Hemodynamic and clinical impact of prosthesis-patient mismatch in the aortic valve position and its prevention

Postimplant biological aortic prosthesis degeneration: challenges in transcatheter valve implants

Surgical aortic valve replacement (SAVR) is highly effective and can be achieved with relatively low risk in patients with severe aortic stenosis. Bioprostheses have been used most frequently during the past 60 years. However, the function of biological valves usually declines after 10-15 years from implant when structural valve degeneration occurs often mandating a reoperation once valve dysfunction becomes haemodynamically significant. Known for many years by surgeons and cardiologists taking care of patients with SAVR, the issue of postimplant structural valve degeneration has been recently highlighted also in patients with transcatheter aortic valve implant (TAVI). There is growing concern that TAVI valves exhibit structural valve degeneration due to inherent challenges of the deployment mode. The impact on postimplant degeneration of TAVI valves compared to SAVR has still to be understood and defined. Based on the ongoing process of expanding TAVI indications, several potential shortcomings and caveats, learned during the last 60 years of SAVR experience, should be taken into consideration to refine this technique.

Konno-Rastan Combined with Manougiaun Root Enlargement for Small Aortic Root with Coronary Anomaly in a Young Woman

Aortic root enlargement (ARE) is an established procedure to deal with small aortic annulus. It becomes very important to place adequate size prosthesis to prevent patient–prosthesis mismatch (PPM). Aortic root enlargement procedures procedures are technically demanding operations, particularly in obese patients. The presence of coronary artery anomalies adds more complexity to the procedure. We present an interesting case of a 22-year-old obese female with symptomatic severe aortic valve stenosis and anomalous coronary arteries. We successfully performed aortic valve replacement using the combined Konno aortoventriculoplasty and Manouguian posterior aortic root enlargement. Combined aortic root enlargement techniques techniques should be considered in the presence of major coronary anomalies.

Safety, efficacy, and hemodynamic performance of a stented bovine pericardial aortic valve bioprosthesis: Two-year analysis

OBJECTIVES

The study objectives were to evaluate the safety, efficacy, and hemodynamic performance of a novel stented bovine pericardial aortic valve bioprosthesis 2 years after implantation.

METHODS

The PERIcardial SurGical AOrtic Valve ReplacemeNT Pivotal Trial enrolled patients with symptomatic moderate/severe aortic stenosis or regurgitation at centers in Canada, Europe, and the United States. We report the outcomes and hemodynamic performance in patients with up to 2 years of follow-up.

RESULTS

A total of 1273 patients were enrolled, and 1110 underwent implantation. Among patients undergoing implantation, the mean age was 70.2 ± 8.9 years; 833 (75.0%) were male. Risk of mortality (Society of Thoracic Surgeons) was 2.0% ± 1.4%. At the time of analysis, 604 patients had completed the 2-year follow-up visit. Linearized late event rates were as follows: all death, 2.68%; valve-related death, 0.42%; valve thrombosis, 0.05%; endocarditis, 0.94%; thromboembolism, 1.68%; all hemorrhage, 2.94%; major hemorrhage, 1.99%; all paravalvular leak, 0.26%; and major paravalvular leak, 0.05% per patient-year. Mean 2-year aortic gradient and effective orifice area were 13.4 ± 5.0 mm Hg and 1.5 ± 0.37 cm², respectively. Moderate and severe prosthesis-patient mismatch were observed in 43.5% and 34.8% of patients at 2 years, respectively. Improvement in New York Heart Association class compared with baseline was observed in 73.0% with moderate mismatch and 74.1% with severe mismatch.

CONCLUSIONS

The Avalus (Medtronic, Minneapolis, Minn) bovine pericardial valve demonstrates good clinical and safety outcomes at 2 years. Hemodynamic performance shows mean gradients comparable to currently available bovine pericardial aortic valves. There was no clinical impact of moderate to severe mismatch at 2 years. Further follow-up is required to evaluate midterm to long-term clinical outcome.

Long-Term Outcomes After Transcatheter Aortic Valve-in-Valve Replacement

BACKGROUND

Data on long-term outcomes after valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) are scarce. The objective of this study was to determine the long-term clinical outcomes and structural valve degeneration (SVD) over time in patients undergoing ViV-TAVR.

METHODS AND RESULTS

Consecutive patients undergoing ViV-TAVR in 9 centers between 2009 and 2015 were included. Patients were followed yearly, and clinical and echocardiography data were collected prospectively. SVD was defined as subclinical (increase >10 mm Hg in mean transvalvular gradient+decrease >0.3 cm² in valve area or new-onset mild or moderate aortic regurgitation) and clinically relevant (increase >20 mm Hg in mean transvalvular gradient+decrease >0.6 cm² in valve area or new-onset moderate-to-severe aortic regurgitation). A total of 116 patients (mean age, 76±11 years; 64.7% male; mean Society of Thoracic Surgeons score, 8.0±5.1%) were included. Balloon- and self-expandable valves were used in 47.9% and 52.1% of patients, respectively, and 30-day mortality was 6.9%. At a median follow-up of 3 years (range, 2-7 years), 30 patients (25.9%) had died, 20 of them (17.2%) from cardiovascular causes. Average mean transvalvular gradients remained stable up to 5-year follow-up ( P=0.92), but clinically relevant SVD occurred in 3/99 patients (3.0%), and 15/99 patients (15.1%) had subclinical SVD. One patient with SVD had redo ViV-TAVR.

CONCLUSIONS

About one-fourth of ViV-TAVR recipients had died after a median follow-up of 3 years. Overall valve hemodynamics remained stable over time and clinically relevant SVD was infrequent, but 1 out of 10 patients exhibited some degree of SVD.

Bioprosthetic Valve Fracture for Valve-in-Valve Transcatheter Aortic Valve Replacement: Rationale, Patient Selection, Technique, and Outcomes

Patient-prosthesis mismatch (PPM) is common after surgical valve aortic replacement. A significant percentage of patients with a small annulus have moderate to severe PPM. The outcomes for patients with larger effective orifice areas and lower gradients are better than for patients with PPM. With the advent of valve-in-valve TAVR, a degenerated surgical bioprosthesis can be treated with a percutaneous approach. However, the issue of PPM cannot be overcome by simply implanting a new valve. The technique of bioprosthetic valve fracture was therefore developed. This allows for implantation of a fully expanded transcatheter valve and results in a large effective orifice.

Hemodynamic Performance and Outcomes of Mosaic Valve for Aortic Stenosis with Decreased Left Ventricular Function: Results from J-MOVE Study

We evaluated impact of a small-sized Mosaic porcine bioprosthesis on hemodynamic performance and outcomes in patients with aortic stenosis (AS) and low left ventricular ejection fraction (LVEF) in a Japan multicenter cohort. Of 1,202 patients enrolled, 105 (8.7%) who had LVEF < 50% and AS underwent aortic valve replacement (AVR). Fifty-two patients received Mosaic porcine bioprosthesis ≤ 21 mm (S-AVR), and 53 received a bioprosthesis ≥ 23 mm (L-AVR). The median follow-up period was 3.1 [1.2, 5.1] years. At 5 years, LVEF significantly improved from median 41.2 [33.8, 45.9]% to 64.2 [49.8, 72.5]% in S-AVR (p < 0.001) and from median 43.2 [37.3, 46.8]% to 61.2 [47.2, 68.0]% in L-AVR (p < 0.001). The left ventricular mass index significantly decreased from median 158.4 [122.2, 194.9] to 110.0 [83.6, 129.4] gm/m in S-AVR (p < 0.001) and from median 169.8 [132.2, 203.6] to 109.6 [101.8, 132.4] gm/m in L-AVR (p < 0.001). There were no significant differences between S-AVR and L-AVR groups regarding freedom from cardiac death (93.1 ± 3.9% vs. 96.2 ± 3.8%; p = 0.119) and valve-related death (97.6 ± 2.4% vs. 100.0 ± 0.0%; p = 0.953). Clinical outcomes and improved hemodynamic performance were similar in both groups.

Transcatheter valve-in-valve implantation in a degenerated very small Mitroflow prosthesis

OBJECTIVES

To assess the feasibility and results of 'valve-in-valve' implantation using the 23-mm CoreValve for the treatment of degenerated 19-mm and 21-mm Mitroflow bioprostheses.

METHODS

We retrospectively analysed all consecutive patients who underwent transcatheter aortic valve implantation for 19-mm and 21-mm Mitroflow bioprostheses. The height of implantation with respect to the ring of the Mitroflow prosthesis was targeted at -6 mm for the first 3 cases. In the following cases, the target was higher to promote free supra-annular movement of the leaflets.

RESULTS

The procedure was successful in 17 of 18 patients (94%). For implantations above the limit of -6 mm, the mean gradient was 10.4 ± 2.6 mmHg compared with 28.1 ± 11.6 mmHg for implantations below the limit of -6 mm (P < 0.01). For patients with severe stenosis as main mechanism of failure of the bioprosthesis, the mean post-procedural gradient was 31.2 ± 11.8 mmHg compared with 12.7 ± 6 mmHg in the absence of severe stenosis (P < 0.01). Patient-prosthesis mismatch (indexed effective orifice area ≤ 0.85 cm2/m2) and severe mismatch (indexed effective orifice area ≤ 0.65 cm2/m2) were present in 83% (15 of 18) and 27% (5 of 18) of patients, respectively. We did not notice any complications following the procedures. Six months after the procedure, functional status was improved in all patients.

CONCLUSIONS

Our short series demonstrates the ability to perform transcatheter 'valve-in-valve' implantation in 19-mm and 21-mm Mitroflow prostheses with satisfactory results, but high post-procedural gradients and patient-prosthesis mismatch remain a relatively frequent problem mostly when severe stenosis is the main mechanism of failure. Implantation in a high position is critical to decrease the rate of high postimplantation gradients.

Impact of Prosthesis-Patient Mismatch on 1-Year Outcomes after Transcatheter Aortic Valve Implantation: Meta-analysis of 71,106 Patients

OBJECTIVES

This study sought to evaluate the impact of prosthesis-patient mismatch (PPM) on the risk of early-term mortality after transcatheter aortic valve implantation (TAVI).

METHODS

Databases (Medical Literature Analysis and Retrieval System Online [MEDLINE], Excerpta Medica dataBASE [EMBASE], Cochrane Controlled Trials Register [CENTRAL/CCTR], ClinicalTrials.gov, Scientific Electronic Library Online [SciELO], Latin American and Caribbean Literature on Health Sciences [LILACS], and Google Scholar) were searched for studies published until February 2019. PPM after TAVI was defined as moderate if the indexed effective orifice area (iEOA) was between 0.85 cm2/m2 and 0.65 cm2/m2 and as severe if iEOA ≤ 0.65 cm2/m2.

RESULTS

The search yielded 1,092 studies for inclusion. Of these, 18 articles were analyzed, and their data extracted. The total number of patients included who underwent TAVI was 71,106. The incidence of PPM after TAVI was 36.3% (25,846 with PPM and 45,260 without PPM). One-year mortality was not increased in patients with any PPM (odds ratio [OR] 1.021, 95% confidence interval [CI] 0.979-1.065, P=0.338) neither in those with moderate PPM (OR 0.980, 95% CI 0.933-1.029, P=0.423). Severe PPM was separately associated with high risk (OR 1.109, 95% CI 1.041-1.181, P=0.001).

CONCLUSION

The presence of severe PPM after TAVI increased early-term mortality. Although moderate PPM seemed harmless, the findings of this study cannot not rule out the possibility of it being detrimental, since there are other registries that did not address this issue yet.

Multimodality Imaging of Complications of Cardiac Valve Surgeries

Replacement with a prosthetic heart valve (PHV) remains the definitive surgical procedure for management of severe cardiac valve disease. PHV dysfunction is uncommon but can be a life-threatening condition. The broad hemodynamic and pathophysiologic manifestations of PHV dysfunction are stenosis, regurgitation, and a stuck leaflet. Specific structural abnormalities that cause PHV dysfunction include prosthetic valve-patient mismatch, structural failure, valve calcification, dehiscence, paravalvular leak, infective endocarditis, abscess, pseudoaneurysm, abnormal connections, thrombus, hypoattenuating leaflet thickening, and pannus. Multiple imaging modalities are available for evaluating a PHV and its dysfunction. Transthoracic echocardiography is often the first-line imaging modality, with additional modalities such as transesophageal echocardiography, CT, MRI, cine fluoroscopy, and nuclear medicine used for further characterization and establishing a specific cause. The authors review PHVs and the role of imaging modalities in evaluation of PHV dysfunction and illustrate the imaging appearances of different complications. Online supplemental material is available for this article. ^©RSNA, 2019.

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.

Patient prosthesis mismatch and its impact on left ventricular regression following aortic valve replacement in aortic stenosis patients

Introduction

Patient prosthesis mismatch is known to alter post-operative remodeling of left ventricle adversely in aortic stenosis patients. An indexed orifice area of 0.85 is considered as conventional cutoff for patient prosthesis mismatch based on hemodynamic principles. Many patients have smaller annulus and annulus enlargement techniques may be required to avoid this benchmark which complicates the surgery.

Aims and objectives

To determine incidence of patient prosthesis mismatch (PPM) in our population, to assess left ventricle (LV) regression and impact of indexed effective orifice area on LV regression, and to determine a minimum acceptable cut off indexed orifice area that will result in LV regression.

Materials and methods

A single-center retrospective observational study of all patients who underwent aortic valve replacement surgery for severe aortic stenosis between July 2015 and December 2015 was conducted. Patients who underwent concomitant revascularization or other valve surgery were excluded. Data regarding conventional risk factors for PPM, valve type, and indexed orifice area as well as pre-operative and late post-operative LV mass were collected.

Observations

Thirty-seven of the 91 patients satisfied inclusion criteria. All patients had significant regression in LV mass. The incidence of PPM was 68%. Regression of indexed left ventricular mass showed a positive correlation of with indexed effective orifice area of the prosthetic valve. The correlation coefficient is + 0.48 (95% CI 0.18-0.698). Left ventricular mass regression was significantly higher in patients with indexed effective orifice area more than 0.75 (68.89 ± 29 vs 122.55 ± 58.84, p = 0.028). Relative left ventricular regression also was significantly higher in patients with an indexed effective orifice area more than 0.75 (39.53 ± 13.13 vs 49.73 ± 15.56, p = 0.022). There is a positive correlation between left ventricular regression and the reduction in mean gradient achieved by valve replacement. The correlation coefficient was + 0.35 (95% CI 0.03-0.61).

Conclusions

The incidence of PPM was found to be comparable to literature. There is a positive correlation between left ventricular regression and indexed effective orifice area of the prosthetic valve. Left ventricular regression was significantly higher in patients with an indexed effective area more than 0.75. This can be considered as criteria for significant PPM in study population.

Stented versus Stentless Aortic Valve Replacement in Patients with Small Aortic Root

Objective

The aim of the study was to compare hemodynamic and perioperative outcomes of stented against stentless aortic valve replacement in patients with small aortic root (21 mm or less).

Methods

A comprehensive search was undertaken among the four major databases (PubMed, Embase, Scopus, and Ovid) to identify all randomized and nonrandomized controlled trials comparing stentless to stented bioprosthetic valves in small aortic root patients. Odds ratios, weighted mean differences, or standardized mean differences and their 95% confidence intervals were analyzed.

Results

A total of seven studies with a total of 965 patients fulfilled the inclusion criteria. There was no significant difference in preoperative baselines including mean age between both groups ( P = 0.08), peak aortic valve gradient ( P = 0.06), and effective orifice area ( P = 0.28), whereas higher mean aortic valve gradient in the stented group ( P = 0.007). No difference in cardiopulmonary bypass time ( P = 0.74), aortic cross-clamp times ( P = 0.88), intensive care unit stay ( P = 0.13), and stroke rate ( P = 0.56) were noted. However, stented group of patients showed higher rate of patient prosthesis mismatch ( P = 0.0001) and longer total hospital stay ( P = 0.002). Postoperatively, stentless group showed lower peak and mean aortic valve gradient ( P = 0.003 and P = 0.008, respectively) with a better effective orifice area ( P < 0.00001) at 6 months of follow-up. Mortality rates while in-hospital and at 1 year were similar in both groups ( P = 0.94 and P = 0.86, respectively).

Conclusions

Stentless aortic valves offer superior short-term hemodynamic outcomes in patients with small aortic root when compared with stented aortic valves. Although both groups have similar perioperative complications rates, stentless valves bring about a shorter hospital stay. A further large multicenter randomized controlled trial should address the longer-term benefit of stentless aortic valve over stented valve.

Left ventricular outflow obstruction predicts increase in systolic pressure gradients and blood residence time after transcatheter mitral valve replacement

Left ventricular outflow tract (LVOT) obstruction is a relatively common consequence of transcatheter mitral valve replacement (TMVR). Although LVOT obstruction is associated with heart failure and adverse remodelling, its effects upon left ventricular hemodynamics remain poorly characterised. This study uses validated computational models to identify the LVOT obstruction degree that causes significant changes in ventricular hemodynamics after TMVR. Seven TMVR patients underwent personalised flow simulations based on pre-procedural imaging data. Different virtual valve configurations were simulated in each case, for a total of 32 simulations, and the resulting obstruction degree was correlated with pressure gradients and flow residence times. These simulations identified a threshold LVOT obstruction degree of 35%, beyond which significant deterioration of systolic function was observed. The mean increase from baseline (pre-TMVR) in the peak systolic pressure gradient rose from 5.7% to 30.1% above this threshold value. The average blood volume staying inside the ventricle for more than two cycles also increased from 4.4% to 57.5% for obstruction degrees above 35%, while the flow entering and leaving the ventricle within one cycle decreased by 13.9%. These results demonstrate the unique ability of modelling to predict the hemodynamic consequences of TMVR and to assist in the clinical decision-making process.

Structural valve deterioration of bioprosthetic aortic valves: An underestimated complication

OBJECTIVES

Structural valve deterioration (SVD) remains a major bioprosthesis-related complication, as recently described for the Mitroflow valve (models LX and 12A) (LivaNova, London, United Kingdom). The real incidence of the SVD risk remains unclear, often due to methodologic pitfalls by systematically using the Kaplan-Meier estimator and/or the Cox model. In this report, we propose for the first time a precise statistical modeling of this issue.

METHODS

Five hundred sixty-one patients who underwent aortic valve replacement with the aortic Mitroflow valve between 2002 and 2007 were included. We used an illness-death model for interval-censored data. Median follow-up was 6.6 years; 103 cases of SVD were diagnosed.

RESULTS

The 4-year and 7-year SVD cumulative incidences after the first anniversary of surgery were 15.2% (95% confidence interval, 11.9-19.1) and 31.0% (95% confidence interval, 25.8-37.2), respectively. Female gender, dyslipidemia, chronic obstructive pulmonary disease, and severe patient-prosthesis mismatch were significant risk factors of SVD. The occurrence of SVD was associated with a 2-fold increase in the risk of death.

CONCLUSIONS

Appropriate statistical models should be used to avoid underestimating the SVD complication associated with worse long-term survival.

Early hemodynamic performance of the Trifecta™ surgical bioprosthesis aortic valve in Indian patient population: 12 month outcomes of the EVEREST post-market study

BACKGROUND

Indian patients undergoing surgical aortic valve replacement (SAVR) differ from western populations with respect to aortic annulus size and valve disease morphology. The purpose of this post-market, non-randomized observational study was to evaluate the early hemodynamic performance of the Trifecta™ bioprosthesis (Abbott, previously St. Jude Medical, Minneapolis, US) in an Indian patient population.

METHODS

From January 2014 to September 2015, 100 patients (mean age 64.4 ± 7.1 years, 62% male) undergoing SAVR for valve disease (68% stenosis, 7% insufficiency, 25% mixed pathology) were enrolled across 10 centers in India. Patients implanted with a 19-27 mm Trifecta™ valve were eligible to participate and were prospectively followed for 12-months post-implantation. Echocardiographic hemodynamic performance was evaluated at pre-implant, pre-discharge and at 12-months by an independent core laboratory. Adverse events were adjudicated by the study sponsor. Functional status at 12-months was assessed according to NYHA classification. Continuous data was summarized using descriptive statistics (mean &standard deviation,) and categorical data was summarized using frequencies and percentages.

RESULT

Ninety patients (mean age 64.5, 62.2% male) completed the 12-month follow up. Significant improvements in hemodynamic valve performance were reported in 81 patients with available echocardiographic data at 12 months. Compared to baseline at 12-month follow up visit, mean effective orifice area increased from 0.75cm² to 1.61cm² (p < 0.0001), mean pressure gradient reduced to 10.42 mmHg from 51.47 mmHg (p < 0.0001), cardiac output increased from 4.46 l/min to 4.85 l/min (P 0.9254). Compared to baseline, functional status improved by ≥1 NYHA class in 75% of patients at 12 months (95% Clopper-Pearson (Exact) confidence limit [64.6%, 83.6%]). No instances of early mortality (< 30 days from index procedure) or structural valve dysfunction were reported.

CONCLUSION

In an Indian patient population, implantation of the Trifecta™ bioprosthesis is shown to be safe and associated with favorable early hemodynamic performance and improved functional status at 12 months.

TRIAL REGISTRATION

The clinical study has been registered under Clinical Trial Registry-India ( http://www.ctri.nic.in ) and registration number is CTRI/2014/02/004434 registered on 25 February 2014 retrospectively registered.

Exercise Hemodynamics After Aortic Valve Replacement for Severe Aortic Stenosis

BACKGROUND

Severe aortic stenosis (AS) is often accompanied by diastolic dysfunction. After aortic valve replacement (AVR), the left ventricle often undergoes considerable reverse remodeling. Despite this, diastolic dysfunction may persist after AVR. The aims of this study were to determine the incidence of elevated left ventricular (LV) filling pressure at rest and during exercise among patients with severe AS after AVR and to describe factors related to elevated LV filling pressure, especially its association with LV and left atrial remodeling and myocardial fibrosis.

METHODS

Thirty-seven patients undergoing AVR were included. Echocardiography, cardiac computed tomography, and magnetic resonance imaging were performed before AVR. An LV biopsy sample was obtained during AVR and analyzed for collagen fraction. One year after AVR, right heart catheterization with exercise was performed. A mean pulmonary capillary wedge pressure (PCWP) ≥ 28 mm Hg during exercise was considered elevated.

RESULTS

Twelve patients (32%) had elevated exercise PCWP 1 year after AVR. Exercise PCWP was highest among patients undergoing concomitant coronary artery bypass graft surgery (30 ± 7 vs 25 ± 6 mm Hg, P = .04) and among patients with preoperative stroke volume index < 35 mL/m² (28 ± 8 vs 23 ± 4 mm Hg, P < .05). Baseline LV ejection fraction was lower among patients with elevated PCWP (56 ± 8% vs 64 ± 8%, P = .01), and coronary calcium score was significantly higher (median 870 AU [interquartile range, 454-2,491 AU] vs 179 AU [interquartile range, 63-513 AU], P = .02). Conversely, exercise PCWP was not related to the presence of high LV wall mass or to the severity of AS. Among patients undergoing isolated AVR, there was a correlation between LV interstitial volume fraction and PCWP (r = 0.57, P = .01) and mean pulmonary artery pressure (r = 0.51, P = .03) during exercise.

CONCLUSIONS

Elevated filling pressure during exercise was seen in one third of patients after AVR in this population and was seen primarily among patients with coexisting ischemic heart disease or diffuse myocardial fibrosis but was unrelated to preoperative severity of AS and LV remodeling.

Discongruence Index - Simple Indicator to Predict Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Replacement

BACKGROUND

Prosthesis-patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR) remains an important issue. The aim of this study was to assess the value of a new discongruence index, to predict PPM after TAVR.Methods and Results: A total of 185 patients with severe aortic stenosis who underwent TAVR with the Edwards Sapien prosthesis or CoreValve Revalving system were included (Edwards valve, n=119; Core Valve Revalving system, n=66). Discongruence index was calculated pre-procedurally as the ratio of selected transcatheter valve size (mm) to body surface area (cm²). PPM was defined as effective orifice area (EOA) ≤0.85 cm²/m² on transthoracic echocardiography before hospital discharge. Mean age was 82±5 years and 72 patients (38.9%) were men. The overall incidence of post-TAVR PPM was 35.1% (n=65). Discongruence index correlated with post-TAVR indexed EOA (y=0.18+0.057x; P<0.001). On multivariate logistic regression analysis, discongruence index was the only independent predictor of post-TAVR PPM (OR, 0.15; 95% CI: 0.03-0.66; P=0.012), and the area under the receiver operating characteristic curve was 0.62 (95% CI: 0.54-0.70, P=0.003), with an optimal cut-off point of 15.02 (sensitivity, 86.2%; specificity, 72.5%; positive predictive value, 74.3%; negative predictive value, 83.4%).

CONCLUSIONS

The new discongruence index may be useful tool to predict PPM after TAVR.

Structural valve deterioration in the Mitroflow biological heart valve prosthesis

OBJECTIVES

Concern has been raised regarding the long-term durability of the Mitroflow biological heart valve prosthesis. Our aim was to assess the incidence of structural valve degeneration (SVD) for the Mitroflow bioprosthesis in a nationwide study in Denmark including all patients alive in Denmark who had received a Mitroflow aortic bioprosthesis since 2000.

METHODS

Patients alive in Denmark with a Mitroflow bioprosthesis implanted since January 2000 were invited to participate in a nationwide cross-sectional study with a predefined definition of SVD. Of 1552 patients, 861 patients had died and 47 patients had been reoperated with 40 reoperations due to SVD. The remaining 644 patients were invited for evaluation; 574 patients accepted and were evaluated for SVD. The incidence of SVD was calculated using competing risk regression analysis with death as the competing event.

RESULTS

A total of 173 patients were diagnosed with SVD by echocardiography. Of these, 64 (11%) patients had severe SVD and 109 (19%) patients moderate SVD. Severe SVD was associated with the age of the prosthesis and small prosthesis size [Size 21: hazard ratio (95% confidence interval, CI) 2.72 (0.97-8.56), P = 0.06; Size 19: 6.26 (1.63-24.06), P = 0.008]. The cumulative incidences of reoperation or severe SVD at Year 9 were 12.5% for Size 19, 7.6% for Size 21 and 3.1 (1.2-6.4)% for Size 23. Median survival in patients with prosthesis Sizes 23-29 was 6.4 (95% CI 5.7-7.0) years, with Size 21 it was 6.5 (95% CI 5.9-7.1) years and with Size 19 it was 6.9 (95% CI 5.7-8.2) years (P = 0.78).

CONCLUSIONS

The incidence of undetected severe SVD was as high as the incidence of operated SVD. The overall risk for SVD is high for the Mitroflow bioprosthesis, especially if the prosthesis is small and older than 5 years.

Effect of prosthesis patient mismatch in mitral position on pulmonary hypertension

OBJECTIVES

Pulmonary arterial hypertension (PAH) is associated with poor outcome after mitral valve replacement (MVR). We proposed to evaluate the effect of valve prosthesis patient mismatch (PPM) on pulmonary arterial (PA) pressure following MVR.

METHODS

Five hundred patients who have undergone MVR were studied retrospectively. Postoperative PA systolic pressure (PASP) measured 6 months postoperatively by Doppler echocardiography was compared with preoperative values. PASP ≥ 40 mmHg was defined as PAH. Mitral valve effective orifice area was calculated by the continuity equation and indexed for body surface area. PPM was defined as indexed effective orifice area ≤ 1.2 cm2/m2. A multivariate model was constructed to ascertain the independent determinants of systolic PA pressure. Also, a propensity score model was constructed to overcome the baseline differences between the PPM and no PPM groups.

RESULTS

The incidence of PPM in this study was 37.2%. The average postoperative PASPs were 30.49 and 42.35 mmHg in the no PPM and PPM groups, respectively; (P < 0.001). Regression of PAH in the PPM and no PPM groups was 76.26% and 20.64%, respectively; (P < 0.001). The indexed effective orifice area correlated well with postoperative PASP (r = 0.71). The overall survival and freedom from cardiac death at 10 years were 79.8% and 85.3%; and at 20 years were 66.5% and 74.3%, respectively. Both, overall survival and the freedom from cardiac death were higher in the no PPM group than in the PPM group; (P < 0.001). Propensity score matching analysis yielded 112 pairs of the PPM and no PPM cohorts, which revealed higher overall survival and freedom from cardiac death in the no PPM group; (P = 0.028 and 0.012, respectively).

CONCLUSIONS

Mitral PPM is an independent predictor of persistent PAH after MVR along with associated morbidity and reduced survival.

The Prognostic Significance of Patient-Prosthesis Mismatch after Aortic Valve Replacement

Patient-prosthesis mismatch (PPM) is a controversial issue in current clinical practice. PPM has been reported to have a negative impact on patients’ prognosis after aortic valve replacement in several studies, showing increased all-cause and cardiac mortality. Moreover, a close relationship has recently been described between PPM and structural valve deterioration in biological prostheses. In patients at risk for PPM, several issues should be considered, and in the current era of cardiac surgery, preoperative planning should consider the different types of valves available and the various surgical techniques that can be used to prevent PPM. The present paper analyses the state of the art of the PPM issue.

Surgical Enlargement of the Aortic Root Does Not Increase the Operative Risk of Aortic Valve Replacement

Background:

Surgical aortic root enlargement (ARE) during aortic valve replacement (AVR) allows for larger prosthesis implantation and may be an important adjunct to surgical AVR in the transcatheter valve-in-valve era. The incremental operative risk of adding ARE to AVR has not been established. We aimed to evaluate the early outcomes of patients undergoing AVR with or without ARE.

Methods:

From January 1990 to August 2014, 7039 patients underwent AVR (AVR+ARE, n=1854; AVR, n=5185) at a single institution. Patients with aortic dissection and active endocarditis were excluded. Mean age was 65±14 years and 63% were male. Logistic regression and propensity score matching were used to adjust for unbalanced variables in group comparisons.

Results:

Patients undergoing AVR+ARE were more likely to be female (46% versus 34%, P <0.001) and had higher rates of previous cardiac surgery (18% versus 12%, P <0.001), chronic obstructive pulmonary disease (5% versus 3%, P =0.004), urgent/emergent status (6% versus 4%, P =0.01), and worse New York Heart Association status ( P <0.001). Most patients received bioprosthetic valves (AVR+ARE: 73.4% versus AVR: 73.3%, P =0.98) and also underwent concomitant cardiac procedures (AVR+ARE: 68% versus AVR: 67%, P =0.31). Mean prosthesis size implanted was slightly smaller in patients requiring AVR+ARE versus AVR (23.4±2.1 versus 24.1±2.3, P <0.001). In-hospital mortality was higher after AVR+ARE (4.3% versus 3.0%, P =0.008), although when the cohort was restricted to patients undergoing isolated aortic valve replacement with or without root enlargement, mortality was not statistically different (AVR+ARE: 1.7% versus AVR: 1.1%, P =0.29). After adjustment for baseline characteristics, AVR+ARE was not associated with an increased risk of in-hospital mortality when compared with AVR (odds ratio, 1.03; 95% confidence interval, 0.75–1.41; P =0.85). Furthermore, AVR+ARE was not associated with an increased risk of postoperative adverse events. Results were similar if propensity matching was used instead of multivariable adjustments for baseline characteristics.

Conclusions:

In the largest analysis to date, ARE was not associated with increased risk of mortality or adverse events. Surgical ARE is a safe adjunct to AVR in the modern era.

Can Perceval sutureless valve reduce the rate of patient-prosthesis mismatch?†

OBJECTIVES

The aim of this study is to compare the theoretical incidence of patient-prosthesis mismatch (PPM) in patients undergoing a sutureless or a sutured aortic valve replacement using an exact statistical matching.

METHODS

Between May 2012 and March 2016, 65 patients with severe symptomatic aortic stenosis underwent a sutureless aortic valve replacement with the Perceval bioprosthesis in 2 centres. Moreover, 177 aortic valve replacements with conventional sutured bioprosthesis were performed between August 2003 and September 2015. Perceval and sutured patients were 1:1 exactly matched for sex and body surface area (BSA), resulting in 62 couples (sutureless: BSA 1.77 ± 0.16 m 2 , female 62.9% vs sutured: BSA 1.77 ± 0.15 m 2 , female 62.9%).

RESULTS

After matching, the indexed effective orifice area was 1.50 ± 0.18 cm 2 /m 2 and 0.81 ± 0.19 cm 2 /m 2 in the sutureless and the sutured group, respectively ( P  < 0.001). No PPM occurred in patients who received a Perceval bioprosthesis ( n  = 62). In the sutured group ( n  = 62), 38 patients (61.3%) developed a PPM, which was moderate in 41.9% ( n  = 26) and severe in 19.4% ( n  = 12) ( P  < 0.001).

CONCLUSIONS

The indexed effective orifice area of the sutureless group was significantly larger than in the sutured one. The incidence of PPM with the conventional sutured biprosthesis was 61.3%, while it decreases to 0% in the sutureless group. No PPM was reported in the sutureless valve group. Therefore, the Perceval sutureless valve provides larger effective orifice areas compared to the sutured conventional bioprosthesis and could be considered as a good option to reduce the risk of a PPM.

Early and mid-term haemodynamic performance and clinical outcomes of St. Jude Medical Trifecta™ valve

Background

New models of aortic bioprostheses have proven excellent early haemodynamic profile, but their mid and long-term performance warrants further systematic assessment. The aim of this study is to report clinical and haemodynamic performance of St. Jude Medical Trifecta bioprosthesis during 5 years of implantation.

Methods

We performed a single centre, retrospective, observational and descriptive study including all 556 individuals who underwent aortic valve replacement (AVR) with the Trifecta bioprosthesis (between July of 2011 and June of 2016). Survival and re-intervention were censored in February 2017. Postoperative ambulatory echocardiographic data was available for 490 patients. A complete clinical follow-up was available in 463 individuals (mean follow-up time, 27±17 months).

Results

In our sample the mean age was 73±9 years, 57.6% were male and median European System for Cardiac Operative Risk Evaluation (EuroSCORE) II was 2.9 (interquartile range, 1.6-5.8). There were 301 (54.1%) combined procedures, mostly coronary artery bypass grafting in 170 (30.6%). Overall 30-days mortality was 5.4% (n=30) and cumulative survival at 5-years was 72.3%. There were 23 (4.3%) permanent pacemaker implantations. During follow-up, 5 (0.9%) patients presented non-structural valve dysfunction (NSVD) and 4 (0.8%) underwent reoperation due to prosthesis endocarditis. At the first ambulatory evaluation transvalvular mean gradient and effective orifice area (EOA) were 10.9±4.1 mmHg and 2.0±0.5 cm², respectively. Severe patient-prosthesis mismatch (PPM) was observed in 5 (1.1%) individuals and moderate in 52 (11.3%).

Conclusions

In a "real-world" clinical setting, our findings support the good overall mid-term haemodynamic and safety profile of the Trifecta bioprosthesis.

Incidence, predictors and clinical outcomes of residual stenosis after aortic valve-in-valve

Objective

We aimed to analyse the incidence of prosthesis–patient mismatch (PPM) and elevated gradients after aortic valve in valve (ViV), and to evaluate predictors and associations with clinical outcomes of this adverse event.

Methods

A total of 910 aortic ViV patients were investigated. Elevated residual gradients were defined as ≥20 mm Hg. PPM was identified based on the indexed effective orifice area (EOA), measured by echocardiography, and patient body mass index (BMI). Moderate and severe PPM (cases) were defined by European Association of Cardiovascular Imaging (EACVI) criteria and compared with patients without PPM (controls).

Results

Moderate or greater PPM was found in 61% of the patients, and severe in 24.6%. Elevated residual gradients were found in 27.9%. Independent risk factors for the occurrence of lower indexed EOA and therefore severe PPM were higher gradients of the failed bioprosthesis at baseline (unstandardised beta −0.023; 95% CI −0.032 to –0.014; P<0.001), a stented (vs a stentless) surgical bioprosthesis (unstandardised beta −0.11; 95% CI −0.161 to –0.071; P<0.001), higher BMI (unstandardised beta −0.01; 95% CI −0.013 to –0.007; P<0.001) and implantation of a SAPIEN/SAPIEN XT/SAPIEN 3 transcatheter device (unstandardised beta −0.064; 95% CI −0.095 to –0.032; P<0.001). Neither severe PPM nor elevated gradients had an association with VARC II-defined outcomes or 1-year survival (90.9% severe vs 91.5% moderate vs 89.3% none, P=0.44).

Conclusions

Severe PPM and elevated gradients after aortic ViV are very common but were not associated with short-term survival and clinical outcomes. The long-term effect of poor post-ViV haemodynamics on clinical outcomes requires further evaluation.

Hemodynamics of Pericardial Aortic Valves: Contemporary Stented versus Stentless Valves in a Matched Comparison

PURPOSE

Hemodynamic performance of aortic valve bioprostheses is essential for reliable function and durability. So far, the supra-annularly implanted stentless Sorin Freedom Solo (SFS) demonstrated unsurpassed hemodynamic properties. As contemporary stented and externally mounted pericardial bioprostheses, like the Labcor Dokimos Plus (LDP), also improve hemodynamic performance, these types of valves were compared in this study.

METHODS

A total of 218 patients, who underwent aortic valve replacement with the LDP or the SFS, were matched retrospectively 1:1 on variables affecting hemodynamic measurements: implanted valve size, age, sex, and body surface area (BSA). With matching tolerance for valve size and gender of 0%, for age and BSA of 5%, 57 patient-pairs were yielded. Operative data, clinical, and hemodynamic outcome were analyzed.

RESULTS

Except for slightly higher left ventricular function and lower procedural times in the SFS group, preoperative, operative, and postoperative characteristics of patient-pairs did not differ significantly. Mean pressure gradients, effective orifice areas (EOAs), and indexed EOAs were comparable. Corresponding to valve sizes of 21, 23, 25, and 27 mm, the indexed EOAs of the LDP and SFS prostheses were 1.08 ± 0.33, 0.92 ± 0.19, 0.93 ± 0.24, 0.99 ± 0.13 cm²/m² and 0.81 ± 0.13, 0.92 ± 0.28, 0.95 ± 0.20, 1.04 ± 0.27 cm²/m², respectively.

CONCLUSION

Contemporary stented and stentless pericardial bioprostheses showed excellent hemodynamic properties without significant differences in EOAs and indexed EOAs.

Postoperative Reverse Remodeling and Symptomatic Improvement in Normal-Flow Low-Gradient Aortic Stenosis After Aortic Valve Replacement

Background—

Severe aortic stenosis (AS) most often presents with reduced aortic valve area (<1 cm 2 ), normal stroke volume index (≥35 mL/m 2 ), and either high mean gradient (≥40 mm Hg; normal-flow high-gradient AS) or low mean gradient (normal-flow low-gradient [NFLG] AS). The benefit of aortic valve replacement (AVR) among NFLG patients is controversial. We compared the impact of NFLG condition on preoperative left ventricular (LV) remodeling and myocardial fibrosis and postoperative remodeling and symptomatic benefit.

Methods and Results—

Eighty-seven consecutive patients with reduced aortic valve area and normal stroke volume index undergoing AVR underwent echocardiography, magnetic resonance imaging, a 6-minute walk test, and measurement of natriuretic peptides before and 1 year after AVR. Myocardial fibrosis was assessed from magnetic resonance imaging. Patients were stratified as NFLG or normal-flow high-gradient. In total, 33 patients (38%) had NFLG. Before AVR, they were characterized by similar symptom burden but less severe AS measured by aortic valve area index (0.50±0.09 versus 0.40±0.08 cm 2 /m 2 ; P <0.0001), lower LV mass index (74±18 versus 90±26 g/m 2 ; P =0.01), but the same degree of myocardial fibrosis. After AVR, NFLG had a smaller reduction in LV mass index (−3±10 versus −±18 g/m 2 ; P <0.0001) and a smaller reduction in natriuretic peptides. Both groups experienced similar symptomatic improvement. Normal-flow high-gradient condition independently predicted change in LV mass index.

Conclusions—

Patients with NFLG had less severe AS and LV remodeling than patients with normal-flow high-gradient. Furthermore, NFLG patients experienced less reverse remodeling but the same symptomatic benefit.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT02316587.

Efficacy and safety of transcatheter aortic valve implantation with Edwards SAPIEN 3 and XT in smaller Asian anatomy

We aimed to compare the efficacy and safety of transcatheter aortic valve implantation (TAVI) using Edwards SAPIEN 3 (S3) valve and SAPIEN XT) in smaller anatomy. The new generation S3 TAVI device has been used worldwide; however, its efficacy and safety in smaller Asian anatomy remain unknown. Between February 2014 and March 2017, 166 consecutive patients (S3, 54; XT, 112) were treated with balloon-expandable TAVI in a single center and their outcomes were analyzed. Median patient age was 85 (range: 81-88) years and mean body surface area was 1.41 ± 0.15 m². A 23-mm size valve was used in S3 and XT groups (70 vs. 62%, p = 0.224). The transfemoral approach was more frequently used in the S3 than in the XT group (96 vs. 72%, p < 0.001). Although, the minimal luminal diameter of the femoral artery was smaller in the S3 group (5.9 vs. 6.4 mm, p = 0.001), the rates of major (2 vs. 11%, p = 0.226) and minor (11 vs. 5%, p = 0.107) vascular complications did not increase. The frequency of paravalvular leaks (PVL) ≥ 2 was significantly reduced in the S3 group (11 vs. 61%, p < 0.001); however, pre- (24 vs. 91%, p < 0.001) and post- (4 vs. 19%, p < 0.001) dilatations were less frequently performed. Pacemaker implantation incidence did not increase (4 vs. 5%, p = 1.0) and peak velocity of the transcatheter heart valve was significantly higher in the S3 group (2.3 vs. 2.2 m/s, p = 0.046). Device success was high (89 vs. 93%, p = 0.387) while the 30-day all-cause mortality was low (2 vs. 1%, p = 0.583) in both groups. TAVI with the S3 device was safe and effective, with low incidence of vascular complications and reduced PVL, in smaller body-sized Asians.

Incidence, Predictors and Outcome of Prosthesis-Patient Mismatch after Transcatheter Aortic Valve Replacement: a Systematic Review and Meta-analysis

The aim of this study was to investigate the incidence, predictors and outcome of prosthesis-patient mismatch (PPM) following transcatheter aortic valve replacement (TAVR). A total of 30 articles incorporating 4,691 patients were identified. The pooled incidences of overall, moderate and severe PPM following TAVR were 33.0%, 25.0% and 11.0% respectively. Medtronic CoreValve (MCV) had lower incidence of overall (32% vs: 40%, P < 0.0001) and moderate (23% vs 32%, P < 0.0001) than Edwards Sapien (ESV). PPM was associated with a younger age, smaller annulus diameter and lower left ventricular ejection fraction in comparison with those patients without PPM. Post-dilation (OR, 0.51, 95% CI, 0.38 to 0.68, p < 0.001) during TAVR would decrease the incidence of PPM. Although PPM was common after TAVR, no significant differences were observed both in short- and mid-term all-cause mortality (30 day: OR: 1.1, 95% CI, 0.70 to 1.73 and 2 year: OR: 1.01, 95% CI, 0.74 to 1.38) between patients with PPM and those without PPM. In conclusion, despite being common after TAVR, the incidence of PPM was lower than that of surgical aortic valve replacement (SAVR) and decreased with the experience accumulating, and PPM was not seen to impact on short- and mid-term survival, regardless of its magnitude.

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.

Hemodynamic Evaluation of a Biological and Mechanical Aortic Valve Prosthesis Using Patient-Specific MRI-Based CFD

Modeling different treatment options before a procedure is performed is a promising approach for surgical decision making and patient care in heart valve disease. This study investigated the hemodynamic impact of different prostheses through patient-specific MRI-based CFD simulations. Ten time-resolved MRI data sets with and without velocity encoding were obtained to reconstruct the aorta and set hemodynamic boundary conditions for simulations. Aortic hemodynamics after virtual valve replacement with a biological and mechanical valve prosthesis were investigated. Wall shear stress (WSS), secondary flow degree (SFD), transvalvular pressure drop (TPD), turbulent kinetic energy (TKE), and normalized flow displacement (NFD) were evaluated to characterize valve-induced hemodynamics. The biological prostheses induced significantly higher WSS (medians: 9.3 vs. 8.6 Pa, P = 0.027) and SFD (means: 0.78 vs. 0.49, P = 0.002) in the ascending aorta, TPD (medians: 11.4 vs. 2.7 mm Hg, P = 0.002), TKE (means: 400 vs. 283 cm² /s² , P = 0.037), and NFD (means: 0.0994 vs. 0.0607, P = 0.020) than the mechanical prostheses. The differences between the prosthesis types showed great inter-patient variability, however. Given this variability, a patient-specific evaluation is warranted. In conclusion, MRI-based CFD offers an opportunity to assess the interactions between prosthesis and patient-specific boundary conditions, which may help in optimizing surgical decision making and providing additional guidance to clinicians.

Impact of prosthesis-patient mismatch on short-term outcomes after aortic valve replacement: a retrospective analysis in East China

BACKGROUND

Prosthesis-patient mismatch (PPM) may affect the clinical outcomes of patients undergoing aortic valve replacement (AVR). We aimed to determine the incidence of PPM, its effect on short-term mortality, and the factors contributing to PPM in China.

METHODS

We retrospectively examined all consecutive patients with isolated or concomitant AVR at our hospital between January 1, 2013 and December 31, 2015. PPM was defined as an effective orifice area index (EOAi) of ≤ 0.85 cm²/m². The baseline, echocardiographic, operative, and outcome data of all patients were collected from the national database.

RESULTS

A total of 869 patients were included in the study. PPM was detected in 15.9% (138/869) of the patients. Four patients (0.5%) met the criteria for severe PPM. Patients with PPM were older and had a higher prevalence of diabetes, coronary heart disease, aortic stenosis (AS), and preoperative left ventricular dysfunction but a lower incidence of smoking history and aortic regurgitation. Logistic regression analysis showed that female gender (P < 0.001), AS (P = 0.014), higher body mass index (BMI) (P < 0.001), and bioprosthesis (P < 0.001) were independent predictors of PPM. We also found that PPM (P = 0.005) was associated with 30-day all-cause mortality, along with smoking history (P = 0.001) and low preoperative left ventricular ejection fraction (LVEF) (P = 0.004).

CONCLUSIONS

PPM is associated with high short-term mortality after AVR in China. Female gender, aortic stenosis, bioprosthesis, and high BMI are risk factors for the incidence of PPM.