Ten-year comparison of pericardial tissue valves versus mechanical prostheses for aortic valve replacement in patients younger than 60 years of age

Long-Term Outcomes of Mechanical Versus Bioprosthetic Aortic Valve Replacement in Patients Aged Under 50 Years: Meta-Analysis of Reconstructed Time-to-Event Data

To compare the long-term outcomes of mechanical versus bioprosthetic aortic valve replacement (AVR) in patients aged <50 years, we performed a study-level meta-analysis with reconstructed time-to-event data including studies published by December of 2023. The primary outcome was overall survival. Secondary outcomes included reoperation, major bleeding, and stroke. A total of 5 studies met our inclusion criteria, with a total of 4,245 patients (2,311 mechanical and 1,934 bioprosthetic). All studies were observational and the mean age of groups across the studies ranged from 38.2 to 43.0 years. The median follow-up time was 11.4 years (interquartile range 6.9 to 15.0). Bioprosthetic AVR was associated with reduced overall survival and higher risk of all-cause death (hazard ratio [HR] 1.170 95% confidence interval [CI] 1.002 to 1.364, p = 0.046), increased risk of reoperation over time (HR 2.581, 95% CI 2.102 to 3.168, p <0.001), decreased risk of major bleeding (HR 0.500, 95% CI 0.367 to 0.682, p <0.001), and decreased risk of stroke (HR 0.751, 95% C, 0.565 to 0.998, p = 0.049) compared with mechanical AVR in patients aged <50 years. In conclusion, for patients aged <50 years, bioprosthetic AVR is associated with increased mortality and risk of reoperation compared with mechanical valves. In contrast, mechanical AVR is associated with an increased risk of major bleeding events and stroke. These aspects should be carefully considered during the selection of valve type in this age group; however, we should keep in mind that the statistically significant differences in the risk of all-cause death and stroke might not be clinically relevant (because of marginal statistical significance).

Antithrombotic management after aortic valve replacement with biological prosthesis: a meta-analysis

BACKGROUND

We aimed to summarise the existing knowledge regarding antithrombotic medications following surgical aortic valve replacement (SAVR) using a biological valve prosthesis.

METHODS

We performed a meta-analysis of studies that reported the results of using antithrombotic medication to prevent thromboembolic events after SAVR using a biological aortic valve prosthesis and recorded the outcomes 12 months after surgery. Since no randomised controlled trials were identified, observational studies were included. The analyses were conducted separately for periods of 0-12 months and 3-12 months after surgery. A random effects model was used to calculate pooled outcome event rates and 95% confidence intervals (CIs).

RESULTS

The search yielded eight eligible observational studies covering 6727 patients overall. The lowest 0- to 12-month mortality was observed in patients with anticoagulation (2.0%, 95% CI 0.4-9.7%) and anticoagulation combined with antiplatelet therapy (2.2%, 95% CI 0.9-5.5%), and the highest was in patients without antithrombotic medication (7.3%, 95% CI 3.6-14.2%). Three months after surgery, mortality was lower in anticoagulant patients (0.5%, 95% CI 0.1-2.6%) than in antiplatelet patients (3.0%, 95% CI 1.2-7.4%) and those without antithrombotics (3.5%, 95% CI 1.3-9.3%). There was no eligible evidence of differences in stroke rates observed among medication strategies. At 0- to 12-month follow-up, all antithrombotic treatment regimens resulted in an increased bleeding rate (antiplatelet 4.2%, 95% CI 2.9-6.1%; anticoagulation 7.5%, 95% CI 3.8-14.4%; anticoagulation combined with antiplatelet therapy 8.3%, 95% CI 5.7-11.8%) compared to no antithrombotic medication (1.1%, 95% CI 0.4-3.4%). At 3- to 12-month follow-up, there was up to an eight-fold increase in the bleeding rate in patients with anticoagulation combined with antiplatelet therapy when compared to those with no antithrombotic medication. Overall, the evidence certainty was ranked as very low.

CONCLUSION

Although this meta-analysis reveals that anticoagulation therapy has a beneficial tendency in terms of mortality at 1 year after biological SAVR and suggests potential advantages in continuing anticoagulation beyond 3 months, it is limited by very low evidence certainty. The imperative for cautious interpretation and the urgent need for more robust randomised research underscore the complexity of determining optimal antithrombotic strategies in this patient population.

Twenty-year experience following aortic valve replacement in patients younger than 60 years of age

OBJECTIVE

Reports on long-term outcomes of surgical aortic valve replacement (AVR) for patients aged < 60 years are scarce in Japan. Hence, we aimed to evaluate these outcomes in patients aged < 60 years.

METHODS

Between March 2000 and December 2020, 1477 patients underwent aortic valve replacement. In total, 170 patients aged < 60 years who underwent aortic valve replacement were recruited. Patients aged < 18 years were excluded. Patient data collected from the operative records and follow-up assessments were reviewed.

RESULTS

The mean age was 49 ± 9 years, and 64.1% of patients were male. One-hundred-and-fifty-two patients (89.4%) underwent aortic valve replacement with a mechanical valve and 18 (10.6%) with a bioprosthetic valve. The mean follow-up period was 8.1 ± 5.5 years. No operative mortality occurred, and in-hospital mortality occurred in one patient (0.6%). Ten late deaths occurred, with seven cardiac-related deaths. The overall survival rate was 95.4 ± 1.7%, 93.9 ± 2.3%, 90.6 ± 3.9%, and 73.2 ± 11.8% at 5, 10, 15, and 20 years, respectively. Freedom from major bleeding was 96.4 ± 1.6% at 5, 10, and 15 years, and 89.0 ± 7.3% at 20 years. Freedom from thromboembolic events was 98.7 ± 1.3%, 97.3 ± 1.9%, 90.5 ± 4.5%, and 79.0 ± 11.3% at 5, 10, 15, and 20 years, respectively. Freedom from valve-related reoperation was 99.4 ± 0.6% at 5 years, 97.8 ± 1.7% at 10 and 15 years, and 63.9 ± 14.5% at 20 years.

CONCLUSIONS

Patients aged < 60 years undergoing aortic valve replacement with a high mechanical valve implantation rate had favorable long-term outcomes.

Mechanical versus Bioprosthetic Aortic Valve Replacement in Patients Aged 50 to 70 Years

Background

This study compared the outcomes of surgical aortic valve replacement (AVR) in patients aged 50 to 70 years based on the type of prosthetic valve used.

Methods

We compared patients who underwent mechanical AVR to those who underwent bioprosthetic AVR at our institution between January 2000 and March 2019. Competing risk analysis and the inverse probability of treatment weighting (IPTW) method based on propensity score were employed for comparisons.

Results

A total of 1,580 patients (984 patients with mechanical AVR; 596 patients with bioprosthetic AVR) were enrolled. There was no significant difference in early mortality between the mechanical AVR and bioprosthetic AVR groups (0.9% vs. 1.7%, p=0.177). After IPTW adjustment, the risk of all-cause mortality was significantly higher in the bioprosthetic AVR group than in the mechanical AVR group (hazard ratio [HR], 1.39; 95% confidence interval [CI], 1.07-1.80; p=0.014). Competing risk analysis revealed lower risks of stroke (sub-distributional hazard ratio [sHR], 0.44; 95% CI, 0.28-0.67; p<0.001) and anticoagulation- related bleeding (sHR, 0.35; 95% CI, 0.23-0.53; p<0.001) in the bioprosthetic AVR group. Conversely, the risk of aortic valve (AV) reintervention was higher in the bioprosthetic AVR group (sHR, 6.14; 95% CI, 3.17-11.93; p<0.001).

Conclusion

Among patients aged 50 to 70 years who underwent surgical AVR, those receiving mechanical valves showed better survival than those with bioprosthetic valves. The mechanical AVR group exhibited a higher risk of stroke and anticoagulation-related bleeding, while the bioprosthetic AVR group showed a higher risk of AV reintervention.

Transcatheter aortic valve replacement in low-risk young population: A double edge sword?

Since the advent of transcatheter aortic valve replacement (TAVR) in 2002, it has now become the default interventional strategy for symptomatic patients presenting with severe aortic stenosis, particularly in intermediate to high-surgical risk patients. In 2019, the United States Food and Drug Administration approved TAVR in low-risk patients based on two randomized trials. However, these breakthrough trials excluded patients with certain unfavorable anatomies and odd profiles. While currently there is no randomized study of TAVR in young patients, it may be preferred by the young population given the benefits of early discharge, shorter hospital stay, and expedite recovery. Nonetheless, it is important to ruminate various factors including lifetime expectancy, risk of pacemaker implantation, and the need for future valve or coronary interventions in young cohorts before considering TAVR in these patients. Furthermore, the data on long-term durability (> 10 years) of TAVR is still unknown given most of the procedures were initially performed in the high or prohibitive surgical risk population. Thus, this editorial aims to highlight the importance of considering an individualized approach in young patients with consideration of various factors including lifetime expectancy while choosing TAVR against surgical aortic valve replacement.

Revisiting aortic valve prosthesis choice in patients younger than 50 years: 10 years results of the AUTHEARTVISIT study

OBJECTIVES

This population-based cohort study investigated mid-term outcome after surgical aortic valve replacement with a bioprosthetic or mechanical valve prosthesis in patients aged <50 years in a European social welfare state.

METHODS

We analysed patient data from the main social insurance carriers in Austria (2010-2020). Subsequent patient-level record linkage with national health data provided patient characteristics and clinical outcome. Survival, reoperation, myocardial infarction, heart failure, embolic stroke or intracerebral haemorrhage, bleeding other than intracerebral haemorrhage and major adverse cardiac events were evaluated as outcomes.

RESULTS

A total of 991 patients were analysed. Regarding demographics, no major differences between groups were observed. Multivariable Cox regression revealed no significant difference in overall survival (P = 0.352) with a median follow-up time of 6.2 years. Reoperation-free survival was decreased (hazard ratio = 1.560 [95% CI: 1.076-2.262], P = 0.019) and the risk for reoperation was increased (hazard ratio = 2.770 [95% CI: 1.402-5.472], P = 0.003) in patients who received bioprostheses. Estimated probability of death after reoperation was 0.23 (CL: 0.08-0.35) after 2 years and 0.34 (CL: 0.06-0.53) after 10 years over both groups. Regarding further outcomes, no significant differences between the two groups were observed.

CONCLUSIONS

In patients below 50 years of age receiving aortic valve replacement, implantation of bioprostheses when compared to mechanical heart valve prostheses was associated with a significantly higher rate of reoperations and reduced reoperation-free survival. Nevertheless, we could not observe a difference in overall survival. However, long-term follow-up has to evaluate that a significantly lower rate of reoperations may translate in consistently improved long-term survival.

Clinical Impact of Patient-Prosthesis Mismatch After Aortic Valve Replacement With a Mechanical or Biological Prosthesis

BACKGROUND

Patient-prosthesis mismatch (PPM) may impair functional capacity and survival after aortic valve replacement. This study aimed to investigate the impact of PPM on long-term survival and quality of life after mechanical and biological aortic valve replacement.

METHODS

This study included 595 consecutive patients who had undergone isolated aortic valve replacement. Patients were divided into 2 groups according to prosthesis type. The baseline and operative characteristics, survival rates, complications, and quality of life of the groups with and without PPM were compared for up to 6 years. The PPM calculation was performed using the effective orifice area value provided by the manufacturer divided by the patient's body surface area.

RESULTS

The moderate to severe PPM rates were 69.8% and 3.7% after biological and mechanical prosthesis implantation, respectively. Mean survival for patients in the biological group who had PPM was statistically significantly shorter (50.2 months [95% CI, 45.2-55.3]) than for patients in the biological group without PPM (60.1 months [95% CI, 55.7-64.4]; P = .04). In the mechanical prosthesis group, there was no difference in mean survival between the subgroup with PPM (66.6 months [95% CI, 58.3-74.9]) and the subgroup without PPM (64.9 months [95% CI, 62.6-67.2]; P = .50). A quality-of-life questionnaire's scores did not differ between the groups.

CONCLUSION

Mismatch is common after biological valve implantation and statistically significantly affects long-term survival and quality of life. If the risk of PPM after implantation of a biological prosthesis is suspected, adopting strategies to avoid PPM at the time of surgery is warranted.

Comparison of long-term outcomes of bioprosthetic and mechanical aortic valve replacement in patients younger than 65 years

OBJECTIVES

The objectives of this study were to compare rates of mortality and reoperations for patients aged younger than 65 years who underwent surgical aortic valve replacement (AVR). AVR with a bioprosthetic valve (BV) is increasing among younger patients, however evidence to inform the choice between BV or mechanical valve is limited.

METHODS

We performed a retrospective cohort study using linked hospital and mortality data from Australia, for 3969 AVR patients between 2003 and 2018. We compared outcomes for valves in inverse probability of treatment-weighted cohorts, stratified according to age (18-54 years; 55-64 years). We used weighted Cox regression models to estimate hazard ratios (HRs) and weighted cumulative incidence function for subdistribution hazards, for follow-up intervals: 0 to 10 and >10 to 15 years.

RESULTS

Among patients aged 55 to 64 years, there was no difference in mortality at 0 to 10 years. However, at >10 to 15 years, mortality was higher among BV recipients (HR, 1.56; 95% CI, 1.01-2.42). There was no difference among patients aged 18 to 54 years. Reoperation rates for patients aged 55 to 64 years did not differ according to valve type at 0 to 10 years, but were higher for BV than mechanical valve at >10 to 15 years (HR, 2.87; 95% CI, 1.69-4.86). For patients aged 18 to 54 years, reoperation rates were consistently higher for BV at both time intervals (HR, 2.54 [95% CI, 1.03-6.25] and HR, 4.48 [95% CI, 2.15-9.32], respectively).

CONCLUSIONS

Patients aged 55 to 64 years who received a BV had a higher risk of mortality beyond 10 years. Rates of reoperations were higher among patients implanted with a BV in the entire cohort. Further investigation of long-term outcomes among patients with a BV is necessary. Continuous long-term monitoring of BV technologies will ensure evidence-based decision-making and regulation.

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.

ESC/EACTS vs. ACC/AHA guidelines for the management of severe aortic stenosis

Aortic stenosis (AS) is a serious and complex condition, for which optimal management continues to evolve rapidly. An understanding of current clinical practice guidelines is critical to effective patient care and shared decision-making. This state of the art review of the 2021 European Society of Cardiology/European Association for Cardio-Thoracic Surgery Guidelines and 2020 American College of Cardiology/American Heart Association Guidelines compares their recommendations for AS based on the evidence to date. The European and American guidelines were generally congruent with the exception of three key distinctions. First, the European guidelines recommend intervening at a left ventricular ejection fraction of 55%, compared with 60% over serial imaging by the American guidelines for asymptomatic patients. Second, the European guidelines recommend a threshold of ≥65 years for surgical bioprosthesis, whereas the American guidelines employ multiple age categories, providing latitude for patient factors and preferences. Third, the guidelines endorse different age cut-offs for transcatheter vs. surgical aortic valve replacement, despite limited evidence. This review also discusses trends indicating a decreasing proportion of mechanical valve replacements. Finally, the review identifies gaps in the literature for areas including transcatheter aortic valve implantation in asymptomatic patients, the appropriateness of Ross procedures, concomitant coronary revascularization with aortic valve replacement, and bicuspid AS. To summarize, this state of the art review compares the latest European and American guidelines on the management of AS to highlight three areas of divergence: timing of intervention, valve selection, and surgical vs. transcatheter aortic valve replacement criteria.

TAVR in 2023: Who Should Not Get It?

Since the first transcatheter delivery of an aortic valve prosthesis was performed by Cribier et al in 2002, the picture of aortic stenosis (AS) therapeutics has changed dramatically. Initiated from an indication of inoperable to high surgical risk, extending to intermediate and low risk, transcatheter aortic valve replacement (TAVR) is now an approved treatment for patients with severe, symptomatic AS across all the risk categories. The current evidence supports TAVR as a frontline therapy for treating severe AS. The crucial question remains concerning the subset of patients who still are not ideal candidates for TAVR because of certain inherent anatomic, nonmodifiable, and procedure-specific factors. Therefore, in this study, we focus on these scenarios and reasons for referring selected patients for surgical aortic valve replacement in 2023.

Clinical performance of a novel bioprosthetic surgical aortic valve in a German high-volume center

BACKGROUND AND AIM

Bioprosthetic surgical aortic valve replacement (SAVR) is increasingly adopted in younger patients. We aimed to analyze mid-term follow-up data after SAVR to assess the performance of the prosthesis.

METHODS

Data were collected from a single-center series of 154 patients, who underwent SAVR with a bioprosthetic heart valve with the RESILIA tissue at our Heart Centre in Siegburg. All procedural and midterm patient outcomes were documented.

RESULTS

Patients had a mean age of 56.8 ± 9.9 years, 35.7% were female, and the mean logistic European system for cardiac operative risk evaluation (EuroSCORE) was 3.4 ± 3.6%. Diabetes (12.3%), atrial fibrillation (10.4%), and chronic obstructive pulmonary disease (COPD) (5.8%) were common comorbidities. The mean surgery duration was 163.8 ± 73.4 min, with the 23 mm (34.4%) and 25 mm (33.8%) heart valves being most frequently implanted. At 3-year follow-up, mean pressure gradient was 13.9 ± 5.9 mmHg, peak gradient was 23.6 ± 7.7 mmHg, and effective orifice area (EOA) was 1.9 ± 0.4 cm². No patient died during the operation, 3 (2.1%) patients within 30 days, and 4 (2.7%) thereafter with an overall mortality of n = 7. Of the surviving patients, 97.8% were in New York Heart Association (NYHA) class I/II and none had structural valve deterioration (SVD).

CONCLUSION

Results of our single-center study indicate favorable procedural outcomes. The safety outcomes confirm preliminary earlier results of this novel bioprosthesis but include more patients and a longer midterm follow-up.

Looking Back to Look Forward: What to Expect in a Redo Surgery for a Bioprosthesis Replacement

Redo surgeries are becoming more common because of an increased rate of bioprosthesis implantation. We performed a retrospective study on patients who underwent redo replacement of an aortic and/or mitral bioprosthesis between 2005 and 2018 to evaluate intra-hospital mortality and morbidity. Univariate analysis was performed on the propensity score variables to determine predictors of mortality. A total of 180 patients were enrolled in the study: Group A (replacement of aortic bioprosthesis) with 136 patients (75.56%) and group B (replacement of mitral bioprosthesis ± aortic bioprosthesis) with 44 patients (24.44%). NYHA class ≥ 3 and female sex were significantly more common in group B. Cardiopulmonary-bypass time and aortic cross-clamping time in group A and group B were, respectively, 154.95 ± 74.35 and 190.25 ± 77.44 (p = 0.0005) and 115.99 ± 53.54 and 144.91 ± 52.53 (p = 0.0004). Overall mortality was 8.89%. After propensity score adjustment, Group B was confirmed to have an increased risk of death (OR 3.32 CI 95% 1.02−10.88 p < 0.0001), gastrointestinal complications (OR 7.784 CI 95% 1.005−60.282 p < 0.0002) and pulmonary complications (OR 2.381 CI 95% 1.038−5.46 p < 0.0001). At the univariate analysis, endocarditis, cardiopulmonary-bypass and aortic cross clamping time, NYHA class ≥ 3 and urgency setting were significantly associated to death. Intra-hospital outcomes were acceptable regarding mortality and complications. Patients who need redo surgery on mitral bioprosthesis have an increased risk of post-operative pulmonary and gastrointestinal complications and mortality. Therefore the choice of mitral bioprosthesis at time of first surgery should be carefully evaluated.

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.

Surgical Management of Complex Aortic Valve Disease in Young Adults: Repair, Replacement, and Future Alternatives

The ideal aortic valve substitute in young adults remains unknown. Prosthetic valves are associated with a suboptimal survival and carry a significant risk of valve-related complications in young patients, mainly reinterventions with tissue valves and, thromboembolic events and major bleeding with mechanical prostheses. The Ross procedure is the only substitute that restores a survival curve similar to that of a matched general population, and permits a normal life without functional limitations. Though the risk of reintervention is the Achilles' heel of this procedure, it is very low in patients with aortic stenosis and can be mitigated in patients with aortic regurgitation by tailored surgical techniques. Finally, the Ozaki procedure and the transcatheter aortic valve implantation are seen by many as future alternatives but lack evidence and long-term follow-up in this specific patient population.

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.

Controversy pro: Mechanical AVR for better long-term survival of 50-70 years old

Selection of the most appropriate type of aortic valve prosthesis (mechanical or biologic) for patients 50-70 years of age is a matter of frequent debate. The purpose of this article is to review overlooked concepts and misconceptions in valve-related complications, prosthesis durability, and late survival to aid decision making in contemporary practice. A trend favoring improved long-term survival was found among patients who receive a mechanical prosthesis compared to a biologic substitute. Additionally, an acceptably low rate of long-term valve-related thromboembolism and hemorrhage was found among those with mechanical prostheses. Implantation of a biologic valve substitute did not appear to reduce the risk of thromboembolism, may not eliminate the need for long-term anticoagulation and may be associated with an increased risk of late mortality. These findings may aid providers (and patients) in the preoperative consultation and seem to support consideration of a mechanical heart valve substitute over a biologic valve for patients 50-70 years age.

Treatment of valvular heart disease in young patients-"early evidence" versus "latest fashion"

Is the performance of locally manufactured mechanical valve prostheses relevant for modern cardiac surgery, in which mechanical valve replacement has become a rarity? This question comes to mind reading the article in this issue of the Journal demonstrating equal outcomes of the TTK Chitra tilting disk mechanical heart valve prostheses in comparison to the SJM bi-leaflet blockbuster. The evidence documenting efficacy of mechanical valve replacement stems from the early ages of cardiac surgery, but often demonstrates superior outcomes in terms of survival and hemodynamics. Yet, the latest fashion in the Western world consists biological choices in combination with new transcatheter techniques (valve in valve options) or the Ozaki or Ross procedures. As long-term results are often missing and documented advantages for mechanical valves stems from early evidence, the local emphasis of mechanical valve replacement may possibly result in superior individual prognoses compared to following the Western world's latest fashions. Individual patient information and decision making moves into focus.

Mechanical aortic valve prostheses offer a survival benefit in 50-65 year olds: AUTHEARTVISIT study

BACKGROUND

The present population-based cohort study investigated long-term mortality after surgical aortic valve replacement (AVR) with bioprosthetic (B) or mechanical aortic valve prostheses (M) in a European social welfare state.

METHODS

We analysed patient data from health insurance records covering 98% of the Austrian population between 2010 and 2018. Subsequent patient-level record linkage with national health data provided patient characteristics and clinical outcomes. Further reoperation, myocardial infarction, heart failure and stroke were evaluated as secondary outcomes.

RESULTS

A total of 13,993 patients were analysed and the following age groups were examined separately: <50 years (727 patients: 57.77% M, 42.23% B), 50-65 years (2612 patients: 26.88% M, 73.12% B) and >65 years (10,654 patients: 1.26% M, 98.74% B). Multivariable Cox regression revealed that the use of B-AVR was significantly associated with higher mortality in patients aged 50-65 years compared to M-AVR (HR = 1.676 [1.289-2.181], p < 0.001). B-AVR also performed worse in a competing risk analysis regarding reoperation (HR = 3.483 [1.445-8.396], p = 0.005) and myocardial infarction (HR = 2.868 [1.255-6.555], p = 0.012). However, the risk of developing heart failure and stroke did not differ significantly after AVR in any age group.

CONCLUSIONS

Patients aged 50-65 years who underwent M-AVR had better long-term survival, and a lower risk of reoperation and myocardial infarction. Even though anticoagulation is crucial in patients with M-AVR, we did not observe significantly increased stroke rates in patients with M-AVR. This evident survival benefit in recipients of mechanical aortic valve prostheses aged <65 years critically questions current guideline recommendations.

Bioprosthetic aortic valve replacement in patients aged 50 years old and younger: Structural valve deterioration at long-term follow-up. Retrospective study

Background

Structural valve deterioration (SVD) remains the major determinant of bioprosthesis durability. The aim of this study was to investigate the SVD incidence, predictors and outcomes in patients aged 50 years and younger after bioprosthetic aortic valve replacement (bAVR).

Methods

We retrospectively analyzed 73 consecutive patients ≤50 years old who underwent bioprosthetic AVR at our center between 2005 and 2015. Median age at surgery was 44 (interquartile range [IQR]: 39-47) years. Follow-up was 93.2% complete at a median time of 7.2 (IQR: 5.5-9.5) years. Cumulative follow-up was 545.5 valve-years. Bioprosthesis SVD was determined by strict echocardiographic assessment.

Results

The overall survival-rate at 10/15 years and freedom from SVD at 10/12.5 years were 89.6 ± 5.2%/81.5 ± 9.1% and 73.5 ± 8.2%/41.9 ± 18.9%, respectively. SVD occurred at a median time of 8.2 (IQR: 6.0-9.9) years after bAVR. Age was not found as an independent predictor for SVD at the multivariable model, despite a higher rate of SVD in the age group ≤30 years. Freedom from reoperation due to SVD at 10/15 years was 71.3 ± 14.1%/13.6 ± 12.3%. Reoperation was performed at a median time of 10.0 (IQR: 8.9-11.9) years since first bAVR and was associated with a 100% 12-month survival.

Conclusions

In our study, the rate and time of SVD occurrence were comparable to those of other studies' older age groups. Strict echocardiographic monitoring of valve performance is mandatory to set the appropriate timing of eventual reoperation. This attitude can improve outcomes of bAVR in younger patients.

Long-term outcomes of patients undergoing mechanical versus bioprosthetic aortic root replacement

BACKGROUND

We evaluated the impact of valve type (mechanical vs. bioprosthetic) on survival after aortic root replacement (ARR).

METHODS

In a propensity-matched analysis, we evaluated consecutive operations from 2010 to 2018. Patients were identified using a prospectively maintained institutional database. Patients with infective endocarditis were excluded. Kaplan-Meier survival estimation and multivariable Cox regression analysis were performed. Cox regression adjusted for age, sex, baseline comorbidities, and operative variables. Propensity score matching yielded 153 pairs of patients.

RESULTS

A total of 893 patients were identified. We excluded 192 patients with endocarditis and evaluated 701 patients. Of these patients, 455 (64.9%) received a bioprosthetic valve, 246 (35.1%) received a mechanical valve. Median follow-up was 4.06 years. The proportion of aortic dissections and circulatory arrest as well as cardiopulmonary bypass and ischemic times were similar across groups (p = .207, p = .086, p = .668, p = .454, respectively). Operative mortality was significantly higher in the bioprosthetic valve group (7.9% vs. 2.4%, p = .004). Total length of hospital stay was longer (11.4 ± 11.0 vs. 9.5 ± 10.1, p < .001) and there was a higher proportion of prolonged postoperative ventilation >24 h (21.3% vs. 13.0%, p = .007) in the bioprosthetic group. Postoperative outcomes were similar, regarding stroke (p = .077), re-exploration for bleeding (p = .211), new dialysis requirement (p = .077), long-term bleeding complications (p = .561), and reoperations (p = .755). Mechanical valve replacement was associated with improved long-term survival (adjusted HR 0.42, 95% CI: 0.23-0.77, p = .005).

CONCLUSIONS

These findings suggest that mechanical valves for ARRs may confer a survival benefit over bioprosthetic valves. Surgeon bias was likely to account for this survival advantage.

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.

Lifetime management for aortic stenosis: Planning for future therapies

A shift to lifetime management has gained more focus with the approval of low-risk transcatheter aortic valve replacement (TAVR). This paper is therefore focused on the different approaches for lifetime management. Herein we discuss the procedural safety, durability, performance, and future options for each lifetime management strategy. In younger patients that elect to undergo surgical aortic valve replacement (SAVR), options for bioprosthetic failure are TAV-in-SAV or redo SAVR. Among patients that undergo TAVR, options for valve failure include TAVR explant with SAVR or TAV-in-TAV. Additionally, there are patients who may require a third valvular intervention. The initial therapy may limit re-intervention options down the road. This review discusses how options for future therapies affect the decision of SAVR vs TAVR in younger patients.

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.

Aortic valve replacement in sheep with a novel trileaflet mechanical heart valve prosthesis without anticoagulation

Background

Even after decades of intensive research, an ideal heart valve prosthesis remains elusive. Shortcomings of conventional devices include reduced durability of bioprostheses and the thrombogenicity of mechanical substitutes, necessitating anticoagulation and resulting in imperfect hemodynamics. Here we present in vivo results of a novel mechanical heart valve prosthesis aiming for freedom from anticoagulation.

Methods

Four female sheep had their aortic valves replaced using the novel mechanical heart valve (size 21 mm), with no postoperative anticoagulation treatment. This trileaflet heart valve was designed with the pivots in the systolic central flow. Hemodynamics, biochemistry, hematology, and macroscopy and microscopy were studied at 90 days in 2 sheep and at 1 year in the other 2 sheep.

Results

Mean (<6 mm Hg) and peak (<10 mm Hg) aortic transvalvular gradients remained low during the study period. Aortic regurgitation was trivial, and central traces were only rarely observed. The rate of thrombotic events was very low, with none macroscopically and microscopically visible thrombotic material on the device. Biochemistry and hemotology were unchanged without hemolysis. In 3 sheep, the fibrous pannus and mitral leaflet were partially folded over the edge of the annular body. Apart from organic/inorganic deposits on the leaflets after 1 year, the ultrastructurally evaluated leaflets were similar to those of nonimplanted controls.

Conclusions

The preliminary in vivo results of this novel anticoagulation-free aortic mechanical heart valve are promising with excellent hemodynamics and a very low risk of thrombotic events.

The Ross procedure is the optimal solution for young adults with unrepairable aortic valve disease

While aortic valve repair remains the ideal intervention to restore normal valvular function, the optimal aortic valve substitute for patients with a non-repairable aortic valve remains an ongoing subject for debate. In particular, younger patients with a non-repairable valve represent a unique challenge because of their active lifestyle and long life expectancy, which carries a higher cumulative risk of prosthesis-related complications. The Ross procedure, unlike prosthetic or homograft aortic valve replacement (AVR), provides an expected survival equivalent to that of the age and gender-matched general population. Contemporary data has shown that the Ross procedure can be performed safely in centers with expertise, and is associated with improved valvular durability, hemodynamics and quality of life.

Aortic valve neocuspidization with autologous pericardium in adult patients: UK experience and meta-analytic comparison with other aortic valve substitutes

OBJECTIVES

We sought to provide further evidence on the safety and efficacy of aortic valve neocuspidization (AVNeo) using autologous pericardium in adult patients with aortic valve disease by reporting clinical and echocardiographic results from the first UK experience and performing a meta-analytic comparison with other biological valve substitutes.

METHODS

We reported clinical and echocardiographic outcomes of 55 patients (mean age 58 ± 15 years) undergoing AVNeo with autologous pericardium in 2 UK centres from 2018 to 2020. These results were included in a meta-analytic comparison between series on AVNeo (7 studies, 1205 patients, mean weighted follow-up 3.6 years) versus Trifecta (10 studies, 8705 patients, 3.8 years), Magna Ease (3 studies, 3137 patients, 4.1 years), Freedom Solo (4 studies, 1869 patients, 4.4 years), Freestyle (4 studies, 4307 patients, 7 years), Mitroflow (4 studies, 4760 patients, 4.1 years) and autograft aortic valve (7 papers, 3839 patients, 9.1 years).

RESULTS

In the present series no patients required intraoperative conversion. After mean follow-up of 12.5 ± 0.9 months, 3 patients presented with endocarditis and 1 required reintervention. The remaining patients had absent or mild aortic valve insufficiency with very low peak and mean transvalvular gradients (16 ± 3.7 and 9 ± 2.2 mmHg, respectively). Meta-analytic estimates showed non-significant difference between AVNeo and all but Magna Ease valves with regards to structural valve degeneration, reintervention and endocarditis. When compared Magna Ease valve, AVNeo and other valve substitutes showed an excess of valve-related events.

CONCLUSIONS

AVNeo is safe, associated with excellent haemodynamic profile. Its midterm risk of valve-related events is comparable to most biological valve substitutes. Magna Ease is potentially the best biological choice as far as risk of reintervention is concerned.

Increased utilization of bioprosthetic aortic valve technology:Trends, drivers, controversies and future directions

Introduction: Bioprosthetic valves (BPV) implanted surgically or by transcatheter valve implantation (TAVI) comprise an overwhelming majority of substitute aortic valves implanted worldwide.Areas Covered: Prominent drivers of this trend are: 1) BPV patients have generally better outcomes than those with a mechanical valve, and remain largely free of anticoagulation and its consequences; 2) BPV durability has improved over the years; and 3) the expanding use of TAVI and valve-in-valve (VIV) procedures permitting interventional management of structural valve degeneration (SVD). Nevertheless, key controversies exist: 1) optimal anticoagulation regimens for surgical and TAVI BPVs; 2) the incidence, mechanisms and mitigation strategies for SVD; 3) the use of VIV for treatment of SVD, and 4) valve selection recommendations for difficult cohorts, (e.g. patients 50-70 years, patients <50, childbearing age women). This communication reviews trends in and drivers of BPV utilization, current controversies, and future directions affecting BPV use.Expert Opinion: Long-term data are needed in several areas related to aortic BPV use, including anticoagulation/antiplatelet therapy, especially following TAVI. TAVI and especially VIV durability and optimal use warrant will benefit greatly from long-term data. Certain populations may benefit from such high-quality data on multi-year outcomes, particularly younger patients.

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.

Current Therapeutic Options in Aortic Stenosis

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

Predictors of Use and Outcomes of Mechanical Valve Replacement in the United States (2008-2017)

Background

Contemporary nationwide data on the use, predictors, and outcomes of mechanical valve replacement in patients less than 70 years of age are limited.

Methods and Results

We identified hospitalizations for aortic valve replacement (AVR) or mitral valve replacement (MVR) in the Nationwide Inpatient Sample between January 1, 2008, and December 31, 2017. The study's end points included predictors of mechanical valve replacement and risk‐adjusted in‐hospital mortality. Among 253 100 hospitalizations for AVR, the use rate of mechanical prosthesis decreased from 45.3% in 2008 to 17.0% in 2017. Among 284 962 hospitalizations for MVR, mechanical prosthesis use decreased from 59.5% in 2008 to 29.2% in 2017 (P for trend<0.001). In multilogistic regression analyses, female sex, prior sternotomy, prior defibrillator, and South/West geographic location were predictive of mechanical valve use. The presence of bicuspid valve was a negative predictor of mechanical AVR (odds ratio [OR], 0.68; 95% CI, 0.66–0.69; P<0.001), whereas mitral stenosis was associated with higher mechanical MVR (OR, 1.28; 95% CI, 1.22–1.33; P<0.001). Unadjusted in‐hospital mortality decreased over time with AVR but not with MVR, regardless of prosthesis choice. Using years 2008 and 2009 as a reference, risk‐adjusted mortality also decreased over time with AVR but did not decrease after MVR.

Conclusions

There is a substantial decline in the use of mechanical valve replacement among patients aged ≤70 years in the United States. Long‐term durability data on bioprosthetic valve replacement are needed to better define the future role of mechanical valves in this age group.

The current diagnosis and treatment of patients with aortic valve stenosis

Aortic valve stenosis (AS) is the third most frequent cardiovascular abnormality after coronary artery disease and hypertension. A bicuspid aortic valve is the most common cause for AS until seventh decade and calcific valve degeneration is responsible thereafter. In symptomatic patients, The risk of death increases from ≤1%/year to 2%/month. An echo valve area ≤1 cm², peak transaortic velocity ≥4 m/s, mean valve gradient ≥40 mmHg and/or computerized tomography valve calcium score >2000 Agatston units (AU) for males or more than 1200 AU for females indicate severe AS. AS stages and management are discussed. Valve replacement is based on surgical risk, valve durability/hemodynamics, need for anticoagulation and patient preferences. EuroSCORE ≥20%, Society of Thoracic Surgeons Predicted Risk of Mortality ≥8% and co-morbidities indicate high surgical risk. Surgery is recommended for low-intermediate risk patients. Transcatheter aortic valve implantation is an alternative in older patients at low, intermediate, high or prohibitive risk. Transaortic valve implantation/replacement trials are summarized.

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.

[Clinical results of cardiac valve repair with bicuspid full-flow mechanical prosthesis 'MedEng-ST']

Prosthetic repair of cardiac valves with artificial mechanical prostheses is ubiquitously performed using prostheses consisting of two cusps (bicuspidal). Several years ago, new bicuspid full-flow prostheses appeared on the market. From the first use they immediately proved reliable, with stable haemodynamic characteristics. At the Interregional Clinical and Diagnostic Centre, bicuspid full-flow mechanical prostheses 'MedEng-ST' have been used since 2017. We carried out a retrospective follow up of 84 patients subjected to prosthetic repair of cardiac valves with full-flow prostheses 'MedEng-ST' in mitral and aortic positions. There were no prosthesis-associated or procedural complications during follow up. Neither were there major complications in the postoperative period. All complications were related to peculiarities of the approach to the heart. We assessed the functional parameters of the heart by standard echocardiography. The obtained findings demonstrated good haemodynamic parameters on the 'MedEng-ST' prostheses, improved intracardiac haemodynamics, which eventually had a beneficial effect on the patients' clinical picture. The transprosthetic gradients had stable parameters with a decrease in time when placing the 'MedEng-ST' prosthesis into the aortic position (p≤0.05). Proceeding from the obtained results, as well as taking into account the absence of thromboembolic events it may be stated that the proposed design of the device is universal for replacement of the aortic and mitral valves of the heart. Based on the obtained findings of the study we recommend to use the 'MedEng'ST' prostheses in clinical practice. Further studies are required for more convincing data and explicit recommendations.

The long term results of the Ross procedure: The importance of candidate selection

The Ross procedure has been considered in children as an optimal surgical procedure due to potential growth of the aortic annulus, lack of anticoagulation requirement, very low morbidity rate and excellent survival. Five-hundred-thirty-six (366 male, mean age 29.4 ± 11.1 years) underwent Ross procedure between 1990 and 2016 and had complete clinical and echocardiographic follow-up. Mean follow-up was 16.3 ± 4.9 years. Patients were divided in 2 groups according to age at surgery. Group 1 consisted of 320 (60%) patients less than 18 years old (223 male, mean age at surgery of 9.5 ± 5.6 years). Group 2 consisted of 216 (40%) patients older than 18 years of age (143 male, mean age at surgery of 26.3 ± 8.2 years). One-hundred-thirty (24%) patients had a redo procedure or surgery. Freedom from all re-operation and or percutaneous reintervention on either the aortic and pulmonary valves was 99% after 1 year, 94% after 5 years, 89% after 10 years, 83% after 15 years and 78% after 20 years. Freedom from redo surgery for AV 99% after 1 year, 94% after 5 years, 90% after 10 years, 81% after 15 years and 80% after 20 years. Freedom from redo surgery for PV was 100% after 1 year, 95% after 5 years, 89% after 10 years, 78% after 15 years and 76% after 20 years. The ideal candidate for Ross operation is a patient with congenital aetiology and an aortic root diameter ≤ 15 mm/m². A pulmonary fresh preserved homograft seems to perform better on the long term.

Endocarditis risk with bioprosthetic and mechanical valves: systematic review and meta-analysis

OBJECTIVE

Bioprosthetic valves are being used with increased frequency for valve replacement, with controversy regarding risk:benefit ratio compared with mechanical valves in younger patients. However, prior studies have been too small to provide comparative estimates of less common but serious adverse events such as infective endocarditis. We aimed to compare the incidence of infective endocarditis between bioprosthetic valves and mechanical valves.

METHODS

We searched PubMed, Cochrane, EMBASE, Scopus and Web of Science from inception to April 2018 for studies comparing left-sided aortic and mitral bioprosthetic to mechanical valves for randomised trials or observational studies with propensity matching. We used random-effects model for our meta-analysis. Our primary outcome of interest was the rate of infective endocarditis at follow-up.

RESULTS

13 comparison groups with 43 941 patients were included. Mean age was 59±7 years with a mean follow-up of 10.4±5.0 years. Patients with bioprosthetic valves had a higher risk of infective endocarditis compared with patients receiving mechanical valves (OR 1.59, 95% CI 1.35 to 1.88, p<0.001) with an absolute risk reduction of 9 per 1000 (95% CI 6 to 14). Heterogeneity within the included studies was low (I²=0%). Exclusion of the study with maximum weight did not change the results of the analysis (OR 1.57, 95% CI 1.14 to 2.17, p=0.006). A meta-regression of follow-up time on incidence of infective endocarditis was not statistically significant (p=0.788) indicating difference in follow-up times did not alter the pooled risk of infective endocarditis.

CONCLUSIONS

Bioprosthetic valves may be associated with a higher risk of infective endocarditis. These data should help guide the discussion when deciding between bioprosthetic and mechanical valves in individual patients.

Soft robotic in the construction of prosthetic heart valve: a novel approach

In this study, we describe the design, fabrication and computational testing of a new prosthetic device for aortic valve replacement. The device is an active stent composed of a silicone rubber during initial prototyping, with adaptation towards a hydrogel, poly-vinyl alcohol reinforced with bacterial cellulose nanofibres underway. The nature of the stent is soft robotic (SR), where an increase in internal pressure of the pneumatic network causes an increase in the internal diameter of the device. When working in tandem with the SR heart valve, described briefly, pulsations of the blood and the energy gained from ventricular pressure actuates the valve-and-stent combination. This increases the effective orifice area of the entire device and addresses an issue with small sized heart valves facing prosthesis-patient mismatch.

Improved Survival After the Ross Procedure Compared With Mechanical Aortic Valve Replacement

BACKGROUND

It is unclear whether the Ross procedure offers superior survival compared with mechanical aortic valve replacement (AVR).

OBJECTIVES

This study evaluated experience and compared long-term survival between the Ross procedure and mechanical AVR.

METHODS

Between 1992 and 2016, a total of 392 Ross procedures were performed. These were compared with 1,928 isolated mechanical AVRs performed during the same time period as identified using the University of Melbourne and Australia and New Zealand Society of Cardiac and Thoracic Surgeons' Cardiac Surgery Databases. Only patients between 18 and 65 years of age were included. Propensity-score matching was performed for risk adjustment.

RESULTS

Ross procedure patients were younger, and had fewer cardiovascular risk factors. The Ross procedure was associated with longer cardiopulmonary bypass and aortic cross-clamp times. Thirty-day mortality was similar (Ross, 0.3%; mechanical, 0.8%; p = 0.5). Ross procedure patients experienced superior unadjusted long-term survival at 20 years (Ross, 95%; mechanical, 68%; p < 0.001). Multivariable analysis showed the Ross procedure to be associated with a reduced risk of late mortality (hazard ratio: 0.34; 95% confidence internal: 0.17 to 0.67; p < 0.001). Among 275 propensity-score matched pairs, Ross procedure patients had superior survival at 20 years (Ross, 94%; mechanical, 84%; p = 0.018).

CONCLUSIONS

In this Australian, propensity-score matched study, the Ross procedure was associated with better long-term survival compared with mechanical AVR. In younger patients, with a long life expectancy, the Ross procedure should be considered in centers with sufficient expertise.

The Use of Biological Heart Valves

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Clinical and cost-effectiveness of the Ross procedure versus conventional aortic valve replacement in young adults

Objectives

In young and middle-aged adults, there are three current options for aortic valve replacement (AVR), namely mechanical AVR (mechAVR), tissue AVR (biological AVR) and the Ross operation, with no clear guidance on the best option. We aim to compare the clinical effectiveness and cost-effectiveness of the Ross procedure with conventional AVR in young and middle-aged adults.

Methods

This is a systematic literature review and meta-analysis of AVR options. Markov multistate model was adopted to compare cost-effectiveness. Lifetime costs, quality-adjusted life years (QALYs), net monetary benefit (NMB), population expected value of perfect information (EVPI) and expected value of partial perfect information were estimated.

Results

We identified 48 cohorts with a total number of 12 975 patients (mean age 44.5 years, mean follow-up 7.1 years). Mortality, bleeding and thromboembolic events over the follow-up period were lowest after the Ross operation, compared with mechAVR and biological AVR (p<0.001). Aortic reoperation rates were lower after Ross compared with biological AVR, but slightly higher when compared with mechAVR (p<0.001). At a willingness-to-pay threshold of £20effective. At a willingness-to-pay threshold of £20, 000 per QALY000 per QALY, the Ross procedure is more cost-effective compared the Ross procedure is more cost-effective compared withwith conventional AVR, with a lifetime incremental NMB of £60 conventional AVR, with a lifetime incremental NMB of £60 952 (952 (££3030 236236 to to ££7979 464). Incremental costs were £12464). Incremental costs were £12 323 (323 (££61086108 to to ££1515 972) and incremental QALYs 3.66 (1.81972) and incremental QALYs 3.66 (1.81 to to 4.76). The population EVPI indicates that a trial costing up to £2.03 million could be cost 4.76). The population EVPI indicates that a trial costing up to £2.03 million could be cost--effective.

At a willingness-to-pay threshold of £20 000 per QALY, the Ross procedure is more cost-effective compared with conventional AVR, with a lifetime incremental NMB of £60 952 (£30 236 to £79 464). Incremental costs were £12 323 (£6108 to £15 972) and incremental QALYs 3.66 (1.81 to 4.76). The population EVPI indicates that a trial costing up to £2.03 million could be cost-effective.

Conclusions

In young and middle-aged adults with aortic valve disease, the Ross procedure may confer greater quality of life and be more cost-effective than conventional AVR. A high-quality randomised trial could be warranted and cost-effective.