Long-term outcome after biologic versus mechanical aortic valve replacement in 841 patients

Importance of surgeon's experience in practicing valve-sparing aortic root replacement

Background

Valve-sparing root replacement (VSRR) requires a unique skill set. This study aimed to examine the influence of surgeon's procedural volume on outcomes of VSRR.

Methods

This retrospective study included 1697 patients from 2 large, high-volume aortic centers who underwent aortic root replacement (ARR) between 2004 and 2021 and were potentially eligible for VSRR. Surgeons were classified as performing <5 ARRs or ≥5 ARRs annually. Multivariable logistic regression was used to examine the independent association of surgeon volume and the decision to perform VSRR. Inverse probability treatment weighting (IPTW) was used to match patients who were operated on by <5 ARR surgeons or ≥5 ARR surgeons and compare long-term survival probability. Cumulative incidence curves with mortality as a competing risk were plotted to compare the rate of aortic valve reoperation.

Results

Of 1697 patients who met the study inclusion criteria, 944 underwent composite-valve conduit ARR and 753 underwent VSRR. The median age of the cohort was 57 years (interquartile range, 45-66 years), and 268 (15.8%) were female. Aortic insufficiency was present in 1105 patients (65.1%), and 200 of the procedures (11.8%) were reoperations. The indication for surgery was aneurysm in 1496 patients (88.2%) and dissection in 201 (11.8%). Among the 743 patients who underwent VSRR, 691 (92%) were operated on by ≥ 5 ARR surgeons and 62 (8%) were operated on by <5 ARR surgeons. In multivariable logistic regression, ≥5 ARRs (odds ratio, 3.33; 95% confidence interval, 2.34-4.73; P < .001) was associated with VSRR as the procedure of choice. Following IPTW, there was no significant difference between <5 ARR and ≥5 ARR surgeons in survival probability after VSRR (P = .59) or in the rate of aortic valve reoperation (P = .60).

Conclusions

In the setting of a high-volume aortic center, patients who undergo ARR are less likely to receive VSRR if operated on by a <5 ARR surgeon; however, VSRR may be safely performed by <5 ARR surgeons.

A fast in silico model for preoperative risk assessment of paravalvular leakage

In silico simulations can be used to evaluate and optimize the safety, quality, efficacy and applicability of medical devices. Furthermore, in silico modeling is a powerful tool in therapy planning to optimally tailor treatment for each patient. For this purpose, a workflow to perform fast preoperative risk assessment of paravalvular leakage (PVL) after transcatheter aortic valve replacement (TAVR) is presented in this paper. To this end, a novel, efficient method is introduced to calculate the regurgitant volume in a simplified, but sufficiently accurate manner. A proof of concept of the method is obtained by comparison of the calculated results with results obtained from in vitro experiments. Furthermore, computational fluid dynamics (CFD) simulations are used to validate more complex stenosis scenarios. Comparing the simplified leakage model to CFD simulations reveals its potential for procedure planning and qualitative preoperative risk assessment of PVL. Finally, a 3D device deployment model and the efficient leakage model are combined to showcase the application of the presented leakage model, by studying the effect of stent size and the degree of stenosis on the regurgitant volume. The presented leakage model is also used to visualize the leakage path. To generalize the leakage model to a wide range of clinical applications, further validation on a large cohort of patients is needed to validate the accuracy of the model's prediction under various patient-specific conditions.

Utilization of mechanical prostheses and outcomes of surgical aortic valve replacement at safety net hospitals

Background

Safety-net hospitals care for a high proportion of uninsured/underinsured patients who may lack access to longitudinal care. The present study characterized the use of mechanical valves and clinical outcomes of surgical aortic valve replacement at safety net hospitals.

Methods

All adults undergoing surgical aortic valve replacement were abstracted from the 2016–2018 Nationwide Readmissions Database. Hospitals were divided into quartiles based on volume of all Medicaid and uninsured admissions, with the highest quartile defined as safety net hospitals. Multivariable regression was used to determine the association between safety net hospitals and several outcomes including mechanical valve use, perioperative complications, index hospitalization costs, 90-day readmission, and complications at readmission.

Results

Of the 94,580 patients undergoing surgical aortic valve replacement, 14.5% of operations were at safety net hospitals. Patients at safety net hospitals more commonly received mechanical valves (20.3% vs 16.9%, P < .01) compared to those at non–safety net hospitals. After adjustment, safety net hospitals remained associated with a greater odds of mechanical aortic valve use (adjusted odds ratio, 1.13, 95% confidence interval 1.05–1.21). However, operation at safety net hospitals was also associated with increased odds of perioperative complications (adjusted odds ratio 1.10, 95% confidence interval 1.03–1.17) and higher hospitalization costs (β coefficient +$6.15K, 95% confidence interval +$5.26 − +$7.03) despite similar 90-day readmissions. Upon readmission, safety net hospitals patients were more likely to experience mortality (adjusted odds ratio 1.87, 95% confidence interval 1.18–2.98) and stroke (adjusted odds ratio 2.41, 95% confidence interval 1.23–4.70) compared to those at non–safety net hospitals.

Conclusion

Hospital safety net status is associated with increased use of mechanical valves for surgical aortic valve replacement despite also being associated with increased perioperative complications, costs, and significant complications upon readmission. Ability to access adequate follow-up care may be an important consideration for surgical aortic valve replacement at safety net hospitals.

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.

Incidence and factors associated with infective endocarditis in patients undergoing left-sided heart valve replacement

Aims

Patients with left-sided heart valve replacement are considered at high-risk of infective endocarditis (IE). However, data on the incidence and risk factors associated with IE are sparse.

Methods and results

Through Danish administrative registries, we identified patients who underwent left-sided heart valve replacement from January 1996 to December 2015. Patients were categorized in mitral and aortic valve replacement (MVR and AVR) and followed until: 12 years after valve surgery, end of study, death, emigration, or hospitalization due to IE, whichever came first. Multivariable adjusted Cox proportional hazard analysis was used to investigate which baseline characteristics were associated with IE. A total of 18 041 patients were included. The cumulative IE risk at 10 years follow-up was 5.2% in both MVR and AVR patients. In patients with MVR, male sex [hazard ratio (HR) = 1.68, 95% confidence interval (95% CI) 1.06-2.68], bioprosthetic valve (HR = 1.91, 95% CI 1.08-3.37), and heart failure (HR = 1.69, 95% CI 1.06-2.68) were among factors associated with an increased risk of IE. In AVR patients, male sex (HR = 1.59, 95% CI 1.33-1.89), bioprosthetic valve (HR = 1.70, 95% CI 1.35-2.15), and cardiac implantable electronic device (CIED) (HR = 1.57, 95% CI 1.19-2.06) were among factors associated with an increased risk of IE.

Conclusion

Infective endocarditis after left-sided heart valve replacement is not uncommon and occurs in about 1/20 over 10 years. Male, bioprosthetic valve, and heart failure were among factors associated with IE in MVR patients while male, bioprosthetic valve, and CIED were among factors associated with IE in AVR patients.

Acute coronary syndromes and atherosclerotic plaque burden distribution in coronary arteries among patients with valvular heart disease (BIA-WAD registry)

INTRODUCTION

Valvular heart diseases (VHD) are a significant problem in the Polish population. Coexistence of coronary artery disease (CAD) in patients with VHD increases the risk of death and affects the further therapeutic strategy.

AIM

Analysis of atherosclerotic plaque burden distribution in coronary arteries and long-term prognosis among patients with VHD.

MATERIAL AND METHODS

Inclusion criteria were met by 1025 patients with moderate and severe VHD. Mean observation time was 2528 ±1454 days.

RESULTS

Severe aortic valve stenosis (AVS) occurred in 28.2%, severe mitral valve insufficiency (MVI) in 20%. CAD with severe angiographic stenoses was noted in 42.3% (n = 434). Among patients with severe MVI, CAD was noted in 47.1% of cases, and prior acute coronary syndromes (ACS) in 27.1% of patients (n = 58). In severe AVS patients, significant angiographic atherosclerotic changes were observed in 29.6% (n = 86), and prior ACS in 7.6% (n = 22) of patients. During the observation 52.7% of patients died, including 62.9% of patients with severe MVI and 51.6% of those with severe AVS. Age (OR = 1.038; 95% CI: 1.005-1.072; p = 0.022) and coexisting aortic valve insufficiency (AVI) (OR = 2.39, 95% CI: 5.370-11.065, p = 0.035) increased the mortality rate.

CONCLUSIONS

Severe AVS is starting to be the most prevalent VHD. CAD is one of the most significant factors deteriorating prognosis of patients with VHD. AVI and age were significant risk factors for mortality. The worst prognosis was observed in severe MVI, which may result from more frequent occurrence of CAD in this group. A lesser burden of CAD and ACS in the group of patients with severe AVS did not affect survival.

Reversed L-type Upper Partial Sternotomy in Aortic Valve Replacement: an Initial Experience

Introduction:

Degenerative aortic stenosis (AS) is the most frequent cause among aortic valve stenotic changes. Mini Sternotomy Aortic Valve Replacement is a replacement of aortic valve through upper partial sternotomy.

Aim:

The aim of this approach is to improve postoperative convalescence by leaving pleural spaces closed and do not compromise respiratory function, to decrease bleeding, and reduce post op ventilation time and ICU stay. All these advantages decrease cost during hospital stay by reducing ICU stay, respiration time, bleeding and using blood products, pain killers and shortening hospital stay. Esthetic effect is also considerable result of this method.

Case report:

This case report presents an initial experience with Reversed L-Type Upper Partial Sternotomy in Aortic Valve Replacement. The goal is to demonstrate that minimally invasive advanced cardiac surgery procedures can be performed in our country.

Long-Term Outcomes of the Ross Procedure Versus Mechanical Aortic Valve Replacement: Propensity-Matched Cohort Study

BACKGROUND

The ideal aortic valve substitute in young and middle-aged adults remains unknown. We sought to compare the long-term outcomes of patients undergoing the Ross procedure and those receiving a mechanical aortic valve replacement (AVR).

METHODS

From 1990 to 2014, 258 patients underwent a Ross procedure and 1444 had a mechanical AVR at a single institution. Patients were matched into 208 pairs through the use of a propensity score. Mean age was 37.2±10.2 years, and 63% were male. Mean follow-up was 14.2±6.5 years.

RESULTS

Overall survival was equivalent (Ross versus AVR: hazard ratio, 0.91, 95% confidence interval, 0.38-2.16; P=0.83), although freedom from cardiac- and valve-related mortality was improved in the Ross group (Ross versus AVR: hazard ratio, 0.22; 95% confidence interval, 0.034-0.86; P=0.03). Freedom from reintervention was equivalent after both procedures (Ross versus AVR: hazard ratio, 1.86; 95% confidence interval, 0.76-4.94; P=0.18). Long-term freedom from stroke or major bleeding was superior after the Ross procedure (Ross versus AVR: hazard ratio, 0.09; 95% confidence interval, 0.02-0.31; P<0.001).

CONCLUSIONS

Long-term survival and freedom from reintervention were comparable between the Ross procedure and mechanical AVR. However, the Ross procedure was associated with improved freedom from cardiac- and valve-related mortality and a significant reduction in the incidence of stroke and major bleeding. In specialized centers, the Ross procedure represents an excellent option and should be considered for young and middle-aged adults undergoing AVR.

Choice of prosthetic heart valve in a developing country

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

Comparison of clinical outcomes in patients undergoing mitral valve replacement with mechanical or biological substitutes: a 20 years cohort

Background

The choice of prosthesis for mitral valve replacement still remains controversial. This study assessed mortality, bleeding events and reoperation in patients who underwent mitral valve replacement surgery with biological or mechanical substitutes.

Methods

A total of 352 patients who underwent mitral valve replacement surgery between 1990 and 2008 with 5 to 23 years of follow-up were retrospectively evaluated in a cohort study.

Results

The 5, 10, 15 and 20 year survival rates after surgery using a mechanical substitute were 87.7%, 74.2%, 69.3% and 69.3%, respectively, while after surgery with a biological substitute, they were 87.6%, 71.0%, 64.2% and 56.6%, respectively. There was no significant difference between the two groups (p = 0.38). In the multivariate analysis, the factors associated with death were age, bleeding events and renal failure. The probabilities of remaining free of reoperation at 5, 10, 15 and 20 years after surgery using a mechanical substitute were 94.4%, 92.7%, 92.7% and 92.7%; after surgery with a bioprosthesis, they were 95.9%, 86.4%, 81.2% and 76.5%, respectively (p = 0.073). There was a significantly higher incidence of reoperation for the bioprosthetic valve replacement group (p = 0.008). The probabilities of remaining free of bleeding events at 5, 10, 15 and 20 years after surgery using a mechanical substitute were 95.0%, 91.0%, 89.6% and 89.6%, respectively, while after surgery with a bioprosthesis, they were 96.9%, 94.0%, 94.0% and 94.0%, (p = 0.267).

Conclusions

The authors concluded that: 1) mortality during follow-up was statistically similar for both groups; 2) there was a greater tendency to reoperation in the bioprosthesis group; 3) the probability of remaining free from reoperation remained unchanged after 10 years’ follow-up for patients with mechanical substitute valves; 4) the probability of remaining fee from bleeding events remained unchanged after 10 years’ follow-up for patients given bioprostheses; 5) the baseline characteristics of patients were the greatest determinants of later mortality after surgery; 6) the type of prosthesis was not an independent predictive factor of any of the outcomes tested in the multivariate analysis.

Comparison between biological and mechanical aortic valve prostheses in middle-aged patients matched through propensity score analysis: long-term results

OBJECTIVES

Choice of prosthesis type in middle-aged patients undergoing aortic valve replacement (AVR) is still debated. The aim of this study is to compare long-term follow-up results in middle-aged patients who underwent isolated AVR with a biological or mechanical prosthesis.

METHODS

A retrospective analysis of a single-centre database was performed to identify patients aged between 55 and 65 years old who underwent isolated AVR with a biological or mechanical prosthesis from January 1996 to January 2008. Sixty patients with a biological aortic valve prosthesis (Group A) were identified and matched through propensity score analysis to other 60 patients with a mechanical aortic valve prosthesis (Group B).

RESULTS

There was no difference among groups regarding postoperative complications. Follow-up amounted to 117 ± 51 months. In Group A and B patients, 10- and 15-year survival was 77 ± 6 vs 75 ± 6 and 54 ± 13 vs 53 ± 8%, respectively (P = 0.95); 10- and 15-year freedom from structural valve deterioration, 81 ± 7 vs 100 and 64 ± 12 vs 93 ± 5%, respectively (P = 0.003); 10- and 15-year freedom from redo AVR, 87 ± 6 vs 91 ± 5 and 73 ± 11 vs 91 ± 5%, respectively (P = 0.04); 10- and 15-year freedom from endocarditis, 94 ± 3 vs 98 ± 2 and 83 ± 8 vs 98 ± 2%, respectively (P = 0.05); 10- and 15-year freedom from bleeding events, 98 ± 2 vs 96 ± 5 and 88 ± 6 vs 77 ± 10%, respectively (P = 0.98); and 10- and 15-year freedom from cerebrovascular events, 94 ± 3 vs 97 ± 3 and 83 ± 8 vs 97 ± 3%, respectively (P = 0.03).

CONCLUSIONS

While survival was not different among groups, patients with a biological prosthesis showed a higher valve-related morbidity at follow-up. Therefore, middle-aged patients should preferably receive a mechanical prosthesis.

Clinical evaluation of new heart valve prostheses: update of objective performance criteria

This article summarizes the long-term clinical results of the Food and Drug Administration-approved heart valves, provides current updates to the objective performance criteria (OPC) used to evaluate new heart valve prostheses, and documents the steps that the International Organization for Standardization Committee used to arrive at the updated OPC. Data were extracted from 19 Food and Drug Administration summaries of safety and effectiveness data reports (31 series) and 56 literature articles (85 series) published from 1999 to 2012. The OPC were calculated for five valve-related complications by valve type (mechanical and bioprosthetic) and valve position (aortic and mitral).

How to approach aortic valve disease in the elderly: a 25-year retrospective study

OBJECTIVE

In the last decade, the number of elderly patients suffering from aortic valve disease has significantly increased. This study aimed to identify possible factors that could affect surgical and long-term outcomes in the light of a literature review regarding the management of aortic valve disease in the elderly.

METHODS

Between January 1990 and December 2012, a total of 114 patients (64 males, 50 females; mean age 76.6 ± 3.6 years; range 70-87 years) with aortic valve replacement (AVR) alone, or combined with coronary artery bypass grafting (CABG) or mitral surgery in our hospital, were retrospectively analysed.

RESULTS

In-hospital mortality was seen in 19 patients. The major causes of in-hospital mortality were low-cardiac output syndrome in eight patients (42.1%), respiratory insufficiency or infection in six (31.5%), multi-organ failure in four (21%), and stroke in one patient (5.2%). The main postoperative complications included arrhythmia in 26 patients (22.8%), renal failure in 11 (9.6%), respiratory infection in nine (7.9%), and stroke in three patients (2.6%). The mean length of intensive care unit and hospital stays were 6.4 ± 4.3 and 18 ± 12.8 days, respectively. During follow up, late mortality was seen in 28 patients (29.4%). Possible risk factors for long-term mortality were type of prosthesis, EuroSCORE ≥ 15, postoperative pacemaker implantation, respiratory infection, and haemodialysis. Among 65 long-term survivors, their activity level was good in 53 (81.5%) and poor in two.

CONCLUSIONS

Our study results demonstrated that an individually tailored approach including scheduled surgery increases short- and long-term outcomes of AVR in patients aged ≥ 70 years. In addition, shorter cardiopulmonary bypass time may be more beneficial in this high-risk patient population.

Aortic valve replacement in octogenarians

BACKGROUND

With improved life expectancy more octogenarians now present with aortic valve disease. Cardiac surgery in this group of patients has previously been considered high risk due to co-morbidities and challenges of rehabilitation. This study seeks to challenge the concept of octogenarian cardiac surgery "unsuitability" by analysing operative outcomes and long term survival following aortic valve replacement.

METHODS

Eighty-seven consecutive patients undergoing aortic valve replacement between 2000 and 2009 at St Vincent's Hospital were retrospectively identified. Statistical analysis was performed using SPSS (version 15 and 19).

RESULTS

The average age was 82.7 ± 2.4 years. The mean logistic EuroSCORE was 18.86 ± 14.11. Post-operatively, four patients required insertion of a permanent pacemaker (4.6%) and five patients had a myocardial infarction (5.8%). In-hospital mortality was 3.4%. Follow-up was 93.1% complete. One-year survival was 92.9%, three-year survival was 86.7% and five-year survival was 75.0%. At follow-up 98.1% of patients were New York Heart Association (NYHA) Class I or II.

CONCLUSIONS

Results were excellent despite reasonable co-morbidities and Euroscore risk. Survival was impressive and the NYHA class reflected the success of the surgery in relieving the pathological aortic valve process. Patient age should not be the primary exclusion for cardiac surgery for aortic valve disease.

Long-term outcomes after elective isolated mechanical aortic valve replacement in young adults

OBJECTIVES

The aim of this study was to determine long-term survival and clinical outcomes after elective isolated mechanical aortic valve replacement in young adults.

METHODS

A clinical observational study was conducted in a cohort of 450 consecutive adults less than 65 years of age who had undergone elective isolated mechanical aortic valve replacement (AVR) between 1997 and 2006. Patients who had undergone previous cardiac surgery, and those undergoing concomitant procedures or urgent surgery were excluded. Follow-up was 93.3% complete with a mean follow-up of 9.1±3.5 years. The primary end point was survival. Life table analyses were used to determine age- and gender-matched general population survival. Secondary end points were reoperation and valve-related complications.

RESULTS

Overall actuarial survival at 1, 5, and 10 years was 98%±1%, 95%±1%, and 87%±1%, respectively, which was lower than expected in the age- and gender-matched general population in Quebec. Actuarial freedom from prosthetic valve dysfunction was 99%±0.4%, 95%±1%, and 91%±1% at 1, 5, and 10 years, respectively. Actuarial freedom from valve reintervention was 98%±1%, 96%±1%, and 94%±1% at 1, 5 and 10 years, respectively. Actuarial survival free from reoperation at 10 years was 82%±2%. Actuarial freedom from major hemorrhage was 98%±1%, 96%±1%, and 90%±2% at 1, 5, and 10 years, respectively.

CONCLUSIONS

In young adults undergoing elective isolated mechanical AVR, survival remains suboptimal compared with an age- and gender-matched general population. Furthermore, there is a low but constant hazard of prosthetic valve reintervention after mechanical AVR.

Long-term safety and effectiveness of mechanical versus biologic aortic valve prostheses in older patients: results from the Society of Thoracic Surgeons Adult Cardiac Surgery National Database

BACKGROUND

There is a paucity of long-term data comparing biological versus mechanical aortic valve prostheses in older individuals.

METHODS AND RESULTS

We performed follow-up of patients aged 65 to 80 years undergoing aortic valve replacement with a biological (n=24 410) or mechanical (n=14 789) prosthesis from 1991 to 1999 at 605 centers within the Society of Thoracic Surgeons Adult Cardiac Surgery Database using Medicare inpatient claims (mean, 12.6 years; maximum, 17 years; minimum, 8 years), and outcomes were compared by propensity methods. Among Medicare-linked patients undergoing aortic valve replacement (mean age, 73 years), both reoperation (4.0%) and endocarditis (1.9%) were uncommon to 12 years; however, the risk for other adverse outcomes was high, including death (66.5%), stroke (14.1%), and bleeding (17.9%). Compared with those receiving a mechanical valve, patients given a bioprosthesis had a similar adjusted risk for death (hazard ratio, 1.04; 95% confidence interval, 1.01-1.07), higher risks for reoperation (hazard ratio, 2.55; 95% confidence interval, 2.14-3.03) and endocarditis (hazard ratio, 1.60; 95% confidence interval, 1.31-1.94), and lower risks for stroke (hazard ratio, 0.87; 95% confidence interval, 0.82-0.93) and bleeding (hazard ratio, 0.66; 95% confidence interval, 0.62-0.70). Although these results were generally consistent among patient subgroups, bioprosthesis patients aged 65 to 69 years had a substantially elevated 12-year absolute risk of reoperation (10.5%).

CONCLUSIONS

Among patients undergoing aortic valve replacement, long-term mortality rates were similar for those who received bioprosthetic versus mechanical valves. Bioprostheses were associated with a higher long-term risk of reoperation and endocarditis but a lower risk of stroke and hemorrhage. These risks varied as a function of a patient's age and comorbidities.

Management of prosthetic heart valve complications

OPINION STATEMENT

With greater awareness and treatment of valvular heart disease, there are now an increasing number of patients with prosthetic heart valves. However, replacement of a diseased valve with a prosthetic valve creates the opportunity for new and unique complications that once diagnosed require specific treatments. Complications which may occur depend not only on the type of prosthesis but also are influenced by clinical factors that are important to understand and may affect treatment strategies. Tissue prostheses tend to deteriorate over time while mechanical prostheses require anticoagulation with its attendant risks. The rate of serious prosthetic heart valve complications is approximately 3 % per year. They include bleeding, systemic embolization, obstruction due to thrombus or pannus formation, patient-prosthesis mismatch, infective endocarditis, structural deterioration, prosthetic and peri-prosthetic regurgitation, and hemolysis. Importantly, the risk of prosthetic heart valve complications can be reduced by appropriate choices made at the time of surgery such as utilization of the correct prosthesis size and type. In addition, adherence to current guidelines for anticoagulation, endocarditis prophylaxis, and the timing of clinical and echocardiographic surveillance is also important to prevent complications. Should complications occur, rapid diagnosis, usually with echocardiography, is pivotal and can provide important hemodynamic as well as anatomic information critical to determining appropriate treatment and timing of surgical re-intervention if necessary. Optimal treatment of prosthetic heart valve complications remains a challenge and new treatment strategies continue to evolve.

Comparative evaluation of left ventricular mass regression after aortic valve replacement: a prospective randomized analysis

BACKGROUND

We assessed the hemodynamic performance of various prostheses and the clinical outcomes after aortic valve replacement, in different age groups.

METHODS

One-hundred-and-twenty patients with isolated aortic valve stenosis were included in this prospective randomized randomised trial and allocated in three age-groups to receive either pulmonary autograft (PA, n = 20) or mechanical prosthesis (MP, Edwards Mira n = 20) in group 1 (age < 55 years), either stentless bioprosthesis (CE Prima Plus n = 20) or MP (Edwards Mira n = 20) in group 2 (age 55-75 years) and either stentless (CE Prima Plus n = 20) or stented bioprosthesis (CE Perimount n = 20) in group 3 (age > 75). Clinical outcomes and hemodynamic performance were evaluated at discharge, six months and one year.

RESULTS

In group 1, patients with PA had significantly lower mean gradients than the MP (2.6 vs. 10.9 mmHg, p = 0.0005) with comparable left ventricular mass regression (LVMR). Morbidity included 1 stroke in the PA population and 1 gastrointestinal bleeding in the MP subgroup. In group 2, mean gradients did not differ significantly between both populations (7.0 vs. 8.9 mmHg, p = 0.81). The rate of LVMR and EF were comparable at 12 months; each group with one mortality. Morbidity included 1 stroke and 1 gastrointestinal bleeding in the stentless and 3 bleeding complications in the MP group. In group 3, mean gradients did not differ significantly (7.8 vs 6.5 mmHg, p = 0.06). Postoperative EF and LVMR were comparable. There were 3 deaths in the stented group and no mortality in the stentless group. Morbidity included 1 endocarditis and 1 stroke in the stentless compared to 1 endocarditis, 1 stroke and one pulmonary embolism in the stented group.

CONCLUSIONS

Clinical outcomes justify valve replacement with either valve substitute in the respective age groups. The PA hemodynamically outperformed the MPs. Stentless valves however, did not demonstrate significantly superior hemodynamics or outcomes in comparison to stented bioprosthesis or MPs.

Aortic Valve Replacement in the Elderly

Background—

Few data exist on long-term outcomes of elderly patients after aortic valve replacement. We evaluated latest follow-up information for patients ≥70 years of age after aortic valve replacement.

Methods and Results—

Late overall survival of 2890 consecutive patients ≥70 years of age who underwent aortic valve replacement between January 1993 and December 2007 was reviewed retrospectively, analyzed, and stratified by preoperative and intraoperative variables. Observed 5-, 10-, and 15-year late postoperative survival was lower than generally expected (68%, 34%, and 8% versus 70%, 42%, and 20%, respectively; P <0.001). Independent predictors of late death included older age, renal failure, diabetes mellitus, stroke, myocardial infarction, immunosuppression, prior coronary artery bypass grafting, implanted pacemaker, lower ejection fraction, hypertension, and New York Heart Association class III or IV. After stratification by age–comorbidity risk score, 10-year survival for the lowest-risk group (n=946 [33%]) was similar to expected survival (55% versus 55%; P =0.50), but for the highest-risk group (n=564 [20%]), survival was significantly lower than expected (9% versus 26%; P <0.001). For 229 pairs of propensity-matched patients with mechanical or biological prostheses, survival was not significantly different (67%, 40%, and 19% versus 71%, 45%, and 7% at 5, 10, and 15 years, respectively; P =0.81). Structural deterioration of bioprostheses occurred in 64 patients (2.4%).

Conclusions—

Survival of elderly patients after aortic valve replacement is influenced by age and preoperative comorbidities; 33% at lowest risk had overall survival similar to that of an age- and sex-matched general population. There was no sufficient evidence that valve type affected survival. Structural deterioration of aortic bioprostheses was rare.

In vivo tissue engineering of heart valves: evolution of a novel concept

Current tissue-engineering principles of heart valves include tissue- or stem cell-derived cells with subsequent in vitro incubation on various scaffolds prior to implantation. Limitations of this approach include a long in vitro culture, an accompanied risk of infection and sophisticated, cost-intensive infrastructures. An 'off-the-shelf' heart valve with in vivo endothelialization and tissue-regeneration potential would overcome these limitations. Additionally, the development of a heart valve with growth potential would be a huge improvement for pediatric patients. This article discusses different starter matrices, homing and immobilization strategies of host cells and masking approaches of inflammatory structures for in vivo surface and tissue engineering of heart valves. Novel concepts will be presented based on highly specific DNA-aptamers immobilized on the heart valve surface as capture molecules for endothelial progenitor cells circulating in the bloodstream.

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

Background— Several centers favor replacing a diseased native heart valve with a tissue rather than a mechanical prosthesis, even in younger adult patients. However, long-term data supporting this approach are lacking. We examined the survival implications of selecting a tissue versus a mechanical prosthesis at initial left-heart valve replacement in a cohort of adults <60 years of age who were followed for over 20 years.

Methods and Results— Comorbid and procedural data were available from 6554 patients who underwent valve replacement at our institution over the last 35 years. Of these, 1512 patients contributed follow-up data beyond 20 years, of whom 567 were adults <60 years of age at first left-heart valve operation (mean survivor follow-up, 24.0±3.1 years). Late outcomes were examined with Cox regression. Valve reoperation, often for prostheses that are no longer commercially available, occurred in 89% and 84% of patients by 20 years after tissue aortic and mitral valve replacement, respectively, and was associated with a mortality of 4.3%. There was no survival difference between patients implanted with a tissue versus a mechanical prosthesis at initial aortic valve replacement (hazard ratio 0.95; 95% CI: 0.7, 1.3; P =0.7). For mitral valve replacement patients, long-term survival was poorer than after aortic valve replacement (hazard ratio 1.4; 95% CI: 1.1, 1.8; P =0.003), but again no detrimental effect was associated with use of a tissue versus a mechanical prosthesis (hazard ratio 0.9; 95% CI 0.5, 1.4; P =0.5).

Conclusions— In our experience, selecting a tissue prosthesis at initial operation in younger adults does not negatively impact survival into the third decade of follow-up, despite the risk of reoperation.

Technique for implant of the stentless aortic valve Freedom Solo

In this presentation we provide a summary of aortic valve replacement with a supra-annular stentless aortic valve, the Freedom Solo prosthesis. Stentless valves were designed to provide more physiological flow and lower transvalvular gradient, which is offered by the novel design of the valve and by its implantation technique. The supra-annular stentless aortic valve implantation is demonstrated with a special emphasis on its surgical technique peculiarities.

Short-Term and Intermediate-Term Outcomes of Aortic Root Replacement with St. Jude Mechanical Conduits and Aortic Allografts

BACKGROUND

Few studies have directly evaluated outcomes in patients undergoing aortic root replacement with St. Jude mechanical conduits or aortic allografts (ALLO), yet both approaches have been advocated. The purpose of this study was to provide a detailed description of outcomes in a large series of aortic root replacements performed with either St. Jude mechanical conduits or aortic allografts.

METHODS

A retrospective analysis was performed on 172 consecutive adult patients undergoing aortic root replacement with either St. Jude mechanical conduits (n = 73) or aortic allografts (n = 99) from January 1990 to December 2002. Maximal follow-up was 15 years, and median follow-up was 5 years.

RESULTS

Both groups were similar with regard to median age, preoperative ejection fraction, and New York Heart Association class. The aortic allograft patient group had a higher proportion (p < 0.05) of women (43% versus 18%), prior sternotomies (52% versus 26%), preoperative renal failure (9% versus 1%), and cerebrovascular disease (16% versus 4%). Operative indications for the aortic allograft group were more frequently endocarditis (29% versus 3%; p < 0.0001) and prosthetic valve dysfunction (13% versus 1%; p < 0.01), and less frequently annuloaortic ectasia (34% versus 60%; p < 0.001) or aortic dissection (3% versus 26%; p < 0.0001). Concomitant coronary artery bypass grafting or other valve surgery was performed in 30% of patients in both groups. Incidence of early postoperative complications, including bleeding, stroke, renal failure, and respiratory failure, was similar in both groups. Thirty-day mortality was 5.5% in the St. Jude mechanical conduit group and 8.1% in the aortic allograft group (p = 0.4). Unadjusted actuarial survival at 1, 5, and 10 years was 90%, 81%, 67%, and 86%, 70%, 67%, for the St. Jude mechanical conduit and aortic allograft groups, respectively (p = 0.09). Event-free survival at 1 and 5 years was similar for both groups (p = 0.4). By multivariate analysis, New York Heart Association class III or IV, emergently performed aortic root replacement, and postoperative respiratory failure, but not valve conduit type (p = 0.3), were independent predictors of mortality.

CONCLUSIONS

Aortic root replacement can be safely performed with either allograft or mechanical conduits, even in the setting of acute dissection, redo sternotomy, or endocarditis.

Are Stentless Valves Superior to Modern Stented Valves?: A Prospective Randomized Trial

BACKGROUND

It is presumed that stentless aortic bioprostheses are hemodynamically superior to stented bioprostheses. A prospective randomized controlled trial was undertaken to compare stentless versus modern stented valves.

METHODS AND RESULTS

Patients with severe aortic valve stenosis (n=161) undergoing aortic valve replacement (AVR) were randomized intraoperatively to receive either the C-E Perimount stented bioprosthesis (n=81) or the Prima Plus stentless bioprosthesis (n =80). We assessed left ventricular mass (LVM) regression with transthoracic echocardiography (TTE) and magnetic resonance imaging (MRI). Transvalvular gradients were measured postoperatively by Doppler echocardiography to compare hemodynamic performance. There was no difference between groups with regard to age, symptom status, need for concomitant coronary artery bypass surgery, or baseline LVM. LVM regressed in both groups but with no significant difference between groups at 1 year. In a subset of 50 patients, MRI was also used to assess LVM regression, and again there was no significant difference between groups at 1 year. Hemodynamic performance of the 2 valves was similar with no difference in mean and peak systolic transvalvular gradients 1 year after surgery. In patients with reduced ventricular function (left ventricular ejection fraction [LVEF] <60%), there was a significantly greater improvement in LVEF from baseline to 1 year in stentless valve recipients.

CONCLUSIONS

Both stented and stentless bioprostheses are associated with excellent clinical and hemodynamic outcomes 1 year after AVR. Comparable hemodynamics and LVM regression can be achieved using a second-generation stented pericardial bioprosthesis. In patients with ventricular impairment, stentless bioprostheses may allow for greater improvement in left ventricular function postoperatively.

Risk-corrected impact of mechanical versus bioprosthetic valves on long-term mortality after aortic valve replacement

OBJECTIVE

Choice of a mechanical or biologic valve in aortic valve replacement remains controversial and rotates around different complications with different time-related incidence rates. Because serious complications will always "spill over" into mortality, our aim was to perform a meta-analysis on overall mortality after aortic valve replacement from series with a maximum follow-up of at least 10 years to determine the age- and risk factor-corrected impact of currently available mechanical versus stented bioprosthetic valves.

METHODS

Following a formal study protocol, we performed a dedicated literature search of publications during 1989 to 2004 and included articles on adult aortic valve replacement with a mechanical or stented bioprosthetic valve if age, mortality statistics, and prevalences of well-known risk factors could be extracted. We used standard and robust regression analyses of the case series data with valve type as a fixed variable.

RESULTS

We could include 32 articles with 15 mechanical and 23 biologic valve series totaling 17,439 patients and 101,819 patient-years. The mechanical and biologic valve series differed in regard to mean age (58 vs 69 years), mean follow-up (6.4 vs 5.3 years), coronary artery bypass grafting (16% vs 34%), endocarditis (7% vs 2%), and overall death rate (3.99 vs 6.33 %/patient-year). Mean age of the valve series was directly related to death rate with no interaction with valve type. Death rate corrected for age, New York Heart Association classes III and IV, aortic regurgitation, and coronary artery bypass grafting left valve type with no effect. Included articles that abided by current guidelines and compared a mechanical and biologic valve found no differences in rates of thromboembolism.

CONCLUSION

There was no difference in risk factor-corrected overall death rate between mechanical or bioprosthetic aortic valves irrespective of age. Choice of prosthetic valve should therefore not be rigorously based on age alone. Risk of bioprosthetic valve degeneration in young and middle-aged patients and in the elderly and old with a long life expectancy would be an important factor because risk of stroke may primarily be related to patient factors.

The Stentless Freestyle Bioprosthesis: Impact of Age Over 80 Years on Quality of Life, Perioperative, and Mid-Term Outcome

BACKGROUND

The steadily increasing life expectancy of the population in the Western World, together with the progress in noninvasive diagnostic methods and operating techniques lead to an increase in aortic valve surgery in elderly people.

AIM OF THE STUDY

Is there an increased risk of adverse perioperative and mid-term outcome for octogenarians and do they benefit from aortic valve replacement (AVR) with stentless bioprostheses?

METHODS

Between 1996 and 2002, 503 patients older than 60 years underwent AVR with a stentless Freestyle bioprosthesis. Seventy-six of them were older than 80 years. The risk of operative mortality, perioperative complications, valve-related morbidity for octogenarians was determined by multivariate logistic regression.

RESULTS

In general, risk-adjusted analyses did not reveal an increased risk of operative mortality (p = 0.4), postoperative atrial fibrillation (p = 0.2), prolonged ventilation (p = 0.5), prolonged stay in the intensive care unit (p = 0.3), or mid-term valve-related morbidity as prosthetic valve endocarditis (p = 0.2), reoperation (p = 0.4), bleeding events (p = 0.1), and stroke (p = 0.8) for octogenarians. Continuously increasing age was an independent risk factor for postoperative neurological complications (OR = 1.8 per 10 years, p = 0.04). Quality of life was equal to or better than the general population of the same age. Median survival time of octogenarians was 5.2 +/- 0.5 years.

CONCLUSIONS

Except for postoperative neurological complications, octogenarians receiving stentless bioprostheses had no increased risk of adverse perioperative and mid-term outcome in comparison to younger patients. As quality of life and life expectancy after AVR with stentless valves were equal to the general population, AVR with stentless bioprostheses should not be withheld from octogenarians.

Performance of bioprostheses and mechanical prostheses assessed by composites of valve-related complications to 15 years after aortic valve replacement

OBJECTIVE

This study was conducted to compare the composites of valve-related complications, namely reoperation, morbidity (defined as permanent neurologic or other functional impairment), and mortality, between bioprostheses and mechanical prostheses for aortic valve replacement.

METHODS

Between 1982 and 1998, 2195 bioprostheses were implanted in 2179 patients and 980 mechanical prostheses were implanted in 883 patients. Total follow-up was 16,442 years and 5740 years for bioprostheses and mechanical prostheses, respectively. Eight variables were considered as predictors of risk for the composites of valve-related complications.

RESULTS

Linearized rates for valve-related reoperation were 1.3%/patient-year and 0.3%/patient-year for bioprostheses and mechanical prostheses (P < .001), respectively. All age groups were differentiated, except >70 years. Valve-related morbidity was differentiated for all age groups and overall, for bioprostheses and mechanical protheses, was 0.4 %/patient-year and 2.1%/patient-year, respectively (P < .001). Overall valve-related mortality was 1.0%/patient-year for bioprostheses and 0.7%/patient-year for mechanical prostheses (P = .018). Age and valve-type were predictive risk factors for reoperation and morbidity, whereas age alone was predictive of mortality. Actual freedom from valve-related reoperation favored mechanical prostheses for all age groups, except 61-70 years and >70 years. Actual freedom from valve-related morbidity favored bioprostheses in all age groups, except < or =40 years. Actual freedom from valve-related mortality was undifferentiated in patients 51-60, 61-70, and >70 years.

CONCLUSION

No differences were observed in valve-related reoperation and mortality in patients >60 years. Comparative evaluation gives high priority for bioprostheses in patients >60 years based on improved morbidity profile. This evaluation extends this center's recommendation for bioprostheses in aortic valve replacement to include patients >60 years.

Percutaneous closure of prosthetic paravalvular leaks: Case series and review

BACKGROUND

Paravalvular leaks (PVLs) are a well-recognized complication of prosthetic valve replacement. Most are asymptomatic and benign, but some may cause symptoms due to a large regurgitant volume or hemolysis. Medical therapy is palliative, while reoperation carries significant morbidity and mortality. Percutaneous transcatheter closure techniques, now routinely applied in the management of pathological cardiac and vascular communications, may be adaptable to PVL closure, potentially offer symptomatic relief.

METHODS

We reviewed our experience with attempted percutaneous closure of PVLs, using data from medical and procedural records.

RESULTS

Between 2001 and 2004, 14 procedures were performed in 10 patients, all under general anesthesia, with transesophageal and radiographic guidance. Mitral (9) and aortic (1) valve replacements were involved, both mechanical and bioprosthetic. A variety of devices were used, including atrial septal occluders, patent ductus arteriosus occluders, and coils (all of label use). Six had a single procedure, which was technically successful in four: in two, the PVL could not be crossed. Four underwent a second procedure, which was technically successful in three; in one the previously deployed device was dislodged necessitating urgent, but ultimately uneventful, surgical removal and leak repair. One patient had transient severe hemolysis, which resolved after 1 week. At 1-year follow-up (9/10 pts) three had died, five had sustained symptomatic improvement while 1 patient with a residual leak still required regular blood transfusions.

CONCLUSIONS

Percutaneous closure of PVLs is time-consuming but feasible in selected patients, with a reasonable degree of technical and clinical success. A second procedure may be necessary and a variety of complications can occur.

Do pulmonary autografts provide better outcomes than mechanical valves? A prospective randomized trial

BACKGROUND

The objective of this study was to compare the performance of pulmonary autografts with mechanical aortic valves, in the treatment of aortic valve stenosis.

METHODS

Forty patients with aortic valve stenoses, and below the age of 55 years, were randomly assigned to receive either pulmonary autografts (n = 20) or mechanical valve (Edwards MIRA; Edwards Lifesciences, Irvine, CA) prostheses (n = 20). Clinical outcomes, left ventricular mass regression, effective orifice area, ejection fraction, and mean gradients were evaluated at discharge, 6 months, and one year after surgery. Follow-up was complete for all patients.

RESULTS

Hemodynamic performance was significantly better in the Ross group (mean gradient 2.6 mm Hg vs 10.9 mm Hg, p = 0.0005). Overall, a significant decrease in left ventricular mass was found one year postoperatively. However, there was no significant difference in the rate and extent of regression between the groups. There was one stroke in the Ross group and one major bleeding complication in the mechanical valve group. Both patients recovered fully.

CONCLUSIONS

In our randomized cohort of young patients with aortic valve stenoses, the Ross procedure was superior to the mechanical prostheses with regard to hemodynamic performance. However, this did not result in an accelerated left ventricular mass regression. Clinical advantages like reduced valve-related complications and lesser myocardial strain will have to be proven in the long term.

Mid term outcome and quality of life after aortic valve replacement in elderly people: mechanical versus stentless biological valves

OBJECTIVE

To assess the benefit for patients older than 65 years of aortic valve replacement with stentless biological heart valves in comparison with mechanical valves.

DESIGN

Multiple regression analysis of a retrospective follow up study.

SETTING

Single cardiothoracic centre.

PATIENTS

Between 1996 and 2001, 392 patients with a mean age of 74 years underwent aortic valve replacement with stentless Freestyle bioprostheses or mechanical St Jude Medical prostheses.

MAIN OUTCOME MEASURE

Operative mortality and morbidity, postoperative morbid events, mid term survival, and New York Heart Association (NYHA) class improvement, and quality of life.

RESULTS

No significant differences were found between patients receiving stentless biological valves and patients receiving mechanical prostheses. However, analysis of subgroups showed that patients older than 75 years with mechanical valves had an increased risk of major bleeding events (p = 0.007). Patients requiring anticoagulation by means of coumarin had a twofold increased risk of an impaired emotional reaction (p = 0.052). However, for patients who received a mechanical valve for severe combined aortic valve disease a survival advantage (p = 0.045) and a decreased risk of prolonged ventilation (p = 0.001) was observed. On the other hand, patients receiving a stentless bioprosthesis had an increased risk of a prolonged stay in intensive care (p = 0.04) and stroke (p = 0.01) if they had severely reduced cardiac function (NYHA class IV).

CONCLUSIONS

Elderly people receiving stentless bioprostheses benefit emotionally because of the avoidance of coumarin. However, in patients with severe hypertrophied ventricles and extraordinary calcifications, stentless bioprostheses should be chosen with caution.

The Risks and Benefits of Reoperative Aortic Valve Replacement

BACKGROUND

Many patients are advised to have mechanical aortic valve replacement (AVR) because their expected longevity exceeds that of tissue prostheses. This strategy may avoid the risks of reoperation but exposes patients to the risks of long-term anticoagulation therapy. Which risk is greater?

METHODS

We reviewed the records of 1213 consecutive, unselected AVR patients, 60% of whom had concomitant procedures, who were treated from 1994 through 2002. Of these patients, 887 were first-time AVR patients, and 326 underwent reoperation. Of the reoperation patients, 134 had previously undergone AVR (redo). We constructed a risk model from these 1213 cases to assess the factors that predicted mortality and to examine the extent to which reoperation affected outcome.

RESULTS

Multiple logistic regression analysis indicated that factors of reoperation and redo operation did not predict mortality. In fact, the mortality rate was 4.1% for all first AVR operations and 3.1% for all reoperation AVR ( P =.891). Significant predicting factors (with odds ratios) were reoperative dialysis (6.03), preoperative shock (3.68), New York Heart Association class IV (2.20), female sex (1.76), age (1.61), and cardiopulmonary bypass time (1.26).

CONCLUSIONS

In this series, the risk of reoperation AVR is comparable with the published risks of long-term warfarin sodium (Coumadin) administration after mechanical AVR. Any adult who requires AVR may be well advised to consider tissue prostheses.

Comparison of outcomes after aortic valve replacement with a mechanical valve or a bioprosthesis using microsimulation

BACKGROUND

Mechanical valves and bioprostheses are widely used for aortic valve replacement. Though previous randomised studies indicate that there is no important difference in outcome after implantation with either type of valve, knowledge of outcomes after aortic valve replacement is incomplete.

OBJECTIVE

To predict age and sex specific outcomes of patients after aortic valve replacement with bileaflet mechanical valves and stented porcine bioprostheses, and to provide evidence based support for the choice of prosthesis.

METHODS

Meta-analysis of published results of primary aortic valve replacement with bileaflet mechanical prostheses (nine reports, 4274 patients, and 25,726 patient-years) and stented porcine bioprostheses (13 reports, 9007 patients, and 54,151 patient-years) was used to estimate the annual risks of postoperative valve related events and their outcomes. These estimates were entered into a microsimulation model, which was employed to calculate age and sex specific outcomes after aortic valve replacement.

RESULTS

Life expectancy (LE) and event-free life expectancy (EFLE) for a 65 year old man after implantation with a mechanical valve or a bioprosthesis were 10.4 and 10.7 years and 7.7 and 8.4 years, respectively. The lifetime risk of at least one valve related event for a mechanical valve was 48%, and for a bioprosthesis, 44%. For LE and EFLE, the age crossover point between the two valve types was 59 and 60 years, respectively.

CONCLUSIONS

Meta-analysis based microsimulation provides insight into the long term outcome after aortic valve replacement and suggests that the currently recommended age threshold for implanting a bioprosthesis could be lowered further.

Should coronary artery bypass graft surgery patients with mild or moderate aortic stenosis undergo concomitant aortic valve replacement?

OBJECTIVES

This study utilizes Markov decision analysis to assess the relative benefits of prophylactic aortic valve replacement (AVR) at the time of coronary artery bypass graft surgery (CABG). Multiple sensitivity analyses were also performed to determine the variables that most profoundly affect outcome.

BACKGROUND

The decision to perform CABG or concomitant CABG and AVR (CABG/AVR) in asymptomatic patients who need CABG surgery but have mild to moderate aortic stenosis (AS) is not clear-cut.

METHODS

We performed Markov decision analysis comparing long-term, quality-adjusted life outcomes of patients with mild to moderate AS undergoing CABG versus CABG/AVR. Age-specific morbidity and mortality risks with CABG, CABG/AVR, and AVR after a prior CABG were based on the Society of Thoracic Surgeons national database (n = 1,344,100). Probabilities of progression to symptomatic AS, valve-related morbidity, and age-adjusted mortality rates were obtained from available published reports.

RESULTS

For average AS progression, the decision to replace the aortic valve at the time of elective CABG should be based on patient age and severity of AS measured by echocardiography. For patients under age 70 years, an AVR for mild AS is preferred if the peak valve gradient is >25 to 30 mm Hg. For older patients, the threshold increases by 1 to 2 mm Hg/year, so that an 85-year-old patient undergoing CABG should have AVR only if the gradient exceeds 50 mm Hg. The AS progression rate also influences outcomes. With slow progression (<3 mm Hg/year), CABG is favored for all patients with AS gradients <50 mm Hg; with rapid progression (>10 mm Hg/year), CABG/AVR is favored except for patients >80 years old with a valve gradient <25 mm Hg.

CONCLUSIONS

This study provides a decision aid for treating patients with mild to moderate AS requiring CABG surgery. Predictors of AS progression in individual patients need to be better defined.