Early and Late Outcomes of Aortic Valve Replacement Using Bioprosthetic Versus Mechanical Valve in Elderly Patients: A Propensity Analysis

A chronological history of heart valve prostheses to offer perspectives of their limitations

Prosthetic heart valves (PHV) have been studied for around 70 years. They are the best alternative to save the life of patients with cardiac valve diseases. However, current PHVs may still cause significant disadvantages to patients. In general, native heart valves show complex structures and reproducing their functions challenges scientists. Valve repair and replacement are the options to heal heart valve diseases (VHDs), such as stenosis and regurgitation, which show high morbidity and mortality worldwide. Valve repair contributes to the performance of cardiac cycles. However, it fails to restore valve anatomy to its normal condition. On the other hand, replacement is the only alternative to treat valve degeneration. It may do so by mechanical or bioprosthetic valves. Although prostheses may restructure patients' cardiac cycle, both prostheses may show limitations and potential disadvantages, such as mechanical valves causing thrombogenicity or bioprosthetic valves, calcification. Thus, prostheses require constant improvements to remedy these limitations. Although the design of mechanical valve structures has improved, their raw materials cause great disadvantages, and alternatives for this problem remain scarce. Cardiac valve tissue engineering emerged 30 years ago and has improved over time, e.g., xenografts and fabricated heart valves serving as scaffolds for cell seeding. Thus, this review describes cardiac valve substitutes, starting with the history of valvular prosthesis transplants and ending with some perspectives to alleviate the limitations of artificial valves.

Impact of sarcopenia on long-term survival after cardiac surgery for end-stage renal disease patients

BACKGROUND

The long-term mortality of end-stage renal disease (ESRD) patients is still unsatisfactory. Therefore, long-term risk assessments in ESRD patients undergoing cardiac surgery are needed. Recently, sarcopenia is major concern in cardiac surgery because of its association with poor long-term survival. However, the impact of sarcopenia on the long-term survival of ESRD patients undergoing cardiac surgery is not well understood.

METHODS

Eighty-two ESRD patients who underwent elective cardiac surgery were enrolled. Sarcopenia was identified based on noncontrast abdominal computed tomography. The impact of preoperative and intraoperative factors on long-term survival was investigated.

RESULTS

Forty-three patients (52%) were diagnosed with sarcopenia. The in-hospital mortality rate was 4.9%. The 5-year overall survival rate was 48%. The multivariate analyses revealed that STS score ≥ 4 (odds ratio, 6.0; confidence interval, 2.5-14.7; p < 0.01) and presence of sarcopenia (odds ratio, 2.4; confidence interval, 1.3-4.5; p  =  0.03) were independent risk factors for overall survival. The 5-year survival rates of low-risk (Society of Thoracic Surgeons score of < 4) patients without sarcopenia, low-risk with sarcopenia, more than intermediate-risk (Society of Thoracic Surgeons score of ≥ 4) without sarcopenia, and more than intermediate-risk with sarcopenia groups were 80%, 51%, 50%, and 26%, respectively.

CONCLUSIONS

Among the ESRD patients, the low risk without sarcopenia group showed an excellent long-term survival, in contrast to more than intermediate-risk patients with sarcopenia, who can expect poor long-term survival. Preoperative assessment of sarcopenia in addition to the surgical risk score can be useful in developing a therapeutic strategy.

Trends in SAVR with biological vs. mechanical valves in middle-aged patients: results from a French large multi-centric survey

Background/introduction

Currently, despite continued issues with durability ( 1), biological prosthetic valves are increasingly chosen over mechanical valves for surgical aortic valve replacement (SAVR) in adult patients of all ages, at least in Western countries. For younger patients, this choice means assuming the risks associated with a redo SAVR or valve-in-valve procedure.

Purpose

To assess the use of mechanical vs. biological valve prostheses for SAVR relative to patient's age and implant time in a large population extracted from the French National Database EPICARD.

Methods

Patients in EPICARD undergoing SAVR from 2007 to 2022 were included from 22 participating public or private centers chosen to represent a balanced representation of centre sizes and geographical discrepancies. Patients with associated pathology of the aorta (aneurysm or dissection) and requiring a vascular aortic prosthesis were excluded. Comparisons were made amongst centers, valve choice, implant date range, and patient age.

Results

We considered 101,070 valvular heart disease patients and included 72,375 SAVR (mean age 71.4 ± 12.2 years). We observed a mechanical vs. biological prosthesis ratio (MBPR) of 0.14 for the overall population. Before 50 years old (y-o), MBPR was >1.3 (p < 0.001) while patients above 60 years-old received principally biological SAVR (p < 0.0001). Concerning patients between 50 and 60 years-old patients, MPVR was 1.04 (p = 0.03). Patients 50-60 years-old from the first and second study duration quartile (before August 2015) received preferentially mechanical SAVR (p < 0.001). We observed a shift towards more biological SAVR (p < 0.001) for patients from the third and fourth quartile to reach a MBPR at 0.43 during the last years of the series. Incidentally, simultaneous mitral valve replacement were more common in case of mechanical SAVR (p < 0.0001), while associated CABGs were more frequent in case of biological SAVR (p < 0.0001).

Conclusion

In a large contemporary French patient population, real world practice showed a recent shift towards a lower age-threshold for biological SAVR as compared to what would suggest contemporary guidelines.

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.

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.

Epidemiology of Heart Valve Disease in Taiwan

Studies conducted in developed nations have shown that increase in life expectancy has brought with it a rise in the incidence and treatment of degenerative aortic and mitral heart valve diseases. Current standards recommend valve replacement among even some asymptomatic patients. In this research, we examine the epidemiology of valvular heart disease and rate of valve replacement in Taiwan, where life expectancy now stands at 80.69 years. Patients were enrolled based on claims from a widely used national database and categorized into cohorts defined by type of valve disease and, further, by valve replacements and type of valve (mechanical, porcine, or bovine). Data, including disease type, age, and gender, were analyzed to determine annual and cumulative incidence rates and prosthetic usage from 2000 to 2017. Results showed that across the cohorts, the cumulative incidence rate in 2017 was 3.59%, and in the aortic valve cohort, the percentage of surgical valve replacement for those ≥60 years was 6.99%. Compared with other developed nations, this demonstrates that incidence rates are slightly higher, yet surgical replacements are less than half that of other developed nations. This under-treatment of patients with valvular heart disease presents an important public health challenge in Taiwan.

Minimally-invasive versus transcatheter aortic valve implantation: systematic review with meta-analysis of propensity-matched studies

Background

Minimally invasive aortic valve replacement (MiAVR) and transcatheter aortic valve implantation (TAVI) provide aortic valve replacement (AVR) by less invasive methods than conventional surgical AVR, by avoiding complete sternotomy. This study directly compares and analyses the available evidence for early outcomes between these two AVR methods.

Methods

Electronic databases were searched from inception until August 2019 for studies comparing MiAVR to TAVI, according to predefined search criteria. Propensity-matched studies with sufficient data were included in a meta-analysis.

Results

Eight studies with 9,744 patients were included in the quantitative analysis. Analysis of risk-matched patients showed no difference in early mortality (RR 0.76, 95% CI, 0.37–1.54, P=0.44). MiAVR had a signal towards lower rate of postoperative stroke, although this did not reach statistical significance (OR 0.42, 95% CI, 0.13–1.29, P=0.13). MiAVR had significantly lower rates of new pacemaker (PPM) requirement (OR 0.29, 95% CI, 0.16–0.52, P<0.0001) and postoperative aortic insufficiency (AI) or paravalvular leak (PVL) (OR 0.05, 95% CI, 0.01–0.20, P<0.0001) compared to TAVI, (OR 0.42, 95% CI, 0.13–1.29, P=0.13), while acute kidney injury (AKI) was higher in MiAVR compared to TAVI (11.1% vs. 5.2%, OR 2.28, 95% CI, 1.25–4.16, P=0.007).

Conclusions

In patients of equivalent surgical risk scores, MiAVR may be performed with lower rates of postoperative PPM requirement and AI/PVL, higher rates of AKI and no statistical difference in postoperative stroke or short-term mortality, compared to TAVI. Further prospective trials are needed to validate these results.

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

BACKGROUND AND AIM OF THE STUDY

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Aortic valve cell seeding into decellularized animal pericardium by perfusion-assisted bioreactor

Animal-derived pericardium is the elective tissue employed in manufacturing heart valve prostheses. The preparation of this tissue for biological valve production consists of fixation with aldehydes, which reduces, but not eliminates, the xenoantigens and the donor cellular material. As a consequence, especially in patients below 65-70 years of age, the employment of valve substitutes contaning pericardium is not indicated due to progressive calcification that causes tissue degeneration and recurrence of valve insufficiency. Decellularization with ionic or nonionic detergents has been proposed as an alternative procedure to prepare aldehyde- or xenoantigen-free pericardium for biological valve manufacturing. In the present contribution, we optimized a decellularization procedure that is permissive for seeding and culturing valve competent cells able to colonize and reconstitute a valve-like tissue. A high-efficiency cellularization was achieved by forcing cell penetration inside the pericardium matrix using a perfusion bioreactor. Because the decellularization procedure was found not to alter the collagen composition of the pericardial matrix and cells seeded in the tissue constructs consistently grew and acquired the phenotype of "quiescent" valve interstitial cells, our investigation sets a novel standard in pericardium application for tissue engineering of "living" valve implants.

Aortic Valve Cusp Coaptation Surface Area Using 3-Dimensional Transesophageal Echocardiography Correlates with Severity of Aortic Valve Insufficiency

OBJECTIVE

The aim of this study was to test both in humans and using finite element (FE) aortic valve (AV) models whether the coaptation surface area (CoapSA) correlates with aortic insufficiency (AI) severity due to dilated aortic roots to determine the validity and utility of 3-dimensional transesophageal echocardiographic-measured CoapSA.

DESIGN

Two-pronged, clinical and computational approach.

SETTING

Single university hospital.

PARTICIPANTS

The study comprised 10 patients with known AI and 98 FE simulations of increasingly dilated human aortic roots.

INTERVENTIONS

The CoapSA was calculated using intraoperative 3-dimensional transesophageal echocardiography data of patients with isolated AI and compared with established quantifiers of AI. In addition, the CoapSA and effective regurgitant orifice area (EROA) were determined using FE simulations.

MEASUREMENTS AND MAIN RESULTS

In the 10 AI patients, regurgitant fraction (RF) increased with EROA (R² = 0.77, p = 0.0008); CoapSA decreased with RF (R² = 0.72, p = 0.0020); CoapSA decreased with EROA (R² = 0.71, p = 0.0021); and normalized CoapSA (CoapSA / [Ventriculo-Aortic Junction × Sinotubular Junction]) decreased with EROA (R² = 0.60, p = 0.0088). In the 98 FE simulations, normalized CoapSA decreased with EROA (R² = 0.50, p = 0.0001).

CONCLUSIONS

In both human and FE AV models, CoapSA was observed to be inversely correlated with AI severity, EROA, and RF, thereby supporting the validity and utility of 3D TEE-measured CoapSA. A clinical implication is the expectation that high values of CoapSA, measured intraoperatively after AV repairs, would correlate with better long-term outcomes of those repairs.