Prosthesis–Patient Mismatch After Aortic Valve Replacement: Effect on Long-Term Survival

Hemodynamic Comparison between the Avalus and the Perimount Magna Ease Aortic Bioprosthesis up to 5 Years

BACKGROUND

 We aimed to compare hemodynamic performance of the Avalus (Medtronic) and the Perimount Magna Ease (PME, Edwards Lifesciences) bioprosthesis up to 5 years by serial echocardiographic examinations.

METHODS

 In patients undergoing aortic valve replacement, 58 received PME prostheses between October 2007 and October 2008, and another 60 received Avalus prostheses between October 2014 and November 2015. To ensure similar baseline characteristics, we performed a propensity score matching based on left ventricular ejection fraction, age, body surface area, and aortic annulus diameter measured by intraoperative transesophageal echocardiography. Thereafter, 48 patients remained in each group. Mean age at operation was 67 ± 6 years and mean EuroSCORE-II was 1.7 ± 1.1. Both values did not differ significantly between the two groups.

RESULTS

 At 1 year the mean pressure gradient (MPG) was 15.4 ± 4.3 mm Hg in the PME group and 14.7 ± 5.1 mm Hg in the Avalus group (p = 0.32). The effective orifice area (EOA) was 1.65 ± 0.45 cm2 in the PME group and 1.62 ± 0.45 cm2 in the Avalus group (p = 0.79). At 5 years the MPG was 16.6 ± 5.1 mm Hg in the PME group and 14.7 ± 7.1 mm Hg in the Avalus group (p = 0.20). The EOA was 1.60 ± 0.49 cm2 in the PME group and 1.51 ± 0.40 cm2 in the Avalus group (p = 0.38). Five-year survival was 88% in the PME group and 91% in the Avalus group (p = 0.5). In the PME group, there were no reoperations on the aortic valve, whereas in the Avalus group three patients required a reoperation due to endocarditis.

CONCLUSION

 Both bioprostheses exhibit similar hemodynamic performance during a 5-year follow-up.

Real-World Comparison of Transcatheter Versus Surgical Aortic Valve Replacement in the Era of Current-Generation Devices

Few studies have reported comparisons of out-of-hospital clinical outcomes after transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) in patients with severe aortic stenosis (AS) in the era of current-generation valves that reflect the real-world situation. Data on patients with severe AS aged 65 years or older who underwent TAVR or SAVR between 2015 and 2018 were obtained from the National Health Insurance Service in Korea and clinical event rate was analyzed. The primary endpoint was all-cause death at 1 year. The cohort included a total of 4623 patients over 65 years of age, of whom 1269 (27.4%) were treated with TAVR. After 1:1 propensity score matching, 2120 patients were included in the study. TAVR was associated with reduced 1-year mortality (hazard ratio (HR): 0.55; 95% confidence interval (CI): 0.42−0.70; p < 0.001). There was no difference between the groups in the incidence of ischemic stroke (HR: 0.72, 95% CI: 0.43−1.20; p = 0.21) and intracranial hemorrhage (HR: 1.10; p = 0.74). Permanent pacemaker insertion was observed more frequently in the TAVR cohort (9.4% vs. 2.5%, HR: 3.95, 95% CI: 2.57−6.09; p < 0.001), whereas repeat procedures were rare in both treatments (0.5% vs. 0.3%, p = 0.499). In the nation-wide real-world data analysis, TAVR with current-generation devices showed significantly lower 1-year mortality compared to SAVR in severe AS patients.

Standardized Aortic Valve Neocuspidization for Treatment of Aortic Valve Diseases

BACKGROUND

Aortic valve replacement is the traditional surgical treatment for aortic valve diseases, yet standardized aortic valve neocuspidization (AVNeo) is a promising alternative that is gaining popularity. The purpose of this article is to review the available published literature of AVNeo using glutaraldehyde-treated autologous pericardium, also known as the Ozaki procedure, including indications, outcomes, potential benefits, and modes of failure for the reconstructed valve.

METHODS

A comprehensive literature search was performed using keywords related to aortic valve repair, AVNeo, or Ozaki procedure. All articles describing performance of AVNeo were reviewed.

RESULTS

Reported early mortality after AVNeo varies from 0% to 5.88%. The largest cohort of patients in the literature includes 850 patients with an inhospital mortality rate of 1.88%. Cumulative incidence of aortic valve reoperation was 4.2% in the largest series. Reoperation was uncommon and mainly due to infective endocarditis or degeneration of the reconstructed valve (most commonly due to aortic valve regurgitation, rather than stenosis).

CONCLUSIONS

Aortic valve neocuspidization is a versatile and standardized alternative to aortic valve replacement with a biological prosthesis. Early to midterm outcomes from a number of centers are excellent and demonstrate the safety and durability of the procedure. Long-term outcomes and clinical trial data are necessary to determine which patients benefit the most from this procedure.

Patient-Prosthesis Mismatch in Contemporary Small-Size Mechanical Prostheses Does Not Impact Survival at 10 Years

BACKGROUND

The effect of PPM in mechanical prostheses on long-term survival is not well-established.

METHODS

Patients who received a 21 mm or smaller aortic valve between 2000 and 2011 were retrospectively analyzed (n = 416). Propensity matching was used in order to account for baseline differences in patient subgroups (PPM vs. no PPM; severe PPM vs. no severe PPM).

RESULTS

Five- and ten-year survival was 78 ± 3.52% and 64.51 ± 4.51% in patients with PPM, versus 83.3 ± 3.12% and 69.37 ± 4.36% in patients without (p = 0.28) when analyzed at 10.39 ± 5.25 years after the primary procedure. Independent risk factors for impaired survival, after matching, were age, serum creatinine, and severe pulmonary hypertension. Five- and ten-year survival in patients with severe PPM was 73.34 ± 6.01% and 61.76 ± 8.17%, respectively, versus 74.72 ± 5.68% and 67.50 ± 7.09% in those without (p = 0.49), at 8.82 ± 5.17 years after SAVR. Age was the only independent variable that influenced long-term survival when severe PPM was added to the model.

CONCLUSIONS

PPM or severe PPM does not impact long-term survival up to 10 years in mechanical valve recipients when matching for preoperative variables.

What Can We Learn from the Past by Means of Very Long-Term Follow-Up after Aortic Valve Replacement?

Background: Studies on very long-term outcomes after aortic valve replacement are sparse. Methods: In this retrospective cohort study, long-term outcomes during 25.1 ± 2.8 years of follow-up were determined in 673 patients who underwent aortic valve replacement with or without concomitant coronary artery bypass surgery for severe aortic stenosis and/or regurgitation. Independent predictors of decreased long-term survival were determined. Cumulative incidence rates of major adverse events in patients with a mechanical versus those with a biologic prosthesis were assessed, as well as of major bleeding events in patients with a mechanical prosthesis under the age of 60 versus those above the age of 60. Results: Impaired left ventricular function, severe prosthesis–patient mismatch, and increased aortic cross-clamp time were independent predictors of decreased long-term survival. Left ventricular hypertrophy, a mechanical or biologic prosthesis, increased cardiopulmonary bypass time, new-onset postoperative atrial fibrillation, and the presence of symptoms did not independently predict decreased long-term survival. The risk of major bleeding events was higher in patients with a mechanical in comparison with those with a biologic prosthesis. Younger age (under 60 years) did not protect patients with a mechanical prosthesis against major bleeding events. Conclusions: Very long-term outcome data are invaluable for careful decision-making on aortic valve replacement.

Prosthesis-patient mismatch affects late survival after valve surgery for severe aortic stenosis

BACKGROUND

The effect of prosthesis-patient mismatch (PPM) on late survival after aortic valve replacement (AVR) in patient with symptomatic severe aortic stenosis (AS) remains unclear. Also, late follow-up in previous studies is confined to only one decade. We aimed to determine the effect of PPM on late survival after isolated AVR for symptomatic severe AS during 25 years of follow-up.

METHODS

In this retrospective cohort study, Kaplan-Meier survival analysis was performed to determine late survival in 404 consecutive patients with moderate PPM (N.=86), severe (N.=11), or no/mild PPM (N.=307) after isolated AVR for symptomatic severe AS during a mean follow-up of 25.0±2.9 years. Moderate, severe, and no/mild PPM were defined as indexed effective orifice area of >0.65≤0.85, ≤0.65, and >0.85 cm2/m2, respectively. Multivariable analysis was performed to identify possible independent predictors of decreased late survival, including moderate or severe PPM.

RESULTS

Late survival of patients with severe PPM was worse in comparison with those with no/mild PPM: 7.4±2.6 (95% confidence interval 2.2-12.5) vs. 13.6±0.5 (95% confidence interval 12.6-14.6) years, respectively; P=0.020. Late survival of patients with moderate PPM was similar to those with no/mild PPM. Severe PPM was an independent predictor of decreased late survival: hazards ratio 4.002 (95% confidence interval 1.869-8.569); P<0.001. Moderate PPM was not an independent predictor of decreased late survival.

CONCLUSIONS

Severe PPM was independently associated with decreased late survival after isolated AVR for symptomatic severe AS during a mean follow-up of 25.0±2.9 years. Therefore, severe PPM should be prevented as much as possible.

The fallacy of indexed effective orifice area charts to predict prosthesis-patient mismatch after prosthesis implantation

Aims 

Indexed effective orifice area (EOAi) charts are used to determine the likelihood of prosthesis–patient mismatch (PPM) after aortic valve replacement (AVR). The aim of this study is to validate whether these EOAi charts, based on echocardiographic normal reference values, can accurately predict PPM.

Methods and results 

In the PERIcardial SurGical AOrtic Valve ReplacemeNt (PERIGON) Pivotal Trial, 986 patients with aortic valve stenosis/regurgitation underwent AVR with an Avalus valve. Patients were randomly split (50:50) into training and test sets. The mean measured EOAs for each valve size from the training set were used to create an Avalus EOAi chart. This chart was subsequently used to predict PPM in the test set and measures of diagnostic accuracy (sensitivity, specificity, and negative and positive predictive value) were assessed. PPM was defined by an EOAi ≤0.85 cm²/m^2, and severe PPM was defined as EOAi ≤0.65 cm²/m². The reference values obtained from the training set ranged from 1.27 cm² for size 19 mm up to 1.81 cm² for size 27 mm. The test set had an incidence of 66% of PPM and 24% of severe PPM. The EOAi chart inaccurately predicted PPM in 30% of patients and severe PPM in 22% of patients. For the prediction of PPM, the sensitivity was 87% and the specificity 37%. For the prediction of severe PPM, the sensitivity was 13% and the specificity 98%.

Conclusion 

The use of echocardiographic normal reference values for EOAi charts to predict PPM is unreliable due to the large proportion of misclassifications.

Prosthesis-patient mismatch after surgical aortic valve replacement in patients with aortic stenosis

OBJECTIVES

The issue of prosthesis-patient mismatch (PPM) after surgical aortic valve replacement (SAVR) has been a controversial topic. We sought to evaluate the long-term clinical impacts of PPM in patients undergoing SAVR in an updated, homogeneous cohort.

METHODS

Using the prospective institutional database, we identified 895 adult patients (median age 66, interquartile range 58-72; 45.6% women) who underwent isolated SAVR from January 2000 to March 2016. Those with pure aortic insufficiency and concomitant other cardiac operations were excluded from this study cohort. The presence of a significant PPM was defined as an indexed effective orifice area 0.85 cm2/m2 or less. The outcome of interest was all-cause deaths. Propensity score matching was performed for adjusting bias.

RESULTS

Significant PPM was present in 247 patients (27.6%). During the follow-up period (mean 71.2 ± 51.04 months), 134 patients (15%) died. Survival rates at 10 and 15 years were 78.3% vs 83.8% and 71.3% vs 57.6% in the PPM and non-PPM groups (P = 0.972). Risk factor analysis indicated that developing PPM was not associated with a risk of death. After propensity score matching (1:1), developing PPM was not a risk factor for long-term death as well (P = 0.584).

CONCLUSIONS

Significant PPM was common after SAVR in patients with aortic stenosis. However, there was no significant difference in survival rate between those with and without PPM.

Aortic Annular Enlargement in the Elderly: Short and Long-Term Outcomes in the United States

BACKGROUND

Patient prosthesis mismatch is associated with significant long-term morbidity and mortality after aortic valve replacement, but the role and outcomes of annular enlargement (AE) remain poorly defined. We hypothesized that increasing rates of AE may lead to improved outcomes for patients at risk for severe patient prosthesis mismatch.

METHODS

Patients over age 65 years undergoing surgical aortic valve replacement with or without coronary artery bypass grafting from 2008-2016 in The Society of Thoracic Surgeons Adult Cardiac Surgery Database with matching Centers for Medicare & Medicaid Services data were included (n=189,268). Univariate, multivariate, and time-to-event analysis was used to evaluate the association between AE and early and late outcomes. Patients were stratified by projected degree of patient prosthesis mismatch based on calculated effective orifice area index.

RESULTS

A total of 5412 (2.9%) patients underwent AE. The Society of Thoracic Surgeons Adult Cardiac Surgery Database-predicted mortality was similar between AE and non-AE groups (2.97% vs 2.99%, P = .052). Patients undergoing AE had higher risk-adjusted rates of 30-day complications and death (5.4% vs 3.4%, P < .0001), but no differences in long-term rates of stroke, heart failure re-hospitalization,s or aortic valve reoperation. Survival analysis demonstrated a higher risk of mortality with AE during the first 3 years, after which the survival curves cross, favoring AE.

CONCLUSIONS

These data suggest that annular enlargement during surgical aortic valve replacement is associated with increased short-term risk in a Medicare population. Survival curves crossed after 3 years, which may portend a benefit in select patients. However, annular enlargement is still only performed in the minority of patients who are at risk for patient prosthesis mismatch.

Why the categorization of indexed effective orifice area is not justified for the classification of prosthesis-patient mismatch

OBJECTIVES

Although the impact of prosthesis-patient mismatch (PPM) on survival has been widely studied, there has been little debate about whether the current definition of PPM truly reflects hemodynamic obstruction. This study aimed to validate the categorization of indexed effective orifice area (EOAi) for the classification of PPM.

METHODS

In total, 2171 patients who underwent aortic valve replacement with a surgical stented bioprosthesis in 5 trials (CoreValve US High-Risk, SURTAVI [Surgical Replacement and Transcatheter Aortic Valve Implantation Trial], Evolut Low Risk, PERIGON [PERIcardial SurGical AOrtic Valve ReplacemeNt] Pivotal Trial for the Avalus valve, and PERIGON Japan) were used for this analysis. The echocardiographic images at the 1-year follow-up visit were evaluated to explore the association between EOAi and mean aortic gradient and its interaction with other patient characteristics, including obesity. In addition, different criteria of PPM were compared with reflect elevated mean aortic gradients (≥20 mm Hg).

RESULTS

A relatively smaller exponential decay in mean aortic gradient was found for increasing EOAi, as the slope on the log scale was -0.83 versus -2.5 in the publication from which the current cut-offs for PPM originate. The accuracy of the American Society of Echocardiography, Valve Academic Research Consortium-2, and European Association of Cardiovascular Imaging definitions of PPM to reflect elevated mean aortic gradients was 49%, 57%, and 57%, respectively. The relation between EOAi and mean aortic gradient was not significantly different between obese and non-obese patients (P = .20).

CONCLUSIONS

The use of EOAi thresholds to classify patients with PPM is undermined by a less-pronounced exponential relationship between EOAi and mean aortic gradient than previously demonstrated. Moreover, recent adjustment for obesity in the definition of PPM is not supported by these data.

Excellent Hemodynamic Performance After Aortic Valve Neocuspidization Using Autologous Pericardium

BACKGROUND

Aortic valve neocuspidization (AVNeo) for trileaflet aortic valve reconstruction using autologous pericardium (Ozaki procedure) offers an alternative treatment modality to overcome drawbacks of conventional prosthetic aortic valve replacement.

METHODS

Between October 2016 and April 2019, 103 patients underwent surgery. Mean follow-up was 426 ± 270 days. Aortic stenosis was the leading diagnosis in 80 patients (77.7%) and aortic regurgitation in 23 (22.3%), respectively. Mean age was 54.0 ± 16.4 years (range, 13.8-78.5). A bicuspid valve was found in 81 patients (78.6%). Transthoracic echocardiography was performed at discharge and at 6 to 12 months after surgery. During AVNeo surgery valve sizing for an Abbott/St Jude Trifecta bioprosthesis (virtually implanted Trifecta bioprosthesis; St Jude Medical, St Paul, MN) was performed to compare pressure gradients and effective orifice area with published data.

RESULTS

Trileaflet aortic valve reconstruction was achieved in all patients. In 38 patients neocommissures were created (36.9%). Mean cross-clamp time was 135 ± 20 minutes. Four patients underwent reoperation; the overall freedom from reoperation was 96.1%. Echocardiographic 6- to 12-months follow-up after surgery was available in 93.8% of patients and did not show any change in hemodynamic parameters compared with discharge. Comparison between AVNeo and virtually implanted Trifecta Bioprosthesis revealed a significantly lower mean pressure gradient (8.5 ± 3.7 mm Hg vs 10.2 ± 2.0 mm Hg, P < .001) and higher mean effective orifice area (2.2 ± 0.7 cm² vs 2.1 ± 0.4 cm², P = .037) for AVNeo.

CONCLUSIONS

AVNeo shows low reoperation rates after surgery within the first 2 years. The hemodynamic performance is excellent, and the effective orifice area and mean pressure gradient remain stable within the first year.

Determinants of effective orifice area in aortic valve replacement: anatomic and clinical factors

Background

Obtaining adequate effective orifice area (EOA) in surgical aortic valve replacement (SAVR) is important to minimize pressure gradients across the prosthetic aortic valve (AV) and improve clinical outcomes. However, the predictors of EOA are unclear.

Methods

From July 2011 to March 2016, patients undergoing SAVR who were preoperatively evaluated using a computed tomography (CT) on the aortic root were enrolled. Indexed EOA (iEOA) was used as an indicator of prosthetic AV opening area. The aortic root parameters investigated were the annular diameter (max and min), annular perimeter, annular area, and maximal dimensions of the proximal ascending aorta. These variables were evaluated as predictors of EOA, and an individual surgeon was incorporated in analysis for verifying surgeon dependent factors.

Results

Among the 710 patients included in this study [age: 64.9±10.8 years; females: n=285 (40.1%)], 370 (52.1%) were implanted with bio-prosthesis. Mean prosthetic iEOA was 1.1±0.3 cm²/m². Univariable linear regression analysis showed that all indexed aortic root parameters (maximal and minimal annular diameters, annular perimeter, annular area, and sinus dimensions) were significantly associated with iEOA (P<0.001). Multivariable analysis showed that indexed aortic annular area, indexed maximal diameter of the Valsalva sinus, female sex, and bio-prosthesis, supra-annular type prosthesis and surgeon were significant and independent determinants of iEOA (adjusted R²=0.513, P<0.001).

Conclusions

Aortic annular area and Valsalva sinus diameter are independent determinants for iEOA measured by preoperative CT; surgeon-dependent factors are also significant determinants in SAVR.

The effect of patient-prosthesis mismatch on survival after aortic and mitral valve replacement: a 10 year, single institution experience

Background

The evidence on the impact of patient-prosthesis Mismatch (PPM) on survival thus far has been conflicting. The aim of this study was to 1) study the effect of PPM on survival after isolated aortic and mitral valve replacement and 2) Assess the interaction between left ventricular function and PPM on survival.

Methods

The study cohort was patients who underwent isolated Aortic valve replacement (AVR) and Mitral valve replacement (MVR) over a 10-year period from 2008 to 2018. PPM was defined using the projected indexed effective orifice area (EOAi). The cohort was divided into different groups based on the degree of PPM. The severity of PPM was classified using threshold values of EOAi used in the literature. The Kaplan- Meier method was used to compare survival by degree of PPM. Multivariate Cox proportional hazards models were used to generate adjusted hazard ratios (HR) with 95% confidence intervals. An interactive term for ejection fraction (EF) was added to test whether EF modifies the effect of the PPM grade on survival. In addition, sub-group analysis based on left ventricular function was performed.

Results

In the AVR cohort, there were a total of 1953 patients. The distribution of patients in the different PPM categories was as follows: no PPM 59.7%; moderate PPM 36.8%; severe PPM 3.5%. There was no significant difference in survival between the different groups. At 10 years, the adjusted HR between patients with severe PPM versus no PPM was 1.1(CI 0.5–2.4, p >  0.05) and the HR between those with moderate PPM versus no PPM was 0.97 (CI 0.74–1.23, p >  0.05). In the MVR cohort, there were a total of 298 patients. The distribution of PPM is as follows: no PPM 59.4%; and with PPM 40.6%. Again, there was no significant difference in survival between the groups. At 5 years, the adjusted HR between patients with PPM versus no PPM was 1.45 (CI 0.67–3.14, p >  0.05). In both groups, there was no significant interaction between left ventricular function (LVF) and degree of PPM on survival.

Conclusions

In our study cohort, the degree of PPM was not an independent predictor of survival after AVR or MVR. There was also no significant interaction between LV function and degree of PPM on survival.

Patient-prosthesis mismatch following aortic valve replacement

Patient-prosthesis mismatch (PPM) occurs when an implanted prosthetic valve is too small for the patient; severe PPM is defined as an indexed effective orifice area (iEOA) <0.65 cm2/m2 following aortic valve replacement (AVR). This review examines articles from the past 10 years addressing the prevalence, outcomes and options for prevention and treatment of PPM after AVR. Prevalence of PPM ranges from 8% to almost 80% in individual studies. PPM is thought to have an impact on mortality, mainly in patients with severe PPM, although severe PPM accounts for only 10–15% of cases. Outcomes of patients with moderate PPM are not significantly different to those without PPM. PPM is associated with higher rates of perioperative stroke and renal failure and lack of left ventricular mass regression. Predictors include female sex, older age, hypertension, diabetes, renal failure and higher surgical risk score. PPM may be a marker of comorbidity rather than a risk factor for adverse outcomes. PPM should be suspected in patients with persistent cardiac symptoms after AVR when there is high prosthetic valve velocity or gradient and a small calculated effective orifice area. After exclusion of other causes of increased transvalvular gradient, re-intervention may be considered if symptoms persist and are unresponsive to medical therapy. However, this decision needs to consider the available options to relieve PPM and whether expected benefits justify the risk of intervention. The only effective intervention is redo surgery with implantation of a larger valve and/or annular enlargement. Therefore, focus needs to be on prevention.

Trifecta has lower gradient and less prosthesis-patient mismatch than Mosaic Ultra in the aortic position: A prospective randomized study

OBJECTIVE

When aortic valve replacement is needed, a biological valve is usually implanted in patients older than age 60 to 65 years. A large valvular opening area is important to avoid prosthesis-patient mismatch and facilitate reverse left ventricular remodeling. The Trifecta biological valve (St Jude Medical, St Paul, Minn) is, because of its design, believed to reduce transvalvular gradient compared with other biological valves, especially in smaller annuli. Several retrospective studies have compared transvalvular gradients of implanted valves prostheses using the respective manufacturers given size and not the actual annulus size measured by a metric sizer. This makes comparison of the hemodynamic properties of different valve brands and sizes difficult. We therefore performed a prospective randomized study, using the same metric sizer to measure annulus size, and compared hemodynamic profiles of the Trifecta to our standard Mosaic Ultra biological valve (Medtronic, Minneapolis, Minn).

METHODS

Ninety elective patients with small to medium annulus diameter undergoing aortic valve replacement were randomized to either Trifecta or Mosaic Ultra. After native valve removal and decalcification, a Hegar-sizer was used to measure true annulus size. Then the largest possible valve of either brand was implanted according to the randomization protocol. Echocardiography was performed 6 months postoperatively.

RESULTS

Baseline parameters of the 2 cohorts were comparable. There were lower transvalvular gradients in the Trifecta compared with the Mosaic Ultra group for the given annulus sizes. Severe prosthesis-patient mismatch was present in 28% of patients in the Mosaic group and 3% of patients in the Trifecta group.

CONCLUSIONS

Trifecta showed lower transvalvular gradients and less severe prosthesis-patient mismatch compared with Mosaic Ultra for the given annulus sizes. ClinicalTrials.gov Protocol ID: 2011/2596/REK.

Prosthesis-patient mismatch - what cardiac anesthesiologists need to know?

Prosthesis-patient Mismatch (PPM) is not uncommon with an incidence reported up to 70% after aortic valve (AV) replacement. Severe forms of PPM are less common (up to 20%); PPM can lead to increased short- and long-term morbidity and mortality. It is important to discriminate PPM from other forms of prosthetic valve dysfunction. Sometimes, prosthetic valve degenerative disease may coexist with PPM. Echocardiography plays an important role in the prevention and diagnosis of PPM. Preemptive strategies to prevent PPM include insertion of newer generation prosthetic valves with better hemodynamic characteristics, stentless prosthesis, aortic root enlargement to insert a larger prosthesis, aortic homograft, and transcutaneous AV implantation. We present an illustrative case and review the literature on PPM pertinent to anesthesiologists.