Prosthesis Leaflet Research Articles

Cinefluoroscopy for assessment of mechanical heart valves with suspected dysfunction.

BackgroundMechanical heart valves (MHVs) are preferred prosthesis types in many, especially younger patients who need surgical valve replacement. Although echocardiography is most frequently performed for prosthesis assessment during follow-up, ultrasound artifacts usually preclude a precise investigation of prosthesis function. Cinefluoroscopy (CF) is a simple and effective method to analyze and quantify opening and closing of prosthesis leaflets but requires careful visualization of the valve using optimal viewing angles. Here, we investigated the quality of CF studies in clinical routine and their suitability for quantitative analysis of prosthesis function.Methods and resultsWe retrospectively identified 94 patients with 118 cinefluoroscopies performed by 31 different investigators in one tertiary center from 2012 to 2021. Of 150 MHVs (98% bi-leaflet prostheses), 87 (58%) were aortic, 53 (34%) mitral, 7 (5%) tricuspid, and 5 (3%) pulmonary valve prostheses, respectively. CF studies were categorized by their suitability to quantitatively assess opening and closing angles. Visualization of valve function was “sufficient” in 23%, “suboptimal” in 46%, and “unsuitable” in 31% of the cases.ConclusionIn clinical routine, only one-fourth of CF studies allow for a complete assessment of leaflet motion of MHVs. Although this may be in part due to the varying experience of operators, the high number of unsuitable studies suggests that optimal viewing angles may not be achievable in all patients. Further research is required to investigate standard viewing angles and anatomy after MHV implantation to improve the quality of CF studies and reduce radiation exposure of patients and operators.

3D-Printing to Plan Complex Transcatheter Paravalvular Leaks Closure.

Background: Percutaneous closure of paravalvular leak (PVL) has emerged as an alternative to surgical management in selected cases. Achieving complete PVL occlusion, while respecting prosthesis function remains challenging. A multimodal imaging analysis of PVL morphology before and during the procedure is mandatory to select an appropriate device. We aim to explore the additional value of 3D printing in predicting device related adverse events including mechanical valve leaflet blockade, risk of device embolization and residual shunting. Methods: From the FFPP registries (NCT05089136 and NCT05117359), we included 11 transcatheter PVL closure procedures from three centers for which 3D printed models were produced. Cardiac CT was used for segmentation for 3D printed models (3D-heartmodeling, Caissargues, France). Technology used a laser to fuse very fine powders (TPU Thermoplastic polyurethane) into a final part-laser sintering technology (SLS) with an adapted elasticity. A simulation on 3D printed model was performed using a set of occluders. Results: PVLs were located around aortic prostheses in six cases, mitral prostheses in four cases and tricuspid ring in one case. The device chosen during the simulation on the 3D printed model matched the one implanted in eight cases. In the three other cases, a similar device type was chosen during the procedures but with a different size. A risk of prosthesis leaflet blockade was identified on 3D printed models in four cases. During the procedure, the occluder was removed before release in one case. In another case the device was successfully repositioned and released. In two patients, leaflet impingement was observed post-operatively and surgical device removal had to be performed. Conclusion: In a case-series of complex transcatheter PVL closure procedures, hands-on simulation testing on 3D printed models proved its usefulness to plan and facilitate these challenging procedures.

Deformation of Transcatheter Aortic Valve Prostheses: Implications for Hypoattenuating Leaflet Thickening and Clinical Outcomes.

Although transcatheter aortic valve replacement (TAVR) therapy continues to grow, there have been concerns about the occurrence of hypoattenuating leaflet thickening (HALT), which may affect prosthesis function or durability. This study aimed to examine prosthesis frame factors and correlate their extent to the frequency of HALT and clinical outcomes. We prospectively examined 565 patients with cardiac computed tomography screening for HALT at 30 days after balloon-expandable SAPIEN3 and self-expanding EVOLUT TAVR. Deformation of the TAVR prostheses, asymmetric prosthesis leaflet expansion, prosthesis sinus volumes, and commissural alignment were analyzed on the postprocedural computed tomography. For descriptive purposes, an index of prosthesis deformation was calculated, with values >1.00 representing relative midsegment underexpansion. A time-to-event model was performed to evaluate the association of HALT with the clinical outcome. Overall, HALT was present in 21% of SAPIEN3 patients and in 16% of EVOLUT patients at 30 days after TAVR. The occurrence of HALT was directly associated with greater prosthesis frame deformation (P<0.001), worse asymmetry of the leaflets (P<0.001), and smaller TAVR neosinus volumes (P<0.001). These relations were present in both prosthetic types and in all of their size ranges (all P<0.05). In multivariable analyses that include clinical variables previously associated with HALT (eg, anticoagulant therapy), variables of TAVR prosthesis deformation remained predictive of HALT. Although HALT was not associated with changes in prosthetic hemodynamics, its presence was associated with the risk of mortality at 1 year, with respect to greater incidences of all-cause mortality (hazard ratio, 2.98 [95% CI, 1.57-5.63]; P=0.001), cardiac death (hazard ratio, 4.58 [95% CI, 1.81-11.6]; P=0.001), and a composite outcome of all-cause mortality and heart failure hospitalization (hazard ratio, 1.94 [95% CI, 1.14-3.30]; P=0.02) with adjustment for age, sex, and comorbidities. Nonuniform expansion of TAVR prostheses resulting in frame deformation, asymmetric leaflet, and smaller neosinus volume is related to occurrence of HALT in patients who undergo TAVR. These data may have implications for both prosthesis valve design and deployment techniques to improve clinical outcomes for these patients.

P49 SURGICAL OPEN AORTA TRANSCATHETER VALVE IN VALVE IMPLANT FOR A MALFUNCTIONING AORTIC BIOPROSTHESIS

Abstract Background Most cases of aortic valve bioprosthesis degenerative disease are currently best managed by transcatheter aortic valve replacement (TAVR). Compared to redo surgery, advantages of TAVR include reduced invasiveness and a minimized prosthesis gradient; however, this approach is occasionally unfeasible due to the risk for coronary flow impairment or prosthesis stent dimensions unfit to accommodate an appropriately sized device. We present a case of an open TAVR after surgical leaflets excision of a failing aortic valve bioprosthesis. Case Summary A 76 years old female with type 2 diabetes, hypertension and dyslipidemia was referred to our institution for a malfunctioning 21 Carpentier Edwards pericardial aortic valve bioprosthesis implanted 9 years earlier. Patient was initially considered for a valve in valve TAVR. However, because of very low–lying coronary arteries origin at preoperative CT scan we estimated substantial chances for ostia impingement when prosthesis leaflets would have been stretched out by the deploying transcatheter device (Figure 1); although feasible, conventional redo surgery with bioprosthesis excision and re–suture was not preferred because of patients age and comorbidities; risk of damaging the aortic ring and wall including coronaries emergence when dissecting out the stent of the biopsosthesis and reimplanting a new one was also evaluated. We therefore opted for an hybrid procedure. After redo median sternotomy, careful dissection of adhesions, central Cardio–Pulmonary Bypass (CPB), aortic cross clamp and antegrade cardioplegia, a transverse aortotomy was done. The prosthesis was inspected and found grossly deteriorated: leaflets only were excised leaving the stent intact (Figure 2) and a 23 Sapien3 Ultra valve was carefully deployed under direct vision. Coronary ostia were checked and found patent. Myocardial ischemia and CPB times were 61 and 85 minutes respectively. Intensive care unit stay was 2 days. After a reassuring postoperative CT scan (Figure 3), patient was discharged home 11 days after surgery. Conclusions We found this approach a good compromise when dealing with challenging aortic valve reoperations, as it is associated to reduced surgical complexity and potential for less morbidity and mortality compared to conventional surgery when low coronary ostia make valve in valve TAVR unachievable.

Prosthesis Geometrical Predictors of Leaflet Thrombosis Following Transcatheter Aortic Valve Replacement With Intra-Annular Prostheses

To determine the association between prosthesis geometry with leaflet thrombosis (LT). Leaflet thrombosis following transcatheter aortic valve replacement (TAVR) is a recognised entity. The association between prosthesis geometry with LT is unclear but maybe a potential modifiable factor in its prevention. Patients who received an intra-annular TAVR prosthesis and were prospectively planned to undergo post-procedural computed tomography (CT) imaging were included. Leaflet thrombosis was defined as at least 50% restricted leaflet motion on CT. Prosthesis expansion and eccentricity was measured at prosthesis inflow, annulus and outflow levels. Prosthesis misalignment was defined as the average angle deviation between native and prosthesis leaflet commissure, greater than 30°. Prevalence of LT was 13.7% in 117 patients. None of the patients with LT were on anticoagulation therapy. Patients with LT had reduced prosthesis annular expansion (89.4±5.2% vs 97.0±4.4%, p<0.01), greater prosthesis misalignment (81.3% vs 48.5%, p=0.02) and deeper implants (6.3±1.7 mm vs 4.3±1.5 mm, p<0.01). Threshold for the presence of LT on ROC analysis was an implant depth of 5.7 mm (AUC [area under curve]=0.81). Independent predictors of LT were annular under-expansion (Odds ratio [OR] 1.4, 95% confidence interval [CI] 1.2-1.7, p=0.03) prosthesis misalignment (OR 6.8, 95%CI 1.1-45.5, p=0.04) and implant depth (OR 1.9, 95%CI 1.1-3.2, p=0.03). Anticoagulation therapy was a protective factor (OR 0.2; 95%CI 0.1-0.4, p<0.01). Geometrical predictors of LT post intra-annular TAVR were reduced prosthesis expansion at the annular level, lower implant depth and greater prosthesis misalignment. These factors may be important considerations during procedural planning for TAVR.

Association between prosthesis geometry and leaflet thrombosis following transcatheter aortic valve replacement

Abstract Introduction Leaflet thrombosis (LT) following transcatheter aortic valve replacement (TAVR) is a recognised condition. The association between prosthesis geometry [expansion, implant depth and commissural alignment (CA)] and LT is unclear. Methods Patients that received intra-annular TAVR prosthesis and post-procedure computed tomography (CT) with a 320-slice scanner were included. LT, defined as at least 50% restricted leaflet motion, was assessed with a dedicated 3Mensio workstation by two experienced CT readers. Prosthesis expansion was defined as actual divided by expected prosthesis area as a percentage of expected area whilst eccentricity was [(maximum diameter − minimum diameter) / maximum diameter) × 100%], both measured at prosthesis inflow, annulus and outflow. Implant depth was the average distance between prosthesis inflow and nadir of each cusp. CA was the average angle between each native and prosthesis leaflet coaptations. Significant commissural misalignment (CMA) was defined as CA greater than 30 degrees. To exclude anticoagulation bias, similar analysis was also performed in the cohort of non-anticoagulated patients. Results 117 patients were included; the prevalence of LT was 13.7% [13/93 cases (14.0%) of Lotus valves and 3/24 cases (12.5%) of Sapien 3 valves]. Baseline demographics (age, STS score, cardiac risk factors) and procedural characteristics (access site, post-dilation, repositioning) were similar in both groups. None of the patients with LT were discharged on anticoagulation therapy (0.0% vs 22.8%, p&amp;lt;0.01). There were no differences in actual prosthesis area, perimeter or eccentricity at the three prosthesis levels. Patients with LT had reduced annulus expansion (89.3±9.8% vs 94.6±8.3%, p=0.02), lower implant depth (6.9±1.5mm vs 4.9±1.5mm, p&amp;lt;0.01) and more significant CMA (81.3% vs 48.5%, p=0.02). These findings were similar in patients that were not anticoagulated (94/117 patients). Conclusion Patients with LT had reduced annulus expansion, lower implant depth and greater CMA. These findings were not affected by presence or absence of anticoagulation. These factors may be important considerations during procedural planning for TAVR. Graphical abstract Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Health and Medical Research Council (NHMRC). National Heart Foundation (NHF) Australia.

Transcatheter valve-in-valve implantation of the 'MedLab-KT' prosthesis

Valve-in-valve repeat prosthetic reconstruction is a less invasive alternative to 'open' redo operation for degenerative dysfunction of an aortic bioprosthesis. At the beginning of the history of using this method it was resorted to only in cases of high surgical risk, involving virtually inoperable patients. Currently, the world experience numbers in thousands of such interventions, known to be also performed in patients not belonging to a high-risk group. Recent studies have demonstrated a decrease in the perioperative mortality and improved quality of life in the remote period after valve-in-valve transcatheter implantation of an aortic bioprosthesis. High gradients, occlusion of coronary arteries, and thrombosis of the prosthesis's leaflets remain the major problems encountered while using this method. Nevertheless, valve-in-valve prosthetic reconstruction proved to be a reliably safe and efficient procedure of correcting dysfunction of a previously implanted biological prosthesis.

427 Utilisation of 320-slice Computed Tomography (CT) to Determine Association Between Prosthesis Geometry and Leaflet Thrombosis (LT) following Transcatheter Aortic Valve Replacement (TAVR)

CT-defined LT following TAVR is a recognised condition. The association between CT-assessed prosthesis geometry and LT is unclear. 117 patients that received intra-annular TAVR prosthesis and post-procedure TAVR-CT were included. LT was defined as hypo-attenuated leaflet-thickening with ≥50% restricted leaflet motion on 4-dimensional CT. Prosthesis expansion [(actual prosthesis area)/(expected prosthesis area)x100%] and eccentricity [(max–min diameter)/(max diameter)x100%] was measured at prosthesis inflow, annulus and outflow. Implant depth was the average distance between inflow and nadir of cusps. Commissural alignment was the average angle between native and prosthesis leaflet commissures; significant commissural misalignment was defined as commissural alignment >30°. Prevalence of LT was 13.7% [13/93 cases (14.0%) of Lotus and 3/24 cases (12.5%) of Sapien 3 valves]. Baseline (age, STS-score, cardiac risk factors) and procedural (access-site, post-dilation, valve-repositioning) characteristics were similar in both groups. None of the patients with LT were on anticoagulation therapy (0.0% vs 22.8%,p<0.01). There were no differences in actual prosthesis area, perimeter or eccentricity at separate prosthesis levels. Patients with LT had reduced annulus expansion (89.3±9.8% vs 94.6±8.3%,p=0.02), lower implant depth (6.9±1.5mm vs 4.9±1.5mm,p<0.01) and more significant commissural misalignment (81.3% vs 48.5%,p=0.02). To exclude anticoagulation bias, analysis was repeated only in non-anticoagulated patients (94/117 patients) and the previous significant findings were similar in this cohort. Patients with LT had reduced annulus expansion, lower implant depth and greater commissural misalignment on CT assessment. These findings were not affected by presence or absence of anticoagulation. These factors may be important considerations during pre-procedural TAVR planning.

P247 Added value of 3D echo in diagnosing and monitoring transcatheter valve in mac procedure in a patient with severe mitral stenosis

Abstract INTRODUCTION Mitral annular calcification (MAC) is a chronic degenerative process involving calcification of the fibrous base of the mitral valve accounting for 12% to 26% of all mitral stenosis (MS) and eventually for significant mitral regurgitation. Calcification often extends to other parts of the mitral valve apparatus but, unlike rheumatic stenosis, does not produce commissural fusion. Surgical treatment carries a high mortality rate due to technical difficulties involving the heavily calcified annulus, advanced age and comorbidities of affected patients. In recent years, transcatheter mitral valve replacement using ballon expandable transcatheter aortic valves in severe MAC (valve-in-MAC) has been used with acceptable success rates. PURPOSE To describe the added value of 3D echo in the diagnostic work-up, decision making and monitoring during the interventional procedure of valve-in-MAC. CASE PRESENTATION Two years ago a 90-year-old female in sinus rhythm with hypertension and known coronary artery disease (CAD) was admitted with symptoms of pulmonary congestion (PC). At that time, a transthoracic 3D echocardiogram showed important MAC with a mitral valve area (MVA) estimated through 3D planimetry of 1.1 cm2, pulmonary artery pressure (PAP) of 53 mmHg, preserved biventricular function and left atrial enlargement. One year later, she was readmitted with unstable CAD and treated with percutaneous transluminal angioplasty. At that time a 3D transesophageal echocardiogram (3DTOE) showed worsening of the MVA now estimated in 0.6 cm2, a mean gradient of 19 mmHg and PAP of 88 mmHg. Albeit optimized medical therapy, her functional status worsened and less than a month later she was again readmitted in NYHA functional class III. Therefore decision making for valve-in-MAC was undertaken. Valve sizing was performed with computed tomography (CT) using the D-shape method with similar findings when compared with 3D TOE measurements. Both methods showed a favourable anatomy of the left ventricular outflow tract. Valve-in-MAC procedure was performed through transvenous transseptal access and an Edwards Sapien3-nr 29 balloon-expandable valve was deployed uneventfully, except for a residual interatrial septal defect measuring 2.2x0.8cm closed two weeks after, as she persisted with PC and pulmonary hypertension. During the procedure, 3DTOE showed a partial thrombosis involving one of the prosthesis leaflets with preserved transvalvular gradients despite anticoagulation. After that, PC resolved and PAP dropped dramatically. The patient was discharged under lifelong anticoagulation and remains asymptomatic until now. CONCLUSION Diagnosing and treating patients with severe MS due to MAC remains a challenge as traditional parameters and interventional procedures don’t apply for this population. Valve-in-MAC is a feasible alternative and 3DTOE may have a pivotal role in the diagnostic work-up and interventional monitoring of these cases. Abstract P247 Figure. 3D echo timeline valve in MAC

Reinterventions after freestyle stentless aortic valve replacement: an assessment of procedural risks.

OBJECTIVESRepeat aortic valve interventions after previous stentless aortic valve replacement (AVR) are considered technically challenging with an increased perioperative risk, especially after full-root replacement. We analysed our experience with reinterventions after stentless AVR.METHODSA total of 75 patients with previous AVR using a Freestyle stentless bioprosthesis (31 subcoronary, 15 root-inclusion and 29 full-root replacement) underwent reintervention in our centre from 1993 until December 2018. Periprocedural data were retrospectively collected from the department database and follow-up data were prospectively collected.RESULTSMedian age was 62 years (interquartile range 47–72 years). Indications for reintervention were structural valve deterioration (SVD) in 47, non-SVD in 13 and endocarditis in 15 patients. Urgent surgery was required in 24 (32%) patients. Reinterventions were surgical AVR in 16 (21%), root replacement in 51 (68%) and transcatheter AVR in 8 (11%) patients. Early mortality was 9.3% (n = 7), but decreased to zero in the past decade in 28 patients undergoing elective reoperation. Per indication, early mortality was 9% for SVD, 8% for non-SVD and 13% for endocarditis. Aortic root replacement had the lowest early mortality rate (6%), followed by surgical AVR (13%) and transcatheter AVR (25%, 2 patients with coronary artery obstruction). Pacemaker implantation rate was 7%. Overall survival rate at 10 years was 69% (95% confidence interval 53–81%).CONCLUSIONSRepeat aortic valve interventions after stentless AVR carry an increased, but acceptable, early mortality risk. Transcatheter valve-in-valve procedures after stentless AVR require careful consideration of prosthesis leaflet position to prevent obstruction of the coronary arteries.

Septal Bulge and Risk of Paravalvular Leak After Transcatheter Aortic Valve Replacement

ABSTRACT Background: Proximal septal bulge (SB) is a subaortic protuberance of the interventricular septum into the left ventricular outflow tract (LVOT) without extension to the middle and distal septum. Our aim was to evaluate the impact of SB presence on the incidence of paravalvular leak (PVL) after transcatheter aortic valve replacement (TAVR) in a hypothesis-generating study. Methods: Patients who underwent TAVR in a single center were screened. Those patients with non self-expanding devices with annular leaflet position (Edward Sapien, Lotus) or self-expanding prosthesis and supra-annular leaflet design (Evolut, CoreValve) were included; devices in the early learning curve were excluded. Transesophageal echocardiography (TOE) images performed during TAVR were reviewed and SB nonstandard measurements were obtained from LVOT view. The presence of PVL was evaluated in the TOE immediately after TAVR. ANOVA and Bonferroni statistical tests were used to compare quantitative variables among groups. Results: We included 147 patients (mean age 78 ± 12 years, 59% females). The implanted devices were: 33 Evolut R, 56 CoreValve, 41 Lotus Valve and 17 Edwards Sapien. There were no significant differences between SB parameters among the different devices. Maximal SB thickness in the LVOT was related to PVL grade in the self-expanding valves. Moderate-severe PVL was less frequently observed in the non self-expanding devices group (2.4%), the differences among this group were not significant. Conclusions: The presence of a prominent SB in the LVOT could be related to a higher risk of PVL, likely in self-expandable devices with supra-annular leaflet position.

Paravalvular leak repair after balloon-expandable transcatheter mitral valve implantation in mitral annular calcification: Early experience and lessons learned.

Treatment of hemodynamically significant mitral annular calcification (MAC) using transcatheter approaches is in the early learning phase. The occurrence of paravalvular leak (PVL) following transcatheter mitral valve in MAC is common. To report the initial experience and techniques of percutaneous PVL closure after transcatheter valve in MAC. This series includes five consecutive patients who underwent percutaneous PVL closure following transcatheter balloon expandable SAPIEN S3 valve in MAC. Mean patient age was 73.6 ± 5.4 years (4 [80%] female), with average Society of Thoracic Surgeons score of 8.1 ± 2.8%. Three patients had a single PVL defect while two patients had two defects; all were located at the commissural sites. Closure was performed primarily for heart failure in four patients and hemolytic anemia in one patient. Transfemoral transseptal antegrade approach and Amplatz Vascular Plug (AVP)-II occluders were utilized in all patients. Procedure success was achieved in three patients. One patient developed significant occluder related leaflet impingement and subsequent severe prosthetic mitral regurgitation requiring a second transcatheter mitral valve in valve implantation. The procedure was aborted in one patient due to difficulty crossing PVL defect after balloon post-dilatation of SAPIEN prosthesis with 10 mL of additional volume. There was no in hospital or 30 day mortality or the need for emergent surgery. Early experience with percutaneous PVL closure of SAPIEN valve in MAC demonstrated feasibility of this approach. Careful procedure planning and monitoring for SAPIEN prosthesis leaflet impingement and frame instability is of utmost importance to increase the chances of procedural success.

Sudden death after valve-in-valve procedure due to delayed coronary obstruction: a case report

BackgroundValve-in-valve transcatheter aortic valve implantation for degenerated aortic bioprostheses is an effective option for patients at high risk for redo surgery, even if it may be burdened by complications more common in specific settings, such as, coronary artery obstruction.Case presentationWe present the case of a Caucasic 84-year-old woman with degeneration of a previously implanted aortic Mitroflow bioprosthesis. She underwent a valve-in-valve transcatheter aortic valve implantation with a CoreValve® bioprosthesis. End-procedure coronary angiography demonstrated maintained perfusion of both coronary arteries. However, few hours later, she experienced sudden cardiac death. An autopsy showed that Mitroflow prosthesis leaflets were higher than the left main coronary ostium, and no other possible cause for the sudden death. Fatality was thus ascribed to left main coronary ostium obstruction due to apposition of the Mitroflow leaflet pushed upward by the late expansion of CoreValve®.ConclusionsCoronary artery obstruction is a frequently fatal complication which usually presents just after valve implantation, but, as reported in our case, it may also have a delayed presentation. Accurate patient’s selection and intraoperative preventive measures can reduce this eventuality.

Are the Current Doppler Echocardiography Criteria Able to Discriminate Mitral Bileaflet Mechanical Heart Valve Malfunction? An In Vitro Study

Malfunction of bileaflet mechanical heart valves in the mitral position could either be due to patient-prosthesis mismatch (PPM) or leaflet obstruction. The aim of this article is to investigate the validity of current echocardiographic criteria used for diagnosis of mitral prosthesis malfunction, namely maximum velocity, mean transvalvular pressure gradient, effective orifice area, and Doppler velocity index. In vitro testing was performed on a double activation left heart duplicator. Both PPM and leaflet obstruction were investigated on a St. Jude Medical Master. PPM was studied by varying the St. Jude prosthesis size (21, 25, and 29 mm) and stroke volume (70 and 90 mL). Prosthesis leaflet obstruction was studied by partially or totally blocking the movement of one valve leaflet. Mitral flow conditions were altered in terms of E/A ratios (0.5, 1.0, and 1.5) to simulate physiologic panel of diastolic function. Maximum velocity, effective orifice area, and Doppler velocity index are shown to be insufficient to distinguish normal from malfunctioning St. Jude prostheses. Doppler velocity index and effective orifice area were 1.3 ± 0.49 and 1.83 ± 0.43 cm(2) for testing conditions with no malfunction below the 2.2 and 2 cm(2) thresholds (1.19 cm(2) for severe PPM and 1.23 cm(2) for fully blocked leaflet). The mean pressure gradient reached 5 mm Hg thresholds for several conditions of severe PPM only (6.9 mm Hg and mean maximum velocity value: 183.4 cm/s) whereas such value was never attained in the case of leaflet obstruction. In the case of leaflet obstruction, the maximum velocity averaged over the nine pulsed-wave Doppler locations increased by 38% for partial leaflet obstruction and 75% for a fully blocked leaflet when compared with normal conditions. Current echocardiographic criteria might be suboptimal for the detection of bileaflet mechanical heart valve malfunction. Further developments and investigations are required in order to further improve current guidelines.

Platypnea-Orthodeoxia Syndrome after Transcatheter Aortic Valve Implantation.

Progressive dyspnea and hypoxaemia in the subacute phase after transcatheter aortic valve implantation (TAVI) are uncommon and warrant immediate assessment of valve and prosthesis leaflet function to exclude thrombosis, as well as investigation for other causes related to the procedure, such as left ventricular dysfunction, pulmonary embolism, and respiratory sepsis. In this case, we report the observation of a patient presenting two weeks after TAVI with arterial hypoxaemia in an upright position, relieved by lying flat, and coupled with an intracardiac shunt detected on echocardiography in the absence of pulmonary hypertension, raising the suspicion of Platypnea-Orthodeoxia Syndrome (POS). Invasive intracardiac haemodynamic assessment showed a significant right-to-left shunt (Qp/Qs = 0.74), which confirmed the diagnosis, with subsequent closure of the intracardiac defect resulting in immediate relief of symptoms and hypoxaemia. To our knowledge, this is the first reported case of an interatrial defect and shunt causing Platypnea-Orthodeoxia Syndrome after transcatheter aortic valve implantation, resolved by percutaneous device closure.

Feasibility of pig and human-derived aortic valve interstitial cells seeding on fixative-free decellularized animal pericardium.

Glutaraldehyde-fixed pericardium of animal origin is the elective material for the fabrication of bio-prosthetic valves for surgical replacement of insufficient/stenotic cardiac valves. However, the pericardial tissue employed to this aim undergoes severe calcification due to chronic inflammation resulting from a non-complete immunological compatibility of the animal-derived pericardial tissue resulting from failure to remove animal-derived xeno-antigens. In the mid/long-term, this leads to structural deterioration, mechanical failure, and prosthesis leaflets rupture, with consequent need for re-intervention. In the search for novel procedures to maximize biological compatibility of the pericardial tissue into immunocompetent background, we have recently devised a procedure to decellularize the human pericardium as an alternative to fixation with aldehydes. In the present contribution, we used this procedure to derive sheets of decellularized pig pericardium. The decellularized tissue was first tested for the presence of 1,3 α-galactose (αGal), one of the main xenoantigens involved in prosthetic valve rejection, as well as for mechanical tensile behavior and distensibility, and finally seeded with pig- and human-derived aortic valve interstitial cells. We demonstrate that the decellularization procedure removed the αGAL antigen, maintained the mechanical characteristics of the native pig pericardium, and ensured an efficient surface colonization of the tissue by animal- and human-derived aortic valve interstitial cells. This establishes, for the first time, the feasibility of fixative-free pericardial tissue seeding with valve competent cells for derivation of tissue engineered heart valve leaflets.

Transcatheter aortic valve implantation in a patient with mechanical mitral prosthesis: A lesson learned from an intraventricular clash

We hereby present the case of a patient with severe aortic stenosis who underwent in her previous medical history a mitral valve replacement with a mechanical valve (Omnicarbon 27), and progressively developed a severe aortic stenosis. This patient was judged inoperable and then scheduled for CoreValve Revalving System implantation. Despite a good positioning of the CoreValve, an acute, severe mitral regurgitation developed soon after implantation as a consequence of the impaired movement of the mitral prosthesis leaflet. A condition of cardiogenic shock quickly developed. A good mitral prosthesis function was restored disengaging the CoreValve from the aortic annulus. After few months, the patients underwent successful Edwards-Sapien valve implantation through the Corevalve. This case strongly demonstrates how much a careful evaluation of the features of the mitral prosthesis and patient anatomy is crucial to select which specific transcatheter bioprosthesis would better perform.

Transcatheter aortic valve implantation for severe, non‐calcified aortic regurgitation and narrow aortic root: Description from a case report of a new approach to potentially avoid coronary artery obstruction

Transcatheter aortic valve implantation is a possible, although off-label, alternative to conventional aortic valve replacement for high-surgical-risk patients with severe, non-calcified aortic regurgitation (AR). To date, feasibility has only been demonstrated with the Medtronic CoreValve prosthesis (MCV). This prosthesis needs the aortic sinuses to have enough width to avoid coronary obstruction. We report a case of MCV implantation for severe AR where the narrow aortic root theoretically precluded the technique. Good procedural outcome was achieved thanks to a strategy of implantation with planned positioning of the prosthesis leaflets away from the coronary arteries.

Imaging the prosthetic valve sewing ring thrombosis using real-time three-dimensional transoesophageal echocardiography

A 56-year-old man was admitted for transoesophageal echocardiography (TEE) evaluation before electrical cardioversion of persistent atrial fibrillation to sinus rhythm. He had undergone mitral valve replacement with a bileaflet prosthetic mitral valve (SORIN prosthetic valve) for rheumatic disease 3 months previously. Inadequate anticoagulation was noted with an INR of 1.7. TEE revealed the presence of thick mobile filamentous fibrin strands attached to the prosthesis sewing ring with a diastolic movement within the prosthesis without obstruction (normal 5 mmHg transprosthetic mean pressure gradient) (Fig. 1 and video 1). Three-dimensional transoesophageal echocardiography showed the presence of a circular thrombus like a crown attached to the whole prosthesis sewing ring protruding between the prosthesis leaflets and the sewing ring (Fig. 2 arrows and video 2) highlighting the presence of sewing ring thrombosis when compared with two-dimensional TEE evaluation of the same image. Considering the presence of non-obstructive thrombosis, a conservative approach with heparin was used. Fig. 1 Two-dimensional transoesophageal echocardiography two-chamber view showing the presence of thick filamentous fibrin strands attached on the atrial side of the prosthesis sewing ring (arrows) Fig. 2 Real-time three-dimensional transoesophageal echocardiography showing the presence of a circular thrombus attached to the whole prosthesis sewing ring Real-time three-dimensional TEE provided a more comprehensive delineation of prosthetic mitral valve thrombosis, a better visualisation of the thrombus and a better understanding of the relationship between all the structures when compared with two-dimensional transoesophageal echocardiographic images [1].

Failed Closure of Paravalvular Leak with an Amplatzer® Occluder Device After Mitral Valve Replacement

Failed Closure of Paravalvular Leak with an Amplatzer® Occluder Device After Mitral Valve Replacement