Prosthesis-patient Mismatch In Patients Research Articles

Patient-prosthesis mismatch in patients treated with transcatheter aortic valve implantation - predictors, incidence and impact on clinical efficacy. A preliminary study.

IntroductionPatient-prosthesis mismatch (PPM) is relatively frequent after surgical aortic valve replacement (SAVR) and negatively impacts prognosis.AimWe sought to determine the frequency and clinical effects of PPM after transcatheter aortic valve implantation (TAVI).Material and methodsOverall, 238 patients who underwent TAVI were screened. Moderate PPM was defined as indexed effective orifice area (EOAi) between 0.65 and 0.85 cm2/m2, and severe PPM as < 0.65 cm2/m2. All-cause mortality and the Valve Academic Research Consortium 2 (VARC-2) defined composite of clinical efficacy at 1 year were the primary endpoints.ResultsFinally, 201 patients were included (mean age: 79.6 ±7.4 years, 52% females). The femoral artery served as the delivery route in 79% and most of the prostheses were self-expanding (68%). Any PPM was present in 48 (24%) subjects, and only 7 (3.5%) had severe PPM. Body surface area (BSA) independently predicted any PPM (OR = 16.9, p < 0.001) whereas post-dilation tended to protect against PPM (OR = 0.46, p = 0.09). All-cause mortality was similar in patients with moderate or severe PPM as compared to those with no PPM (14.6% vs. 14.3% vs. 13.1%, respectively, log-rank p = 0.98). Neither moderate (OR = 1.6, 95% CI: 0.8–3.2, p = 0.16) nor severe PPM (OR = 1.67, 95% CI: 0.36–7.7, p = 0.51) had a significant impact on composite endpoint, or its elements, with the exception of transvalvular pressure gradient > 20 mm Hg.ConclusionsSevere PPM after TAVI is rare, can be predicted by larger BSA and does not seem to affect mid-term mortality or composite clinical outcome. Larger studies are needed to find different independent predictors of PPM and elucidate its impact in terms of device durability and long-term clinical efficacy.

Prosthesis-patient mismatch and left ventricle systolic strain in patients with severe degenerative aortic stenosis, who are undergoing surgical valve replacement

Prosthesis-patient mismatch (PPM) is an independent predictor of post-operative mortality after aortic valve replacement (AVR), particularly when it is associated with a left ventricle (LV) dysfunction. Two-dimensional speckle-tracking echocardiography (2D-STE) could be useful in assessing LV function in patients with PPM. To evaluate the impact of PPM on myocardial multidirectional LV systolic strain in patients who are undergoing AVR for severe degenerative aortic stenosis (AS). Sixty-five patients (38 females, 27 males, age: 69.9 ± 9.1 years) with severe degenerative AS and preserved LV ejection fraction were enrolled into the study. Pre- and three-month postoperative 2D-STE was performed to assess LV peak systolic longitudinal strain (LV PSLS), circumferential strain, and LV rotation. The indexed prosthesis effective orifice area (iEOAprosth) was used to define PPM (≤ 0.65 cm2/m2), and it was used to distinguish the study groups: PPM (+) (n = 35) and PPM (-) (n = 30). A significant association of LV PSLS and interaction in the groups [PPM (+) vs. PPM (-)] and intervention (before vs. after AVR; p = 0.019) was observed - the lowest value of LV PSLS was in the PPM (+) group (-14.9 ± 3.5%) after AVR. A significant difference in the mean delta (before/after AVR) values of LV PSLS (0.7 ± 3.1% vs. -1.2 ± 3.6%; p = 0.04) in the PPM (+) vs. the PPM (-) groups was found. LV PSLS correlated with iEOAprosth (r = -0.520, p < 0.001) that was obtained three months after AVR. The occurrence of PPM in patients undergoing AVR for severe degenerative AS was associated with reduced LV PSLS in a three-month observation.

Prevalence and long-term outcome of aortic prosthesis-patient mismatch in patients with paradoxical low-flow severe aortic stenosis.

Patients with severe aortic stenosis (AS) and paradoxical low flow (PLF) have worse outcome compared with those with normal flow. Furthermore, prosthesis-patient mismatch (PPM) after aortic valve replacement is a predictor of reduced survival. However, the prevalence and prognostic impact of PPM in patients with PLF-AS are unknown. We aimed to analyze the prevalence and long-term survival of PPM in patients with PLF-AS. Between 2000 and 2010, 677 patients with severe AS, preserved left ventricular ejection fraction, and aortic valve replacement were included (74±8 years; 42% women; aortic valve area, 0.69±0.16 cm(2)). A PLF (indexed stroke volume ≤35 mL/m(2)) was found in 26%, and after aortic valve replacement, 54% of patients had PPM, defined as an indexed effective orifice area ≤0.85 cm(2)/m(2). The combined presence of PLF and PPM was found in 15%. Compared with patients with noPLF/noPPM, those with PLF/PPM were significantly older, with more comorbidities. They also received smaller and biological bioprosthesis more often (all P<0.01). Although early mortality was not significantly different between groups, the 10-year survival rate was significantly reduced in case of PLF/PPM compared with noPLF/noPPM (38±9% versus 70±5%; P=0.002), even after multivariable adjustment (hazard ratio, 2.58; 95% confidence interval, 1.5-4.45; P=0.0007). In this large catheterization-based study, the coexistence of PLF-AS before surgery and PPM after surgery is associated with the poorest outcome.

The impact of prosthesis–patient mismatch after aortic valve replacement varies according to age at operation

Objectives Age may modify the impact of prosthesis–patient mismatch (PPM) on outcomes after aortic valve replacement (AVR), as physical functioning decreases with age, and comorbidities become more prevalent. We hypothesised...

Patient-prosthesis mismatch in patients undergoing bioprosthetic aortic valve implantation increases risk of reoperation for structural valve deterioration.

Patient-prosthesis mismatch has been identified as a risk factor for mortality after aortic valve replacement and for structural valve deterioration (SVD) in patients receiving a bioprosthetic aortic valve. The aim of the present study was to compare the incidence of aortic valve bioprosthesis replacement for SVD in patients with mismatch to a population without mismatch. Three hundred eighty-seven adult patients who underwent aortic valve replacement with a bioprosthesis from 1974 to 2009 were retrospectively reviewed. Mismatch was considered to be present if the anticipated indexed effective orifice area was <0.70 cm(2) /m(2) . The median follow-up period was 7.2 years. Follow-up was 97% complete. Patient-prosthesis mismatch was present in 12% of the study population (n = 47). Ten-year freedom from reoperation for aortic bioprosthesis replacement was 74.3 ± 3.2%. During follow-up, 111 patients underwent reoperation for aortic bioprosthesis replacement. Causes of aortic bioprosthesis replacement were SVD of the bioprosthesis (n = 96), paravalvular leak (n = 10), and acute endocarditis (n = 5). According to unadjusted Kaplan-Meier analysis, patients with mismatch had a higher incidence of aortic bioprosthesis replacement for SVD when compared with patients without mismatch (log rank test: p 0.05). This result was confirmed by multivariable Cox regression analysis, which identified two independent predictors of aortic bioprosthesis replacement for SVD: patients' age (hazard ratio (HR) 0.967) and patient-prosthesis mismatch (HR 2.161). Patients suffering from mismatch were twice as likely to undergo reoperation for aortic bioprosthesis replacement for SVD than those without mismatch.

Prediction of Acute Kidney Injury Within 30 Days of Cardiac Surgery

Introduction: It is unclear whethermanufacturer provided charts actually predict the probability of aortic valve patientprosthesis mismatch (PPM). The aim of the study was to determine whether these charts reliably predict PPM in patients undergoing aortic valve replacement (AVR). Methods: We undertook a retrospective analysis of echocardiographic data from Geelong Hospital with institutional ethics approval. Between January 2006 and December 2010, 405 patients in our hospital underwent AVR with either a mechanical prosthesis or a stented bioprosthesis. 152 patients had adequate echocardiographic follow up (mean time to follow up 104 days). The measured gradient and effective orifice area index (EOAI) were compared to the values provided by the manufacturer. Results: Despite no patient having preoperatively predicted severe PPM according to manufacturer charts, 62 patients (40.8%) had postoperative echocardiographic evidence of severe PPM. The accuracy of the charts to predict severe PPM was 59.2%. The rate of postoperatively measured moderate or greater PPM was 77.6%. Sensitivity and specificity of manufacturer charts for moderate or greater PPM were 27.1% (19.5–36.2%) and 88.2% (71.6–96.1%) respectively. The accuracy of the charts for moderate or greater PPM was 41.4%. Postoperatively measured average EOA across all valve types and sizes were lower than those provided by the manufacturer. Postoperative aortic valvemean pressure gradient in patients with severe PPM was 18.5 6.3 mmHg, moderate PPM 13.7 4.3 mmHg and no PPM 12.6 3.2 mmHg. Discussion: The accuracy of industry provided charts for EOAI calculation is poor. We conclude that these charts are not useful in the pre-operative prediction of severe PPM in patients undergoing AVR.

Deep Sternal Wound Infection Following Cardiac Surgery: Risk and Outcomes

Introduction: It is unclear whethermanufacturer provided charts actually predict the probability of aortic valve patientprosthesis mismatch (PPM). The aim of the study was to determine whether these charts reliably predict PPM in patients undergoing aortic valve replacement (AVR). Methods: We undertook a retrospective analysis of echocardiographic data from Geelong Hospital with institutional ethics approval. Between January 2006 and December 2010, 405 patients in our hospital underwent AVR with either a mechanical prosthesis or a stented bioprosthesis. 152 patients had adequate echocardiographic follow up (mean time to follow up 104 days). The measured gradient and effective orifice area index (EOAI) were compared to the values provided by the manufacturer. Results: Despite no patient having preoperatively predicted severe PPM according to manufacturer charts, 62 patients (40.8%) had postoperative echocardiographic evidence of severe PPM. The accuracy of the charts to predict severe PPM was 59.2%. The rate of postoperatively measured moderate or greater PPM was 77.6%. Sensitivity and specificity of manufacturer charts for moderate or greater PPM were 27.1% (19.5–36.2%) and 88.2% (71.6–96.1%) respectively. The accuracy of the charts for moderate or greater PPM was 41.4%. Postoperatively measured average EOA across all valve types and sizes were lower than those provided by the manufacturer. Postoperative aortic valvemean pressure gradient in patients with severe PPM was 18.5 6.3 mmHg, moderate PPM 13.7 4.3 mmHg and no PPM 12.6 3.2 mmHg. Discussion: The accuracy of industry provided charts for EOAI calculation is poor. We conclude that these charts are not useful in the pre-operative prediction of severe PPM in patients undergoing AVR.

EComment. Incidence of patient-prosthesis mismatch in patients with a Perceval S valve

I read with great interest the paper by Shrestha et al. regarding the use of the sutureless Perceval S valve (Sorin Group, Saluggia, Italy) in the elderly with small aortic annulus [1]. The most important change in the present study is likely the introduction of a control group, which had been woefully lacking in the earlier trials assessing exclusively the safety and efficacy of this relatively new aortic valve bioprosthesis [2-3]. The authors compared the results of aortic valve replacement using the sutureless Perceval S valves against those with conventional bioprostheses. Although patients in the sutureless valves group had higher Logistic EuroSCORE than patients in the conventional valves group, they showed after 3 years of follow-up that there were no differences in mortality rates between the 2 groups. Furthermore, the mean gradient across the bioprostheses was comparable during the follow-up period. Considering this, it can be questioned whether the method used by the authors to compare these bioprostheses should really be considered the best approach to answer their question? I would like to take the opportunity to rephrase the question that needs to be resolved: after Perceval implantation, do patients with a small aortic annulus exhibit less patient-prosthesis mismatch (PPM) than patients treated conventionally? I think that the article by Shrestha et al. will add substantially valuable data if the incidence of severe PPM is evaluated in each treated group. Recently, D'Onofrio et al. [4] conducted a propensity-matched multicentre study to compare echocardiographic and clinical outcomes in high risk patients with severe aortic valve stenosis undergoing transapical transcatheter aortic valve implantation (TAVI) using the Edwards Sapien bioprosthesis versus patient undergoing sutureless aortic valve replacement using the Perceval S valve. They showed that in this subset of high risk patients, the Perceval S valve is as safe and effective as a transapical TAVI, and that the higher incidence of paravalvular leak in the TAVI group casts a shadow on the overall benefit of the latter technique. Another established advantage of using the Perceval S aortic valve is the reduction of cross-clamp and cardiopulmonary bypass times [3]. Aortic cross-clamp duration plays an important role in patient outcomes because it has been demonstrated to be an independent predictor of 30-day mortality after cardiac surgery. More recently, the merit of Perceval S valve has been reiterated by Santarpino et al. [5] in a comparative study. Despite the higher surgical risk, patients with a Perceval S bioprosthesis required less blood transfusion, shorter intubation time and intensive care unit stay than patients in the conventional group. Even though, the high cost of the Perceval S is not to be dismissed, in the current era of stringent budget, one should consider implanting this valve in patients who are at high risk for surgical aortic valve replacement but who are not actually ainoperable. Conflict of interest: none declared

Prevalence and impact of prosthesis-patient mismatch in patients with paradoxical low-flow severe aortic stenosis

Purpose: Patients with severe aortic stenosis (AS) and paradoxical low flow (PLF) (indexed stroke volume 50%, have worse outcome compared to those with AS but normal flow. Moreover, Prosthesis-Patient Mismatch (PPM) (indexed prosthetic valve effective orifice area< 0.85cm2/m2) after aortic valve replacement (AVR) is a predictor of higher mortality. However, the impact of PPM in patients with PLFAS on long-term survival is unknown. Our aim was to analyze the prevalence and the impact on long-term survival of PPM in patients with PLFAS. Methods: 667 consecutive patients (age 74±8 years, 42% female, AVA 0.69±0.16 cm2) with preserved LVEF who underwent AVR for severe AS at our institution between 2000 and 2010 were included in this study. Patients were divided into 4 groups according to the presence/absence of PLF at cardiac catheterization and presence/absence of PPM following AVR and we compared short and long-term survival between these groups. Results: Among the 667 patients, 26% had PLFAS and PPM occurred in 54% of patients after AVR. Compared to patients with no PLF & no PPM (36% of the total cohort), those with PLF & PPM (15%) were significantly older, with more comorbidities. The 30-day mortality did not differ between the PLF- PPM and no-PLF-no PPM group. The 10-yr survival rate was significantly reduced in the PLF-PPM (37±9%) group compared to no PLF-no PPM (70±5%; p=0.003). In multivariate analysis adjusting for all predictors of survival, concomitant presence of PLF & PPM was an independent predictor of survival (HR= 2.68 95% CI: 1.5-4.4; p=0.0003) ![Figure][1] 10-year survival according to PPM/PLF Conclusion: In this catheterization-based study, patients with PLF and PPM have worse outcome when compared to those without these 2 conditions. [1]: pending:yes

Aortic Valve Prosthesis–Patient Mismatch and Long-Term Outcomes: 19-Year Single-Center Experience

The clinical effects of prosthesis-patient mismatch (PPM) after aortic valve replacement, with respect to morbidity and survival, remain controversial, particularly in high-risk patient subgroups. Patients undergoing aortic valve replacement from January 1992 to December 2010 were classified according to effective orifice area index into severe PPM (effective orifice area index<0.65 cm²/m²), moderate PPM (effective orifice area index 0.65 to 0.85 cm²/m²), and absent PPM (effective orifice area index>0.85 cm²/m²). Analyses examined major morbidity and total all-cause death. Prosthesis-patient mismatch was classified as severe (92 of 1,060; 8.7%), moderate (440 of 1,060; 41.5%), or absent (528 of 1,060; 49.8%). Moderate and severe PPM were unrelated to in-hospital morbidity or mortality. There were 440 deaths (41.5%) at 5.6 years median follow-up (interquartile range, 2.9 to 9.1). Trend toward poorer survival according to PPM group (χ2=5.46; p=0.07) was attenuated further with covariate adjustment. Sensitivity analyses demonstrated discrete mortality effects for moderate PPM in association with concomitant coronary artery bypass grafting, impaired left ventricular function, and older age (significant hazard ratios range, 1.05 to 1.57). Severe PPM also increased mortality risk in association with older age, concomitant coronary artery bypass grafting, and New York Heart Association Class III or IV (significant hazard ratios range, 1.06 to 2.65). Prosthesis-patient mismatch was not associated with mortality in covariate-adjusted models. However, a discrete mortality risk was attributable to moderate and severe PPM in patients of older age, or those with left ventricular dysfunction, New York Heart Association class III or IV, and concomitant coronary artery bypass grafting.

Patient-prosthesis mismatch in patients with aortic valve replacement

ObjectivePatient-prosthesis mismatch (PPM) may affect clinical outcomes in patients with aortic valve replacement (AVR). We retrospectively examined the PPM in patients with isolated AVR in the Japan Adult Cardiovascular Surgery Database (JACVSD).MethodsWe examined all patients with isolated AVR between January 1, 2008 and December 31, 2009. The JACVSD data collection form has a total of 255 variables. We defined PPM as an effective orifice area index of ≤0.85 m2/cm2.ResultsPPM was observed in 306 of 3,609 cases analyzed, PPM rate was 8.5 %. Body surface area was larger and body mass index was higher in the PPM group than the non-PPM group (P < 0.001). Patients with PPM were older (P = 0.001) and had a higher prevalence of diabetes (P = 0.004), dyslipidemia (P < 0.001), hypertension (P < 0.001), cerebrovascular disease (P = 0.031), old myocardial infarction (P = 0.006), previous percutaneous coronary artery intervention (P = 0.001), coronary artery disease (P = 0.018), and aortic valve stenosis (P < 0.001). Perioperative blood transfusion (P < 0.001) and dialysis (P = 0.005) were more frequent in the PPM group. Postoperative ventilation (P = 0.004) and intensive care unit stay (P = 0.004) were significantly longer in the PPM group.ConclusionsAge, aortic valve stenosis, dyslipidemia, hypertension, old myocardial infarction, previous percutaneous coronary artery intervention, diabetes mellitus, cerebrovascular disease, and high body mass index were the risk factors for PPM. PPM was not an independent risk factor for short-term mortality.

Invited Commentary

Invited Commentary

Accuracy of Industry Generated Effective Orifice Area Calculators for Aortic Valve Replacement

Introduction: It is unclear whethermanufacturer provided charts actually predict the probability of aortic valve patientprosthesis mismatch (PPM). The aim of the study was to determine whether these charts reliably predict PPM in patients undergoing aortic valve replacement (AVR). Methods: We undertook a retrospective analysis of echocardiographic data from Geelong Hospital with institutional ethics approval. Between January 2006 and December 2010, 405 patients in our hospital underwent AVR with either a mechanical prosthesis or a stented bioprosthesis. 152 patients had adequate echocardiographic follow up (mean time to follow up 104 days). The measured gradient and effective orifice area index (EOAI) were compared to the values provided by the manufacturer. Results: Despite no patient having preoperatively predicted severe PPM according to manufacturer charts, 62 patients (40.8%) had postoperative echocardiographic evidence of severe PPM. The accuracy of the charts to predict severe PPM was 59.2%. The rate of postoperatively measured moderate or greater PPM was 77.6%. Sensitivity and specificity of manufacturer charts for moderate or greater PPM were 27.1% (19.5–36.2%) and 88.2% (71.6–96.1%) respectively. The accuracy of the charts for moderate or greater PPM was 41.4%. Postoperatively measured average EOA across all valve types and sizes were lower than those provided by the manufacturer. Postoperative aortic valvemean pressure gradient in patients with severe PPM was 18.5 6.3 mmHg, moderate PPM 13.7 4.3 mmHg and no PPM 12.6 3.2 mmHg. Discussion: The accuracy of industry provided charts for EOAI calculation is poor. We conclude that these charts are not useful in the pre-operative prediction of severe PPM in patients undergoing AVR.

Impact of Prosthesis-Patient Mismatch on the Regression of Secondary Mitral Regurgitation After Isolated Aortic Valve Replacement With a Bioprosthetic Valve in Patients With Severe Aortic Stenosis

Secondary mitral regurgitation (SMR) is generally reduced after isolated aortic valve replacement (AVR), but there is important interindividual variability in the magnitude of this reduction. Prosthesis-patient mismatch (PPM) may hinder normalization of left ventricular geometry and pressure overload following AVR, therefore we aimed to investigate the relationship between PPM and regression of SMR following AVR for aortic valve stenosis. A total of 419 patients with AS who underwent isolated AVR at 2 institutions and presenting moderate SMR (mitral regurgitant volume 30 to 45 mL/beat) not considered for surgical correction were included in this study. Clinical and echocardiographic follow-up were completed at a median follow-up time of 37 months. PPM was defined as an indexed effective orifice area ≤0.85 cm(2)/m(2) and was found in 170/419 patients (40.6%). There were no significant differences in baseline and operative characteristics between patients with or without PPM. Patients with PPM had less regression of SMR following AVR compared with those with no PPM (change in mitral regurgitant volume: -11±4 versus -17±5 mL, respectively; P<0.0001). Variables significantly associated with postoperative change in mitral regurgitant volume on univariable analysis were entered in a multivariable linear regression model, which showed indexed effective orifice area (P<0.0001) and left atrial diameter (P=0.006) to be independently associated with mitral regurgitant volume improvement. Patients with PPM also had less postoperative improvement in 6-minute walking test distance (80±78 versus 42±41 m, P<0.0001). PPM is associated with lesser regression of SMR following AVR. This unfavorable effect was associated with worse functional capacity. These findings emphasize the importance of operative strategies aiming to prevent PPM in patients with aortic valve stenosis and concomitant SMR.

Hemodynamic and Clinical Impact of Prosthesis–Patient Mismatch After Transcatheter Aortic Valve Implantation

This study examined the mid-term hemodynamic and clinical impact of prosthesis-patient mismatch (PPM) in patients undergoing transcatheter aortic valve implantation (TAVI) with balloon-expandable valves. PPM can be observed after aortic valve surgery. However, little is known about the incidence of PPM in patients undergoing TAVI. Echocardiography and clinical assessment were performed in 165 patients at baseline, before hospital discharge, and at 6 months after TAVI. PPM was defined as an indexed effective orifice area ≤0.85 cm(2)/m(2). Thirty patients (18.2%) showed PPM before hospital discharge. At baseline, patients with PPM had a larger body surface area (1.84 ± 0.18 m(2) vs. 1.73 ± 0.18 m(2), p = 0.003) and a greater severity of aortic stenosis (indexed valve area 0.35 ± 0.09 cm(2)/m(2) vs. 0.40 ± 0.10 cm(2)/m(2), p = 0.005) than patients without PPM. Patients with PPM demonstrated a slower and smaller reduction in mean transaortic gradient, limited left ventricular (LV) mass regression, and left atrial volume reduction over 6 months compared with patients without PPM. LV filling pressure, measured by E/e', tended to remain elevated in patients with PPM. Importantly, a higher proportion of patients with PPM did not improve in New York Heart Association functional class compared with patients without PPM (36.7% vs. 1.5%, p < 0.001), although major adverse valve-related and cardiovascular events did not differ between the 2 groups. PPM may be observed after TAVI and when present may be accompanied by less favorable changes in transvalvular hemodynamics, limited LV mass regression, persistent elevated LV filling pressure, and less improvement in clinical functional status.

Patient-Prosthesis Mismatch in Patients With Aortic Stenosis Undergoing Isolated Aortic Valve Replacement Does Not Affect Survival

Data suggest that patient-prosthesis mismatch (PPM) adversely effects late survival after aortic valve replacement (AVR). This study examined the incidence and implications of PPM in patients undergoing isolated AVR. Prospectively collected data on patients undergoing isolated AVR for aortic stenosis between January 1, 1997 and December 31, 2007 were analyzed. The projected effective valve orifice area from in vivo data was indexed to body surface area (EOAi). PPM was defined as moderate for EOAi of < or = 0.85 cm(2)/m(2) and severe if < or = 0.6 cm(2)/m(2). The reference group comprised patients with EOAi > 0.85 cm(2)/m(2). The effect of PPM on postoperative survival was assessed by multivariate analysis. Of 801 patients, PPM was severe in 48 (6.0%), moderate in 462 (57.8%), and nonexistent in 291 (36.4%). Mismatch was associated with increasing age and female gender, thus resulting in an increase in the EuroSCORE (reference group, 4.9 +/- 2.6; moderate PPM, 5.8 +/- 2.4; and severe PPM, 6.1+/-2.1; p < 0.001). PPM did not significantly increase hospital mortality. Four deaths occurred in the reference group (1.4%), 12 in the moderate PPM (2.6%), and none in the severe PPM group (p = 0.311). The 5-year survival estimates were 83% in reference, 86% in moderate PPM, and 89% in severe PPM (p = 0.25). By multivariate analysis, PPM was not an independent risk factor for reduced in-hospital or late survival. Moderate PPM is common in patients undergoing AVR for aortic stenosis, but severe mismatch is rare. Patients with PPM have similar early and late postoperative survival rate.

Prosthesis–patient mismatch is less frequent and more clinically indolent in patients operated for aortic insufficiency

To date, no study has focused on the incidence and effects of prosthesis-patient mismatch in patients requiring aortic valve replacement for aortic insufficiency. We hypothesized that the incidence and implications of prosthesis-patient mismatch in patients with aortic insufficiency might be different than for aortic stenosis or mixed disease because the annulus is generally larger in aortic insufficiency and left ventricular remodeling might differ. Ninety-eight patients with lone aortic insufficiency (>or=3+ with a preoperative mean gradient <30 mm Hg) were followed over 7.7 +/- 4.3 years (maximum, 17.5 years) with clinical and echocardiographic assessments. They were compared with 707 patients who had aortic valve replacement for aortic stenosis or mixed disease. Prosthesis-patient mismatch was defined as an in vivo indexed effective orifice area of 0.85 cm(2)/m(2) or less. Compared with patients with aortic stenosis/mixed disease, patients with aortic insufficiency had approximately half the incidence of prosthesis-patient mismatch (P = .003). Patients with prosthesis-patient mismatch had significantly higher transprosthesis gradients postoperatively. An independent detrimental effect of prosthesis-patient mismatch on survival was observed in patients with aortic stenosis/mixed disease who had preoperative left ventricular dysfunction (hazard ratio, 2.3; P = .03) but not in patients with aortic insufficiency, irrespective of left ventricular function (hazard ratio, 0.7; P = .7). In patients with aortic stenosis/mixed disease with left ventricular dysfunction, prosthesis-patient mismatch predicted heart failure symptoms by 3 years after aortic valve replacement (odds ratio, 6.0; P = .002), but there was no such effect in patients with aortic insufficiency (P = .8). Indexed left ventricular mass regression occurred to a greater extent in patients with aortic insufficiency than in patients with aortic stenosis/mixed disease (by an additional 29 +/- 5 g/m(2), P < .001), and there was a trend for prosthesis-patient mismatch to impair regression in patients with aortic insufficiency (by 30 +/- 17 g/m(2), P = .1). The incidence and significance of prosthesis-patient mismatch differs in patients with aortic insufficiency compared with those with aortic stenosis or mixed disease. In patients with aortic insufficiency, prosthesis-patient mismatch is seen less frequently and has no significant effect on survival and freedom from heart failure but might have a negative effect on left ventricular mass regression.

Validity of identifying patient-prosthesis mismatch from the indexed effective orifice area

The main problem that arises from patient-prosthesis mismatch after aortic valve replacement is a residual high transvalvular pressure gradient, resulting in left ventricular overload. It was demonstrated by Pibarot and Dumesnil that the indexed effective orifice area should be larger than 0.85-0.90 cm2/m2 to prevent any significant transvalvular pressure gradient after operation. However, we have encountered a higher residual transvalvular pressure gradient than expected in some patients with an aortic stented bioprosthesis with an indexed effective orifice area greater than 0.85 cm2/m2. Based on our data, an indexed effective orifice area of less than 1.25 cm2/m2 might be considered the threshold for patient-prosthesis mismatch in patients with a stented bioprosthesis because this indexed effective orifice area is associated with a low mean transvalvular pressure gradient (less than 10 mmHg). The practical implications include the necessity to consider the hemodynamic performance of each prosthesis type when seeking to define patient-prosthesis mismatch and abnormally or significant high postoperative gradients that lead to an increased left ventricular workload, so as to avoid residual significant transvalvular pressure gradients and higher rates of morbidity and mortality.

Moderate patient-prosthesis mismatch after valve replacement for severe aortic stenosis has no impact on short-term and long-term mortality

Background:The importance of moderate patient-prosthesis mismatch (PPM) for the prognosis of patients who undergo aortic valve replacement is unclear.Methods:The presence of PPM was assessed in 361 consecutive patients undergoing valve...

Root Replacement Using Stentless Valves in the Small Aortic Root: A Propensity Score Analysis

Root replacement using a stentless bioprosthesis may be the optimal approach to avoid patient-prosthesis mismatch in patients with a small aortic root. Primary root replacement, however, is considered to be associated with increased surgical risk. We compared early outcome of full root replacement with a stentless bioprosthesis with that of aortic valve replacement with a stented bioprosthesis using propensity score-matching analysis. Of 231 patients undergoing elective, first-time aortic valve replacement with a small root (< or = 22 mm), 120 patients were selected using propensity score-matching analysis. They underwent either root replacement using a 23-mm stentless bioprosthesis (stentless group, n = 60) or supra-annular aortic valve replacement using a 21-mm stented bioprosthesis (stented group, n = 60). Preoperative characteristics and frequency of concomitant operations were identical. Duration of operation (196 +/- 54 versus 174 +/- 49 minutes), cardiopulmonary bypass (112 +/- 36 versus 91 +/- 33 minutes), and aortic cross-clamping (76 +/- 21 versus 61 +/- 21 minutes) were significantly longer in the stentless group. However, the need for perioperative transfusion and the incidence of postoperative reexploration for bleeding (3% versus 8%) was lower, and ventilation time was shorter. Mean duration of intensive care and hospital stay were also significantly shorter (2.3 +/- 1.7 versus 4.0 +/- 3.9 days, 8.9 +/- 3.1 versus 12.4 +/- 5.7 days). In-hospital mortality was identical (5% each). No independent predictor for in-hospital mortality was identified. Full root replacement using a stentless bioprosthesis does not increase postoperative morbidity or mortality of aortic valve replacement and may be advantageous in patients with a small aortic root.