Effect of the valve design on pressure drop, pressure recovery, and spatial positioning of vena contracta

BACKGROUND

Bioprostheses are complex structures and yield a very complex fluid dynamics. Hence, it can be hypothesized that prosthesis structural characteristics affect the position of the vena contracta and, consequently, influences the pattern and the extent of pressure recovery downstream from the vena contracta.

MATERIALS AND METHODS

The study was performed on pericardial aortic prostheses, specifically Crown 21 and 23 (LivaNova PLC, UK), Trifecta 19 and 21 (Edwards Lifescience, USA), and Magna 19 and 21(Abbott, USA), tested in an "ad hoc" devised steady flow loop circuit at four flow rates (10, 15, 20, and 25 L/min). Fluid dynamic quantities were obtained by direct pressure measurement and Doppler interrogation.

RESULTS

Pressure drop at 25 L/min flow rate was 26.5 ± 0.3 mm Hg and 14.9 ± 0.1 mm Hg for the Trifecta 19 and 21, 37.1 ± 1.0 mm Hg and 27.3 ± 0.4 mm Hg for the Magna 19 and 21, and 36.6 ± 1.0 mm Hg and 22.7 ± 0.1 mm Hg for Crown 21 and 23, respectively. The vena contracta was shorter for Trifecta compared with the Magna and the Crown in which it developed further downstream and as far as 1 cm from the valve leaflets fringes. The pressure recovery was 54% ± 1% for Trifecta 21, 39% ± 1% for Magna 21, and 41% ± 2% for Crown 23 with different patterns.

CONCLUSION

The design of bioprosthesis affects pressure recovery and the position of the vena contracta. The different patterns of pressure recovery might have clinical impact.

Long-Term Comparison Between Pulmonary Homograft Versus Bioprosthesis for Pulmonary Valve Replacement in Tetralogy of Fallot

Background

Tetralogy of Fallot repair results in late occurrence of pulmonary regurgitation, which requires pulmonary valve replacement in a large proportion of patients. Both homografts and bioprostheses are used for pulmonary valve replacement as uncertainty remains on which prosthesis should be considered superior. We performed a long‐term imaging and clinical comparison between these 2 strategies.

Methods and Results

We compared echocardiographic and clinical follow‐up data of 209 patients with previous tetralogy of Fallot repair who underwent pulmonary valve replacement with homograft (n=75) or bioprosthesis (n=134) between 1995 and 2018 at a tertiary hospital. The primary end point was the composite of pulmonary valve replacement reintervention and structural valve deterioration, defined as a transpulmonary pressure decrease ≥50 mm Hg or pulmonary regurgitation degree of ≥2. Mixed linear model and Cox regression model were used for comparisons. Echocardiographic follow‐up duration was longer in the homograft group (8 [interquartile range, 4–12] versus 4 [interquartile range, 3–6] years; P<0.001). At the latest echocardiographic follow‐up, homografts showed a significantly lower transpulmonary systolic pressure decrease (16 [interquartile range, 12–25] mm Hg) when compared with bioprostheses (28 [interquartile range, 18–41] mm Hg; mixed model P<0.001) and a similar degree of pulmonary regurgitation (degree 0‐4) (1 [interquartile range, 0–2] versus 2 [interquartile range, 0–2]; mixed model P=0.19). At 9 years, freedom from structural valve deterioration and reintervention was 81.6% (95% CI, 71.5%–91.6%) versus 43.4% (95% CI, 23.6%–63.2%) in the homograft and bioprosthesis groups, respectively (adjusted hazard ratio, 0.27; 95% CI, 0.13–0.55; P<0.001).

Conclusions

When compared with bioprostheses, pulmonary homografts were associated lower transvalvular gradient during follow‐up and were associated with a significantly lower risk of reintervention or structural valve degeneration.

Diepoxy- Versus Glutaraldehyde-Treated Xenografts: Outcomes of Right Ventricular Outflow Tract Reconstruction in Children

BACKGROUND

Xenografts used for right ventricular outflow tract (RVOT) reconstruction are typically treated with glutaraldehyde. However, potential benefit of epoxy treatment was demonstrated in experimental studies. We aimed to compare diepoxy-treated bovine pericardial valved conduits (DE-PVCs) and glutaraldehyde-treated bovine pericardial valved conduits (GA-PVCs) for RVOT reconstruction in pediatric patients.

METHODS

Between 2002 and 2017, 117 patients underwent RVOT reconstruction with PVC in single center: DE-PVC group, n = 39; and GA-PVC group, n = 78. After performing propensity score analysis (1:1) for the entire sample, 29 patients from the DE-PVC group were matched with 29 patients from the GA-PVC group.

RESULTS

There were no conduit-related deaths. In the DE-PVC group, the freedom from conduit failure was 90.9% at four years and 54.3% at eight years postoperatively. In the GA-PVC group, it was 46.3% and 33.1%, respectively. The difference was significant (P = .037). Conduit failure was typically caused by stenosis in both groups. In the DE-PVC group, the main cause of stenosis was xenograft calcification (27.6%); while in the GA-PVC group, it was mostly due to neointimal proliferation (25.0%) and, less often, calcification (14.3%). Conduit thrombosis was the cause of replacement in 6.9% of patients from the GA-PVC group.

CONCLUSIONS

Diepoxy-treated bovine pericardial valved conduit is a suitable alternative to GA-PVC for RVOT reconstruction in pediatric patients. Diepoxy-treated bovine pericardial valved conduits may be less prone to conduit failure and more resistant to neointimal proliferation and conduit thrombosis than GA-PVCs.

Systematic review and meta-analysis of surgical outcomes comparing mechanical valve replacement and bioprosthetic valve replacement in infective endocarditis

Background

Infective endocarditis (IE) is an infection involving either native or prosthetic heart valves, the endocardial surface of the heart or any implanted intracardiac devices. IE is a rare condition affecting 3-15 patients per 100,000 population. In-hospital mortality rates in patients with IE remain high at around 20% despite treatment advances. There is no consensus recommendation favoring either bioprosthetic valve or mechanical valve implantation in the setting of IE; patient age, co-morbidities and preferences should be considered selecting the replacement prosthesis.

Methods

A systematic review and meta-analysis of studies reporting the outcomes of patients undergoing bioprosthetic or mechanical valve replacement for infective endocarditis with data extracted for overall survival, valve reinfection rates and valve reoperation.

Results

Eleven relevant studies were identified, with 2,336 patients receiving a mechanical valve replacement and 2,057 patients receiving a bioprosthetic valve replacement. There was no significant difference for overall survival between patients treated with mechanical valves and those treated with bioprosthetic valves [hazard ratio (HR) 0.94, 95% confidence interval (CI): 0.73-1.21, P=0.62]. There was no significant difference in reoperation rates between patients treated with a bioprosthetic valve and those treated with a mechanical valve (HR 0.82, 95% CI: 0.34-1.98, P=0.66) and there was no significant difference in the rate of valve reinfection rates (HR 0.95, 95% CI: 0.48-1.89, P=0.89).

Conclusions

The presence of infective endocarditis alone should not influence the decision of which type of valve prosthesis that should be implanted. This decision should be based on patient age, co-morbidities and preferences.

Simultaneous Transfemoral Mitral and Tricuspid Valve in Ring Implantation: First Case Report with Edwards Sapien 3 Valve

Patients with advanced valvular disease may be at high or prohibitive risk for surgical management. We describe a patient with previous mitral and tricuspid valve repair and recurrent admissions for New York Heart Association Class IV heart failure symptoms due to severe mitral stenosis and severe tricuspid regurgitation. Due to her comorbidities and two previous sternotomies, the patient was at high risk for surgery. We performed a simultaneous transfemoral mitral and tricuspid valve-in-ring implantation. This is the first report of its kind using a Sapien 3 valve (Edwards Lifesciences).

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.

Early results of a modified biological valved conduit for the Bentall procedure

INTRODUCTION

Few bioprosthetic valved conduits for aortic root surgery are commercially available. Long-term Warfarin therapy (mechanical), potential root calcification (xeno- or homograft valves), and the need for additional ascending aorta grafts are concerns associated with currently used valved conduits. A simplified, self-assembled bioroot conduit comprising currently available materials that facilitates future intervention and exhibits advantages of a bioprosthesis was used.

METHODS

From November 2015 to January 2017, 17 consecutive patients underwent urgent or elective aortic root surgery. A bioroot conduit, constructed using 28 or 30 mm of sinus of Valsalva Gelweave tube graft and a 3 to 5 mm smaller bioprosthetic Trifecta valve sewn into the sinus of Valsalva base, was preconstructed in the operating room before sternotomy. The size of the valved conduit was based on the distal ascending aorta or proximal arch and not aortic annular dimension. The bioroot was sutured to the native aortic annulus at the level of the bottom skirt of the Valsalva graft without contacting the sewing cuff of the bioprosthetic valve.

RESULTS

All patients survived the operation and were discharged home without long-term anticoagulation therapy. The mean age was 65 ± 12 years, and 13 patients were male. The cardiopulmonary bypass duration was 169 ± 84 minutes, and the cross-clamp (XC) duration was 110 ± 32 minutes. The operation was elective in 12 patients, urgent/emergent in five, and redo in three.

CONCLUSION

A simplified self-assembled bioroot Bentall conduit is appropriate for aortic root reconstruction. Use of a patient-tailored valved conduit will not prolong the cardiac ischemic time and will facilitate future valve replacement.

Conventional redo biological valve replacement over 20 years: Surgical benchmarks should guide patient selection for transcatheter valve-in-valve therapy

OBJECTIVES

Although primary transcatheter valve interventions have demonstrated acceptable early- and intermediate-term outcomes, data are lacking to guide patient selection for transcatheter valve-in-valve therapy. Furthermore, very few surgical benchmarks have been established for repeat conventional biological valve replacement to refine momentum for broad application of transcatheter intervention for a degenerated bioprosthesis.

METHODS

From January 1993 to July 2014, 694 patients underwent repeat biological valve replacement at our clinic. Median age at repeat operation was 71 years (range, 26-95 years) and there were 437 men (63%). Hypertension was present in 453 patients (65%), diabetes in 128 patients (18%), prior myocardial infarction in 85 patients (12%), and prior stroke in 81 patients (12%). Prior coronary bypass grafting was performed in 212 patients (31%). Median left ventricular ejection fraction was 41% (range, 20-61) and New York Heart Association functional class III or IV was present in 529 patients (76%).

RESULTS

Biological valve re-replacement included most commonly aortic valve in 464 patients (67%) and mitral valve in 170 (24%). Concomitant coronary bypass grafting was performed in 134 patients (19%). Mortality at 30 days occurred in 56 patients (8%). Multivariable analysis with backward stepwise regression identified New York Heart Association functional class (per 1 increment) (hazard ratio, 2.1; 95% confidence interval, 1.06-4.3; P = .03) and prior coronary bypass grafting (hazard ratio, 3.5; 95% confidence interval, 1.2-10.9; P = .03) as independent predictors of early death. Patients with the combination of prior coronary bypass grafting and New York Heart Association functional class III or IV accounted for 26 out of 56 early deaths (46%) and in the absence of this combination, early death in the cohort was 30 out of 694 (4%). Follow-up was available in 602 out of 638 early survivors (94%) for a median of 45 months (range, 1 month-23.4 years). Survival at 5 and 10 years was 63% and 34%, respectively. For patients who died during follow-up, 2-dimensional scatter plots demonstrate durable length of postoperative survival (median, 5.5 years; maximum, 22 years).

CONCLUSIONS

In a large population of patients undergoing repeat biological valve replacement, prior coronary bypass grafting and advanced New York Heart Association functional class were associated with increased 30-day mortality, with the remaining population having a low 30-day mortality of 4%. This study could serve as a surgical benchmark to guide patient selection for transcatheter valve-in-valve technology rather than employing a broader application of these techniques to those who may otherwise have low early risk of mortality and durable long-term survival after conventional valve surgery.

Prosthetic Aortic Valves: Challenges and Solutions

Aortic Valve Disease (AVD) is the most common Valvular Heart Disease (VHD), affecting millions of people worldwide. Severe AVD is treated in most cases with prosthetic aortic valve replacement, which involves the substitution of the native aortic valve with a prosthetic one. In this review we will discuss the different types of prosthetic aortic valves available for implantation and the challenges faced by patients, medical doctors, researchers and manufacturers, as well as the approaches that are taken to overcome them.

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.

Two-Year Outcomes in Patients With Severe Aortic Valve Stenosis Randomized to Transcatheter Versus Surgical Aortic Valve Replacement: The All-Comers Nordic Aortic Valve Intervention Randomized Clinical Trial

BACKGROUND

The Nordic Aortic Valve Intervention (NOTION) trial was the first to randomize all-comers with severe native aortic valve stenosis to either transcatheter aortic valve replacement (TAVR) with the CoreValve self-expanding bioprosthesis or surgical aortic valve replacement (SAVR), including a lower-risk patient population than previous trials. This article reports 2-year clinical and echocardiographic outcomes from the NOTION trial.

METHODS AND RESULTS

Two-hundred eighty patients from 3 centers in Denmark and Sweden were randomized to either TAVR (n=145) or SAVR (n=135) with follow-up planned for 5 years. There was no difference in all-cause mortality at 2 years between TAVR and SAVR (8.0% versus 9.8%, respectively; P=0.54) or cardiovascular mortality (6.5% versus 9.1%; P=0.40). The composite outcome of all-cause mortality, stroke, or myocardial infarction was also similar (15.8% versus 18.8%, P=0.43). Forward-flow hemodynamics were improved following both procedures, with effective orifice area significantly more improved after TAVR than SAVR (effective orifice area, 1.7 versus 1.4 cm(2) at 3 months). Mean valve gradients were similar after TAVR and SAVR. When patients were categorized according to Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) (<4% versus ≥4%), there was no statistically significant difference for TAVR and SAVR groups in the composite outcome for low-risk (14.7%, 95% confidence interval, 8.3-21.2 versus 16.8%; 95% confidence interval, 9.7-23.8; P=0.58) or intermediate-risk patients (21.1% versus 27.1%; P=0.59).

CONCLUSIONS

Two-year results from the NOTION trial demonstrate the continuing safety and effectiveness of TAVR in lower-risk patients. Longer-term data are needed to verify the durability of this procedure in this patient population.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01057173.

One-year outcomes after rapid-deployment aortic valve replacement

OBJECTIVE

The goals of rapid-deployment aortic valve replacement include facilitation of minimally invasive surgery and reduced aortic crossclamp time. We report the short-term outcomes of a series of 493 patients undergoing rapid-deployment aortic valve replacement with the EDWARDS INTUITY valve system (Edwards Lifesciences, LLC, Irvine, Calif).

METHODS

Assessing Standard oF Care and Clinical Outcomes UsiNg the EDWARDS INTUITY VAlve SysTem in a European multI-center, Active, pOst-market surveillaNce Study was a prospective, multicenter (n = 26) European registry designed to evaluate the safety and performance of the valve system. During rapid-deployment aortic valve replacement, device technical success and crossclamp time were assessed. Procedural outcomes, hemodynamic performance, and various adverse events and clinical outcomes were evaluated up to 2 years.

RESULTS

Between 2012 and 2014, 493 of 517 enrolled patients successfully received implants with the study valve (95.4% technical success). Mean crossclamp times for 163 full sternotomies, 128 mini-upper sternotomies, and 36 right anterior thoracotomies isolated aortic valve replacements were 47.3, 52.0, and 73.3 minutes, respectively. Mean follow-up was 1.8 years, with 870 total patient-years of follow-up. Mean effective orifice area increased from 0.72 (baseline) to 1.88 cm², and mean pressure gradient decreased from 47.6 to 9.6 mm Hg (1 year). Mean effective orifice area index increased (0.39-1.01 cm²/m²), and 28 of 287 patients (9.8%) exhibited severe prosthesis-patient mismatch at 1 year. After 1 year, 68.1% and 21.7% of patients were in New York Heart Association class I and II, respectively. Freedom from death, major bleeding, major perivalvular leak, reoperation, and device explant at 1 year were 0.935, 0.939, 0.976, 0.975, and 0.983, respectively.

CONCLUSIONS

These results demonstrate commendable safety and performance of the test valve system over the short term in a broad European setting.

Technical pitfalls and tips for the valve-in-valve procedure

Transcatheter aortic valve implantation (TAVI) has emerged as a viable treatment modality for patients with severe aortic valve stenosis and multiple co-morbidities. More recent indications include the use of transcatheter heart valves (THV) to treat degenerated bioprosthetic surgical heart valves (SHV), which are failing due to stenosis or regurgitation. Valve-in-valve (VIV) procedures in the aortic position have been performed with a variety of THV devices, although the balloon-expandable SAPIEN valve platform (Edwards Lifesciences Ltd, Irvine, CA, USA) and self-expandable CoreValve platform (Medtronic Inc., MN, USA) have been used in majority of the patients. VIV treatment is appealing as it is less invasive than conventional surgery but optimal patient selection is vital to avoid complications such as malposition, residual high gradients and coronary obstruction. To minimize the risk of complications, thorough procedural planning is critical. The first step is identification of the degenerated SHV, including its model, size, fluoroscopic appearance. Although label size and stent internal diameter (ID) are provided by the manufacturer, it is important to note the true ID. The true ID is the ID of a SHV after the leaflets are mounted and helps determine the optimal size of THV. The second step is to determine the type and size of the THV. Although this is determined in the majority of the cases by user preference, in certain situations one THV may be more suitable than another. As the procedure is performed under fluoroscopy, the third step is to become familiarized with the fluoroscopic appearance of both the SHV and THV. This helps to determine the landmarks for optimal positioning, which in turn determines the gradients and fixation. The fourth step is to assess the risk of coronary obstruction. This is performed with either aortic root angiography or ECG-gated computerised tomography (CT). Finally, the route of approach must be carefully planned. Once these aspects are addressed, the procedure can be performed efficiently with a low risk of complications.

Concomitant transfemoral transcatheter aortic and mitral valve-in-valve replacement

The valve-in-valve (viv) procedure has been shown to be effective in treating patients with a degenerated bioprosthesis who are also considered high risk or inoperable for a reoperation. We describe a case of concomitant transfemoral transcatheter viv aortic and mitral valve replacements.

Hypo-Attenuated Leaflet Thickening and Reduced Leaflet Motion in Sutureless Bioprosthetic Aortic Valves

Background

The prevalence of hypo‐attenuated leaflet thickening (HALT) and reduced leaflet motion (RLM) is unknown in surgically implanted bioprostheses because systematic investigation of HALT and/or RLM is limited to a few catheter‐based valves. The aim of this study was to investigate the prevalence of HALT and RLM by cardiac computed tomography in patients who underwent surgical aortic valve replacement and received a Perceval sutureless aortic valve bioprosthesis.

Methods and Results

This was a single‐center prospective observational study that included 47 patients (83.5% of the total number of implantations) who underwent surgical aortic valve replacement with implantation of the Perceval sutureless bioprosthesis (LivaNova PLC, London, UK) at Karolinska University Hospital in Stockholm, Sweden from 2012 to 2016 and were studied by cardiac computed tomography. Cardiac computed tomography was performed at a median of 491 days (range 36–1247 days) postoperatively. HALT was found in 18 (38%) patients and RLM in 13 (28%) patients. All patients with RLM had HALT. Among patients with HALT, 5 out of 18 patients (28%) were treated with anticoagulation (warfarin or any novel oral anticoagulant) at the time of cardiac computed tomography. Among patients with RLM, 3 out of 13 patients (23%) were treated with anticoagulation.

Conclusions

HALT and RLM were prevalent in the surgically implanted Perceval sutureless aortic valve bioprosthesis. Both HALT and RLM were found in patients with ongoing anticoagulation treatment. Whether these findings are associated with adverse events needs further study.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02671474.

Pulsed Cavitational Ultrasound Softening: a new non-invasive therapeutic approach of calcified bioprosthetic valve stenosis

BACKGROUND

The majority of prosthetic heart valves currently implanted are tissue valves that can be expected to calcify with time and eventually fail. Surgical or percutaneous redux valve replacement is associated with higher rate of complications. We propose a novel non-invasive therapeutic approach based on the use of pulsed cavitational ultrasound (PCU) to improve the valvular function of degenerative calcified bioprosthesis.

OBJECTIVES

Our study aims to demonstrate in vitro and in vivo on an ovine model that PCU can significantly improve the bioprosthesis opening by softening remotely the calcified stiff cusps.

METHODS

All the experiments were performed on calcified bioprosthetic valves explanted from human patients. PCU was performed in vitro on calcified bioprosthesis mounted on a hydraulic bench with pulsatile flow (n=8) and in vivo on an ovine model with implanted calcified bioprosthesis (n=7). We used 3D echocardiography, pressure and flow sensors, quantitative stiffness evaluation using shear wave elastography, micro-CT imaging and histology to evaluate in vitro and in vivo the effect of PCU.

RESULTS

The transvalvular gradient was found to decrease by a mean of 50% after PCU in both in vitro (from 21.1±3.9 to 9.6±1.7 mmHg, p<0.001) and in vivo setup (from 16.2±3.2 to 8.2±1.3 mmHg, p<0.001), with a decrease of valve stiffness (in vitro: from 105.8±9 to 46.6±4 kPa, p<0.001; in vivo: from 82.6±10 to 41.7±7 kPa, p<0.001) and an increase of valve area (from 1.10±0.1 to 1.58±0.1 cm2, p<0.001). Histology and micro-CT imaging showed modifications of calcification structure without loss of calcification volume or alteration of the leaflet superficial structures.

CONCLUSIONS

We have demonstrated in vitro and in vivo that PCU can decrease a calcified bioprosthesis stenosis by softening the leaflets remotely. This new non-invasive approach has the potential to improve the outcome of patients with severe bioprosthesis stenosis.

The effect of balloon valvuloplasty for bioprosthetic valve stenosis at pulmonary positions

BACKGROUND

Balloon dilatation of a bioprosthetic valve in the pulmonary position could be performed to delay valve replacement. We proposed to identify the long-term effectiveness of such a procedure.

METHODS

We reviewed the medical records of 49 patients who underwent balloon valvuloplasty between January 2000 and December 2015. The primary goal was to determine the time interval until the following surgical or catheter intervention.

RESULTS

The mean age at bioprosthetic valve insertion was 5.7 years old, and the mean age for ballooning was 11.7 years. The mean interval after pulmonary valve replacement was 71.6 months. The mean ratio of balloon size to valve size was 0.94. The pressure gradient through the pulmonary valve after balloon valvuloplasty was significantly improved (55.3 ± 18.5 mm Hg vs 33.8 ± 21.5 mm Hg, P < .001). There were no significant changes in pulmonary regurgitation and no serious adverse events. Patients had a mean freedom from re-intervention of 30.6 months after balloon valvuloplasty. The interval of freedom from re-intervention was affected only by the pressure gradient before balloon valvuloplasty and the patient age at insertion. The mean interval to re-intervention in patients with pressure gradients less than 48.5 mm Hg before ballooning was 46.0 months, which was significantly longer than for those with a higher gradient (18.7 months).

CONCLUSION

The effectiveness of this process may depend on the pressure gradient before ballooning and the patient age at valve insertion. It is possible that earlier valvuloplasty at pressure gradient not over 48.5mm Hg may have a benefit to delaying re-operation.

Repositionable self-expanding aortic bioprosthesis

INTRODUCTION

Transcatheter aortic valve implantation/replacement (TAVI or TAVR) has been established as a first line therapy in patients with symptomatic severe aortic stenosis (AS) at high or prohibitive surgical risk and as an alternative in elderly patients with intermediate surgical risk. Since its first-in-human procedure in 2002, the past 15-years have shown rapid developments in TAVI technology with the introduction and further improvement of new transcatheter heart valves (THV). Areas covered: There are currently several THV systems available, based on balloon-expandable, self-expandable or other technologies. Some of these are repositionable and retrievable even after partial or full deployment, potentially reducing the risk of malpositioning. The aim of this review is to describe such repositionable self-expandable THV systems. Expert commentary: Repositionability potentially represents a crucial step towards higher safety and efficacy of TAVI. It is unclear if full self-expandability or a combination of self and mechanical expansion will be more advantageous.