

Every year, thousands of aortic valve replacements must take place due to valve diseases. Tissue-engineered heart valves represent promising valve substitutes with remodeling, regeneration, and growth capabilities. However, the accurate reproduction of the complex three-dimensional (3D) anatomy of the aortic valve remains a challenge for current biofabrication methods. We present a novel technique for rapid fabrication of native-like tricuspid aortic valve scaffolds made of an alginate-based hydrogel. Using this technique, a sodium alginate hydrogel formulation is injected into a mold produced using a custom-made sugar glass 3D printer. The mold is then dissolved using a custom-made dissolving module, revealing the aortic valve scaffold. To assess the reproducibility of the technique, three scaffolds were thoroughly compared. CT (computed tomography) scans showed that the scaffolds respect the complex native geometry with minimal variations. The scaffolds were then tested in a cardiac bioreactor specially designed to reproduce physiological flow and pressure (aortic and ventricular) conditions. The flow and pressure profiles were similar to the physiological ones for the three valve scaffolds, with small variabilities. These early results establish the functional repeatability of this new biofabrication method and suggest its application for rapid fabrication of ready-to-use cell-seeded sodium alginate scaffolds for heart valve tissue engineering.

Isolated aortic valve replacement with bio-prostheses in patients age 50 to 65 years: a decade of statewide data on cost and patient outcomes

BACKGROUND

Guidelines for choice of replacement valve-mechanical versus bio-prosthetic, are well established for patients aged <50 and >65 years. We studied the trends and implications of aortic valve replacement (AVR) with mechanical versus bioprosthetic valve in patients aged 50 to 65 years.

METHODS

STS and cost database of 17 centers for isolated AVR surgery were analyzed by dividing them into bioprosthetic valve (BV) or mechanical valve (MV) groups.

RESULTS

From 2002 to 2011, 3,690 patients had AVR, 18.6% with MV and 81.4% with BV. Use of BV for all ages increased from 71.5% in 2002 to 87% in 2011. There were 1127 (30.5%) patients in the age group 50-65 years. Use of BV in this group almost doubled, 39.6% in 2002 to 76.8% in 2011. Mean age of patients in BV group was higher (59.2±4.2 years vs. 56.7±4.3 years, P≤0.0001). Preoperative renal failure, heart failure and chronic obstructive pulmonary disease favored use of BV, whereas preoperative atrial fibrillation favored AVR with MV. Mortality (MV 2.2% vs. BV 2.36%) and other postoperative outcomes between the groups were similar. Cost of valve replacement increased for both groups (MV $26,191 in 2002 to $42,592 in 2011; BV $27,404 in 2002 to $44,257 in 2011).

CONCLUSIONS

Use of bioprostheses for AVR has increased; this change is more pronounced in patients aged 50-65 years. Specific preoperative risk factors influence the choice of valve for AVR. Postoperative outcomes between the two groups were similar. Long-term implications of this changing practice, in particular, reoperation for bioprosthetic valve degeneration should be examined.

Replacement of a Björk-Shiley tilting disc mitral valve prosthesis 33 years after initial replacement

Björk-Shiley tilting disc prosthesis was the first tilting disc prosthesis to be used worldwide on a large-scale basis. Herein, we report a case of a 67-year-old male presenting with severe prosthetic valvular dysfunction. He had undergone mitral valve replacement with Björk-Shiley valve at some other center in 1987. The surgical challenge was to replace that with an adequately sized prosthesis. To achieve that, we removed all the previously preserved posterior cusp and then reconstructed the sub-valvular apparatus. The patient had a smooth post-operative recovery. This case report highlights the longest reported survival of a Björk-Shiley mitral valve and specific challenges faced during such redo cases.

Similar long-term survival after isolated bioprosthetic versus mechanical aortic valve replacement: A propensity-matched analysis

OBJECTIVES

Improved durability and preference to avoid anticoagulation have led to increasing use of bioprostheses in younger patients despite the need for eventual reoperation. Therefore, we compared in-hospital complications, reoperation, and survival after bioprosthetic and mechanical aortic valve replacement.

METHODS

From January 1990 to January 2020, 6143 patients underwent isolated aortic valve replacement at Cleveland Clinic; 637 patients received a mechanical prosthesis and 5506 a bioprosthesis. Propensity matching identified 527 well-matched pairs (83% of possible matches) for comparison of perioperative outcomes. The average age of patients was 54 years in the bioprosthesis group and 55 years in the mechanical prosthesis group. Random Forest machine-learning analysis was performed to compare survival using the entire cohort of 6143 patients.

RESULTS

Among matched patients, major in-hospital complications, including stroke, deep sternal wound infection, and reoperation for bleeding, were similar, as was in-hospital mortality (2 in the bioprosthesis group [0.38%] vs 3 in the mechanical prosthesis group [0.57%]; P > .9). Patients receiving a bioprosthesis had shorter hospital stays (median 6 vs 7 days, P < .0001). Fifty-one patients (32% at 14 years) in the bioprosthesis group and 17 patients in the mechanical prosthesis group (8% at 14 years) underwent reoperation (P [log-rank] < .0001); 5-year survival after reoperation was 85% versus 82% (P = .6). Risk-adjusted Random Forest prediction of 18-year survival was 60% in the bioprosthetic group and 58% in the mechanical prosthesis group.

CONCLUSIONS

Aortic valve bioprostheses are associated with excellent short-term outcomes and 18-year survival similar to that of patients receiving mechanical valves. Reoperation does not adversely affect survival. These results suggest that risk for reoperation alone should not deter the use of bioprostheses in younger patients.

Long-term results after the Ross procedure with the decellularized AutoTissue Matrix P® bioprosthesis used for pulmonary valve replacement

OBJECTIVES

Since 1967, the Ross procedure has been performed to treat aortic valve disease using homografts for pulmonary valve replacement. The decellularized Matrix P® prosthesis was developed to overcome (some) limitations of homografts. Until now, the long-term outcome data have been unavailable.

METHODS

Between 2002 and 2010, the Ross procedures using the Matrix P prosthesis were performed in 492 adult patients (mean age 57.2 ± 10.6 years, range 21-73 years) at our institution. Patient data were prospectively collected and analysed (3617.3 patient-years, mean follow-up 7.7  ±  4.3 years). Completeness of follow-up at 1, 5 and 10 years was 98.4%, 94.5% and 91.0%, respectively.

RESULTS

Hospital mortality was 3.9% (n  = 19). During follow-up, 121 patients died resulting in a survival rate at 5, 10 and 12.5 years of 82.8  ±  1.7%, 70.4  ±  2.3% and 62.4  ±  2.9%, respectively. Echocardiography revealed a high incidence of relevant dysfunction of the Matrix P prosthesis and subsequent right ventricular failure. Primary reoperation/reintervention was necessary for 150 Matrix P and 48 autografts. Freedom from pulmonary valve reoperation at 5, 10 and 12.5 years was 76.2  ±  2.1%, 58.6  ±  2.9% and 53.4  ±  3.4%, respectively. The autograft function and the left ventricular function showed similar results as previously reported with a freedom from autograft reoperation at 5, 10 and 12.5 years of 91.8  ±  1.4%, 86.1  ±  2.0% and 86.1  ±  2.0%, respectively.

CONCLUSIONS

The Matrix P prosthesis used for the right ventricular outflow tract reconstruction in the Ross procedure showed unfavourable long-term echocardiographic results with a high rate of reoperation/reintervention for structural pulmonary valve failure. As a consequence, long-term survival of this patient cohort was impaired. Based on these findings, the use of the Matrix P prosthesis for pulmonary valve replacement for Ross procedures in adults should not be recommended.

Bioprosthetic or mechanical heart valves: prosthesis choice for borderline patients?-Results from 9,616 cases recorded in Polish national cardiac surgery registry

BACKGROUND

In middle-aged patients undergoing aortic valve replacement (AVR), the selection of prosthesis type is a complex process. Current guidelines do not unequivocally indicate the type of prosthesis (bioprosthetic or mechanical) recommended for patients between 60-70 years of age. The aim of the study was to present the trends in AVR prosthesis selection in borderline patients over a 10-year period, based on real-life registry data.

METHODS

The study population comprised of 9,616 consecutive patients aged between 60-70 years, who underwent isolated AVR between 2006 and 2016 in all cardiac surgery departments in Poland. Data were extracted from the Polish National Registry of Cardiac Surgery.

RESULTS

Among 27,797 consecutive AVR procedures, patients aged 60-70 years represented 34.6% of the population operated on. From 2006 to 2016, bioprosthetic valves (BVs) were implanted in 53.9% cases, (and) mechanical valves (MVs) in 42.1%. The proportion of different valve types changed in time: from 77.5% of MVs vs. 22.5% of BVs in 2006 to 23.2% of MVs vs. 76.8% of BVs in 2016 (P<0.001). The most commonly implanted BV was the Hancock II (used in 36.4% of BV implantations), the most commonly used MV was the Saint Jude Mechanical prosthesis (implanted in 36.4% of MV implantation cases). A multivariable model identified smaller annulus [OR (95% CI) 0.89 (0.86-0.92), P<0.001], atrial fibrillation [OR (95% CI) 1.32 (1.05-1.67), P=0.017], male sex [OR (95% CI) 1.47 (1.24-1.74), P<0.001] and year of implantation [OR (95% CI) 0.75 (0.71-0.79), P<0.001] as predictors of MV implantation.

CONCLUSIONS

Patients aged 60-70 years represent more than one-third of all AVR patients. Between 2006 and 2016, the proportion of implanted prostheses has changed dramatically. In 2016 BVs were implanted in nearly 75% of AVR cases, three times more often than in 2006.

Recent advances in understanding and managing mitral valve disease

Interest in the mitral valve has increased over the past few years with the development of new technologies that allow intervention in patients previously deemed too ill for treatment. This increased attention has resulted in a significant increase in publications on the mitral valve, the majority of which focus on mitral regurgitation and mitral valve surgery/intervention. The focus of this review is on publications in the past few years that offer additional insights into our understanding and management of mitral valve disease and specifically mitral regurgitation. It will discuss mitral valve anatomy, epidemiology of mitral valve disease, changes in the 2017 management guidelines, management of mitral bioprosthetic valves, transcatheter mitral valve procedures and the repair of rheumatic valves.

Complementary Role of the Computed Biomodelling through Finite Element Analysis and Computed Tomography for Diagnosis of Transcatheter Heart Valve Thrombosis

Introduction

The TAVR procedure is associated with a substantial risk of thrombosis. Current guidelines recommend catheter-based aortic valve implantation for prohibitive-high-risk patients with severe aortic valve stenosis but acknowledge that the aetiology and mechanism of thrombosis are unclear.

Methods

From 2015 to 2018, 607 patients with severe aortic valve stenosis underwent either self-expandable or balloon-expandable catheter-based aortic valve implantation at our institute. A complementary study was designed to support computed tomography as a predictor of complications using an advanced biomodelling process through finite element analysis (FEA). The primary evaluation of study was the thrombosis of the valve at 12 months.

Results

At 12 months, 546 patients had normal valvular function. 61 patients had THVT while 6 showed thrombosis and dislodgement with deterioration to NYHA Class IV requiring rehospitalization. The FEA biomodelling revealed a strong link between solid uncrushed calcifications, delayed dislodgement of TAVR and late thrombosis. We observed an interesting phenomenon of fibrosis/calcification originating at the level of the misplaced valve, which was the primary cause of coronary obstruction.

Conclusion

The use of cardiac CT and predictive biomodelling should be integrated into routine practice for the selection of TAVR candidates and as a predictor of negative outcomes given the lack of accurate investigations available. This would assist in effective decision-making and diagnosis especially in a high-risk cohort of patients.

Transcatheter Valve Replacement: Risk Levels and Contemporary Outcomes

Transcatheter aortic valve replacement (TAVR) has exploded into medical care for aortic stenosis, thus changing the treatment options for patients. TAVR is currently approved for extreme-risk, high-risk, and intermediate-risk patients with symptomatic severe aortic stenosis, and randomized trials for low-risk patients are underway. This article traces the trajectory of TAVR as a viable option for higher-risk patients and examines current outcomes.

Transcatheter Aortic Valve-in-Valve Procedure in Patients with Bioprosthetic Structural Valve Deterioration

Surgical aortic valve replacement is the gold standard procedure to treat patients with severe, symptomatic aortic valve stenosis or insufficiency. Bioprosthetic valves are used for surgical aortic valve replacement with a much greater prevalence than mechanical valves. However, bioprosthetic valves may fail over time because of structural valve deterioration; this often requires intervention due to severe bioprosthetic valve stenosis or regurgitation or a combination of both. In select patients, transcatheter aortic valve replacement is an alternative to surgical aortic valve replacement. Transcatheter valve-in-valve (ViV) replacement is performed by implanting a transcatheter heart valve within a failing bioprosthetic valve. The transcatheter ViV operation is a less invasive procedure compared with reoperative surgical aortic valve replacement, but it has been associated with specific complications and requires extensive preoperative work-up and planning by the heart team. Data from experimental studies and analyses of results from clinical procedures have led to strategies to improve outcomes of these procedures. The type, size, and implant position of the transcatheter valve can be optimized for individual patients with knowledge of detailed dimensions of the surgical valve and radiographic and echocardiographic measurements of the patient's anatomy. Understanding the complexities of the ViV procedure can lead surgeons to make choices during the original surgical valve implantation that can make a future ViV operation more technically feasible years before it is required.

Long-term non-institutionalized survival and rehospitalization after surgical aortic and mitral valve replacements in a large provincial cardiac surgery centre

OBJECTIVES

Long-term quality of life following open surgical valve replacement is an increasingly important outcome to patients and their caregivers. This study examines non-institutionalized survival and rehospitalization within our surgical aortic valve replacement (AVR) and mitral valve replacement (MVR) populations.

METHODS

A retrospective single-centre study of all consecutive open surgical valve replacements between 1995 and 2014 was undertaken. Clinical data were linked to provincial administrative data for 3219 patients who underwent AVR, MVR or double (aortic and mitral) valve replacement with or without concomitant coronary artery bypass grafting (CABG). Non-institutionalized survival and cumulative incidence of rehospitalization was examined up to 15 years.

RESULTS

Follow-up was complete for 96.9% of the 2146 patients who underwent AVR ± CABG (66.7% of the overall cohort), 878 who underwent MVR ± CABG (27.3%) and 195 who underwent double (aortic and mitral) valve replacement ± CABG (6.0%) with a median follow-up time of 5.6 years. Overall non-institutionalized survival was 35.4% at 15 years, and the cumulative incidence of rehospitalization was 34.4%, 63.2% and 87.0% at 1, 5 and 15 years, respectively, without significant differences between valve procedure cohorts. Both non-institutionalized survival and cumulative incidence of rehospitalization improved in more recent eras, despite increasing age and comorbidities.

CONCLUSIONS

Non-institutionalized survival and rehospitalization data for up to 15 years suggest good functional outcomes long after surgical AVR and/or MVR. Continued improvements are seen in these metrics over the past 2 decades. This provides a unique insight into the quality of life after surgical valve replacement in the ageing demographics with valvular heart disease.

Porcine pulmonary valve decellularization with NaOH-based vs detergent process: preliminary in vitro and in vivo assessments

Background

Glutaraldehyde fixed xenogeneic heart valve prosthesis are hindered by calcification and lack of growth potential. The aim of tissue decellularization is to remove tissue antigenicity, avoiding the use of glutaraldehyde and improve valve integration with low inflammation and host cell recolonization. In this preliminary study, we investigated the efficacy of a NaOH-based process for decellularization and biocompatibility improvement of porcine pulmonary heart valves in comparison to a detergent-based process (SDS-SDC0, 5%).

Methods

Native cryopreserved porcine pulmonary heart valves were treated with detergent and NaOH-based processes.

Decellularization was assessed by Hematoxylin and eosin/DAPI/alpha-gal/SLA-I staining and DNA quantification of native and processed leaflets, walls and muscles.

Elongation stress test investigated mechanical integrity of leaflets and walls (n = 3 tests/valve component) of valves in the native and treated groups (n = 4/group).

Biochemical integrity (collagen/elastin/glycosaminoglycans content) of leaflet-wall and muscle of the valves (n = 4/group) was assessed and compared between groups with trichrome staining (Sirius Red/Miller/Alcian blue).

Secondly, a preliminary in vivo study assessed biocompatibility (CD3 and CD68 immunostaining) and remodeling (Hematoxylin and eosin/CD31 and ASMA immunofluorescent staining) of NaOH processed valves implanted in orthotopic position in young Landrace pigs, at 1 (n = 1) and 3 months (n = 2).

Results

Decellularization was better achieved with the NaOH-based process (92% vs 69% DNA reduction in the wall). Both treatments did not significantly alter mechanical properties. The detergent-based process induced a significant loss of glycosaminoglycans (p < 0,05).

In vivo, explanted valves exhibited normal morphology without any sign of graft dilatation, degeneration or rejection. Low inflammation was noticed at one and three months follow-up (1,8 +/− 3,03 and 0,9836 +/− 1,3605 CD3 cells/0,12 mm² in the leaflets). In one animal, at three months we documented minimal calcification in the area of sinus leaflet and in one, microthrombi formation on the leaflet surface at 1 month. The endoluminal side of the valves showed partial reendothelialization.

Conclusions

NaOH-based process offers better porcine pulmonary valve decellularization than the detergent process. In vivo, the NaOH processed valves showed low inflammatory response at 3 months and partial recellularization. Regarding additional property of securing, this treatment should be considered for the new generation of heart valves prosthesis.

Graphical abstract

Graphical abstract of the study

Mechanical or Biologic Prostheses for Aortic-Valve and Mitral-Valve Replacement

BACKGROUND

In patients undergoing aortic-valve or mitral-valve replacement, either a mechanical or biologic prosthesis is used. Biologic prostheses have been increasingly favored despite limited evidence supporting this practice.

METHODS

We compared long-term mortality and rates of reoperation, stroke, and bleeding between inverse-probability-weighted cohorts of patients who underwent primary aortic-valve replacement or mitral-valve replacement with a mechanical or biologic prosthesis in California in the period from 1996 through 2013. Patients were stratified into different age groups on the basis of valve position (aortic vs. mitral valve).

RESULTS

From 1996 through 2013, the use of biologic prostheses increased substantially for aortic-valve and mitral-valve replacement, from 11.5% to 51.6% for aortic-valve replacement and from 16.8% to 53.7% for mitral-valve replacement. Among patients who underwent aortic-valve replacement, receipt of a biologic prosthesis was associated with significantly higher 15-year mortality than receipt of a mechanical prosthesis among patients 45 to 54 years of age (30.6% vs. 26.4% at 15 years; hazard ratio, 1.23; 95% confidence interval [CI], 1.02 to 1.48; P=0.03) but not among patients 55 to 64 years of age. Among patients who underwent mitral-valve replacement, receipt of a biologic prosthesis was associated with significantly higher mortality than receipt of a mechanical prosthesis among patients 40 to 49 years of age (44.1% vs. 27.1%; hazard ratio, 1.88; 95% CI, 1.35 to 2.63; P<0.001) and among those 50 to 69 years of age (50.0% vs. 45.3%; hazard ratio, 1.16; 95% CI, 1.04 to 1.30; P=0.01). The incidence of reoperation was significantly higher among recipients of a biologic prosthesis than among recipients of a mechanical prosthesis. Patients who received mechanical valves had a higher cumulative incidence of bleeding and, in some age groups, stroke than did recipients of a biologic prosthesis.

CONCLUSIONS

The long-term mortality benefit that was associated with a mechanical prosthesis, as compared with a biologic prosthesis, persisted until 70 years of age among patients undergoing mitral-valve replacement and until 55 years of age among those undergoing aortic-valve replacement. (Funded by the National Institutes of Health and the Agency for Healthcare Research and Quality.).

Clinical Outcomes Following the Ross Procedure in Adults: A 25-Year Longitudinal Study

BACKGROUND

Very few reports of long-term outcomes of patients who underwent the Ross procedure have been published.

OBJECTIVES

The authors reviewed their 25-year experience with the Ross procedure with the aim of defining very-long-term survival and factors associated with Ross-related failure.

METHODS

Between January 1990 and December 2014, the Ross procedure was performed in 310 adults (mean age 40.8 years) at a single institution. All patients were prospectively added to a dedicated cardiac surgery registry. Complete post-operative clinical examination and history were obtained, and transthoracic echocardiography was performed according to a standardized protocol. There was no loss to follow-up. Median follow-up was 15.1 years and up to 25 years.

RESULTS

Bicuspid aortic valve was diagnosed in 227 patients (73.2%), and the most common indication for surgery was aortic stenosis (n = 225 [72.6%]). Freedom from any Ross-related reintervention was 92.9% and 70.1% at 10 and 20 years, respectively. Independent risk factors for pulmonary autograft degeneration were pre-operative large aortic annulus (hazard ratio: 1.1; p = 0.01), pre-operative aortic insufficiency (hazard ratio: 2.7; p = 0.002), and concomitant replacement of the ascending aorta (hazard ratio: 7.7; p = 0.0003). There were 4 hospital deaths (1.3%), and overall survival at 10 and 20 years was 94.1% and 83.6%, respectively. Long-term survival was not significantly different in patients who required Ross-related reintervention (log-rank p = 0.70). However, compared with the general population, survival was significantly lower in patients following the Ross procedure when matched on age and sex (p < 0.0001).

CONCLUSIONS

The Ross procedure was associated with excellent long-term valvular outcomes and survival, regardless of the need for reintervention. Adults presenting with aortic insufficiency or a dilated aortic annulus or ascending aorta were at greater risk for reintervention. Unlike previous reports, long-term survival was lower in Ross patients compared with matched subjects.

Transcatheter heart valve in valve implantation with Edwards SAPIEN bioprosthetic valve for different degenerated bioprosthetic valve positions (First Iranian ViV report with mid-term follow up)

Introduction: After early successful experience with transcatheter aortic valve replacement (TAVR), concept of transcatheter implantation of a new valve within a failing bioprosthetic valve emerged. Valve-in-valve (ViV) implantation seems to be a simpler option for high risk surgical patients.

Methods: We performed five ViV procedures in different valve positions. We included patients with failing bioprosthetic valves with high surgical risk due to concomitant comorbidities. We performed 2 transapical ViV procedures for failing mitral bioprosthetic valves, 1 transfemoral procedure for failing pulmonary valve and 2 transfemoral ViV implantation for failing tricuspid bioprosthetic valves.

Results: The procedures were successfully completed in all 5 cases with initial excellent fluoroscopic and echocardiographic verification. There was no valve embolization or paravalvular leakage in any of the cases. Transcatheter valve function was appropriate with echocardiography. Post procedural clinical adverse events like pleural effusion and transient ischemic attack were managed successfully. In midterm follow up all cases remained in appropriate functional class except from the transcatheter pulmonary valve which became moderately stenotic and regurgitant.

Conclusion: As the first Iranian all-comers case series with midterm follow up for ViV implantation, we had no mortality. Interestingly none of our patients had neurologic sequelae after the procedure. Midterm follow up for our patients was acceptable with good functional class and appropriate echocardiographic findings. Due to high surgical risk of the redo procedure after failing of a bioprosthetic valve especially in elderly patients with comorbidities, ViV implantation would be a good alternative to surgery for this high risk group.

Bioprosthetic aortic valve replacement: Revisiting prosthesis choice in patients younger than 50 years old

OBJECTIVE

Aortic prosthesis choice is controversial in young adults because robust comparative outcome data are lacking. We therefore compared mortality and morbidity in young adults after bioprosthetic versus mechanical aortic valve replacement.

METHODS

This was a retrospective analysis of 5111 patients aged 18 to 50 years undergoing primary aortic valve replacement in California and New York State from 1997 to 2006. Median follow-up time was 11.8 years (maximum 18.9 years). The primary endpoint was mortality; secondary endpoints were stroke, bleeding, and reoperation. Propensity score matching yielded 1175 patient pairs.

RESULTS

Bioprosthetic valves increased from 14% to 47% of aortic valve replacements between 1997 and 2014 (P < .001). There was no survival difference with bioprosthetic versus mechanical aortic valves in the propensity score-matched cohort: actuarial 15-year survival was 79.0% (95% confidence interval [CI], 75.8%-81.8%) versus 81.5% (95% CI, 78.5%-84.2%) respectively (hazard ratio [HR], 1.14; 95% CI, 0.93-1.40, P = .20). No interaction was found between age and prosthesis choice on survival (P_interaction = 0.16). After bioprosthetic valve replacement, stroke rates were lower (5.4% [95% CI, 3.8%-7.2%] vs 8.1% [95% CI, 6.3%-10.2%], HR 0.62 [95% CI 0.43-0.91]), bleeding rates were lower (4.2% [95% CI, 3.0-5.6%] vs 8.4% [95% CI, 6.6-10.4%], HR 0.48 [95% CI, 0.33-0.69]), but reoperation rates were greater (24.5% [95% CI, 21.3%-27.8%] vs 9.3% [95% CI, 7.2%-11.7%], HR 5.9 [95% CI 3.2-11.0]) at 15 years versus mechanical valve replacement.

CONCLUSIONS

Although lifetime risks are represented incompletely, these findings suggest that in adults aged 18-50 years, bioprostheses are a reasonable alternative to mechanical valves for aortic valve replacement.

A mechanical heart valve is the best choice

The choice of prosthesis type in patients with valvular heart disease should always be individualised. The treating heart team must weigh the concerns surrounding durability of bioprosthetic valves compared with mechanical valves and the need for lifelong anticoagulation required with mechanical valves. In general, guidelines recommend that patients under the age of 60 would benefit from a mechanical valve, and those over 70 would benefit from a bioprosthetic valve. We would argue, in this context, that the most appropriate choice for this patient would be undertaking a mitral valve replacement with a mechanical prosthesis. This recommendation is based on two considerations: first, there is a high likelihood of failure of a bioprosthesis within an unacceptably short period of time, which would then necessitate a higher risk reoperation. Second, there is high likelihood of needing long-term anticoagulation in a patient with severe mitral stenosis due to the development of atrial fibrillation. While we do acknowledge the difficulty in managing long-term anticoagulation of patients in rural settings, there have nonetheless been significant advancements in this realm with the use of pharmacist-led thrombosis clinics and point of care international normalised ratio (INR) devices in the treatment of rural patients in low-income and middle-income countries. For these reasons, therefore, we would strongly advocate for a mechanical valve in this 44-year-old patient from a rural setting.

Effect of Arched Leaflets and Stent Profile on the Hemodynamics of Tri-Leaflet Flexible Polymeric Heart Valves

Polymeric heart valves (PHV) can be engineered to serve as alternatives for existing prosthetic valves due to higher durability and hemodynamics similar to bioprosthetic valves. The purpose of this study is to evaluate the effect of geometry on PHVs coaptation and hemodynamic performance. The two geometric factors considered are stent profile and leaflet arch length, which were varied across six valve configurations. Three models were created with height to diameter ratio of 0.6, 0.7, and 0.88. The other three models were designed by altering arch height to stent diameter ratio, to be 0, 0.081, and 0.116. Particle image velocimetry experiments were conducted on each PHV to characterize velocity, vorticity, turbulent characteristics, effective orifice area, and regurgitant fraction. This study revealed that the presence of arches as well as higher stent profile reduced regurgitant flow down to 5%, while peak systole downstream velocity reduced to 58% and Reynolds Shear Stress values reduced 40%. Further, earlier reattachment of the forward flow jet was observed in PHVs with leaflet arches. These findings indicate that although both geometric factors help diminish the commissural gap during diastole, leaflet arches induce a larger jet opening, yielding to earlier flow reattachment and lower energy dissipation.

Computer-Assisted Transcatheter Heart Valve Implantation in Valve-in-Valve Procedures

Objective

Valve-in-valve (ViV) procedures are increasingly being considered as an alternative to redo surgery for the treatment of degenerated bioprosthetic heart valves in patients with excessive reoperative risk. The objective of our study was to evaluate the feasibility of computer guidance in transcatheter heart valve (THV) implantation during ViV procedures.

Methods

Preprocedural electrocardiogram-gated computed tomography–scan images were processed using semiautomatic segmentation of the degenerated bioprosthesis’ radiopaque landmarks and of the ascending aorta. Virtual three-dimensional (3D) reconstructions were created. A virtual plane was subsequently added to the 3D reconstructions, indicating the optimal landing plane of the THV inside the tissue valve. Within a hybrid operating theater, a 3D/2D registration was used to superimpose the 3D reconstructions, while dynamic tracking was allowed to maintain the superimposition onto the fluoroscopic images. The THV was afterward implanted according to the optimal landing plane. Projection of the ascending aorta and the coronary arteries was used to assess the risk of coronary ostia obstruction.

Results

Between January 2014 and October 2014, nine patients underwent aortic ViV procedures in our institution. Among those nine patients, five procedures were retrospectively evaluated as a validation step using the proposed method. The mean (SD) superimposition error was 1.1 (0.75) mm. Subsequently, two live cases were prospectively carried out using our approach, successfully implanting the THV inside the degenerated tissue valve.

Conclusions

Our study demonstrates the feasibility of a computer-guided implantation of THV in ViV procedures. Moreover, it suggests that augmented reality may increase the reliability of THV implantation inside degenerated bioprostheses through better reproducibility.

Choice of prosthetic heart valve in a developing country

Mechanical prostheses and stented xenografts (bioprosthesis) are most commonly used substitutes for aortic and mitral valve replacement. The mechanical valves have the advantage of durability but are accompanied with the risk of thromboembolism, problems of long-term anticoagulation, and associated risk of bleeding. In contrast, bioprosthetic valves do not require long-term anticoagulation, but carry the risk of structural valve degeneration and re-operation. A mechanical valve is favoured in young patients (<40 years) if reliable anticoagulation is ensured. In elderly patients (>60 years), a bioprosthesis is a suitable substitute. In middle-aged patients (40-60 years), risk of re-operation in a bioprosthesis is equal to that of bleeding in a mechanical valve. Traditionally, a bioprosthesis is opted in patients with limited life expectancy. Calculation of life expectancy, based solely upon chronological age, is erroneous. In developing countries, the calculated life expectancy is much lower than that of Western population, hence age related Western cut-offs are not valid in developing countries. Besides age, cardiac condition of the patient, systemic illnesses, socio-economic status, gender and geographical location also decide the life expectancy of the patients. Selection of the prosthetic valve substitute should be based on: aspiration of the patient, life expectancy, socio-economic and educational background, occupation of the patient, availability, cost, monitoring of anti-coagulation, monitoring of valve function and other valve related complications, and possibility of re-operation.

Durability after aortic valve replacement with the Mitroflow versus the Perimount pericardial bioprosthesis: a single-centre experience in 2393 patients

OBJECTIVES

This study compares the durability and risk of reoperation in patients undergoing aortic valve replacement (AVR) with either a Mitroflow or a Carpentier-Edwards (CE) pericardial bioprosthesis. Since AVR with bioprosthetic valves has increased progressively in recent years as compared to mechanical valves, especially in patients aged 60-70 years, there has been renewed interest in the long-term durability of current pericardial bioprostheses.

METHODS

We compared 440 AVR with Mitroflow valves with 1953 AVR with CE pericardial valves implanted from 1999 to 2014 with regard to reoperation, reoperation for structural valve deterioration (SVD) and all-cause mortality.

RESULTS

Ten-year freedom from explant of any cause was higher for CE Perimount (98 ± 0.7%) than for Mitroflow (95 ± 1.4%, P < 0.01). Reasons for explant for CE Perimount were SVD (n = 2), endocarditis (n = 8) and paraprosthetic leak (n = 10). The reasons for explant for Mitroflow were SVD (n = 11), endocarditis (n = 3) SVD and pericarditis (n = 1) and paraprosthetic leak (n = 2). Ten-year freedom from explant due to SVD was higher for CE Perimount (100%) than for Mitroflow (96%) (P < 0.01). In small aortic annuli (bioprosthesis size 19-21 mm), freedom from SVD at 10 years for CE Perimount and Mitroflow was 100 versus 96%, respectively. By multivariate analysis, it was found that bioprosthesis size was not a risk factor for SVD. The choice of valve type could not be demonstrated to influence long-term survival.

CONCLUSIONS

The Mitroflow pericardial bioprosthesis provides less than optimal mid- and long-term durability compared with the CE Perimount pericardial valve, especially for small aortic diameter implants (19 and 21 mm). This study hereby confirms the existence of a real risk of valvular deterioration of the Mitroflow valve that might compromise the prognosis of the patients.

Mitral valve replacement for mitral stenosis: A 15-year single center experience

Objectives

Mitral valve replacement with either a bioprosthetic or a mechanical valve is the treatment of choice for severe mitral stenosis. However, choosing a valve implant type is still a subject of debate. This study aimed to evaluate and compare the early and late outcomes of mitral valve replacement [mechanical (MMV) vs. bioprosthetic (BMV)] for severe mitral stenosis.

Methods

A retrospective cohort study was performed on data involving mitral stenosis patients who have undergone mitral valve replacement with either BMV (n = 50) or MMV (n = 145) valves from 1999 to 2012. Data were collected from the patients’ records and follow-up through telephone calls. Data were analyzed for early and late mortality, New York Heart Association (NYHA) functional classes, stroke, pre- and postoperative echocardiographic findings, early and late valve-related complications, and survival. Chi-square test, logistic regression, Kaplan–Meier curve, and dependent proportions tests were some of the tests employed in the analysis.

Results

A total of 195 patients were included in the study with a 30-day follow-up echocardiogram available for 190 patients (97.5%), while 103 (53%) were available for follow-up over the telephone. One patient died early postoperatively; twelve patients died late in the postoperative period, six in the bioprosthesis group and six in the mechanical group. The late mortality had a significant association with postoperative stroke (p < 0.001) and postoperative NYHA Classes III and IV (p = 0.002). Postoperative NYHA class was significantly associated with age (p = 0.003), pulmonary disease (p = 0.02), mitral valve implant type (p = 0.01), and postoperative stroke (p = 0.02); 14 patients had strokes in the mechanical (9) and in the bioprosthetic (5) groups. NYHA classes were significantly better after the replacement surgeries (p < 0.001). BMV were significantly associated with worse survival (p = 0.03), worse NYHA postoperatively (p = 0.01), and more reoperations (p = 0.006). Survival was significantly better with MMV (p = 0.03). When the two groups were matched for age and mitral regurgitation, the analysis revealed that BMV were significantly associated with reoperations (p = 0.02) but not significantly associated with worse survival (p = 0.4) or worse NYHA (p = 0.4).

Conclusion

MMV replacement in mitral stenosis patients is associated with a lower reoperation rate, but there was no difference in survival compared with BMV replacement.

The Carpentier-Edwards Perimount Magna mitral valve bioprosthesis: intermediate-term efficacy and durability

Background

The Carpentier-Edwards Perimount Magna mitral valve bioprosthesis (Edwards Lifesciences, Irvine, CA) is a low-profile version of the earlier Perimount valve that uses the ThermaFix process for enhanced calcium removal. The Magna valve has been in use since 2008, yet no publication, until now, has verified its intermediate-term safety and efficacy.

Methods

From 2008 through 2011 (our 4-year study period), 70 Magna valves were implanted in the mitral position at a single institution (the Cleveland Clinic). Echocardiograms were prospectively interpreted. For this study, we reviewed patients’ charts; endpoints included hemodynamic measurements, in-hospital morbidity and mortality, valve-related events, resource utilization, and 5-year survival rates.

Results

The mean patient age was 68 years; 43 % of the patients had New York Heart Association (NYHA) class III or IV disease, and 51.4 % had moderately severe, or worse, mitral regurgitation (MR). For 43 % of the patients, the Magna valve implantation was a reoperation. For 83 %, the Magna valve implantation also included a concomitant cardiac procedure. The median survival rate was 4.7 years and 90 % of patients were free from significant structural valve degeneration at 5 years. Preoperative atrial fibrillation, ischemic MR, intraaortic balloon pump placement, cardiogenic shock, cardiac arrest, and renal failure were associated with increased mortality. Right ventricular systolic pressure decreased from 50 mmHg preoperatively to 40 mmHg postoperatively, according to our matched-pair analysis (P = 0.003). Per their final echocardiogram during our study period, 98 % of surviving patients had trivial or no MR, one patient had mild MR, and one patient had severe MR.

Conclusions

Our 5-year experience indicates that the Magna valve offers excellent intermediate-term durability and substantial echocardiographic improvement; its low-profile design make it ideal for reoperations and for concomitant cardiac procedures, including valve replacement.

Transcatheter valve-in-valve implantation for failed mitral prosthesis: the first experience in Japan

An 82-year-old woman had a history of mitral valve replacement with a 25-mm MOSAIC (Medtronic, USA) for severe mitral regurgitation (MR) 8 years previously. Recently, she developed heart failure due to MR secondary to prosthetic valve failure. She underwent transcatheter valve-in-valve implantation with a 23-mm SAPIEN XT (Edwards Lifesciences, USA) to the prosthetic mitral valve by transapical approach. To our knowledge, this is the first reported case of transcatheter valve implantation for failed mitral prosthetic valve using valve-in-valve technique in Japan.

Mid- to long-term outcome comparison of the Medtronic Hancock II and bi-leaflet mechanical aortic valve replacement in patients younger than 60 years of age: a propensity-matched analysis

OBJECTIVE

This study aims to compare mid-long-term clinical outcomes between patients younger than 60 years of age undergoing bioprosthetic and mechanical aortic valve replacement.

METHODS

From January 2002 to December 2009, patients younger than 60 years of age who received Medtronic Hancock II porcine bioprostheses were selected and compared with those who received mechanical bi-leaflet valves in the aortic position. A stepwise logistic regression propensity score identified a subset of 112 evenly matched patient-pairs. Mid-long-term outcomes of survival, valve-related reoperations, thromboembolic events and bleeding events were assessed.

RESULTS

The follow-up was only 95.1% complete. Fourteen measurable variables were statistically similar for the matched cohort. Postoperative in-hospital mortality was 3.6% (bioprosthetic valves) and 2.7% (mechanical valves) (P = 0.700). Survival at 5 and 10 years was 96.3 and 88.7% for patients receiving bioprosthetic valve replacement versus 96.3 and 87.9% for patients receiving mechanical valve replacement (P = 0.860), respectively. At 5 and 10 years after operations, freedom from valve-related reoperation was 97.2 and 94.8% for patients receiving mechanical valve replacement, and 96.3 and 90.2% for patients receiving bioprosthetic valve replacement (P = 0.296), respectively. There was no difference between freedom from thromboembolic events (P = 0.528) and bleeding events (P = 0.128) between the matched groups during the postoperative 10 years.

CONCLUSIONS

In patients younger than 60 years of age undergoing aortic valve replacement, mid-long-term survival rate was similar for patients receiving bioprosthetic versus mechanical valve replacement. Bioprosthetic valves were associated with a trend for a lower risk of anticoagulation treatment and did not have significantly greater likelihood of a reoperation. These findings suggest that a bioprosthetic valve may be a reasonable choice for AVR in patients younger than 60 years of age.

Prosthetic aortic valve selection: current patient experience, preferences and knowledge

Objective

Current clinical practice guidelines advocate shared decision-making (SDM) in prosthetic valve selection. This study assesses among adult patients accepted for aortic valve replacement (AVR): (1) experience with current clinical decision-making regarding prosthetic valve selection, (2) preferences for SDM and risk presentation and (3) prosthetic valve knowledge and numeracy.

Methods

In a prospective multicentre cohort study, AVR patients were surveyed preoperatively and 3 months postoperatively.

Results

132 patients (89 males/43 females; mean age 67 years (range 23–86)) responded preoperatively. Decisional conflict was observed in 56% of patients, and in 25% to such an extent that it made them feel unsure about the decision. 68% wanted to be involved in decision-making, whereas 53% agreed that they actually were. 69% were able to answer three basic knowledge questions concerning prosthetic valves correctly. 56% were able to answer three basic numeracy questions correctly. Three months postsurgery, 90% (n=110) were satisfied with their aortic valve prosthesis, with no difference between mechanical and bioprosthetic valve recipients.

Conclusions

In current clinical practice, many AVR patients experience decisional conflict and suboptimal involvement in prosthetic valve selection, and exhibit impaired knowledge concerning prosthetic valves and numeracy. Given the broad support for SDM among AVR patients and the obvious need for understandable information, to-be-developed tools to support SDM in the setting of prosthetic valve selection will help to improve quality of decision-making, better inform and actively involve patients, and reduce decisional conflict.

Trial registration number

NTR3618.