Impact of Prosthesis-Patient Mismatch on Cardiac Events and Midterm Mortality After Aortic Valve Replacement in Patients With Pure Aortic Stenosis

N-terminal pro-B-type natriuretic peptide measurement is useful in predicting left ventricular hypertrophy regression after aortic valve replacement in patients with severe aortic stenosis

BACKGROUND

The predictive factors for early left ventricular hypertrophy (LVH) regression after aortic valve replacement (AVR) have not been fully elucidated. This study was conducted to investigate which preoperative parameters predict early LVH regression after AVR.

METHODS AND RESULTS

87 consecutive patients who underwent AVR due to isolated severe aortic stenosis (AS) were analysed. Patients with ejection fraction <50% or concomitant coronary artery disease were excluded from the analysis. Preoperative evaluation including echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurement was performed and midterm follow-up echocardiography was done at a median of 9 months after AVR. The presence of complete regression of LVH at the midterm follow-up was determined. In multivariate analysis, including preoperative echocardiographic parameters, only E/e' ratio was associated with midterm LVH regression (OR 1.11, 95% CI 1.01 to 1.22; p=0.035). When preoperative NT-proBNP was added to the analysis, logNT-proBNP was found to be the single significant predictor of midterm LVH regression (OR 2.00, 95% CI 1.08 to 3.71; p=0.028). By receiver operating characteristic curve analysis, a cut-off value of 440 pg/mL for NT-proBNP yielded a sensitivity of 72% and a specificity of 77% for the prediction of LVH regression after AVR.

CONCLUSIONS

Preoperative NT-proBNP was an independent predictor for early LVH regression after AVR in patients with isolated severe AS.

Steady flow hemodynamic and energy loss measurements in normal and simulated calcified tricuspid and bicuspid aortic valves

The bicuspid aortic valve (BAV), which forms with two leaflets instead of three as in the normal tricuspid aortic valve (TAV), is associated with a spectrum of secondary valvulopathies and aortopathies potentially triggered by hemodynamic abnormalities. While studies have demonstrated an intrinsic degree of stenosis and the existence of a skewed orifice jet in the BAV, the impact of those abnormalities on BAV hemodynamic performance and energy loss has not been examined. This steady-flow study presents the comparative in vitro assessment of the flow field and energy loss in a TAV and type-I BAV under normal and simulated calcified states. Particle-image velocimetry (PIV) measurements were performed to quantify velocity, vorticity, viscous, and Reynolds shear stress fields in normal and simulated calcified porcine TAV and BAV models at six flow rates spanning the systolic phase. The BAV model was created by suturing the two coronary leaflets of a porcine TAV. Calcification was simulated via deposition of glue beads in the base of the leaflets. Valvular performance was characterized in terms of geometric orifice area (GOA), pressure drop, effective orifice area (EOA), energy loss (EL), and energy loss index (ELI). The BAV generated an elliptical orifice and a jet skewed toward the noncoronary leaflet. In contrast, the TAV featured a circular orifice and a jet aligned along the valve long axis. While the BAV exhibited an intrinsic degree of stenosis (18% increase in maximum jet velocity and 7% decrease in EOA relative to the TAV at the maximum flow rate), it generated only a 3% increase in EL and its average ELI (2.10 cm2/m2) remained above the clinical threshold characterizing severe aortic stenosis. The presence of simulated calcific lesions normalized the alignment of the BAV jet and resulted in the loss of jet axisymmetry in the TAV. It also amplified the degree of stenosis in the TAV and BAV, as indicated by the 342% and 404% increase in EL, 70% and 51% reduction in ELI and 48% and 51% decrease in EOA, respectively, relative to the nontreated valve models at the maximum flow rate. This study indicates the ability of the BAV to function as a TAV despite its intrinsic degree of stenosis and suggests the weak dependence of pressure drop on orifice area in calcified valves.

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

BACKGROUND

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.

METHODS AND RESULTS

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).

CONCLUSIONS

In this large catheterization-based study, the coexistence of PLF-AS before surgery and PPM after surgery is associated with the poorest outcome.

Progress in developing a living human tissue-engineered tri-leaflet heart valve assembled from tissue produced by the self-assembly approach

The aortic heart valve is constantly subjected to pulsatile flow and pressure gradients which, associated with cardiovascular risk factors and abnormal hemodynamics (i.e. altered wall shear stress), can cause stenosis and calcification of the leaflets and result in valve malfunction and impaired circulation. Available options for valve replacement include homograft, allogenic or xenogenic graft as well as the implantation of a mechanical valve. A tissue-engineered heart valve containing living autologous cells would represent an alternative option, particularly for pediatric patients, but still needs to be developed. The present study was designed to demonstrate the feasibility of using a living tissue sheet produced by the self-assembly method, to replace the bovine pericardium currently used for the reconstruction of a stented human heart valve. In this study, human fibroblasts were cultured in the presence of sodium ascorbate to produce tissue sheets. These sheets were superimposed to create a thick construct. Tissue pieces were cut from these constructs and assembled together on a stent, based on techniques used for commercially available replacement valves. Histology and transmission electron microscopy analysis showed that the fibroblasts were embedded in a dense extracellular matrix produced in vitro. The mechanical properties measured were consistent with the fact that the engineered tissue was resistant and could be cut, sutured and assembled on a wire frame typically used in bioprosthetic valve assembly. After a culture period in vitro, the construct was cohesive and did not disrupt or disassemble. The tissue engineered heart valve was stimulated in a pulsatile flow bioreactor and was able to sustain multiple duty cycles. This prototype of a tissue-engineered heart valve containing cells embedded in their own extracellular matrix and sewn on a wire frame has the potential to be strong enough to support physiological stress. The next step will be to test this valve extensively in a bioreactor and at a later date, in a large animal model in order to assess in vivo patency of the graft.

Early hemodynamic performance of the trifecta bioprosthetic valve in patients with aortic valve disease

BACKGROUND

The Trifecta valve (St Jude Medical) is a novel supra-annular aortic bioprosthesis designed to improve hemodynamic performance. We hypothesized that the Trifecta may offer better hemodynamic performance in Japanese patients, in whom the annulus is smaller, compared with Western populations. We compared the early results of hemodynamic performance between the Trifecta and the Magna (Edwards Lifescience) valves at our institution.

METHODS AND RESULTS

The Trifecta was implanted in 33 patients and the Magna was implanted in 41 patients who had aortic valve disease. Postoperative echocardiography was performed just before discharge, and the mean pressure gradient (MPG), effective orifice area (EOA) index and energy loss coefficient (ELCo) index were compared between the 2 groups. The average prosthesis size was similar between the 2 groups (21.1 vs. 21.3mm). The Trifecta group had a significantly lower MPG (P=0.001) and larger EOA index and ELCo index than the Magna group (P<0.001 for both). On multivariate linear regression analysis, use of the Trifecta was the strongest independent determinant of postoperative MPG, EOA and ELCo index.

CONCLUSIONS

The Trifecta valve provides excellent early postoperative hemodynamic performance in Japanese patients. Patients with a small annulus size relative to body size may benefit more from the Trifecta in terms of postoperative hemodynamic performance.

Factors determining patient-prosthesis mismatch after aortic valve replacement--a prospective cohort study

Objective

“Patient-prosthesis mismatch” (PPM) after aortic valve replacement (AVR) has been reported to increase morbidity and mortality. Although algorithms have been developed to avoid PPM, factors favouring its occurrence have not been well defined.

Design and Setting

This was a prospective cohort study performed at the Medical University of Vienna.

Patients

361 consecutive patients who underwent aortic valve replacement for isolated severe aortic stenosis were enrolled.

Main Outcome Measures

Patient- as well as prosthesis-related factors determining the occurrence of moderate and severe PPM (defined as effective orifice area indexed to body surface area ≤ 0.8 cm²/m²) were studied.

Results

Postoperatively, 172 patients (48%) were diagnosed with PPM. The fact that predominantly female patients were affected (58% with PPM diagnosis in women versus 36% in men, p<0.001) was explained by the finding that they had smaller aortic root diameters (30.5±4.7 mm versus 35.3±4.2 mm, p<0.0001) and a higher proportion of bioprosthetic valves (82% versus 62%, p<0.0001), both independent predictors of PPM (aortic root diameter: OR 0.009 [95% CI, 0.004;0.013]; p = 0.0003, presence of bioprosthetic valve: OR 0.126 [95% CI, 0.078;0.175]; p<0.0001).

Conclusions

The occurrence of PPM is determined by aortic root diameter and prosthesis type. Novel sutureless bioprostheses with optimized hemodynamic performance or transcatheter aortic valves may become a promising alternative to conventional bioprosthetic valves in the future.

Impact of energy loss index on left ventricular mass regression after aortic valve replacement

Background

Recently, the energy loss index (ELI) has been proposed as a new functional index to assess the severity of aortic stenosis (AS). The aim of this study was to investigate the impact of the ELI on left ventricular mass (LVM) regression in patients after aortic valve replacement (AVR) with mechanical valves.

Methods

A total of 30 patients with severe AS who underwent AVR with mechanical valves was studied. Echocardiography was performed to measure the LVM before AVR (pre-LVM) (n = 30) and repeated 12 months later (post-LVM) (n = 19). The ELI was calculated as [effective orifice area (EOA) × aortic cross sectional area]/(aortic cross sectional area − EOA) divided by the body surface area. The LVM regression rate (%) was calculated as 100 × (post-LVM − pre-LVM)/(pre-LVM). A cardiac event was defined as a composite of cardiac death and heart failure requiring hospitalization.

Results

LVM regressed significantly (245.1 ± 84.3 to 173.4 ± 62.6 g, P < 0.01) at 12 months after AVR. The LVM regression rate negatively correlated with the ELI (R = −0.67, P < 0.01). By receiver operating characteristic (ROC) curve analysis, ELI <1.12 cm²/m² predicted smaller (<−30.0 %) LVM regression rates (area under the curve = 0.825; P = 0.030). Patients with ELI <1.12 cm²/m² had significantly lower cardiac event-free survival.

Conclusion

The ELI as well as the EOA index (EOAI) could predict LVM regression after AVR with mechanical valves. Whether the ELI is a stronger predictor of clinical events than EOAI is still unclear, and further large-scale study is necessary to elucidate the clinical impact of the ELI in patients with AVR.

Replacement of the st jude medical regent valve in the aortic position with a continuous suture technique in the small aortic root

BACKGROUND

The aim of this study is to review the strategy of performing aortic valve replacement (AVR) by using the St. Jude Medical (SJM) Regent valve with a continuous suture technique in patients with a small aortic root.

METHODS

Forty-six patients with small aortic annulus underwent AVR by using 19 or 21 mm SJM Regent valves. There were 15 males and 31 females. The mean age of the patients was 51.8 ± 12.4 years. The aortic annular diameter was 20.2 ± 0.9 mm. AVR procedures were performed with continuous suture technique using SJM Regent valves under standard cardiopulmonary bypass. Echocardiaographic data were collected before operation, at discharge, and at a follow-up time, respectively.

RESULTS

The intraoperative course was uneventful and there was no operative mortality. The implanted SJM Regent valves consisted of 21 mm valves in 15 patients and 19 mm valves in 31 patients. Echocardiography at 5.6 ± 1.3 months after operation showed a significant increase in the mean effective orifice area index (0.97 ± 0.24 cm(2) /m(2) ), decrease in the mean and peak transvavluar pressure gradient (12.5 ± 5.9 and 22.3 ± 9.6 mmHg), and decrease in the mean left ventricular mass index (106 ± 41.3 g/m(2) ). Moderate prosthesis-patient mismatch (PPM) (effective orifice area index between 0.65 and 0.85 cm(2) /m(2) ) was present in three patients and no severe PPM (effective orifice area index <0.65 cm(2) /m(2) ) occurred at discharge and during follow-up.

CONCLUSION

Replacement of SJM Regent valve with a continuous suture technique maybe a good option to prevent PPM in the aortic position.

Can postoperative mean transprosthetic pressure gradient predict survival after aortic valve replacement?

Background

In this study, we sought to determine the effect of the mean transprosthetic pressure gradient (TPG), measured at 6 weeks after aortic valve replacement (AVR) or AVR with coronary artery bypass grafting (CABG) on late all-cause mortality.

Methods

Between January 1998 and March 2012, 2,276 patients (mean age 68 ± 11 years) underwent TPG analysis at 6 weeks after AVR (n = 1,318) or AVR with CABG (n = 958) at a single institution. Mean TPG was 11.6 ± 7.8 mmHg and median TPG 11 mmHg. Based on the TPG, the patients were split into three groups: patients with a low TPG (<10 mmHg), patients with a medium TPG (10–19 mmHg) and patients with a high TPG (≥20 mmHg). Cox proportional-hazard regression analysis was used to determine univariate predictors and multivariate independent predictors of late mortality.

Results

Overall survival for the entire group at 1, 3, 5, and 10 years was 97, 93, 87 and 67 %, respectively. There was no significant difference in long-term survival between patients with a low, medium or high TPG (p = 0.258). Independent predictors of late mortality included age, diabetes, peripheral vascular disease, renal dysfunction, chronic obstructive pulmonary disease, a history of a cerebrovascular accident and cardiopulmonary bypass time. Prosthesis–patient mismatch (PPM), severe PPM and TPG measured at 6 weeks postoperatively were not significantly associated with late mortality.

Conclusions

TPG measured at 6 weeks after AVR or AVR with CABG is not an independent predictor of all-cause late mortality and there is no significant difference in long-term survival between patients with a low, medium or high TPG.

Prosthesis-patient mismatch in aortic stenosis

BACKGROUND

The clinical impacts of prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR) have been debated since Rahimtoola first reported PPM in 1978. Many reports discussing several aspects of PPM have been published to date, but the definitive clinical impacts of PPM have not yet been clarified.

PURPOSE

The purpose of this review is to evaluate recent articles regarding PPM and discuss the latest findings.

RESULTS

Moderate PPM (indexed effective orifice area ≤ 0.85 cm(2)/m(2)) did not affect the surgical outcomes in several papers, but severe PPM (indexed effective orifice area ≤ 0.65 cm(2)/m(2)) affected early and late mortality in almost of the all papers in which it was reported. PPM had a greater effect on younger patients and patients with left ventricular dysfunction than it did on elderly patients and patients with preserved left ventricular function.

CONCLUSION

Based on recent findings, it is difficult to define the impact of PPM after AVR. To some degree, PPM affects the clinical outcomes after AVR; therefore, it is important to avoid PPM, especially severe PPM.

Multidetector CT predictors of prosthesis-patient mismatch in transcatheter aortic valve replacement

BACKGROUND

Prosthesis-patient mismatch (PPM) is a predictor of mortality after aortic valve replacement (AVR).

OBJECTIVE

We examined whether accurate 3-dimensional annular sizing with multidetector CT (MDCT) is predictive of PPM after transcatheter AVR (TAVR).

METHODS

One hundred twenty-eight patients underwent MDCT then TAVR. Moderate PPM was defined as an indexed effective orifice area ≤0.85 cm²/m² and severe ≤0.65 cm²/m². MDCT annular measurements (area, short and long axis) were compared with the size of the selected transcatheter heart valve (THV) to obtain (1) the difference between prosthesis size and CT-measured mean annular diameter and (2) the percentage of undersizing or oversizing (calculated as 100 × [MDCT annular area--THV nominal area]/THV nominal area). In addition, the MDCT annular area was indexed to body surface area. These measures were evaluated as potential PPM predictors.

RESULTS

We found that 42.2% of patients had moderate PPM and 9.4% had severe PPM. Procedural characteristics and in-hospital outcomes were similar between patients with or without PPM. THV undersizing of the mean aortic annulus diameter was not predictive of PPM (odds ratio [OR], 0.84; 95% CI, 0.65-1.07; P = .16; area under the receiver-operating characteristic curve [AUC], 0.58). THV undersizing of annular area was not predictive of PPM (OR, 0.96; 95% CI, 0.80-1.16; P = .69; AUC, 0.52). Indexed MDCT annular area was, however, predictive of PPM (OR, 0.24; 95% CI, 0.10-0.59; P < .001; AUC, 0.66).

CONCLUSIONS

PPM is frequent after TAVR. Appropriate annular oversizing does not reduce the rate or severity of PPM. Patient annulus size mismatch, identified by indexed MDCT annular area, is a significant predictor of PPM.

Obesity and the risk of late mortality after aortic valve replacement with small prosthesis

BACKGROUND

Whether obesity is related to late mortality with implantation of small aortic prosthesis remains to be clarified. This study was aimed to evaluate the effect of obesity on late survival of patients after aortic valve replacement (AVR) with implantation of small aortic prosthesis (size ≤ 21 mm).

METHODS

From January 1998 to December 2008, 307 patients in our institution who underwent primary AVR with smaller prostheses survived the 30 days after surgery. Patients were defined as normal if body mass index (BMI) was < 24 kg/m2, as overweight if BMI 24-27.9 kg/m2, and as obese if BMI ≥ 28 kg/m2. Data of New York Heart Association (NYHA) functional classification, left ventricular ejection fraction (LVEF), effective orifice area index (EOAI), and left ventricular mass index (LVMI) of the patients collected at the 3rd month (M), 6th M, 1st year (Y), 3rd Y, 5th Y, 8th Y after operation respectively.

RESULTS

By multivariable analysis, obesity was an independent factor of late mortality (hazard ratio [HR]: 1.62; P = 0.01). The obesity and overweight group had more poor survival (p < 0.001) and higher proportion of NYHA class III/IV (p < 0.01) compared with the normal group. Lower EOAI and higher LVMI were found in obesity and overweight group, but we saw no significant difference about LVEF among the three groups.

CONCLUSIONS

Obesity was associated with increased late mortality of patients after AVR with implantation of small aortic prosthesis. Being obese or and overweight may also affect the NYHA classification, even in the longer term. EOAI should be improved where possible, as it may reduce late mortality and improve quality of life in obese or overweight patients.

Impact of prosthesis-patient mismatch on early and late mortality after aortic valve replacement

BACKGROUND

The influence of prosthesis-patient mismatch (PPM) on survival after aortic valve replacement (AVR) remains controversial. In this study, we sought to determine the effect of PPM on early (≤30 days) and late mortality (>30 days) after AVR or AVR combined with coronary artery bypass grafting (AVR with CABG).

METHODS

Between January 1998 and March 2012, 2976 patients underwent AVR (n= 1718) or AVR with CABG (n=1258) at a single institution. PPM was defined as an indexed effective orifice area (EOAI) ≤0.85 cm2/m2 and patients were divided into two groups based on the existence of PPM. Cumulative probability values of survival were estimated with Kaplan-Meier method and compared between groups using Breslow test. Univariate and multivariate independent predictors of early mortality were identified using logistic regression. Cox proportional-hazard regression analysis was used to determine univariate and multivariate independent predictors of late mortality.

RESULTS

Early mortality was 6.7% in the PPM group vs 4.7% in the group with no PPM (p=0.013). Late mortality for the PPM group at 1, 5 and 10 years was 4%, 16% and 43%, respectively. Late mortality for the group with no PPM at 1, 5 and 10 years was 4%, 15% and 33% respectively. Independent predictors of early mortality included age, severely impaired left ventricular (LV) function, endocarditis, renal dysfunction, chronic obstructive pulmonary disease (COPD) and cardiopulmonary bypass (CPB) time. Multivariate independent predictors of late mortality included age, severely impaired LV function, diabetes, peripheral vascular disease (PVD), renal dysfunction, history of a cerebrovascular accident (CVA), CPB time and a history of previous cardiac surgery. PPM was not an independent predictor of early or late mortality.

CONCLUSION

PPM is not an independent predictor of both early and late mortality after AVR or AVR combined with CABG.

Prosthetic valves in adult patients with congenital heart disease: Rationale and design of the Dutch PROSTAVA study

BACKGROUND

Data on long-term complications in adult patients with congenital heart disease (ACHD) and a prosthetic valve are scarce. Moreover, the influence of prosthetic valves on quality of life (QoL) and functional outcome in ACHD patients with prosthetic valves has not been studied.

OBJECTIVES

The primary objective of the PROSTAVA study is to investigate the relation between prosthetic valve characteristics (type, size and location) and functional outcome as well as QoL in ACHD patients. The secondary objectives are to investigate the prevalence and predictors of prosthesis-related complications including prosthesis-patient mismatch.

METHODS

The PROSTAVA study, a multicentre cross-sectional observational study, will include approximately 550 ACHD patients with prosthetic valves. Primary outcome measures are maximum oxygen uptake during cardiopulmonary exercise testing and QoL. Secondary outcomes are the prevalence and incidence of valve-related complications including prosthesis-patient mismatch. Other evaluations are medical history, physical examination, echocardiography, MRI, rhythm monitoring and laboratory evaluation (including NT-proBNP).

IMPLICATIONS

Identification of the relation between prosthetic valve characteristics in ACHD patients on one hand and functional outcome, QoL, the prevalence and predictors of prosthesis-related complications on the other hand may influence the choice of valve prosthesis, the indication for more extensive surgery and the indication for re-operation.

Valve prosthesis-patient mismatch (VP-PM): a long-term perspective

The concept/phenomenon of valve prosthesis/patient mismatch (VP-PM), described in 1978, has stood the test of time. From that time to 2011, VP-PM has received a great deal of attention but studies have come to varying conclusions. This is largely because of the determination of prosthetic heart valve area [called effective orifice area index (EOAi)] by projection rather than by actual measurement, variable criteria to assess severity of EOAi and the timing of determination of EOAi. All prosthetic heart valves have some degree of VP-PM which must be placed in a proper clinical perspective. This can be done by determining its effects on function and outcomes. For mortality one needs to focus especially on severe/critical degree of VP-PM and determine the cause of death was due to VP-PM. For the period "beyond 2011" a road map is suggested that will have uniformity of assessment of VP-PM and a focusing on the important goals of VP-PM.

Long-Term Clinical and Echocardiographic Follow-Up of the Freestyle Stentless Aortic Bioprosthesis

Background—

Stentless aortic bioprostheses were designed to provide enhanced hemodynamic performance and potentially greater longevity. The present report describes the outcomes of patients with the Freestyle stentless bioprosthesis followed for ≤18 years.

Methods and Results—

Between 1993 and 2011, 430 patients underwent primary aortic valve replacement with a Freestyle bioprosthesis in the subcoronary position. Mean age was 68.2±8.2 years. All of the clinical and echocardiographic data were collected prospectively. Mean overall follow-up was 9.1±4.4 years and was complete in all of the patients. In-hospital mortality was 3.5% (n=15). Overall, 10- and 15-year survival were 60.7% and 35.0%, respectively. Fifty-one patients required reoperation during follow-up, including 27 for structural valve deterioration (SVD). Overall, freedom from reoperation was 91.0% and 75.0% at 10 and 15 years, whereas freedom from reoperation for SVD was 95.9% and 82.3%, respectively. At 10 and 15 years, freedom from reoperation for SVD was 94.0% and 62.6% for patients <60 years of age and 96.3% and 88.4% for patients ≥60 years of age ( P =0.002). The median time to explant for SVD was 10.7 years. SVD presented mostly as acute, severe aortic insufficiency attributed to leaflet tear (77.8%). The independent risk factors for reoperation for SVD were age <60 years ( P =0.001) and dyslipidemia ( P =0.02).

Conclusions—

Aortic valve replacement with the Freestyle bioprosthesis in a subcoronary position provides good long-term clinical and echocardiographic outcomes for patients >60 years of age. Severe aortic insufficiency with leaflet tear is the major mode of SVD leading to reoperation in these patients.

Comparing aortic root replacements: porcine bioroots versus pericardial versus mechanical composite roots: hemodynamic and ventricular remodeling at greater than one-year follow-up

BACKGROUND

Stentless porcine bioroots and pericardial composite roots were developed as prostheses that avoid the anticoagulation necessary for mechanical composite roots. Data on the hemodynamics of all root replacements are lacking and questions remain regarding comparative performance.

METHODS

This study evaluated patients receiving a stentless porcine bioroot, a pericardial, or a mechanical composite root at a single institution from January 2000 to December 2008. All patients underwent preoperative, postoperative and greater than 1-year echocardiograms. All root replacements were performed for aortic insufficiency or aneurysm. Median follow-up was 3.3 years (1 to 8 years).

RESULTS

There were no significant differences in preoperative left ventricular ejection fraction, aortic valve peak gradient, mean gradient, left ventricular end diastolic diameter, and left ventricular end systolic diameter. Postoperative peak and mean gradients in mechanical composite roots were significantly higher than stentless porcine bioroots. At greater than 1 year, stentless porcine bioroots had significantly lower peak and mean gradients than both mechanical composite roots and pericardial composite roots. The end diastolic diameter was also significantly smaller in stentless porcine bioroots at greater than 1 year than mechanical composite roots.

CONCLUSIONS

All prostheses resulted in favorable hemodynamic and ventricular remodeling. Stentless porcine bioroots had the lowest gradients at greater than 1 year of all root replacements, with significantly better ventricular remodeling when compared with mechanical composite roots. Pericardial roots also had favorable hemodynamics and ventricular remodeling, suggesting that they are a viable alternative.

Impact of patient-prosthesis mismatch on 30-day outcomes in young and middle-aged patients undergoing aortic valve replacement

Background

The impact of patient-prosthesis mismatch (PPM) on early outcomes in young and middle-aged patients undergoing conventional aortic valve replacement for severe aortic stenosis remains unknown. Our objective was to evaluate the incidence of some degree of PPM and its influence on early mortality and morbidity.

Methods

We analyzed our single center experience in all patients <70 years undergoing first-time isolated aortic valve replacement for severe stenosis in our center from September 2007 to September 2011. PPM was defined as an indexed effective orifice area ≤ 0,85 cm²/m². The influence of PPM on early mortality and postoperative complications was studied using propensity score analysis. Follow up at 30 postoperative days was 100% complete.

Results

Of 199 patients studied, 61 (30,7%) had some degree of PPM. PPM was associated with an increased postoperative mortality (OR = 8,71; 95% CI = 1,67–45,29; p = 0,04) and major postoperative complications (OR = 2,96; CI = 1,03–8,55; p = 0,044). However, no association between PPM and prolonged hospital or ICU stay was demonstrated.

Conclusions

Moderate PPM is a common finding in young and middle-aged patients undergoing surgery for aortic valve replacement due to severe stenosis. In addition, its influence on early outcomes may be relevant.

Early Doppler-echocardiography evaluation of Carpentier-Edwards Standard and Carpentier-Edwards Magna aortic prosthetic valve: comparison of hemodynamic performance

OBJECTIVES

This study was designed to describe Doppler-echocardiography values of Carpentier-Edwards Perimount Standard (CEPS) and Carpentier-Edwards Perimount Magna (CEPM) aortic prosthetic valves, evaluated by a single, experienced echo-laboratory, early in the postoperative phase.

METHODS

Three-hundred-seventy-seven consecutive patients, who had had a CEPS or a CEPM implanted in our Hospital due to aortic stenosis and/or insufficiency, underwent baseline Doppler echocardiography evaluation within 7 days after surgery. Hemodynamic performances of CEPS and CEPM were accurately described, evaluating flow-dependent (transprosthetic velocities and gradients) and flow-independent (effective orifice area, indexed effective orifice area and Doppler velocity index) Doppler-echocardiography parameters.

RESULTS

Out of the 377 patients 48.8% were men (n = 184), mean age was 74.63 ± 6.77 years, mean BSA was 1.78 ± 0.18 m2, mean ejection fraction was 57.78 ± 8%. Two-hundred and sixty two CEPS and 115 CEPM were implanted. Comparing size-by-size CEPS with CEPM, both prostheses showed a good hemodynamic profile, with fairly similar values of pressure gradients (PGmax and mean, in mmHg, = 37,18 ± 11.57 and 20.81 ± 7.44 in CEPS n°19 compared to 32,47 ± 7,76 and 17,67 ± 4.63 in CEPM n°19 and progressively lower in higher sized prostheses, having PGmax and mean 15 ± 3,16 and 9.15 ± 1,29 in CEPS n°29 compared to 15,67 ± 1,53 and 9 ± 1 in CEPM n°29) and EOAi (being 0,65 ± 0,33 cm²/m² in CEPS n°19 compared to 0,77 ± 0,29 cm²/m² in CEPM n°19 and progressively higher in higher sized prostheses, being 1,28 ± 0,59 cm²/m² in CEPS n°29 compared to 1,07 ± 0,18 cm²/m² in CEPM n°29), the latter resulting, however, basically less flow obstructive.

CONCLUSIONS

Our data confirm the good hemodynamic performance of both aortic bioprostheses and the more favourable hemodynamic profile of CEPM compared to CEPS, pointing out the need to perform routinely an accurate baseline Doppler-echocardiography evaluation early after surgery to allow an adequate interpretation of data at follow-up.

Transcatheter aortic valve implantation in patients with severe aortic stenosis and small aortic annulus

OBJECTIVES

Valve hemodynamics and clinical outcomes among patients with a small aortic annulus who underwent transcatheter aortic valve implantation (TAVI) were examined.

BACKGROUND

The presence of a small aortic annulus may complicate the surgical management of patients with severe aortic stenosis (AS). TAVI is an alternative to aortic valve replacement (AVR) in high-risk patients, but few data exist on the results of TAVI in patients with a small aortic annulus.

METHODS

Between 2007 and 2010, 35 patients (mean age 79.2 ± 9.4 years) with severe AS and an aortic annulus diameter <20 mm (mean 18.5 ± 0.9 mm) underwent TAVI with a 23-mm Edwards SAPIEN bioprosthesis (Edwards Lifesciences, Inc., Irvine, California). Echocardiographic parameters and clinical outcomes were assessed prior to discharge and at 6, 12, and 24 months.

RESULTS

Procedural success was achieved in 34 patients (97.1%). There was 1 in-hospital death. Peak and mean transaortic gradients decreased from 76.3 ± 33.0 mm Hg and 45.2 ± 20.6 mm Hg at baseline to 21.8 ± 8.4 mm Hg and 11.7 ± 4.8 mm Hg post-procedure, respectively, both p < 0.0001. Mean indexed effective orifice area (IEOA) increased from 0.35 ± 0.10 cm(2)/m(2) at baseline to 0.90 ± 0.18 cm(2)/m(2) post-procedure, p < 0.0001. Severe prosthesis-patient mismatch (IEOA <0.65 cm(2)/m(2)) occurred in 2 patients (5.9%). At a mean follow-up of 14 ± 11 months, gradients remained low and 30 of the 31 remaining survivors were in New York Heart Association functional class I or II.

CONCLUSIONS

In high-risk patients with severe AS and a small aortic annulus, TAVI is associated with good post-procedural valve hemodynamics and clinical outcomes. TAVI may provide a reasonable alternative to conventional AVR in elderly patients with a small aortic annulus.

Pulmonary hypertension in cardiac surgery

Pulmonary hypertension is an important prognostic factor in cardiac surgery associated with increased morbidity and mortality. With the aging population and the associated increase severity of illness, the prevalence of pulmonary hypertension in cardiac surgical patients will increase. In this review, the definition of pulmonary hypertension, the mechanisms and its relationship to right ventricular dysfunction will be presented. Finally, pharmacological and non-pharmacological therapeutic and preventive approaches will be presented.

Patient-prosthesis mismatch in the mitral position affects midterm survival and functional status

BACKGROUND

The definition and incidence of patient-prosthesis mismatch (PPM) in the mitral position are unclear.

OBJECTIVES

To determine the impact of PPM on late survival and functional status after mitral valve replacement with a mechanical valve.

METHODS

Between 1992 and 2005, 714 patients (mean [± SD] age 60±10 years) underwent valve replacement with either St Jude (St Jude Medical Inc, USA) (n=295) or Carbomedics (Sulzer Carbomedics Inc, USA) (n=419) valves. There were 52 concomitant procedures (50 tricuspid annuloplasties, 25 foramen oval closures and 20 radiofrequency mazes). The mean clinical follow-up period was 4.4±3.3 years. The severity of PPM was established with cut-off values for an indexed effective orifice area (EOAi) of lower than 1.2 cm(2)⁄m(2), lower than 1.3 cm(2)⁄m(2) and lower than 1.4 cm(2)⁄m(2). Parametric and nonparametric tests were used to determine predictors of outcome.

RESULTS

The prevalence of PPM was 3.7%, 10.1% and 23.5% when considering values of lower than 1.2 cm(2)⁄m(2), lower than 1.3 cm(2)⁄m(2) and lower than 1.4 cm(2)⁄m(2), respectively. When considering functional improvement, patients with an EOAi of 1.4 cm(2)⁄m(2) or greater had a better outcome than those with an EOAi of lower than 1.4 cm(2)⁄m(2) (OR 1.98; P=0.03). When building a Cox-proportional hazard model, PPM with an EOAi of less than 1.3 cm(2)⁄m(2) was an independent predictive factor for midterm survival (HR 2.24, P=0.007). Other factors affecting survival were age (HR 1.039), preoperative New York Heart Association class (HR 1.96) and body surface area (HR 0.31).

CONCLUSIONS

In a large cohort of patients undergoing mitral valve replacement with mechanical prostheses, PPM defined as an EOAi of lower than 1.3 cm(2)⁄m(2) significantly decreased midterm survival. This level of PPM was observed in 10.2% of patients. Patients with an EOAi of 1.4 cm(2)⁄m(2) or greater had greater improvement of their functional status.

Defining patient-prosthesis mismatch and its effect on survival in patients with impaired ejection fraction

BACKGROUND

How best to define patient-prosthesis mismatch (PPM) continues to be debated. Over time, the indexed effective orifice area has become the most widely used method. However, the clinical relevance of PPM remains controversial.

METHODS

The indexed geometric orifice area and indexed effective orifice area were calculated for 143 patients having undergone aortic valve replacement with a normal left ventricular function 0.45 or less. Using the indexed geometric orifice area method, PPM was defined as nonsignificant if 1.2 cm(2)/m(2) or greater and as significant if less than 1.2 cm(2)/m(2). Using the indexed effective orifice area method, PPM was considered as nonsignificant if greater than 0.85 cm(2)/m(2), as moderate if greater than 0.65 cm(2)/m(2) and less than or equal to 0.85 cm(2)/m(2), and as severe PPM if 0.65 cm(2)/m(2) or less.

RESULTS

The number of patients classified as having PPM differed according to the method used to predict its presence (PPM: Effective orifice area method = 72.7%; geometric method = 19.6%). Regardless of the method used to classify PPM there was no significant effect on mortality (adjusted hazard ratio: 2.65 at 1 year, 0.99 at 5 years, 0.92 at 9 years; p = not significant). The postoperative mean transvalvular gradient (17.1 ± 6.5 mm Hg) and left ventricular function (0.50 ± 0.145) improved significantly compared with the preoperative findings.

CONCLUSIONS

The method used to calculate PPM resulted in significant classification discordance. However, regardless of classification, the presence of PPM did not adversely affect long-term outcome.