Transvalvular Pressure Gradient Research Articles

COMPARATIVE ASSESSMENT OF CLINICAL AND HEMODYNAMIC OUTCOMES AFTER AORTIC HEART VALVE REPLACEMENT WITH XENOAORTIC AND XENOPERICARDIAL BIOLOGICAL PROSTHESES FOR DEGENERATIVE AORTIC VALVULAR DISEASE

Aim. To assess clinical and hemodynamic outcomes of aortic valve replacement with xenoaortic biological prosthesis “Aspire Vascutek” and xenopericardial biological prosthesis “UniLine”. Methods. 130 patients who underwent aortic valve replacement with bioprostheses in the period from October 2012 to March 2016 were included in the study. All patients were enrolled into two groups according to the model of the implanted device. 65 recipients of xenoaortic bioprostheses “Aspire Vascutek” were included in Group 1, whereas patients (n = 65) xenopericardial bioprostheses “UniLine” were assigned in Group 2. Males prevailed in Group 1 (63%, the mean age - 66.4±5.5 years). 85% of Group 1 patients had heart failure Strazhesko-Vasilenko IIA grade and 94% of patients had chronic heart failure NYHA III. Similarly, male patients (58%) prevailed in Group 2. The mean age of Group 2 patients was 66.5±3.65 years. All patients in Group 2 II had heart failure Strazhesko-Vasilenko IIA grade and chronic heart failure NYHA III. Results Two patients in Group 1 died in the early postoperative period (the overall mortality was 1.5%). All patients had chronic heart failure NYHA I-II at discharge. Peak transvalvular pressure gradient significantly decreased in the in-hospital period, particularly in Group 2 patients (82,3±22,7 mm Hg vs. 28.8±7.6 mm Hg). 88% of Group 1 patients underwent the 60-month follow-up, and 96% of Group 2 patients - the 48-month follow-up. Transvalvular pressure gradients decreased progressively in both study groups within 60 months follow-up. This decrease was more pronounced in recipients of xenopericardial biological prostheses. Conclusion. Aortic valve replacement with xenopericardial bioprostheses “UniLine” and xenoaortic bioprostheses “Aspire Vascutek” for aortic valvular disease allows treating intracardiac hemodynamic derangements and achieving good clinical and hemodynamic outcomes.

Effect of pannus formation on the prosthetic heart valve: In vitro demonstration using particle image velocimetry.

Although hemodynamic influence of the subprosthetic tissue, termed as pannus, may contribute to prosthetic aortic valve dysfunction, the relationship between pannus extent and hemodynamics in the prosthetic valve has rarely been reported. We investigated the fluid dynamics of pannus formation using in vitro experiments with particle image velocimetry. Subvalvular pannus formation caused substantial changes in prosthetic valve transvalvular peak velocity, transvalvular pressure gradient (TPG) and opening angle. Maximum flow velocity and corresponding TPG were mostly affected by pannus width. When the pannus width was 25% of the valve diameter, pannus formation elevated TPG to >2.5 times higher than that without pannus formation. Opening dysfunction was observed only for a pannus involvement angle of 360°. Although circumferential pannus with an involvement angle of 360° decreased the opening angle of the valve from approximately 82° to 58°, eccentric pannus with an involvement angle of 180° did not induce valve opening dysfunction. The pannus involvement angle largely influenced the velocity flow field at the aortic sinus and corresponding hemodynamic indices, including wall shear stress, principal shear stress and viscous energy loss distributions. Substantial discrepancy between the velocity-based TPG estimation and direct pressure measurements was observed for prosthetic valve flow with pannus formation.

Feasibility and effectiveness of percutaneous balloon mitral valvuloplasty under echocardiographic guidance only

Percutaneous balloon mitral valvuloplasty (PBMV) is the treatment of choice in patients with isolated mitral stenosis. This study aimed to assess the feasibility of PBMV under echocardiography guidance only of isolated mitral stenosis (MS). From October 2016 to Dec 2017, 20 consecutive patients with severe MS underwent PBMV with echocardiography as the only imaging modality at a single center. Outpatient follow-up including chest radiography, electrocardiography, and transthoracic echocardiography was conducted at 1, 3,6, and 12months after the procedure. All 20 patients successfully underwent PBMV under echocardiography guidance without radiation and contrast agent. Among them, 2 patients were pregnant, 5 had chronic renal failure, and 1 had history of allergy to contrast. Mitral transvalvular pressure gradient measured at catheterization dropped from 13.35±2.85mmHg to 5.10±1.17mmHg (P<.01). Mitral valve area increased from 0.82±0.10cm2 pre-PBMV to 1.88±0.24cm2 post-PBMV (P<.01). Mean balloon diameter was 26.63±0.93mm. Mild mitral regurgitation developed in 6 patients. Mean follow-up duration was 6.27±3.12months. At last follow-up, mitral valve area remained high (1.71±0.14cm2 ) and mean transmitral pressure gradient low (6.07±1.03mmHg). No pericardial effusion or peripheral vascular complications occurred. In this small experience, PBMV could be successfully performed under only echocardiography guidance and appeared safe and effective while avoiding radiation and contrast agent use.

An in vitro evaluation of turbulence after transcatheter aortic valve implantation

BackgroundThis study aimed at assessment of post-transcatheter aortic valve (TAV) replacement hemodynamics and turbulence when a same-size SAPIEN 3 (Edwards Lifesciences Corp, Irvine, Calif) and Medtronic Evolut (Minneapolis, Minn) were implanted in a rigid aortic root with physiological dimensions and in a representative root with calcific leaflets obtained from patient computed tomography scans. MethodsTAV hemodynamics were studied by placing a SAPIEN 3 26-mm and an Evolut 26-mm in rigid aortic roots and representative root with calcific leaflets under physiological conditions. Hemodynamics were assessed using high-fidelity particle image velocimetry and high-speed imaging. Transvalvular pressure gradients (PGs), pinwheeling indices, and Reynolds shear stress (RSS) were calculated. Results(1) PGs obtained with the Evolut and the SAPIEN 3 were comparable among the different models (10.5 ± 0.15 mm Hg vs 7.76 ± 0.083 mm Hg in the rigid model along with 13.9 ± 0.19 mm Hg vs 5.0 ± 0.09 mm Hg in representative root with calcific leaflets obtained from patient computed tomography scans respectively); (2) more pinwheeling was found in the SAPIEN 3 than the Evolut (0.231 ± 0.057 vs 0.201 ± 0.05 in the representative root with calcific leaflets and 0.366 ± 0.067 vs 0.122 ± 0.045 in the rigid model); (3) higher rates of RSS were found in the Evolut (161.27 ± 3.45 vs 122.84 ± 1.76 Pa in representative root with calcific leaflets and 337.22 ± 7.05 vs 157.91 ± 1.80 Pa in rigid models). More lateral fluctuations were found in representative root with calcific leaflets. Conclusions(1) Comparable PGs were found among the TAVs in different models; (2) pinwheeling indices were found to be different between both TAVs; (3) turbulence patterns among both TAVs translated according to RSS were different. Rigid aortic models yield more conservative estimates of turbulence; (4) both TAVs exhibit peak maximal RSS that exceeds platelet activation 100 Pa threshold limit.

Lymphocyte and monocyte subpopulations in severe aortic stenosis at the time of surgical intervention.

Aortic stenosis (AS) is the most common acquired valvular heart disease in adults. Immune system involvement becomes evident during AS development. We sought to investigate the role of different circulating lymphocyte and monocyte subpopulations, with focus on CD4+CD8+ and natural killer T (NKT) cells, in AS. Blood samples and aortic valves were obtained from patients undergoing elective aortic valve surgery. Valves were dissected and underwent genetic analyses and calcium content assessment. Lymphocytes and monocytes subsets were assessed by flow cytometry. Thirty-eight AS patients were studied. Maximal transvalvular pressure gradient (PGmax) as well as mean transvalvular pressure gradient (PGmean) correlated with the CD4+CD8+ lymphocyte count (r=0.35, P=.03 and r=0.43, P=.006, respectively) and fraction (r=0.43, P=.007 and r=0.48, P=.002, respectively). PGmax and PGmean correlated with CD16+CD56+CD3+ NKT cell count (r=0.39, P=.01 and r=0.43, P=.007, respectively) and fraction (r=0.49, P=.002 and r=0.47, P=.003, respectively). The classical monocyte subpopulation increased after the surgery by 68% (P<.0001). Patients after mini-sternotomy surgery had 47% lower nonclassical monocyte counts than those with full-sternotomy (P=.03). Patients treated with statins had significantly lower postoperative levels of both classical (-25%, P=.04) and nonclassical monocytes (-37%, P=.004) than nontreated individuals. In patients with severe isolated AS, CD4+CD8+ T cells and CD16+CD56+CD3+ NKT cells are associated with AV pressure gradients. Postoperative monocyte levels are affected by procedure invasiveness and use of statins.

Simulated Transcatheter Aortic Valve Flow: Implications of Elliptical Deployment and Under-Expansion at the Aortic Annulus.

Clinical use of transcatheter aortic valves (TAVs) has been associated with abnormal deployment, including oval deployment and under-expansion when placed into calcified aortic annuli. In this study, we performed an integrated computational and experimental investigation to quantify the impact of abnormal deployment at the aortic annulus on TAV hemodynamics. A size 23 mm generic TAV computational model, developed and published previously, was subjected to elliptical deployment at the annulus with eccentricity levels up to 0.68 and to under-expansion of the TAV at the annulus by up to 25%. The hemodynamic performance was quantified for each TAV deployment configuration. TAV opening geometries were fabricated using stereolithography and then subjected to steady forward flow testing in accordance with ISO-5840. Centerline pressure profiles were compared to validate the computational model. Our findings show that slight ellipticity of the TAV may not lead to degeneration of hydrodynamic performance. However, under large ellipticity, increases in transvalvular pressure gradients were observed. Under-expanded deployment has a much greater negative effect on the TAV hemodynamics compared with elliptical deployment. The maximum turbulent viscous shear stress (TVSS) values were found to be significantly larger in under-expanded TAVs. Although the maximum value of TVSS was not large enough to cause hemolysis in all cases, it may cause platelets activation, especially for under-expanded deployments.

Progression of calcific aortic valve sclerosis in WHHLMI rabbits

Background and aimsAortic valve stenosis (AS) is the most common valvular heart disease and can be life-threatening. The pathogenesis of aortic valve calcification remains largely unknown, primarily due to the lack of an adequate animal model. The high-cholesterol diet-induced AS model in rabbits is one of the established models, but it has the significant limitation of liver dysfunction leading to low survival rates. We hypothesized that a myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbit, an animal model of familial hypercholesterolemia and atherosclerosis, is a useful animal model of AS. MethodsWHHLMI rabbits, aged 20 months and 30 months (n = 19), and control Japanese White rabbits (n = 4), aged 30 months, were used and evaluated by echocardiography under anesthesia. Pathological evaluation and quantitative analyses by polymerase chain reaction (PCR) were also performed. ResultsThe lipid profile was similar between 20 months and 30 months. Two rabbits died due to spontaneous myocardial infarction during the study. Thirty-month-old WHHLMI rabbits exhibited significantly smaller aortic valve area (0.22 ± 0.006 cm2vs. 0.12 ± 0.01 cm2, p < 0.05) and higher maximal transvalvular pressure gradient (7.0 ± 0.32 vs. 9.9 ± 0.95 mmHg, p < 0.05) than 20 month-old rabbits. Macroscopic examination of excised aortic valves demonstrated thickened and degenerated valve leaflets at 30 months. Histological evaluation confirmed thickened leaflets with calcified nodules at 30 months. Real-time PCR of resected aortic valve also showed increased expression level of calcification-related molecules including osteopontin, Sox9, Bmp2, RANKL, osteoprotegerin, and Runx2 (p < 0.05 each) in 30-month-old rabbits. ConclusionsWHHLMI rabbits may be useful models of early-stage AS in vivo.

Determinants of success and hemodynamic impact of balloon postdilatation of self-expanding transcatheter aortic valves.

To explore the rate, the determinants of success, and the hemodynamic impact of balloon postdilatation (BPD) of self-expanding transcatheter heart valves (SE-THVs) BACKGROUND: BPD is commonly used to optimize valve expansion and reduce paravalvular leakage (PVL) after transcatheter aortic valve implantation (TAVI) without clearly knowing its hemodynamic benefits. Patients (n = 307) who received a SE-THV were stratified according to whether a BPD was performed or not. Patients who received BPD were stratified according to the severity of PVL remaining after BPD into two groups: Successful BPD (≤mild PVL + BPD) and Failed BPD (moderate-severe PVL + BPD). BPD was performed in 121 patients (39.4%) and was successful in 106 patients (87.6% of attempts). A ratio of the postdilatation balloon diameter to the annulus diameter ≤0.95 was an independent predictor of BPD failure (OR: 10.72 [2.02-56.76], P = .005). Peak transvalvular pressure gradient (PG) was lower in the Successful BPD group (14[12-22] mm Hg) than in the Failed BPD group (18[16-23] mm Hg, P = .029), and did not rise in either group during follow-up (median [IQR], 364[161-739] days). BPD was performed in 39% of patients who received a SE-THV, and was successful in the majority of attempts. BPD failure was more likely in patients with a small postdilatation balloon-to-annulus diameter ratio. Effective BPD improved THV hemodynamic performance, and this was maintained in the intermediate-term post-TAVI.

Impact of pannus formation on hemodynamic dysfunction of prosthetic aortic valve: pannus extent and its relationship to prosthetic valve motion and degree of stenosis.

Although pannus is an important cause of prosthetic valve dysfunction, the minimum pannus size that can induce hemodynamic dysfunction has not yet been determined. This study investigated the correlation between the limitation of motion (LOM) of the prosthetic valve and pannus extent and determined the pannus extent that could induce severe aortic stenosis. This study included 49 patients who underwent mechanical aortic valve replacement (AVR) and showed pannus on cardiac computed tomography (CT). Pannus width, ratio of pannus width to valve diameter, pannus area, effective orifice area, encroachment ratio by pannus, pannus involvement angle and percent LOM of mechanical valves were evaluated on CT. Transvalvular peak velocity (TPV) and transvalvular pressure gradient (TPG) were measured by transesophageal echocardiography to determine the degree of aortic stenosis. The relationship between percent LOM of the prosthetic valve and pannus extent and the cut-off of pannus extent required to induce severe aortic stenosis were evaluated. The mean interval between AVR and pannus formation was 11years and was longer in patients with than without severe aortic stenosis (14.0 vs. 7.3years). On CT, the percent LOM of the prosthetic valve was significantly associated with the extent of pannus only in patients with pannus involvement angle > 180° (r = 0.55-0.68, P < 0.01). Pannus width, effective orifice area, and encroachment ratio were significantly associated with increased TPV and TPG (r = 0.51-0.62, P < 0.01). Pannus width > 3.5mm, pannus width/valve inner diameter > 0.15, and encroachment ratio > 0.14 were significantly associated with severe aortic stenosis (TPV > 4m/s; mean TPG ≥ 35mmHg), with c-indices of 0.74-079 (P < 0.005). CT-derived pannus extent parameters are good indicators of significant hemodynamic changes with increased TPV and mean TPG.

Aortic valve replacement using autologous pericardium: single centre experience with the Ozaki technique.

To assess the clinical implementation and report preliminary results of a novel technique called the Ozaki procedure for stentless aortic valve replacement through reconstruction of the valve leaflets from autologous pericardium. Between September 2015 and May 2017 30 patients (20 males, mean ± standard deviation age 66.83 ± 10.55 years) suffering from aortic stenosis (AS, n = 7), aortic regurgitation (AR, n = 12), or a combination of both (AS/AR, n = 11) were assigned for an Ozaki procedure. The glutaraldehyde-treated autologous pericardium was intraoperatively customised and tailored according to individual sinus measurements and appropriate Ozaki templates (CE marked). Mean and peak preoperative transvalvular pressure gradients in patients with AS were 46.34 ± 14.71 and 78.00 ± 22.54 mm Hg, respectively and effective orifice area was 0.93 ± 0.26 cm2. Ejection fraction was preserved at 57.37 ± 10.33%. Twenty-four valves were tricuspid and 6 bicuspid; 13 patients had concomitant cardiac surgery (coronary artery bypass graft, mitral valve repair, replacement of ascending aorta). Mean ± SD cross-clamp time for replacement only was 85.18 ± 18.10 minutes and perfusion time 104.76 ± 38.52 minutes. Cusp sizes were 27.76 ± 3.52 mm for the left coronary cusp (CC), 28.20 ± 3.51 mm for the right CC and 29.20 ± 3.34 mm for non-CC. Mean and peak postoperative gradients decreased to 8 ± 3.55 and 14.8 ± 6.21 mm Hg, respectively. Mean length of stay on the intensive care unit was 2.19 ± 2.34 days and in-hospital stay was 8.81 ± 2.04 days after isolated Ozaki procedures. No pacemaker had to be implanted after an isolated Ozaki procedure. Thirty-day mortality was 3.33% (n = 1). After 3 months, no patient presented with aortic stenosis, and regurgitation of the substituted valves was graded nil/trace in 85.71%, mild in 10.71%, and moderate in 3.57% of the patients. Ejection fraction remained unchanged at 58.89 ± 11.29%. No reoperation was required within the first 3 months. This aortic valve replacement technique has become available only recently. In our experience, it can be mastered after a relatively short training period, and has become part of our routine clinical toolbox. The use of autologous pericardium in combination with excellent haemodynamics may have the potential to overcome the structural disadvantages of biological aortic valves, to be beneficial in infective endocarditis, and to represent an alternative for patients with small annuli.

Early Clinical Experience with Sutureless Aortic Valve Replacement for Severe Aortic Stenosis.

BackgroundSutureless aortic valve replacement (SU-AVR) has been developed as an alternative surgical treatment for patients with symptomatic severe aortic stenosis (AS). The aim of this study was to evaluate the clinical outcomes of SU-AVR through an assessment of hemodynamic performance and safety.MethodsFrom December 2014 to June 2016, a total of 12 consecutive patients with severe AS underwent SU-AVR. The endpoints were overall survival and valve-related complications (paravalvular leakage, valve thrombosis, migration, endocarditis, and permanent pacemaker implantation). The mean follow-up duration was 18.1±8.6 months.ResultsThe mean age of the patients was 77.1±5.8 years and their mean Society of Thoracic Surgeons score was 9.2±17.7. The mean cardiopulmonary bypass and aortic cross-clamp times were 94.5±37.3 minutes and 54.9±12.5 minutes, respectively. Follow-up echocardiography showed good prosthesis function with low transvalvular pressure gradients (mean, 13.9±8.6 mm Hg and peak, 27.2±15.0 mm Hg) at a mean of 9.9±4.2 months. No cases of primary paravalvular leakage, valve thrombosis, migration, or endocarditis were reported. A new permanent pacemaker was implanted in 1 patient (8.3%). The 1-year overall survival rate was 83.3%±10.8%.ConclusionOur initial experience with SU-AVR demonstrated excellent early clinical outcomes with good hemodynamic results. However, there was a high incidence of permanent pacemaker implantation compared to the rate for conventional AVR, which is a problem that should be solved.

First-in-man implantation of the retrievable and repositionable VenusA-Plus valve.

No retrievable and repositionable second generation transcatheter aortic valve is available in China. Here, we report the first-in-man implantation of the retrievable and repositionable VenusA-Plus valve. A 76-year-old patient with symptomatic severe aortic stenosis and high surgical risk (STS 13.8%) was recommended for transcatheter aortic valve replacement (TAVR) by heart valve team. Type 0 bicuspid aortic valve with asymmetric calcification was identified by dual source computed tomography, and the unfavorable anatomies increased the possibility of malposition and paravalvular leakage during TAVR. Therefore, we used the retrievable and repositionable VenusA-Plus valve for the patient. Transfemoral TAVR was performed under local anesthesia with sedation, and a 26mm VenusA-Plus valve was successfully implanted. No transvalvular pressure gradient and trace paravalvular leakage were found. The successful first-in-man implantation indicates the retrievable and repositionable VenusA-Plus valve is feasible in complicated TAVR cases such as bicuspid aortic valve.

Role of Three-dimensional Transesophageal Echocardiography in Transcatheter Aortic Valve Implantation of Bicuspid Aortic Valve Stenosis: A Controlled Study and Comparison with Tricuspid Aortic Valve Stenosis

Aims: This study aims to investigate the application of three-dimensional transesophageal echocardiography in aortic valve stenosis for the assessment of aortic valve ring size, to monitor the procedure of transcatheter aortic valve implantation (TAVI), and perform postoperative follow-up. Methods: Eighteen patients with bicuspid valve malformation and severe aortic stenosis bicuspid aortic valve (Group BAV-AS) and 23 patients with a tricuspid valve and severe aortic stenosis trileaflet aortic valve (Group TAV-AS) were enrolled in this study. Preoperative routine transthoracic echocardiographic (TTE) examination and two- and three-dimensional transesophageal echocardiography (2D and 3DTEE) were performed, followed by perioperative 2D and 3D TEE monitoring and postoperative routine TTE at 6-month follow-up. Results: Both BAV-AS and TAV-AS patient groups were successfully implanted with bioprosthetic valves under 3DTEE guidance. Parameters at 6-month postoperatively, including prosthetic valve orifice area, mean aortic transvalvular pressure gradient, and left ventricular ejection fraction, showed significant improvement compared with baseline measures (P

Immediate Therapeutic Outcomes and Medium-term Follow-up of Percutaneous Balloon Pulmonary Valvuloplasty in Infants with Pulmonary Valve Stenosis: A Single-center Retrospective Study.

Background:Percutaneous balloon pulmonary valvuloplasty (PBPV) is the preferred therapy for pulmonary valve stenosis (PVS). This study retrospectively reviewed recent PBPV outcomes in infants with PVS. The aim of this study was to evaluate factors associated with immediate therapeutic outcomes and restenosis during medium-term follow-up.Methods:The study included 158 infants with PVS who underwent PBPV from January 2009 to July 2015. Demographic characteristics and patient records were reviewed, including detailed hospitalization parameters, hemodynamic data before and immediately after balloon dilation, cineangiograms, and echocardiograms before PBPV and at each follow-up. All procedures were performed by more than two experienced operators.Results:Immediately after balloon dilation, the pressure gradient across the pulmonary valve decreased from 73.09 ± 21.89 mmHg (range: 43–151 mmHg) to 24.49 ± 17.00 mmHg (range: 3–92 mmHg; P < 0.001) and the right ventricular systolic pressure decreased from 95.34 ± 23.44 mmHg (range: 60–174 mmHg) to 52.07 ± 18.89 mmHg (range: 22–134 mmHg; P < 0.001). Residual transvalvular pressure gradients of 67.31 ± 15.19 mmHg (range: 50–92 mmHg) were found in 8.2% of patients, indicating poor therapeutic effects; 6.4% of patients had variable-staged restenosis at follow-up and 3.8% underwent reintervention by balloon dilation or surgical repairs. Further analysis demonstrated that the balloon/annulus ratio showed statistically significant differences (P < 0.05) among groups with different therapeutic effects and between the restenosis and no-stenosis groups. Binary logistic regression analysis further revealed that higher balloon/annulus ratio (odds ratio: 0.005, 95% confidence interval: 0–0.39) was an independent protective factor for restenosis. The rate of severe complications was 1.9%.Conclusions:PBPV is a definitive therapy for infants with PVS based on its effectiveness, feasibility, and safety. Restenosis upon medium-term follow-up is relatively rare.

Thrombose de valve post-TAVI

GoalsTranscatheter aortic valve or leaflets thrombosis are mainly misapprehended. It negatively impacts the long-term efficiency of such prosthesis. Moreover, its incidence is presumably higher than previously described. EpidemiologyRecently reported subclinical leaflet thrombosis, occurring between first to third months after implantation, is about 10to 15%. All prosthesis are concerned by potential thrombosis. DiagnosisTranscatheter aortic valve thrombosis is usually detected on the basis of increased transvalvular pressure gradients or symptoms at routine follow-up. Main causes of post-TAVI thrombosis are: elderly patients, incomplete TAVI expansion, incomplete TAVI apposition to the aortic wall, areas of diminished blood flow and stagnation around the prosthesis. Main risk-factors of thrombosis are: large valves, patients with ejection fraction lower than 35%, valve-in-valve implantation, males, patients with large sinus of Valsalva, patients without anticoagulants. TreatmentPost-TAVI anti thrombotic regimen remains empirical. It is based on aspirin alone or dual antiplatelet therapy for 1–6months, followed by aspirin for life. Symptomatic patients with thrombus-based valve dysfunction are to be treated by oral anticoagulation (i.e., VKA or new oral anticoagulants NOAC). This treatment allows the restoration of normal leaflet motion in patients with a median time of 14 days.

Murmur intensity in adult dogs with pulmonic and subaortic stenosis reflects disease severity.

The aims of this study were to determine whether murmur intensity in adult dogs with pulmonic stenosis or subaortic stenosis reflects echocardiographic disease severity and to determine whether a six-level murmur grading scheme provides clinical advantages over a four-level scheme. In this retrospective multi-investigator study on adult dogs with pulmonic stenosis or subaortic stenosis, murmur intensity was compared to echocardiographically determined pressure gradient across the affected valve. Disease severity, based on pressure gradients, was assessed between sequential murmur grades to identify redundancy in classification. A simplified four-level murmur intensity classification scheme ('soft', 'moderate', 'loud', 'palpable') was evaluated. In total, 284 dogs (153 with pulmonic stenosis, 131 with subaortic stenosis) were included; 55 dogs had soft, 59 had moderate, 72 had loud and 98 had palpable murmurs. 95 dogs had mild stenosis, 46 had moderate stenosis, and 143 had severe stenosis. No dogs with soft murmurs of either pulmonic or subaortic stenosis had transvalvular pressure gradients greater than 50 mmHg. Dogs with loud or palpable murmurs mostly, but not always, had severe stenosis. Stenosis severity increased with increasing murmur intensity. The traditional six-level murmur grading scheme provided no additional clinical information than the four-level descriptive murmur grading scheme. A simplified descriptive four-level murmur grading scheme differentiated stenosis severity without loss of clinical information, compared to the traditional six-level scheme. Soft murmurs in dogs with pulmonic or subaortic stenosis are strongly indicative of mild lesions. Loud or palpable murmurs are strongly suggestive of severe stenosis.

Impact of prosthesis-patient mismatch after mitral valve replacement in rheumatic population: Does mitral position prosthesis-patient mismatch really exist?

BackgroundProsthesis-patient mismatch (PPM) is characterised by the effects of inadequate prosthesis size relative to body surface area (BSA).The purpose of this study was to determine the impact of PPM on late clinical outcomes after mitral valve replacement (MVR) in rheumatic population.MethodsFrom 2000 to 2013, a total of 445 patients (mean age 54.2 ± 11.7 years) underwent isolated MVR (±tricuspid annuloplasty) for rheumatic disease were investigated. Effective orifice area (EOA) was determined by the continuity equation and PPM was defined as indexed EOA (EOA/BSA) ≤ 1.2 cm2/m2. Clinical and echocardiographic follow-up (mean follow up 8.7 ± 4.0 years) results were compared.Results37% of patients (n = 165) had PPM. There were no significant differences in baseline and operative characteristics between patients with and without PPM except age and IEOA. A significant decrease in mean trans-valvular pressure gradient (MPG) over time following MVR, however the change of MPG showed no differences between groups (No PPM vs. PPM: 8.9 ± 4.7 mmHg → 3.6 ± 1.2 mmHg vs. 8.7 ± 4.5 mmHg → 3.8 ± 1.4 mmHg, p-value = 0.28). In all patients, there was a reduction of left atrium dimension (58.6 ± 12.0 mm → 53.2 ± 12.0 mm vs. 57.9 ± 8.9 mm → 52.2 ± 8.9 mm, p-value = 0.68) and left ventricular end diastolic diameter (49.9 ± 5.7 mm → 48.9 ± 5.7 mm vs. 49.7 ± 6.0 mm → 48.3 ± 5.0 mm, p = 0.24) without statistical significance. Freedom from TR progression rates at 3 and 5 years (99% vs.98%, 99% vs. 98%, p-value = 0.1), and overall survival rates at 3 and 5 years (97% vs. 96%, 94% vs. 94%, p-value = 0.7) were similar.ConclusionThis study shows that mitral PPM is not associated with atrial /ventricular remodeling and might not influence late clinical outcome including late TR progression, survival in rheumatic population.

Novel stent design for transcatheter mitral valve implantation

In this study, results of a functional in vitro study of 2 newly developed valved stents for transcatheter mitral valve implantation are presented. Two novel stent designs, an oval-shaped and a D-shaped stent with a strut fixation system were developed. The fixation force of the novel stents were tested in vitro in porcine hearts with a tensile test set-up. In further experiments, the stents were equipped with a circular valved stent, and the valve performances were investigated in a pulsatile heart valve tester. Sufficient mean stent fixation forces in the range of 24.2 ± 0.9 N to 28.6 ± 1.9 N were measured for the different stent models. The novel valved stents showed good performance in an in vitro pulsatile heart valve tester. A sufficient opening area and low opening pressures were measured for all tested mitral valved stents. Compared with an established reference valve, the D-shaped stent and the oval-shaped valved stent showed a lower systolic transvalvular pressure gradient, which indicates slightly greater extent of valvular leakage of the closed valved stents. However, the mitral nitinol valved stents demonstrated adequate durability. This study indicates a sufficient annular fixation force of the tested transcatheter mitral valve implantation valved stent prototypes. Therefore, these mitral valved stents demonstrate a new type of mitral valved stent design.

Transvalvular pressure gradients for different methods of mitral valve repair: only neochordoplasty achieves native valve gradients.

Many surgical and interventional methods are available to restore patency for patients with degenerative severe mitral valve regurgitation. Leaflet resection and neochordoplasty, which both include ring annuloplasty, are the most frequently performed techniques for the repair of posterior mitral leaflet flail. It is unclear which technique results in the best haemodynamics. In this study, we investigated the effect of different mitral valve reconstruction techniques on mitral valve haemodynamics and diastolic transvalvular pressure gradient in an ex vivo porcine model. Eight porcine mitral valves were tested under pulsatile flow conditions in an in vitro pulsatile flow loop for haemodynamic quantification. Severe acute posterior mitral leaflet flail was created by resecting the posterior marginal chorda. The acute mitral valve regurgitation was corrected using 4 different repair techniques, in each valve, in a strictly successive order: (i) neochordoplasty with polytetrafluoroethylene sutures alone and (ii) with ring annuloplasty, (iii) edge-to-edge repair and (iv) triangular leaflet resection, both with ring annuloplasty. Valve haemodynamics were measured and quantified for all valve configurations (native, rupture and each surgical reconstruction). The results were analysed using a validated statistical linear mixed model, and the P-values were calculated using a 2-sided Wald test. All surgical reconstruction techniques were able to sufficiently correct the acute mitral valve regurgitation. Neochordoplasty without ring annuloplasty was the only reconstruction technique that resulted in haemodynamic properties similar to the native mitral valve (P-values from 0.071 to 0.901). The diastolic transvalvular gradient remained within the physiological range for all reconstructions but was significantly higher than in the native valve for neochordoplasty with ring annuloplasty (P < 0.000), edge-to-edge repair (P < 0.000) and leaflet resection (P < 0.000). Neochordoplasty without ring annuloplasty resulted in a significantly better pressure gradient than neochordoplasty with a ring annuloplasty (P < 0.000). Additionally, neochordoplasty with a ring annuloplasty resulted in significantly lower transvalvular pressure gradients than edge-to-edge repair (P < 0.000) and leaflet resection (P < 0.000). Neochordoplasty with or without ring annuloplasty was the reconstruction technique that almost achieved native physiological haemodynamics after repair of posterior mitral leaflet flail after acute isolated chordal rupture in our ex vivo porcine model.

Aortic Valve Replacement With Perceval Bioprosthesis: Single-Center Experience With 617 Implants

This study describes the clinical and echocardiographic outcomes in a large single-center cohort of patients who underwent aortic valve replacement (AVR) with a sutureless Perceval (LivaNova, Milan, Italy) aortic bioprosthesis. Between March 2011 and December 2015, 617 patients underwent AVR with a Perceval bioprosthesis. The mean age was 76 ± 7 years, 388 patients were female (63%), and the mean European System for Cardiac Operative Risk Evaluation (EuroSCORE) II was 6.2% ± 5.4%. Concomitant procedures were mitral valve surgery (n= 74), tricuspid valve repair (n= 22), coronary artery bypass grafting (n= 42), myectomy (n= 3), and ascending aorta replacement (n= 2). The 30-day mortality rate was 1.9% (12 of 617). A total of 475 of 516 (92%) patients who had isolated AVR underwent minimally invasive surgery with an upper ministernotomy (n= 81) or a right anterior minithoracotomy (n= 394) approach. Cardiopulmonary bypass and aortic cross-clamp times were 81.7 ± 29.1 minutes and 50.5 ± 19.8 minutes for isolated AVR and 139.7 ± 51.5 minutes and 91.5 ± 29.5 minutes for combined procedures, respectively. At mean follow-up of 16.3 months (range, 0 to 51.9 months), the survival rate was 91.3%, the rate of freedom from reoperation was 99%, and the mean transvalvular pressure gradient was 11.9 ± 5.4 mm Hg. Left ventricular ejection fraction increased from 53.6% ± 8.4% to 54.5% ± 4.8% (p= 0.40), left ventricular mass decreased from 146.5 to 112.6 g/m2 (p < 0.001), and moderate paravalvular leakage occurred in 3 patients without hemolysis who did not require any treatment. AVR with the Perceval bioprosthesis is associated with low mortality rates and excellent hemodynamic performance. Sutureless technology may reduce operative times, especially in combined procedures, and may make minimally invasive AVR more easily reproducible.