Mechanical Versus Bioprosthetic Aortic Valve Replacement in Middle-Aged Adults: A Systematic Review and Meta-Analysis

Age-Based Outcomes After Surgical Aortic Valve Replacement With Bioprosthetic Versus Mechanical Valves

Recommendations for prosthesis type in older patients who underwent surgical aortic valve replacement (SAVR) are established, albeit undervalidated. The purpose of this study is to compare outcomes after bioprosthetic versus mechanical SAVR across various age groups. This was a retrospective study using an institutional SAVR database. All patients who underwent isolated SAVR were compared across valve types and age strata (<65 years, 65 to 75 years, >75 years). Patients who underwent concomitant operations, aortic root interventions, or previous aortic valve replacement were excluded. Objective survival and aortic valve reinterventions were compared. Kaplan-Meier survival estimation and multivariate regression were performed. A total of 1,847 patients underwent SAVR from 2010 to 2023. A total of 1,452 patients (78.6%) received bioprosthetic valves, whereas 395 (21.4%) received mechanical valves. Of those who received bioprosthetic valves, 349 (24.0%) were aged <65 years, 627 (43.2%) were 65 to 75 years, and 476 (32.8%%) were older than 75 years. For patients who received mechanical valves, 308 (78.0%) were aged <65 years, 84 (21.3%) were between 65 and 75 years, and 3 (0.7%) were >75 years. The median follow-up in the total cohort was 6.2 (2.6 to 8.9) years. No statistically significant differences were observed in early-term Kaplan-Meier survival estimates between SAVR valve types in all age groups. However, the cumulative incidence estimates of aortic valve reintervention were significantly higher in patients aged under 65 years who received bioprosthetic than those who received mechanical valves, with 5-year reintervention rates of 5.8% and 3.1%, respectively (p = 0.002). On competing risk analysis for valve reintervention, bioprosthetic valves were significantly associated with an increased hazard of aortic valve reintervention (hazard ratio 3.35, 95% confidence interval 1.73 to 6.49, p <0.001). In conclusion, SAVR with bioprosthetic valves (particularly, in patients aged <65 years) was comparable in survival to mechanical valve SAVR but significantly associated with increased valve reintervention rates.

Age-Specific Outcomes of Bioprosthetic vs. Mechanical Aortic Valve Replacement: Balancing Reoperation Risk with Anticoagulation Burden

BACKGROUND

The choice of prosthesis for aortic valve replacement (AVR) remains challenging. The risk of anticoagulation complications vs. the risk of aortic valve reintervention should be weighed. This study compared the outcomes of bioprosthetic vs. mechanical AVR in patients older and younger than 50.

METHODS

This retrospective study was conducted from 2009 to 2019 and involved 292 adult patients who underwent isolated AVR. The patients were divided according to their age (above 50 years or 50 years and younger) and the type of valves used in each age group. The outcomes of bioprosthetic valves (Groups 1a (>50 years) and 1b (≤50 years)) were compared with those of mechanical valves (Groups 2a (>50 years) and 2b (≤50 years)) in each age group.

RESULTS

The groups had nearly equal rates of preexisting comorbidities except for Group 1b, in which the rate of hypertension was greater (32.6% vs. 14.7%; p = 0.025). This group also had higher rates of old stroke (8.7% vs. 0%, p = 0.011) and higher creatinine clearance (127.62 (108.82-150.23) vs. 110.02 (84.87-144.49) mL/min; p = 0.026) than Group 1b. Patients in Group 1a were significantly older than Group 2a (64 (58-71) vs. 58 (54-67) years; p = 0.002). There was no significant difference in the NYHA class between the groups. The preoperative ejection fraction and other echocardiographic parameters did not differ significantly between the groups. Re-exploration for bleeding was more common in patients older than 50 years who underwent mechanical valve replacement (p = 0.021). There was no difference in other postoperative complications between the groups. The groups had no differences in survival, stroke, or bleeding rates. Aortic valve reintervention was significantly greater in patients ≤ 50 years old with bioprosthetic valves. There were no differences between groups in the changes in left ventricular mass, ejection fraction, or peak aortic valve pressure during the 5-year follow-up.

CONCLUSIONS

The outcomes of mechanical and bioprosthetic valve replacement were comparable in patients older than 50 years. Using bioprosthetic valves in patients younger than 50 years was associated with a greater rate of valve reintervention, with no beneficial effect on the risk of bleeding or stroke.

Mechanical Valves: Past, Present, and Future-A Review

The mechanical valve was first invented in the 1950s, and since then, a wide variety of prostheses have been developed. Although mechanical valves have outstanding durability, their use necessitates life-long treatment with anticoagulants, which increases the risk of bleeding and thromboembolic events. The current guidelines recommend a mechanical prosthetic valve in patients under 50-60 years; however, for patients aged 50-70 years, the data are conflicting and there is not a clear-cut recommendation. In recent decades, progress has been made in several areas. First, the On-X mechanical valve was introduced; this valve has a lower anticoagulant requirement in the aortic position. Second, a potential alternative to vitamin K-antagonist treatment, rivaroxaban, has shown encouraging results in small-scale trials and is currently being tested in a large randomized clinical trial. Lastly, an innovative mechanical valve that eliminates the need for anticoagulant therapy is under development. We attempted to review the current literature on the subject with special emphasis on the role of mechanical valves in the current era and discuss alternatives and future innovations.

Treatment options for isolated aortic valve insufficiency: a review

Aortic insufficiency (AI) is a valvular disease with increasing prevalence in older patients. The modern era provides numerous options for the management of AI which is explored here. Traditional interventions included aortic valve replacement with either mechanical or bioprosthetic aortic valves. While the former is known for its durability, it has grown out of favor due to the potential complications of anticoagulation. The preference for bioprosthetic valves is thus on the rise, especially with the advancements of transcatheter technology and the use of valve-in-valve therapy. Surgical options are also no longer limited to replacement but include complex techniques such as those required for aortic valve repair, Ozaki neocuspidization, Ross procedure and valve-sparring aortic root repair. Transcatheter options for the management of AI are not commercially available currently; however, preliminary data from ad-hoc trials, showed promising results and potential use of transcatheter technology in a variety of patients with pure AI.

Comparative Long-Term Clinical Performance of Mechanical Aortic Valve Prostheses

Importance

Aggregated data and long-term follow-up in national health data registers offer the opportunity to compare the performance of mechanical aortic prostheses within the same population.

Objective

To investigate the clinical performance of mechanical aortic valve prostheses.

Design, Setting, and Participants

This nationwide cohort study included all 5224 patients who underwent primary mechanical aortic valve replacement in Sweden between January 1, 2003, and December 31, 2018. Statistical analysis was performed between May and September 2023.

Exposures

Surgical aortic valve replacement with the On-X, Carbomedics, Bicarbon, Standard, Regent, Open Pivot, Masters, or Advantage valve models.

Main Outcomes and Measures

The primary outcome was all-cause mortality, and secondary outcomes were reintervention, heart failure, major bleeding, stroke, and embolic events. Regression standardization was used to account for baseline differences.

Results

Overall, 5224 patients (mean [SD] age, 56.8 [11.7] years; 3908 men [74.8%]) were included. Total follow-up time was 43 982 person-years (mean [SD], 8.4 [4.6] years; maximum, 17.2 years). After regression standardization, there was a significant difference in 10-year mortality between the Carbomedics model group (17%; 95% CI, 15%-18%), Regent model group (17%; 95% CI, 13%-20%), and Standard model group (17%; 95% CI, 14%-19%) compared with the Bicarbon model group (27%; 95% CI, 21%-34%).

Conclusions and Relevance

In this cohort study of mechanical valve surgical aortic replacement outcomes in Sweden, the rate of all-cause mortality was higher in the Bicarbon group than in the Carbomedics, Regent, and Standard model groups. These findings warrant further research on the long-term clinical performance of the Bicarbon valve.

Ten-Year Long-Term Analysis of Mechanical and Biological Aortic Valve Replacement

BACKGROUND

 For patients undergoing aortic valve replacement (AVR), structural valve deterioration (SVD) of a bioprosthesis (BP) is substantially accelerated in younger patients and valve-in-valve implantation is not always a considerable option. The risk-benefit assessment between SVD versus the risk of bleeding and thromboembolic events in patients with a mechanical prosthesis (MP) resulted in an age limit shift irrespective of inconsistent results reported in literature.

METHOD

 This retrospective single-center study compared 10-year long-term outcomes in patients undergoing isolated AVR with MP or BP. The risk-adjusted comparison of patients undergoing isolated AVR (n = 121) was performed after 1:1 propensity score matching (PSM) for age, sex, endocarditis, and chronic renal impairment (caliper of 0.2) leading to 29 pairs. Short- and long-term outcomes with respect to reoperation, major bleeding, stroke, all-cause and cardiovascular mortality, and overall survival at 10 years were analyzed.

RESULTS

 After PSM, groups were comparable with respect to preoperative characteristics, including patients with a mean age of 65 ± 3 years (MP) and 66 ± 4 years (BP) and an incidence rate of 6.9% for infective endocarditis in both cohorts. Short-term outcomes (transient neurologic disorder = 0.0 vs. 6.9%; stroke = 0.0%; in-hospital mortality = 3.4%) and in-hospital stays were comparable between MP and BP.

CONCLUSION

 After isolated AVR with MP and BP, 10-year long-term outcomes were comparable in the reported single-center cohort. MP can still be implanted safely without a disadvantage as regards long-term survival.

Savings associated with surgical aortic valve replacement with a RESILIA tissue valve based on seven-year COMMENCE trial results

BACKGROUND

Bioprostheses with RESILIA tissue demonstrate a reduction in calcification and improve health outcomes in pre-clinical and clinical studies. Prior economic analyses which relied on 5 years of evidence from the COMMENCE trial demonstrate financial savings for RESILIA tissue valves relative to mechanical valves after surgical aortic valve replacement (SAVR). Given the recent release of 7-year COMMENCE data, this economic evaluation updates the estimate for long-run savings of bioprosthetic valves with RESILIA.

METHODS

Simulation models estimated disease progression across two hypothetical SAVR cohorts (tissue vs. mechanical) of 10,000 patients each in the US. The primary comparison calculated the SAVR-related expenditures associated with each valve type ($US, 2023). Health outcome probabilities were based on the COMMENCE trial though year 7 and projected for an additional 8 years based on prior studies of tissue and mechanical SAVR. Costs for key outcomes (mortality, reoperation, bleeding, thromboembolism, endocarditis) and anticoagulant monitoring were sourced from the literature. Incidence rates of health outcomes associated with mechanical valves relied on relative risks of tissue valve versus mechanical valve patients.

RESULTS

Seven-year savings are $13,415 (95% CI = $10,472-$17,321) per patient when comparing RESILIA versus mechanical SAVR. Projected 15-year savings were $23,001 ($US, 2023; 95% CI = $17,802-$30,421). Most of the 15-year savings are primarily attributed to lower anti-coagulation monitoring costs ($21,073 in ACM savings over 15 years), but lower bleeding cost (savings: $2,294) and thromboembolism-related expenditures (savings: $852) also contribute. Reoperation and endocarditis expenditures were slightly larger in the RESILIA cohort. If reoperation relative risk reverts from 1.1 to 2.2 (the level in legacy tissue valves) after year 7, savings are $18,064. RESILIA SAVR also reduce costs relative to legacy tissue valves.

CONCLUSION

Patients receiving RESILIA tissue valves are projected to have lower SAVR-related health expenditures relative to mechanical and legacy tissue valves.

In vivo performance of a tri-leaflet mechanical heart valve prosthesis in an ovine model

OBJECTIVES

We present the long-term results of a trileaflet (Triflo) versus bileaflet (On-X) mechanical valve in both aortic and pulmonary positions in a sheep model.

METHODS

The Triflo valve was implanted in 21 female sheep in aortic (n = 8) and pulmonary position (n = 13). The On-X valve was implanted in 7 female sheep in aortic (n = 1) and pulmonary (n = 6) positions. No antithrombotic medication of any kind was given postoperatively. In the aortic group, survival cohorts were 3 and 5 months. In the pulmonary group, survival cohorts were 10 and 20 weeks. Valve performance was assessed using haematology, echocardiography and acoustic measurements combined with post-mortem pathology analysis of the downstream organs.

RESULTS

The mean gradients were lower for the Triflo valve in both pulmonary [4.30 mmHg (3.70-5.73) vs 6.80 mmHg (4.63-7.96), P = 0.012] and aortic [5.1 mmHg (4.2-7.7) vs 10.7 mmHg (8.7-12.9), P = 0.007] positions. Peak gradients were lower for the Triflo valve in both pulmonary [8.05 mmHg (6.75-10.23) vs 13.15 mmHg (9.20-14.76), P = 0.005] and aortic [8.7 mmHg (7.5-12.5) vs 16.5 mmHg (14.2-19.6), P = 0.009] positions. In both positions, leaflets and housing surface were free from any deposits macro- and microscopically and comparable to nonimplanted control valves. Peripheral organs showed no signs of thrombo-embolic damage. Biochemical and haematological were comparable to preoperative. The closing click sound pressure level of the Triflo was significantly lower in both aortic [108.4 sound pressure level (102.0-115.7) vs 111.7 sound pressure level (105.5-117.0), P < 0.001] and pulmonary [103.6 sound pressure level (99.1-108.9) vs 118.5 sound pressure level (116.7-120.2), P < 0.001] position.

CONCLUSIONS

Preliminary in vivo results of the Triflo valve are promising in both aortic and pulmonary positions in an ovine model. Excellent haemodynamics, stable long-term function, low valve noise and no thrombo-embolic events in the absence of antithrombotic medication lay the foundation to a future clinical first-in-man trial.

An exploratory cost-effectiveness analysis of a novel tissue valve compared with mechanical valves for surgical aortic valve replacement in subgroups of people aged 55-64 and 65+ with aortic stenosis in the UK

OBJECTIVE

Exploratory analysis to conceptualize and evaluate the potential cost-effectiveness and economic drivers of using a novel tissue valve compared with mechanical heart valves for surgical aortic valve replacement (SAVR) in people aged 55-64 and 65+ with aortic stenosis (AS) from a National Health Service (NHS) UK perspective.

METHODS

A decision-analytic model was developed using a partitioned survival model. Parameter inputs were obtained from published literature. Deterministic and probabilistic sensitivity analyses (DSA and PSA) were conducted to explore the uncertainty around the parameters.

RESULTS

The novel tissue valve was potentially associated with higher quality-adjusted life years (QALYs) of 0.01 per person. Potential cost savings were greatest for those aged 55-64 (£408) versus those aged 65+(£53). DSA indicated the results to be most dependent on relative differences in general mortality, procedure costs, and reoperation rates. PSA estimated around 75% of the iterations to be cost-effective at £20,000 per QALY for those aged 55-64, and 57% for those aged 65+.

CONCLUSIONS

The exploratory analysis suggests that the novel tissue valve could be a cost-effective intervention for people over the age of 55 with AS who are suitable for SAVR in the UK.

Pediatric pulmonary valve replacements: Clinical challenges and emerging technologies

Congenital heart diseases (CHDs) frequently impact the right ventricular outflow tract, resulting in a significant incidence of pulmonary valve replacement in the pediatric population. While contemporary pediatric pulmonary valve replacements (PPVRs) allow satisfactory patient survival, their biocompatibility and durability remain suboptimal and repeat operations are commonplace, especially for very young patients. This places enormous physical, financial, and psychological burdens on patients and their parents, highlighting an urgent clinical need for better PPVRs. An important reason for the clinical failure of PPVRs is biofouling, which instigates various adverse biological responses such as thrombosis and infection, promoting research into various antifouling chemistries that may find utility in PPVR materials. Another significant contributor is the inevitability of somatic growth in pediatric patients, causing structural discrepancies between the patient and PPVR, stimulating the development of various growth-accommodating heart valve prototypes. This review offers an interdisciplinary perspective on these challenges by exploring clinical experiences, physiological understandings, and bioengineering technologies that may contribute to device development. It thus aims to provide an insight into the design requirements of next-generation PPVRs to advance clinical outcomes and promote patient quality of life.

Mechanical versus Bioprosthetic Aortic Valve Replacement in Middle-Aged Adults: A Systematic Review and Meta-Analysis

BACKGROUND

Mechanical prostheses and bioprosthetic prostheses have their own advantages and disadvantages. Mechanical ones are recommended for younger patients (<50 years old), and bioprosthetic ones are recommended for older patients (>70 years old). There is still debate regarding which kind of prosthesis is better for middle-aged patients (50 to 70 years old) receiving aortic valve replacement (AVR). To solve this problem, we conducted this meta-analysis. Given that only one randomized controlled trial (RCT) study was included, we conducted a subgroup analysis of RCT and propensity score matching (PSM) retrospective studies to reduce the bias.

METHODS

We systematically searched articles related to clinical outcomes of mechanical and bioprosthetic prostheses in middle-aged patients receiving AVR in the PubMed, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases. The published date was up to 1 October 2022. Studies were excluded if not only middle-aged patients were included, or if they lacked direct comparisons between mechanical and bioprosthetic prostheses.

RESULTS

In total, 22 studies with 32,298 patients were included in the final analysis. The results show that patients aged between 50 and 70 receiving AVR with mechanical prostheses achieved better long-term survival and fewer reoperations and valve-related events but suffered more with bleeding events. No significant difference could be found in terms of early mortality and long-term cardiac death. The same results could be observed in the subgroup analysis of RCT and PSM retrospective studies.

CONCLUSION

Both mechanical and bioprosthetic prostheses are beneficial to middle-aged patients undertaking AVR procedures. However, mechanical prostheses show better clinical outcomes in long-term survival and comorbidities. Individual recommendation is still necessary.

Estimating the Potential Economic Impact of Tissue Valve Replacement for Heart Valve Disease in China: Patient-Level and Population-Level Cost-Benefit Simulation Analyses

OBJECTIVES

This study seeks to estimate the potential societal economic impact of treating patients with heart valve disease (HVD) in China with surgical tissue valve replacement versus mechanical valves.

METHODS

This societal economic cost-benefit evaluation is based on an individual simulation model for subgroups of patients with HVD that is also aggregated to a macrosocietal model. The individual simulation model was developed to estimate the likely economic impact of surgical aortic valve replacement (SAVR) with tissue versus mechanical valves for different subgroups among all eligible patients with HVD over their remaining lifetimes. Clinical inputs were informed by health claims database analysis, expert clinical opinion, and published literature. Epidemiological inputs and demographic inputs were sourced from the published literature and the China Statistical Yearbook 2020. Health gains were valued at 3 times the average national income.

RESULTS

Projected total lifetime economic gains were greater for patients receiving tissue valves. Costs were reported in 2021 US dollars. The average lifetime net economic gain for tissue valve patients was $51 736 (20.0% more than for mechanical valve patients). Increasing the use of tissue valves to 50% among all eligible patients with HVD would provide aggregate long-term economic gains of $167 billion during their remaining lifetimes. The economic gains from greater tissue valve use were due to avoiding anticoagulation monitoring costs, improved quality of life, and greater post-SAVR labor force participation.

CONCLUSION

Increased use of tissue valves versus mechanical values in SAVR procedures in China would be likely to generate a substantial societal economic gain.

Budget impact analysis of a bovine pericardial aortic bioprosthesis versus mechanical aortic valve replacement in adult patients with aortic stenosis in Romania

AIMS

An analysis of the budget impact of using a bovine pericardial aortic bioprosthesis (BPAB) or a mechanical valve (MV) in aortic stenosis (AS) patients in Romania.

MATERIALS AND METHODS

A decision-tree with a partitioned survival model was used to predict the financial outcomes of using either a BPAB (the Carpentier-Edwards Perimount Magna Ease Valve) or MV in aortic valve replacement (AVR) procedure over a 5-year period. The budget impact of various resource consumption including disabling strokes, reoperations, minor thromboembolic events, major bleeding, endocarditis, anticoagulation treatment and monitoring, and echocardiogram assessments were compared for both types of valves. One-way sensitivity analyses (OWSA) were conducted on the input costs and probabilities.

RESULTS

The use of BPAB compared to MV approaches budget neutrality due to incremental savings year-on-year. The initial surgical procedure and reoperation costs for BPAB are offset by savings in acenocoumarol use, disabling strokes, major bleeding, minor thromboembolic events, and anticoagulation complications. The cost of the initial procedure per patient is 460 euros higher for a BPAB due to the higher valve acquisition cost, although this is partially offset by a shorter hospital stay. The OWSA shows that the total procedure costs, including the hospital stay, are the primary cost drivers in the model.

LIMITATIONS

Results are limited by cost data aggregation in the DRG system, exclusion of costs for consumables and capital equipment use, possible underestimation of outpatient complication costs, age-related variations of event rates, and valve durability.

CONCLUSIONS

Adopting BPAB as a treatment option for AS patients in Romania can lead to cost savings and long-term economic benefits. By mitigating procedure costs and increasing anticoagulation treatment costs, BPAB offers a budget-neutral option that can help healthcare providers, policymakers, and patients alike manage the growing burden of AS in Romania.

Long-run savings associated with surgical aortic valve replacement using a RESILIA tissue bioprosthetic valve versus a mechanical valve

BACKGROUND

Prior economic analyses demonstrate that legacy tissue valves are associated with substantial financial savings over the long run after a surgical aortic valve replacement (SAVR). Bioprostheses with RESILIA tissue reduce calcification, the primary cause of structural valve deterioration (SVD), and have demonstrated promising pre-clinical and 5-year clinical results. This economic evaluation quantifies the expected long-run savings of bioprosthetic valves with RESILIA tissue relative to mechanical valves given 5-year clinical results and expected performance through year 15.

METHODS

Simulation models estimated disease progression across two hypothetical SAVR cohorts (tissue vs. mechanical) of 10,000 patients in the US over 15 years. One comparison evaluated RESILIA tissue valves relative to mechanical valves. The other compared legacy SAVR tissue and mechanical valves. Health outcome probabilities and costs were based on literature and expert opinion. Incidence rates of health outcomes associated with mechanical valve were calculated using relative risks of expected outcomes in tissue valve versus mechanical valve patients. The comparisons also accounted for anti-coagulation monitoring in both cohorts. Savings estimates are based on US healthcare costs and do not yet account for the premium associated use of RESILIA relative to a standard tissue valve.

RESULTS

Relative to mechanical SAVR, the median net discounted savings for a patient receiving SAVR with a RESILIA tissue valve is $20,744 ($US, 2020; 95% CI = $15,835-$26,655) over a 15-year horizon. While 30-day and 1-year savings were not significant, expected savings after 5 years are $9,110 (95% CI = $6,634-$11,969). Net savings for RESILIA SAVR valves were approximately 30-50% larger than savings anticipated using legacy tissue SAVR valves.

CONCLUSION

RESILIA tissue valves are associated with lower health expenditures relative to mechanical valves.

Outcomes of bovine versus porcine surgical aortic valve replacement

INTRODUCTION

There are no guidelines regarding the use of bovine pericardial or porcine valves for aortic valve replacement, and prior studies have yielded conflicting results. The current study sought to compare short- and long-term outcomes in propensity-matched cohorts of patients undergoing isolated aortic valve replacement (AVR) with bovine versus porcine valves.

METHODS

This was a retrospective study utilizing an institutional database of all isolated bioprosthetic surgical aortic valve replacements performed at our center from 2010 to 2020. Patients were stratified according to type of bioprosthetic valve (bovine pericardial or porcine), and 1:1 propensity-score matching was applied. Kaplan-Meier survival estimation and multivariable Cox regression for mortality were performed. Cumulative incidence functions were generated for all-cause readmissions and aortic valve reinterventions.

RESULTS

A total of 1502 patients were identified, 1090 (72.6%) of whom received a bovine prosthesis and 412 (27.4%) of whom received a porcine prosthesis. Propensity-score matching resulted in 412 risk-adjusted pairs. There were no significant differences in clinical or echocardiographic postoperative outcomes in the matched cohorts. Kaplan-Meier survival estimates were comparable, and, on multivariable Cox regression, valve type was not significantly associated with long-term mortality (hazard ratio: 1.02, 95% confidence interval: 0.74, 1.40, p = .924). Additionally, there were no significant differences in competing-risk cumulative incidence estimates for all-cause readmissions (p = .68) or aortic valve reinterventions (p = .25) in the matched cohorts.

CONCLUSION

The use of either bovine or porcine bioprosthetic aortic valves yields comparable postoperative outcomes, long-term survival, freedom from reintervention, and freedom from readmission.

Reimbursement Savings Associated With Tissue Versus Mechanical Surgical Aortic Valve Replacement in Thailand

OBJECTIVES

Surgical aortic valve replacement (SAVR) is an indicated treatment for severe aortic stenosis. Although mechanical valves are typically more durable, tissue SAVR valves do not require lifetime anticoagulation monitoring and may have lower rates of expensive sequelae. This economic evaluation estimates payer costs to the 3 largest Thai health insurance mechanisms for tissue versus mechanical SAVR.

METHODS

A deterministic and Monte Carlo simulation model based on literature and expert opinion estimated total payer costs for tissue and mechanical valves over a 25-year duration for 3 separate age cohorts (45, 55, and 65 years). Reimbursements levels for hospitalization services were from the Thai Diagnosis Related Groups. Separate models are generated for the 3 main Thai health insurance mechanisms.

RESULTS

The discounted expected 25-year reduction in payer savings associated with tissue SAVR are $2540, $2529, and $2311 per surgery for patients aged 45, 55, and 65 years, respectively, for the largest Thai insurer. Expected cost reductions associated with tissue SAVR are larger for each of the other schemes and generally decrease with patient age. Most savings accrue within 10 years of surgery. Reoperation costs are larger with tissue valves, but reductions in complications and anticoagulation monitoring more than offset these expenditures. Results are robust to multiple sensitivity and scenario analyses.

CONCLUSIONS

Coverage and reimbursement of tissue valves can financially benefit Thai insurers and reduce expenditures in the Thai health system compared with mechanical valves. As tissue valve technology evolves and reoperation rates decline, the financial benefit associated with tissue valves will increase.

The role of mechanical valves in the aortic position in the era of bioprostheses and TAVR: Evidence-based appraisal and focus on the On-X valve

Patients who need a prosthetic aortic heart valve may decide, working with their cardiologist and cardiac surgeon, among a variety of options: surgical or transcatheter approach, bioprosthetic or mechanical valve, or a Ross procedure if suitable to their age and anatomy. This review article examines the evidence for survival benefit with mechanical aortic valves, discusses bioprosthetic structural valve degeneration and its consequences, and considers the risks of redo aortic valve surgery or subsequent valve-in-valve (ViV) transcatheter intervention. It highlights the unique characteristics of the On-X aortic valve, including the US Food and Drug Administration approved and American College of Cardiology/American Heart Association guideline supported reduced anticoagulation target INR of 1.5 to 2.0, and discusses the PROACT Xa trial comparing apixaban vs warfarin anticoagulation. The choice of prosthetic valve should be individualized, carefully considering each patient's unique circumstances. In that context, the On-X aortic valve offers a potential lifetime solution without need for a repeat operation, while minimizing the risks of long-term anticoagulation. In an era of enthusiasm for bioprosthetic and transcatheter-based approaches, the option of a second-generation bileaflet mechanical valve with optimized hemodynamics-the On-X aortic valve-may well align with patient expectations.

Prediction of Aortic Stenosis Progression by 18F-FDG and 18F-NaF PET/CT in Different Aortic Valve Phenotypes

Background: Different imaging techniques, such as echocardiography (ECHO) and CT, allow to assess aortic stenosis (AS) severity and could be used to study its progression. But only PET/CT open opportunities to assess activity of valvular inflammation and calcification in vivo. The aim of this study was to assess prognostic value of valvular inflammation and calcification measured by 18F-FDG and 18F-NaF PET/CT in patients with tricuspid (TAV) and bicuspid aortic valve (BAV). Methods: The study included 71 patients aged 40-70 years with mild, moderate and severe asymptomatic calcific AS. Patients were divided into two groups according to valve morphology: with BAV and TAV. All patients underwent standard ECHO, CT calcium scoring PET/CT with 18F-NaF and 18F-FDG. All patients were evaluated during a follow-up visit with evaluation of ECHO parameters. (16.8 ± 4.2 months). Results: TAV and BAV groups were comparable in AS severity by ECHO (peak aortic jet velocity (Vmax): 2.90 [2.60; 3.50] vs. 2.96 [2.55; 3.31] m/s, p = 0.83). TBR max 18F-FDG did not vary in TAV and BAV patients (1.15 [1.06; 1.23] vs. 1.11 [1.03; 1.20], p = 0.39). Both groups did not differ in valvular calcification degree (Agatston score 1,058 [440; 1798] vs. 1,128 [533; 2,360], p = 0.55) and calcification activity assessed by 18F-NaF uptake level (TBR max 1.50 [1.30; 1.78] vs. 1.48 [1.27; 1.83], p = 0.97). 18F-NaF TBR max was associated with AS severity measured by Vmax in men and women with TAV (r = 0.54; p = 0.04 vs. r = 0.53; p = 0.03). In BAV group this relationship was true only in female patients (r = 0.1; p = 0.67 vs. r = 0.7; p = 0.0004). There was no association between Vmax and TBR max 18F-FDG was revealed in TAV and BAV groups. During follow-up period, the most important positive predictors of AS progression in TAV obtained by multinomial logistic regression analysis were Vmax, and 18F-NaF TBR. Whereas in BAV the highest predictive value showed model included age and Vmax. Conclusion: 18F-NaF PET/CT may be considered as the valuable predictor for hemodynamic progression of calcific AS in case of TAV. 18F-FDG PET/CT does not play a significant role to predict the AS progression.

Mechanical versus Bioprosthetic Valve for Aortic Valve Replacement: Systematic Review and Meta-Analysis of Reconstructed Individual Participant Data

OBJECTIVES

To compare biological versus mechanical aortic valve replacement.

METHODS

We searched MEDLINE, Scopus, and Cochrane Library databases for randomized clinical trials and propensity-score matched studies published by October 14th, 2021 according to PRISMA statement. Individual patient data on overall survival were extracted. One- and two-stage survival analyses, and random-effects meta-analyses were conducted.

RESULTS

25 studies were identified, incorporating 8,721 bioprosthetic and 8,962 mechanical valves:. In the one-stage meta-analysis, mechanical valves cumulatively demonstrated decreased hazard for mortality (Hazard Ratio [HR] : 0.79, 95% Confidence interval [CI] : 0.74-0.84, p < 0.0001). Overall survival was similar between the compared arms for patients <50 years old (HR: 0.88, 95% CI : 0.71-1.1, p = 0.216), increased in the mechanical valve arm for patients 50-70 years old (HR : 0.76, 95% CI : 0.70-0.83, p < 0.0001), and increased in the bioprosthetic arm for patients >70 years old (HR : 1.35, 95% CI : 1.17-1.57, p < 0.0001). Meta-regression analysis revealed that the survival in the 50-70 years old group was not influenced by the publication year of the individual studies. No statistically significant difference was observed regarding in-hospital mortality, post-operative strokes and post-operative reoperation. All-cause mortality was found decreased in the mechanical group, cardiac mortality was comparable between the two groups, major bleeding rates were increased in the mechanical valve group, and reoperation rates were increased in the bioprosthetic valve group.

CONCLUSIONS

Survival rates seem to not be influenced by the type of prosthesis in patients <50 years old. A survival advantage in favour of mechanical valves is observed in patients 50-70 years old, while in patients >70 years old bioprosthetic valves offer better survival outcomes.

Contemporary trends and in-hospital outcomes of mechanical and bioprosthetic surgical aortic valve replacement in the United States

INTRODUCTION

The choice between a mechanical versus a bioprosthetic valve in aortic valve replacement (AVR) is based on life expectancy, bleeding risk and comorbidities, since bioprosthetic AVR (bAVR) are associated with a more rapid structural deterioration compared to mechanical AVR (mAVR). The impact of widespread transcatheter valve replacements, on the decision to use bAVR versus mAVR, in the contemporary era and subsequent outcomes remain to be determined.

METHODS

The National Inpatient database (2009-2018) was used to study trends in admissions for bAVR and mAVR and in-hospital mortality and outcomes over time. Survey estimation commands were used to determine weighted national estimates.

RESULTS

There were 700,896 ± 18,285 inpatient visits for AVR with 70.1% (95% CI 69.2%-71.1%) and 29.9% (95% CI 28.9%-30.8%) visits for bAVR and mAVR, respectively. Those undergoing bAVR were significantly older (bAVR [69.8 years] vs. mAVR [62.7 years] p < .001]. The rates of mAVR decreased across all age groups during the study period (p_trend  < .001), including patients ≤50 years (p_trend  < .001). In-hospital mortality for mAVR recipients was higher, both after multivariable adjustment (OR 1.35 95% CI 1.26-1.45 p < .001) and propensity matching (mean difference 0.846% ± 0.19%).

CONCLUSION

In the contemporary era, the utilization of mAVR has decreased across all age groups, including those younger than 50 years old. Although mAVR recipients were healthier with less comorbidities, inpatient mortality was higher after mAVR compared to bAVR. In addition to understanding causes for higher in-hospital mortality after mAVR, future research should focus on developing transcatheter valve replacement friendly bAVR.

Budget impact analysis of a bioprosthetic valve with a novel tissue versus mechanical aortic valve replacement in patients older than 65 years with aortic stenosis in Saudi Arabia

AIMS

A budget impact analysis (BIA) comparing bioprosthetic valves with RESILIA tissue and mechanical valves in aortic stenosis (AS) patients > 65 years in the public and private sectors of Saudi Arabia.

MATERIALS AND METHODS

A decision-tree with a partitioned survival model was adapted to estimate the financial consequences of either a RESILIA tissue valve or a mechanical valve in aortic valve replacement (AVR) procedures up to 5 years. The budget impact of resource consumption for both valve types was compared and included disabling strokes, reoperations, minor thromboembolic events, major bleeding, endocarditis, anticoagulation treatment and monitoring, and echocardiogram assessments. One-way sensitivity analyses (OWSA) were performed on cost and probability inputs.

RESULTS

RESILIA tissue valves versus mechanical valves are overall budget saving commencing in Year 1 and savings gradually increase year-on-year. The higher costs of the initial procedure, reoperation, and additional monitoring (echocardiogram tests and visits) associated with RESILIA tissue valves are offset by savings in warfarin use, disabling strokes, major bleeding, and anticoagulation complications. The cost per initial procedure per patient is SAR795 higher for a RESILIA tissue valve reflecting the higher valve acquisition cost, which is partially offset by a shorter hospital stay. The OWSA suggests that total procedure costs of each valve, including the hospital stay, are the main cost drivers in the model.

LIMITATIONS

The variability of cost inputs and the presence of multiple payers with multiple costing data is a key challenge in Saudi Arabia. Budget impact results may, therefore, change if repeated per AVR center and may also be impacted by the long-term durability of RESILIA tissue valves.

CONCLUSIONS

An AVR in patients > 65 years with a RESILIA tissue valve is budget-saving from the first year in Saudi Arabia. Patients, payers, providers and policymakers may benefit economically from increased implantation of RESILIA tissue valves.

Mechanical vs. bioprosthetic aortic valve replacement in patients younger than 70 years of age - a hazard ratio meta-analysis

BACKGROUND

The choice between mechanical valves (MV) and bioprosthetic valves (BV) in patients undergoing aortic valve surgery is complex, requiring a balance between the inferior durability of BV and the indicated long-term anticoagulation therapy with MV. This is especially challenging in middle age group (<70 years of age) that has seen an increased use of BV over recent years.

METHODS

A meta-analysis of randomized controlled trials (RCTs), observational studies using propensity score matching (PSM) and inverse-probability-weighing (IPW) was conducted to examine the clinical outcomes of patients <70 years of age undergoing aortic valve replacement. Primary outcome was overall long-term mortality. Secondary outcomes included bleeding events, re-operation, systemic thromboembolism, and cerebrovascular accident (CVA).

RESULTS

Fifteen studies (1 RCT, 12 PSM, and 2 IPW studies, aggregated sample size 16,876 patients) were included. Median follow-up was 7.8 years. Mortality was higher with BV vs. MV (HR 1.22 [1.00-1.49]), as was re-operation (HR 3.05 [2.22-4.19]). Bleeding risk was lower with BV (HR 0.58 [0.48-0.69]), and the risk of stroke was similar in both valve types (HR 0.96 [0.83-1.11]) CONCLUSIONS: In this broadest meta-analysis comparing BV and MV, results suggest a survival benefit for MV in patients < 70 years of age. This should lead to reassessment of current patterns used in the choice of valves for patients <70 among the cardiothoracic surgery community.

Surgical Aortic Valve Replacement-Age-Dependent Choice of Prosthesis Type

Background: Recently, the use of surgically implanted aortic bioprostheses has been favoured in younger patients. We aimed to analyse the long-term survival and postoperative MACCE (Major Adverse Cardiovascular and Cerebral Event) rates in patients after isolated aortic valve replacement. Methods: We conducted a single-centre observational retrospective study, including all consecutive patients with isolated aortic valve replacement. 1:1 propensity score matching of the preoperative baseline characteristics was performed. Results: A total of 2172 patients were enrolled in the study. After propensity score matching the study included 428 patients: 214 biological vs. 214 mechanical prostheses, divided into two subgroups: group A < 60 years and group B > 60 years. The mean follow-up time was 7.6 ± 3.9 years. Estimated survival was 97 ± 1.9% and 89 ± 3.4% at 10 years for biological and mechanical prosthesis, respectively in group A (p = 0.06). In group B the survival at 10 years was 79.1 ± 5.8% and 69.8 ± 4.4% for biological and mechanical prosthesis, respectively (p = 0.83). In group A, patients with a bioprosthesis exhibited a tendency for higher cumulative incidence MACCE rates compared to patients with a mechanical prosthesis, p = 0.83 (bio 7.3 ± 5.3% vs. mech 4.6 ± 2.2% at 10 years). In group B, patients with a mechanical prosthesis showed a tendency for higher cumulative incidence MACCE rates compared to patients with bioprosthesis, p = 0.86 (bio 4.3 ± 3.1% vs. mech 9.1 ± 3.1% at 10 years). Conclusions: Long-term survival after surgical aortic valve replacement is similar in patients with a biological and mechanical prosthesis, independent of the patients’ age. Moreover, younger patients (<60 years) with bioprosthesis showed a survival benefit, compared to patients with mechanical prosthesis in this age group.

Pulmonary valve tissue engineering strategies in large animal models

In the last 25 years, numerous tissue engineered heart valve (TEHV) strategies have been studied in large animal models. To evaluate, qualify and summarize all available publications, we conducted a systematic review and meta-analysis. We identified 80 reports that studied TEHVs of synthetic or natural scaffolds in pulmonary position (n = 693 animals). We identified substantial heterogeneity in study designs, methods and outcomes. Most importantly, the quality assessment showed poor reporting in randomization and blinding strategies. Meta-analysis showed no differences in mortality and rate of valve regurgitation between different scaffolds or strategies. However, it revealed a higher transvalvular pressure gradient in synthetic scaffolds (11.6 mmHg; 95% CI, [7.31-15.89]) compared to natural scaffolds (4,67 mmHg; 95% CI, [3,94-5.39]; p = 0.003). These results should be interpreted with caution due to lack of a standardized control group, substantial study heterogeneity, and relatively low number of comparable studies in subgroup analyses. Based on this review, the most adequate scaffold model is still undefined. This review endorses that, to move the TEHV field forward and enable reliable comparisons, it is essential to define standardized methods and ways of reporting. This would greatly enhance the value of individual large animal studies.

Effect of Aortic Valve Type on Patients Who Undergo Type A Aortic Dissection Repair

Aortic valve replacement (AVR) is common in the setting of type A aortic dissection (TAAD) repair. Here, we evaluated the association between prosthesis choice and patient outcomes in an international patient cohort. We reviewed data from the International Registry of Acute Aortic Dissection (IRAD) interventional cohort to examine the relationship between valve choice and short- and mid-term patient outcomes. Between January 1996 and March 2016, 1290 surgically treated patients with TAAD were entered into the IRAD interventional cohort. Of those, 364 patients undergoing TAAD repair underwent aortic valve replacement (AVR; mean age, 57 years). The mechanical valve cohort consisted of 189 patients, of which 151 (79.9%) had a root replacement. The nonmechanical valve cohort consisted of 5 patients who received homografts and 160 patients who received a biologic AVR, with a total of 118 (71.5%) patients who underwent root replacements. The mean follow-up time was 2.92 ± 1.75 years overall (2.46 ± 1.69 years for the mechanical valve cohort and 3.48 ± 1.8 years for the nonmechanical valve cohort). After propensity matching, Kaplan-Meier estimates of 4-year survival rates after surgery were 64.8% in the mechanical valve group compared with 74.7% in the nonmechanical valve group (p = 0.921). A stratified Cox model for 4-year mortality showed no difference in hazard between valve types after adjusting for the propensity score (p = 0.854). A biologic valve is a reasonable option in patients with TAAD who require AVR. Although this option avoids the potential risks of anticoagulation, long-term follow up is necessary to assess the effect of reoperations or transcatheter interventions for structural valve degeneration.

Narrative review of the contemporary surgical treatment of unicuspid aortic valve disease

Unicuspid aortic valve disease (UAVD) is a frequent and long-lasting challenge for adult congenital heart disease centers. UAVD patients become usually symptomatic in their twenties or thirties and require a surgical treatment plan which should respect their complete lifespan combined with an adequate quality of life. Unfortunately, all current surgical strategies of congenital aortic valve disease bear some important limitations: (I) Aortic valve replacement using bioprosthetic valves is associated with early structural degeneration and leads frequently to re-operations. (II) Mechanical valves are commonly associated with lifelong risk of severe bleeding due to oral anticoagulation. (III) Using a pulmonary autograft (i.e., Ross procedure) for aortic valve replacement is associated with excellent long-term results in non-elderly patients. However, failure of pulmonary autograft or pulmonary homograft may require re-operations. (IV) Aortic valve repair or Ozaki procedure is only performed in a few heart centers worldwide and is associated with a limited reproducibility and early patch degeneration, suture dehiscence or increased risk of endocarditis. In contrast to degenerative tricuspid aortic valve disease, UAVD remains relatively understudied and reports on UAVD treatment are rare and usually limited to retrospective single-center observations. For this review, we searched PubMed for papers in the English language by using the search words unicuspid aortic valve, congenital aortic valve, Ross procedure, Ozaki procedure, aortic valve repair, mechanical/bioprosthetic aortic replacement, homograft. We read the abstracts of relevant titles to confirm their relevance, and the full papers were then extracted. References from extracted papers were checked for additional relevant reports. This review summarizes current surgical treatment strategies for UAVD including aortic valve replacement using bioprosthetic or mechanical valves, homografts, pulmonary autografts (i.e., Ross procedure) and aortic valve repair techniques for UAV. Furthermore, Ozaki procedure will be discussed.

A systematic review of the cost-effectiveness of heart valve replacement with a mechanical versus biological prosthesis in patients with heart valvular disease

Heart valve disease (HVD) affects 2.5% of the US population and one million individuals aged 65 years and older in the UK. Given its burden, the aim of the present review was to assess the cost-effectiveness of heart valve replacement with mechanical versus biological prosthesis in HVD patients. We performed a systematic search in various electronic databases from January 1990 to June 2019. Five out of 542 articles were entered into the study, from which 2 papers were subsequently excluded not meeting the minimum number of items of the CHEERS checklist. Quality-Adjusted Life Year, Life Years Gained, and the Incremental Cost-Effectiveness Ratio (ICER) regarding the type of replaced heart valve were extracted and reported. Studies were conducted in three different countries (Iran, France, and USA). ICER ranged from $1253 in Iran to €54,634 in France. Survival rate of mitral mechanical versus biological valves at 10 and 20 years was 72.9% versus 76.0% and 51% versus 30%, respectively. Survival rate at 20 years in patients undergoing atrial valve replacement was 20%. Ten- and 20-year death rates for biological valves were higher with respect to mechanical prosthesis (15.5% versus 8.4% at 10 years), with this difference becoming more relevant at 20 years (36.9% versus 13.9%). Due to higher ICER, mortality rate, and lower success rates in the long term for biological prostheses compared to mechanical ones, these appear to be more suitable for older patients (aged ≥ 70 years).

Transcatheter and ministernotomy aortic valve replacement after bioprosthetic valve failure

BACKGROUND

Transcatheter valve-in-valve implantation (TViV) and minimally invasive reoperative aortic valve replacement (MIrAVR) have rapidly increased as alternatives to conventional reoperative surgical AVR. This study reports a single-center experience of patients undergoing TViV and MIrAVR after bioprosthetic valve failure.

METHODS

In this retrospective review between March 2009 and October 2018, 68 patients without reoperative full sternotomies, concomitant procedures, active endocarditis, and prior homografts or coronary artery bypass grafting underwent isolated AVR for degenerated aortic bioprostheses. Society of Thoracic Surgeons (STS) risk scores and age are reported as median (interquartile range [IQR]) and length of stay is reported as mean (standard deviation [SD]) due to their characteristics of the distribution.

RESULTS

Forty-one (60.3%) patients underwent TViV, and 27 (39.7%) patients underwent MIrAVR. Median [IQR] STS risk scores were 5.7 [4.0-7.8] and 2.0 [1.5-3.4] for TViV and MIrAVR, respectively (p ≤ .001). The median [IQR] age for TViV patients was higher (78 [71-84] vs. 66 [53-72] years, p ≤ 0.001). More permanent pacemakers were implanted (22.2% vs. 9.8%) following MIrAVR. The MIrAVR group had a higher rate of atrial fibrillation (18.5% vs. 9.8%, p = .466). Average (SD) length of stay was less in TViV (5.3 days, SD: 3.4 vs. 8.6 days, SD: 7.4, p = .001). Survival at 1 year was not significantly different for TViV and MIrAVR (94.9% [95% confidence interval [CI]: 81.0%, 98.7%] and 86.9% [95% CI: 64.0%, 95.7%], respectively [p = .969]).

CONCLUSIONS

Despite being at higher-risk, patients undergoing TViV had reduced rates of permanent pacemaker implantations and atrial fibrillation, and a shorter hospital stay as compared to MIrAVR. Survival at 1-year was similar between the two groups.

Long-term Healthcare Expenditures Over Time for Tissue and Mechanical Aortic Valve Replacement

BACKGROUND

Guidelines currently indicate the use of surgical aortic valve replacement (SAVR) to treat severe cases of aortic stenosis, particularly for low- to medium-risk patients. Although several studies have compared health outcomes of tissue and mechanical SAVR, this economic simulation model estimates the difference in long-term healthcare costs associated with tissue relative to mechanical SAVR.

METHODS

The deterministic and Monte Carlo simulation models used literature-based epidemiologic and cost inputs to calculate annual expenditures related to SAVR for up to 25 years after initial surgery. A series of 3 cohort studies across different age groups provided the health outcome probabilities for tissue valve patients. Outcome probabilities for mechanical valve patients were based on relative risks reported in comparative meta-analyses or large cohort studies.

RESULTS

Relative to mechanical SAVR the expected net discounted savings for a patient receiving tissue SAVR at ages 45, 55, and 65 years were $12,266, $15,462, and $16,008, respectively (based on 2018 US dollars) over a 25-year horizon (95% confidence intervals exceed $0). For a 45-year-old tissue SAVR patient, the estimated per-patient cost difference (relative to mechanical SAVR) of reoperation over 25 years ($16,201) were offset by expected savings on anticoagulation monitoring ($26,257) over the same period. In a sensitivity analysis in which mortality risk was assumed equal, significant long-term savings associated with tissue SAVR still accrued in each of the 3 age cohorts.

CONCLUSIONS

Payers, providers, and the healthcare system may financially benefit from the use of tissue valves because significant savings were associated with the use of tissue valves relative to mechanical valves for SAVR.

Age-stratified outcomes of bioprosthetic and mechanical aortic valve replacements in an Australian cohort of 13 377 patients

OBJECTIVES

To quantify age-stratified outcomes of bioprosthetic valve (BV) and mechanical valve (MV) surgical aortic valve replacement (AVR) in Australian patients.

DESIGN

Retrospective cohort study using population-based linked hospital morbidity and mortality data.

SETTING

Public and private hospitals.

PARTICIPANTS

Patients aged 18 years and over undergoing AVR from 2001 to 2013, stratified by age (18-64 years; 65+ years).

MAIN OUTCOME MEASURES

Age-standardized index AVR rates; rates and multivariable-adjusted (age, sex, Charlson Comorbidity Index) incidence rate ratios (IRRs) for reoperation, incident cardiovascular events (hospitalization or death for acute myocardial infarction (AMI), stroke, major hemorrhage or thromboembolism) and mortality (cardiovascular and all-cause).

RESULTS

Our cohort comprised 13 377 patients, of whom 3464 (26%) were aged 18-64 years. Annual age-standardized AVR rates increased by 2.7% with BV implants increasing in both age groups. After 5 years of follow-up, patients implanted with BV had lower rates of stroke (IRR: 0.40, 95% CI 0.27 to 0.60) and hemorrhage (IRR: 0.36, 95% CI 0.26 to 0.50). Among patients 65+ years, those implanted with BV had lower rates of AMI, hemorrhage, and cardiovascular and all-cause mortality than those implanted with MV (IRR: 0.71, 95% CI 0.53 to 0.96; IRR: 0.77, 95% CI 0.62 to 0.95; IRR: 0.80, 95% CI 0.69 to 0.92 and IRR: 0.85, 95% CI 0.74 to 0.97, respectively). After 6-10 years of follow-up, reoperation rates among patients 18-64 years were markedly higher in those implanted with BV compared with MV (IRR: 5.48, 95% CI 2.38 to 12.62) and rates of AMI were lower among patients implanted with BV compared with MV (IRR: 0.49, 95% CI 0.26 to 0.94). Among patients 65+ years rates of cardiovascular and all-cause mortality remained significantly lower for patients implanted with BV compared with MV.

CONCLUSIONS

This study provides real-world evidence of AVR use and outcomes. Use of BV implants is increasing irrespective of age. Valve choice in younger patients requires thorough evaluation of patient factors influencing both short-term outcomes and longer-term risks of reoperation, stroke and hemorrhage.

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.

Outcomes of tissue versus mechanical aortic valve replacement in patients 50 to 70 years of age

BACKGROUND

Societal guidelines suggest that aortic valve replacement (AVR) in patients age 50 to 70 years can be performed with either bioprosthetic or mechanical valves. This study reviewed outcomes between these valve types among patients aged 50 to 70 years undergoing AVR.

METHODS

We examined adult patients 50 to 70 years undergoing isolated AVR with a mechanical or bioprosthetic valve at a single institution between 2010 and 2018. Kaplan-Meier analysis was used to evaluate longitudinal survival and multivariable Cox regression analysis was used for risk adjustment. A propensity-matched analysis was performed as well.

RESULTS

A total of 723 patients underwent isolated AVR with 467 (64.6%) receiving a bioprosthetic valve. At baseline, patients undergoing bioprosthetic AVR were older (median 65 vs 60 years; P < .001). One-year survival was comparable, however, survival at 5 years was significantly higher among patients undergoing mechanical AVR (95.5% vs 82.6%; P = .010). Among the 196 matched pairs, bioprosthetic AVR was associated with an increased adjusted hazard for death (hazards ratio, 3.29; P < .001). Additionally, 5-year freedom from stroke and bleeding were similar following matching, though mechanical AVR was associated with a greater freedom from repeat valve intervention (97.5% vs 92.9%; P = .020).

CONCLUSION

In patients age 50 to 70, mechanical AVR is associated with improved long-term survival and freedom from repeat aortic valve intervention. Further large cohort studies should be performed to explore the potential benefits of mechanical valve replacement in this age range.

Anticoagulation After Surgical or Transcatheter Bioprosthetic Aortic Valve Replacement

BACKGROUND

There is paucity of evidence on the impact of anticoagulation (AC) after bioprosthetic aortic valve replacement (AVR) on valve hemodynamics and clinical outcomes.

OBJECTIVES

The study aimed to assess the impact of AC after bioprosthetic AVR on valve hemodynamics and clinical outcomes.

METHODS

Data on antiplatelet and antithrombotic therapy were collected. Echocardiograms were performed at 30 days and 1 year post-AVR. Linear regression model and propensity-score adjusted cox proportional model were used to assess the impact of AC on valve hemodynamics and clinical outcomes, respectively.

RESULTS

A total of 4,832 patients undergoing bioprosthetic AVR (transcatheter aortic valve replacement [TAVR], n = 3,889 and surgical AVR [SAVR], n = 943) in the pooled cohort of PARTNER2 (Placement of Aortic Transcatheter Valves) randomized trials and nonrandomized registries were studied. Following adjustment for valve size, annular diameter, atrial fibrillation, and ejection fraction at the time of assessment of hemodynamics, there was no significant difference in aortic valve mean gradients or aortic valve areas between patients discharged on AC vs. those not discharged on AC, for either TAVR or SAVR cohorts. A significantly greater proportion of patients not discharged on AC had an increase in mean gradient >10 mm Hg from 30 days to 1 year, compared with those discharged on AC (2.3% vs. 1.1%, p = 0.03). There was no independent association between AC after TAVR and adverse outcomes (death, p = 0.15; rehospitalization, p = 0.16), whereas AC after SAVR was associated with significantly fewer strokes (hazard ratio [HR]: 0.17; 95% confidence interval [CI]: 0.05-0.60; p = 0.006).

CONCLUSIONS

In the short term, early AC after bioprosthetic AVR did not result in adverse clinical events, did not significantly affect aortic valve hemodynamics (aortic valve gradients or area), and was associated with decreased rates of stroke after SAVR (but not after TAVR). Whether early AC after bioprosthetic AVR has impact on long-term outcomes remains to be determined. (Placement of AoRTic TraNscathetER Valves [PARTNERII A]; NCT01314313).

Epoxy Chitosan-Crosslinked Acellular Bovine Pericardium with Improved Anti-calcification and Biological Properties

Glutaraldehyde (GA) was conventionally used to crosslink bovine pericardium to prepare bioprosthetic heart valves (BHVs), which usually fail within 10 years because of valve deterioration and calcification. To overcome the high cytotoxicity and severe calcification of GA-crosslinked BHVs, a quaternary ammonium salt of epoxy chitosan (epoxy group-modified 3-chlorine-2-hydroxypropyl trimethyl chitosan, abbreviated as "eHTCC") was developed to modify the acellular bovine pericardium to substitute GA and improve its anti-calcification and biocompatible properties. Mechanical test, enzymatic stability test, blood compatibility assay, and cytocompatibility assay were used to investigate its mechanical property and biocompatibility. The anti-calcification effect of the eHTCC-modified bovine pericardium (eHTCC-BP) was assessed by in vitro assay and rat subcutaneous implantation assay. The results showed that eHTCC-BP could improve the mechanical properties and anti-enzymolysis ability of BP, as well as retain the original three-dimensional structure, compared with the uncrosslinked-BP group. Moreover, the in vivo calcification level of the eHTCC-BP group was much lower than that of the GA-BP group, which was 5.1% (2 weeks), 2.3% (4 weeks), and 0.8% (8 weeks) of the GA-BP group. In summary, this study demonstrated that eHTCC could be a potential crosslinking agent for the extracellular matrix for its favorable crosslinking effects, anti-enzymolysis, anti-calcification, and biocompatibility.

Active Aortic Endocarditis in Young Adults: Long-term Results of the Ross Procedure

BACKGROUND

The best valvular substitute remains controversial in young adults with active aortic valve endocarditis. The Ross procedure has gained interest because of its theoretical resistance to infection. We aimed to report our long-term outcomes of the Ross procedure in this indication.

METHODS

Between March 1992 and January 2019, 511 patients underwent a Ross procedure in our institution. Among them, we included 38 patients who suffered from an active aortic valve infective endocarditis. The mean age was 33.9 ± 8.1 years. Six patients had emergent procedures and 17 patients had perivalvular involvement. A pulmonary autograft was implanted using the full root technique in 78.9% of patients. Median follow-up was 12 (interquartile range, 1.75-16.25) years.

RESULTS

The hospital mortality rate was 5.3%. Estimated overall survival was 84.2% ± 6.6% at 10 years. There were 2 cases of recurrent endocarditis, both requiring reoperation. Six other patients required reoperation on an autograft or homograft. Estimated freedom from recurrent endocarditis or reoperation was 89.4% ± 5.9% at 10 years.

CONCLUSIONS

In experienced centers, the Ross procedure is a reliable alternative to prosthetic or homograft valve replacement in young adults experiencing active aortic valve endocarditis, with a low operative risk and good long-term results.

The importance of surgical therapy with expansion of TAVR to low-risk patients

Despite the landmark release of recent transcatheter aortic valve replacement data, the gold standard of surgical therapy is here to stay. Surgery remains vital in patient populations with low coronary height raising risk of coronary occlusion, aneurysmal ascending aorta, isolated aortic regurgitation, noncalcific disease, bicuspid valves, and multivessel coronary disease, or other structural abnormality requiring cardiac surgery. Consideration of these issues highlights the ongoing importance of multidisciplinary consideration of individual patient cases, careful review of imaging, and preservation of a robust surgical program to complement transcatheter development. As the landscape of valvular heart disease management continues to evolve, the surgeon's role is changing, but by no means diminished and their engagement in heart team decision making remains paramount.

Longitudinal Hemodynamics of Transcatheter and Surgical Aortic Valves in the PARTNER Trial

Importance

Use of transcatheter aortic valve replacement (TAVR) for severe aortic stenosis is growing rapidly. However, to our knowledge, the durability of these prostheses is incompletely defined.

Objective

To determine the midterm hemodynamic performance of balloon-expandable transcatheter heart valves.

Design, Setting, and Participants

In this study, we analyzed core laboratory-generated data from echocardiograms of all patients enrolled in the Placement of Aortic Transcatheter Valves (PARTNER) 1 Trial with successful TAVR or surgical AVR (SAVR) obtained preimplantation and at 7 days, 1 and 6 months, and 1, 2, 3, 4, and 5 years postimplantation. Patients from continued access observational studies were included for comparison.

Interventions

Successful implantation after randomization to TAVR vs SAVR (PARTNER 1A; TAVR, n = 321; SAVR, n = 313), TAVR vs medical treatment (PARTNER 1B; TAVR, n = 165), and continued access (TAVR, n = 1996). Five-year echocardiogram data were available for 424 patients after TAVR and 49 after SAVR.

Main Outcomes and Measures

Death or reintervention for aortic valve structural indications, measured using aortic valve mean gradient, effective orifice area, Doppler velocity index, and evidence of hemodynamic deterioration by reintervention, adverse hemodynamics, or transvalvular regurgitation.

Results

Of 2795 included patients, the mean (SD) age was 84.5 (7.1) years, and 1313 (47.0%) were female. Population hemodynamic trends derived from nonlinear mixed-effects models showed small early favorable changes in the first few months post-TAVR, with a decrease of -2.9 mm Hg in aortic valve mean gradient, an increase of 0.028 in Doppler velocity index, and an increase of 0.09 cm2 in effective orifice area. There was relative stability at a median follow-up of 3.1 (maximum, 5) years. Moderate/severe transvalvular regurgitation was noted in 89 patients (3.7%) after TAVR and increased over time. Patients with SAVR showed no significant changes. In TAVR, death/reintervention was associated with lower ejection fraction, stroke volume index, and aortic valve mean gradient up to 3 years, with no association with Doppler velocity index or valve area. Reintervention occurred in 20 patients (0.8%) after TAVR and in 1 (0.3%) after SAVR and became less frequent over time. Reintervention was caused by structural deterioration of transcatheter heart valves in only 5 patients. Severely abnormal hemodynamics on echocardiograms were also infrequent and not associated with excess death or reintervention for either TAVR or SAVR.

Conclusions and Relevance

This large, core laboratory-based study of transcatheter heart valves revealed excellent durability of the transcatheter heart valves and SAVR. Abnormal findings in individual patients, suggestive of valve thrombosis or structural deterioration, were rare in this protocol-driven database and require further investigation.

Trial Registration

clinicaltrials.gov Identifier: NCT00530894.

After 50 Years of Heart Transplants: What Does the Next 50 Years Hold for Cardiovascular Medicine? A Perspective From the International Society for Applied Cardiovascular Biology

The first successful heart transplant 50 years ago by Dr.Christiaan Barnard in Cape Town, South Africa revolutionized cardiovascular medicine and research. Following this procedure, numerous other advances have reduced many contributors to cardiovascular morbidity and mortality; yet, cardiovascular disease remains the leading cause of death globally. Various unmet needs in cardiovascular medicine affect developing and underserved communities, where access to state-of-the-art advances remain out of reach. Addressing the remaining challenges in cardiovascular medicine in both developed and developing nations will require collaborative efforts from basic science researchers, engineers, industry, and clinicians. In this perspective, we discuss the advancements made in cardiovascular medicine since Dr. Barnard's groundbreaking procedure and ongoing research efforts to address these medical issues. Particular focus is given to the mission of the International Society for Applied Cardiovascular Biology (ISACB), which was founded in Cape Town during the 20th celebration of the first heart transplant in order to promote collaborative and translational research in the field of cardiovascular medicine.

Tissue versus mechanical aortic valve replacement in younger patients: A multicenter analysis

OBJECTIVE

The goal of this study was to examine the long-term survival of patients between the ages of 50 and 65 years who underwent tissue versus mechanical aortic valve replacement (AVR) in a multicenter cohort.

METHODS

A multicenter, retrospective analysis of all AVR patients (n = 9388) from 1991 to 2015 among 7 medical centers reporting to a prospectively maintained clinical registry was conducted. Inclusion criteria were: patients aged 50 to 65 years who underwent isolated AVR. Baseline comorbidities were balanced using inverse probability weighting for a study cohort of 1449 AVRs: 840 tissue and 609 mechanical. The primary end point of the analysis was all-cause mortality. Secondary end points included in-hospital morbidity, 30-day mortality, length of stay, and risk of reoperation.

RESULTS

During the study period, there was a significant shift from mechanical to tissue valves (P < .001). There was no significant difference in major in-hospital morbidity, mortality, or length of hospitalization. Also, there was no significant difference in adjusted 15-year survival between mechanical versus tissue valves (hazard ratio, 0.87; 95% confidence interval [CI], 0.67-1.13; P = .29), although tissue valves were associated with a higher risk of reoperation with a cumulative incidence of 19.1% (95% CI, 14.4%-24.3%) versus 3.0% (95% CI, 1.7%-4.9%) for mechanical valves. The reoperative 30-day mortality rate was 2.4% (n = 2) for the series.

CONCLUSIONS

Among patients 50 to 65 years old who underwent AVR, there was no difference in adjusted long-term survival according to prosthesis type, but tissue valves were associated with a higher risk of reoperation.