Leaflet Excursion Research Articles

Tricuspid valve repair concomitant with the Norwood operation among babies with hypoplastic left heart syndrome.

Among patients with hypoplastic left heart syndrome (HLHS), tricuspid valve regurgitation (TR) portends a poor prognosis. Our goal was to describe the outcomes of tricuspid valve reconstruction (TVR) concomitant with the Norwood operation and using two-dimensional echocardiography and evaluate the structural factors associated with successful functional correction. We performed a retrospective, single-centre study of patients with HLHS undergoing TVR at the time of the Norwood operation. Structural echocardiographic parameters were compared between patients with successful correction (≤ mild TR) and those with ≥ moderate regurgitation at discharge. Preoperative dimensions of matched HLHS controls with ≤ trivial TR were used as a reference. Of 205 patients with HLHS undergoing the Norwood operation, 18 patients had a concomitant TVR. Ten (56%) patients had an improved TR grade postoperatively, 8 (44%) of whom had ≤ mild TR at discharge. Improvement in TR grade (P = 0.001) and having ≤ mild TR at discharge (P = 0.011) were associated with an improved reintervention and TR-free survival. Patients with successful functional correction had smaller preoperative tricuspid annulus lateral dimensions (P = 0.023), tricuspid valve area (P = 0.007) and right ventricle mid-width (P = 0.064). Preoperatively, the successful TVR cases tended to have had higher anterior leaflet excursion (80 ± 20 vs 55 ± 11, P = 0.010), and a higher proportion of anterior leaflet prolapse (63% vs 10%, P = 0.043) compared to cases where TVR was not successful. Patients with HLHS with significant tricuspid regurgitation undergoing the stage 1 operation were more likely to have successful concomitant tricuspid valve repair if they had less tricuspid annular dilation, less-severe RV enlargement and predominantly anterior leaflet prolapse. Successful tricuspid valve repair was associated with improved mid- and long-term outcomes.

Preoperative Computed Tomography Angiography Reveals Leaflet-Specific Calcification and Excursion Patterns in Aortic Stenosis.

Computed tomography-based evaluation of aortic stenosis (AS) by calcium scoring does not consider interleaflet differences in leaflet characteristics. Here, we sought to examine the functional implications of these differences. We retrospectively reviewed the computed tomography angiograms of 200 male patients with degenerative calcific AS undergoing transcatheter aortic valve replacement and 20 male patients with normal aortic valves. We compared the computed tomography angiography (CTA)-derived aortic valve leaflet calcification load (AVLCCTA), appearance, and systolic leaflet excursion (LEsys) of individual leaflets. We performed computer simulations of normal valves to investigate how interleaflet differences in LEsys affect aortic valve area. We used linear regression to identify predictors of leaflet-specific calcification in patients with AS. In patients with AS, the noncoronary cusp (NCC) carried the greatest AVLCCTA (365.9 [237.3-595.4] Agatston unit), compared to the left coronary cusp (LCC, 278.5 [169.2-478.8] Agatston unit) and the right coronary cusp (RCC, 240.6 [137.3-439.0] Agatston unit; both P<0.001). However, LCC conferred the least LEsys (42.8° [38.8°-49.0°]) compared to NCC (44.8° [41.1°-49.78°], P=0.001) and RCC (47.7° [42.0°-52.3°], P<0.001) and was more often characterized as predominantly thickened (23.5%) compared to NCC (12.5%) and RCC (16.5%). Computer simulations of normal valves revealed greater reductions in aortic valve area following closures of NCC (-32.2 [-38.4 to -25.8]%) and RCC (-35.7 [-40.2 to -32.9]%) than LCC (-24.5 [-28.5 to -18.3]%; both P<0.001). By linear regression, the AVLCCTA of NCC and RCC, but not LCC, predicted LEsys (both P<0.001) in patients with AS. Both ostial occlusion and ostial height of the right coronary artery predicted AVLCCTA, RCC (P=0.005 and P=0.001). In male patients, the AVLCCTA of NCC and RCC contribute more to AS than that of LCC. LCC's propensity for noncalcific leaflet thickening and worse LEsys, however, should not be underestimated when using calcium scores to assess AS severity.

The feasibility of mitral valve device foldoplasty: an in vivo study to evaluate durable retention.

We have previously shown in experimental settings that a leaflet foldoplasty device reduces redundant leaflet area to re-establish mitral valve (MV) coaptation. The current study investigates the in vivo device retention and functional durability following foldoplasty. The prototype is of superelastic nitinol formed into a 3-dimensional shape. It is unfolded to engage a specified area of leaflet tissue and then folded to exclude this tissue from the coaptation surface. Design modifications were made and tested in benchtop studies to determine the optimal design for durable retention within the leaflet. To evaluate in vivo performance, posterior leaflet chordae were severed in Yorkshire pigs to produce complete posterior leaflet prolapse and severe mitral regurgitation. Design modifications were then used for MV repair. Five animals that underwent repair using the optimal design were observed for 2 weeks postoperative to evaluate the functional result and implant retention. Device position and orientation were maintained at 2 weeks while preserving the functional MV repair in all 5 animals. Coaptation height was 5.5 ± 1.5 mm, which was not significantly different from a baseline of 4.9 ± 0.8 mm. The degree of leaflet excursion was 41.0 ± 16.0 compared to a baseline of 58.7 ± 27.5. Device foldoplasty is a new concept for MV repair based on the reduction of redundant leaflet tissue area. This study demonstrates the feasibility of safe maintenance of this repair without early dislodgement or embolization.

An echocardiographic finding mimicking tricuspid atresia in a neonate with dilated cardiomyopathy.

We report a neonate with dilated cardiomyopathy and have echocardiographic findings consistent with "functional" tricuspid atresia. There was an echo-bright, plate-like tissue at the tricuspid valve position with no forward flow across it. This report underscores the role of right ventricle intracavitary haemodynamic influence on the tricuspid valve leaflet excursion and demonstrates a phenomenon of "pseudo or functional tricuspid atresia" mimicking tricuspid atresia in a patient with acute presentation of cardiomyopathy.

Surgical repair of ischemic mitral regurgitation: one ring does not fit all.

The review summarizes the key parameters that can aid in determining the optimal treatment of ischemic mitral regurgitation (IMR). Left ventricular (LV) and mitral valve (MV) parameters are important for surgical planning and risk stratification in IMR. Although LV dimensions is one of the main parameters used in the guidelines, volumes more accurately depict LV remodelling. Furthermore, wall motion abnormalities and wall motion score index can also be useful for surgical planning in treatment of IMR. Viability is best measured with cardiac magnetic resonance, but it is not feasible in certain centres. In contrast, measurement of strain with echocardiography is an emerging and feasible tool for estimating viability. MV leaflet tethering and pattern measured with echocardiography are also useful for MV surgery. Anterior leaflet excursion angle can identify patients in whom undersized ring annuloplasty is potentially unsuitable. Treatment of IMR relies on accurate parameters that can determine the optimal surgical approach. In some patients, lack of viable myocardium suggests inadequacy of revascularization and thus, an adjunctive left ventricular reconstruction may be necessary. Degree and pattern of MV leaflet tethering can indicate whether ring annuloplasty, which is the most common repair technique, is sufficient or an adjunctive sub-valvular intervention is beneficial.

Echocardiographic assessment before and after Percutaneous Transvenous Mitral Commissurotomy in patients with Rheumatic Mitral Stenosis.

Objectives:To determine the changes produced in mitral valve morphology after Percutaneous Trans-Venous Mitral Commissurotomy.Methods:Patients with mitral stenosis who underwent PTMC at the cardiology department of Lady Reading Hospital, Peshawar, Pakistan, from 2006-2016 were included in this study. All the data were manually obtained from the electronic medical record (M.F.E.). Wilkin’s echocardiographic scoring system was used to assess the severity of mitral valve thickness, leaflet mobility, valvular calcification, and Subvalvular disease. The student t-test was used for mean comparison. P-value < 0.05 was considered significant.Results:Of the total 229 patients, males were 96(41.9%), and females were 133(58.1%). The mean [SD] age of the patients was 25 ± 11years. The total Wilkin score was 7 ±1.5. 151(65.9%) were in New York Heart Association (NYHA) functional class III, and 78(34.1%) were in NYHA class IV. There was no immediate change after PTMC in systolic myocardial velocities (SV) measured at the lateral tricuspid annulus. The 2D mitral valve area increased from 0.98±0.94 cm2 to 1.78 ± 0.44 cm2 (P=0.001). Left Atrium diameter was 5.16±0.75 mm prior to PTMC, significantly decreased to 4.7± 0.7 mm (p=0.005) after PTMC. Ejection fraction (Left Ventricular Ejection Fraction) changed from 60.45± 8.25 mm Hg to 62.76±10 mm Hg (p=0.001). Mean Right Ventricular Ejection Fraction (RVEF) of patients before PTMC was 48.7 ± 4.7%, did not change significantly immediately after PTMC.Conclusion:PTMC is associated with significant changes in mitral valve morphology in terms of splitting of the fused mitral commissures, increased MVA, improved leaflet excursion, and splitting of the subvalvular structures.

Abstract 16801: Papillary Muscle Tip Approximation in Repair of Ischemic Mitral Regurgitation in a Chronic Swine Model

Introduction: Mitral valve (MV) repair with undersized annuloplasty (UMA) for ischemic mitral regurgitation (IMR) is being abandoned in favor of valve replacement (MVR) following CTSN trial results. However, in patients with durable repair, survival and left ventricular function (LVF) were significantly better than MVR. Achieving a durable repair with UMA is challenging as it draws leaflets away from papillary muscle (PM) insertions, causing unphysiological tethering and unicuspid configuration that fails (FigA-B). Hypothesis: Drawing PM tips together with an approximating stitch (PMT-A) can relieve leaflet tethering and enable better repair (FigC). A chronic swine model of IMR was used to compare effects of isolated PMT-A, UMA and PMT-A+UMA on MV and LV at 3 months post surgery. Methods: Twenty-five farm swine underwent catheterization and occlusion of left circumflex artery, resulting in postero-lateral myocardial infarction (MI). Two months after MI, IMR severity of &gt;2+ was confirmed on echo, and animals underwent one of the 3 repairs: PMT-A (n=6), UMA (n=8), PMT-A+UMA (n=11). Echo was performed postoperatively and repeated with MRI at 3 months (FigD). MV kinematics, coaptation geometry, and LVF were assessed. Results: IMR was eliminated after all repairs and did not recur through the study. Annulus continued to grow after PMT-A, but not in UMA or PMT-A+UMA group (FigE1) without increasing severity of IMR. Compared to prerepair, tenting depth was significantly reduced only in PMT-A and PMT-A+UMA groups (FigE2). Both leaflet excursion angles (diastolic minus systolic angles) increased after PMT-A, but not in other groups (FigE3-4). LV size and LVF was similar between groups, confirming that PMT-A did not perturb diastolic filling. Conclusions: In this model of IMR, PMT-A improved leaflet mobility, compared to isolated UMA or PMT-A+UMA. PMT-A is a simple technique that can potentially improve durability of MV repair by restoring valvular kinematics.

Abstract 16300: Preoperative Computed Tomography Angiography Reveals Leaflet-specific Contribution to Aortic Stenosis Influenced by Local Coronary Factors

Background: Current computed tomography (CT)-based diagnosis of severe aortic stenosis (AS) using aortic valve calcification (AVC) load does not take into account interleaflet differences in calcification and leaflet dysfunction. Objectives: We sought to assess the functional impact of these differences and identify factors that can influence calcification load in a leaflet-specific manner. Methods: We retrospectively reviewed the CT angiograms (CTA) of 170 AS patients being considered for valvular intervention and 20 control normal-valve patients. We quantified AVC load, aortic valve leaflet calcification (AVLC) load, and systolic leaflet excursion (LE sys ), and used regression analysis to investigate their interrelationships. We further performed computer simulation to examine how interleaflet differences in LE sys affect aortic valve area (AVA). Lastly, we used regression analysis to identify contributors of leaflet-specific calcification. Results: We observed significant interleaflet differences in AVLC load in AS patients, with noncoronary cusp (NCC) carrying the most load (342.0 [220.3-603.1] AU), compared to the right coronary cusp (RCC) (278.5 [168.2-492.1] AU; P &lt; 0.001) and the left coronary cusp (LCC) (240.6 [143.1-450.3] AU; P &lt; 0.001). However, LCC, but not NCC, was associated with the least LE sys (43.0 [38.4-49.2] °), compared to both NCC (45.2 [41.2-49.9] °; P = 0.009) and RCC (47.8 [42.1-53.0] °; P &lt; 0.001). Computer simulation of normal valve dynamics revealed that NCC and RCC contributed 10.4 [-1.6-15.7] % more ( P = 0.004) and 10.7 [4.9-20.4] % more ( P &lt; 0.001) to AVA than LCC. In multiple regression analysis, only NCC and RCC AVLC loads predicted LE sys (b = -0.015, P &lt; 0.001; b = -0.020, P &lt; 0.001), but not LCC AVLC load (b = -0.008; P = 0.065). Both ostial/proximal occlusion and ostial height of right coronary artery predicted RCC AVLC load (b = 71.508, P = 0.007; b = 10.252, P = 0.008). Conclusions: NCC and RCC should be given more weight than LCC in the evaluation of AS because of their greater AVC loads, more predictable LE sys -AVLC relationships, and greater contributions to AVA. Ostial/proximal occlusion and large ostial height of RCA should signify risk for disease progression in RCC.

Abstract 16979: Hemodynamic Comparison of Tricuspid Ring Annuloplasty vs. Hetzer Annuloplasty Technique to Repair Functional Tricuspid Regurgitation

Introduction: Surgical repair of functional tricuspid regurgitation (FTR) is increasingly performed, and the techniques are evolving. Annuloplasty is currently the technique of choice, with different techniques yielding varied results, and thus require optimization. Objective: In this study, we sought to compare tricuspid valve function and kinematics after ring annuloplasty and Hetzer’s double orifice repair in an ex vivo model of FTR. Methods: Ten pig hearts were mounted into a right heart simulator, and studied at 70 bpm while maintaining the total volume of working fluid. FTR was created by increasing afterload, which caused acute right ventricular dilation and TV tethering. Tricuspid valve annuloplasty (TVA) was performed with a 26mm MC 3 ring. Hetzer procedure was performed with pledgeted sutures that approximated the anteroposterior and septal annular segments. Flow probes were used to measure FTR, and leaflet kinematics with echocardiography. Results: FTR of 17.7±9.2mL(p&lt;0.0001) after RV dilation. Repair with TVA and Hetzer reduced FTR to 8.8±6.8ml(p=0.7142) and 7.8±6.9ml(p=0.0919), respectively, but did not eliminate it. Septal leaflet excursion angle decreased by 48.1% with FTR (p=0.04 vs. baseline ) . Repair with TVA and Hetzer increased the angle to 17.3±6.7°(p=0.0312) and 21.5±8.3°(vs FTR, p=0.0034), respectively. The Hetzer improved septal leaflet mobility better than TVA (p=0.0145). The posterior leaflet excursion angle decreased by 49.2% compared to baseline to 18.4±10.5° (p=0.0060) and both TVA and Hetzer significantly improved mobility to 33.6±8.4° (p=0.0081) and 31.6±15.6° (p=0.0256), respectively. Anterior leaflet mobility decreased after FTR by 60.7% to 18.1±8.2°. The effect of these repairs on the sub-valvular apparatus was negligible. Conclusion: TVA and Hetzer both reduced regurgitation but did not eliminate it. Septal and posterior leaflet mobility was improved, while the anterior leaflet remained tethered.

Functional tricuspid valve insufficiency after cardiac transplantation: Which factor is the most important?

ObjectivesTricuspid insufficiency (TI) is the most common valvular complication following orthotopic heart transplantation (HTx) and in serious cases is associated with increased mortality. In this study, we analyze the possible variables influencing TI following HTx and aim to identify the most important risk factors and mechanisms responsible for functional TI development and progression.MethodsWe identified the incidence of TI within our institute in 857 of 1515 patients who underwent HTx using the biatrial anastomosis technique in the years between 1986 and 2010. The risk factors that could influence TI were retrospectively analyzed in detail in a representative group of 152 patients with identical TI distribution as found in the entire program. Patients of the group were subdivided into 2 groups according to the severity of TI: patients with TI grade ≤2 and those with TI grade >2. Impact on long-term survival (>15 years) was assessed.ResultsIn univariable analysis, study variables such as age of recipient (P = .027), donor to recipient right atrium anterior wall ratio (P < .001), tricuspid annulus anterior to septal leaflet excursion ratio (P = .001), dialysis (P = .026), and total biopsy number (P = .003) showed significant differences. The variables, height of recipient (P = .080), body mass index donor to body mass index recipient ratio (P = .080), and number of biopsies with more than moderate grade (P = .067) showed a trend toward significance in the development of severe TI after HTx. In multivariable analysis, we found an independent significant association between TI after HTx and donor to recipient right atrium anterior wall ratio, number of biopsies, and dialysis.ConclusionsChanges in tricuspid annulus geometry, number of biopsies, and dialysis are the most important risk factors for the development and progression of TI following cardiac transplantation. It could be prevented using modified operative techniques, noninvasive diagnostic modalities, and intensified ultrafiltration. In patients with biatrial anastomosis technique with generous atrial cuff, the presence of TI greater than grade 2 did not impact long-term survival.

Cine-Computed Tomography for the Evaluation of Prosthetic Heart Valve Function

Background: After aortic valve replacement (AVR), suspected prosthetic valve dysfunction (mechanical or biological) may arise based on echocardiographic transvalvular velocities and gradients, leading to reoperative surgical intervention being considered. Our experience has found that 4-dimensional (space and time) image reconstruction of ECG-gated computed tomography, termed cine-CT, may be helpful in such cases. We review and illustrate our experience. Methods: Twenty-seven AVR patients operated previously by a single surgeon (who performs >100 AVRs/year) were referred for repeat evaluation of suspected aortic stenosis (AS) based on elevated transvalvular velocities and gradients. The patients were fully evaluated by cine-CT. Results: In all but 2 cases, the cine-CT strikingly and visually confirmed normal leaflet function and excursion, with no valve thrombosis, restriction by pannus, or obstruction by clot. In only 2 cases did cine-CT reveal decreased mechanical valve leaflet excursion. Repeat surgery was required in only 1 case while all other patients continued clinically without cardiac events. Conclusions: Echocardiography is an extraordinarily useful tool for the evaluation of prosthetic valve function. Increased pressure recovery beyond the valve and other factors may occasionally lead to exaggerated gradients. Cine-CT is emerging as an extremely valuable tool for further evaluation of suspected prosthetic valve AS. Our experience has been extremely helpful, as is shown in the dramatically reassuring images.

Pathological Remodeling of Mitral Valve Leaflets from Unphysiologic Leaflet Mechanics after Undersized Mitral Annuloplasty to Repair Ischemic Mitral Regurgitation.

BackgroundUndersized ring annuloplasty is a commonly used surgical repair for ischemic mitral regurgitation, in which annular downsizing corrects regurgitation, but alters valve geometry and elevates tissue stresses. In this study, we investigated if unphysiological leaflet kinematics after annuloplasty might cause pathogenic biological remodeling of the mitral valve leaflets, and if preserving physiologic leaflet kinematics with a better technique can moderate such adverse remodeling.Methods and ResultsTwenty‐nine swine were induced with ischemic mitral regurgitation, and survivors were assigned to groups: 7 underwent annuloplasty, 12 underwent annuloplasty with papillary‐muscle approximation, 6 underwent papillary‐muscle approximation, and 3 were sham controls. Pre‐and post‐surgery leaflet kinematics were measured, and valve tissue was explanted after 3 months to assess biological changes. Anterior leaflet excursion was unchanged across groups, but persistent tethering was observed with annuloplasty. Posterior leaflet was vertically immobile after annuloplasty, better mobile with the combined approach, and substantially (P=0.0028) mobile after papillary‐muscle approximation. Procollagen‐1 was higher in leaflets from annuloplasty compared with the other groups. Heat shock protein‐47 and lysyl oxidase were higher in groups receiving annuloplasty compared with sham. α‐SMA was elevated in leaflets from animals receiving an annuloplasty, indicating activation of quiescent valve interstitial cells, paralleled by elevated transforming growth factor‐β expression.ConclusionsThis is the first study to demonstrate that surgical valve repairs that impose unphysiological leaflet mechanics have a deleterious, pathological impact on valve biology. Surgeons may need to consider restoring physiologic leaflet stresses as well as valve competence, while also exploring pharmacological methods to inhibit the abnormal signaling cascades.

Clinical Leaflet Thrombosis in Transcatheter and Surgical Bioprosthetic Aortic Valves by Four-Dimensional Computed Tomography

The incidence of leaflet thrombosis after transcatheter aortic valve replacement (TAVR) with active surveillance by four-dimensional computed tomography (4DCT) ranges from 7% to 14%. The incidence of leaflet thrombosis when 4DCT is performed for clinical and echocardiographic indications is unknown. All patients with prior TAVR or surgical aortic valve replacement (SAVR) who underwent evaluation between October 2015 and January 2017 at our institution and had clinical or echocardiographic indications of leaflet thrombosis were evaluated by 4DCT. Indications for 4DCT by echocardiography included (1) interval increase in mean gradient of 10 mm Hg or more, (2) interval decrease in ejection fraction of 10% or more, (3) thrombus seen on transthoracic echocardiography, (4) persistent or increasing paravalvular leak, or (5) valve dehiscence or thickened leaflets seen on transthoracic echocardiography. Clinical indicators were (1) stroke, (2) transient ischemic attack, or (3) new or worsening heart failure. During the study period, 612 patients underwent TAVR, and 101 patients (55 TAVR; 46 SAVR) met the criteria for 4DCT imaging. Leaflet thrombosis was seen in 17 of 55 TAVR patients (30.9%) and 15 of 46 SAVR patients (32.6%). Follow-up imaging with 4DCT after treatment with anticoagulation showed improvement or resolution in thrombus burden and leaflet excursion in all TAVR patients and in two-thirds of SAVR patients. One-third of patients with clinical or echocardiographic indications suggestive of leaflet thrombosis were found to have evidence of leaflet thrombosis using 4DCT. This allowed tailored anticoagulation therapy with resolution of the thrombus in most patients and avoiding unnecessary anticoagulation in the remaining two-thirds of patients.

Effect of Mitral Valve Leaflets Excursion on Mitral Valve area after Percutaneous Trans- Venous Mitral Commissurotomy

Background: Aim of our study was to predict the effect of mitral valve leaflets excursion on mitral valve area following percutaneous transvenous mitral commissurotomy PTMC in patients of mitral stenosis.Methods: Total 70 patients with severe mitral stenosis who underwent PTMC were enrolled in the study.Transthoracic echocardiography was done the day before PTMC and 24-48 hours after PTMC. Mitral valve area, anterior and posterior leaflets excursion were recorded. The relation between leaftlet excursion and mitral valve after PTMC was evaluated.Results: Following PTMC there were significant increasein anterior leaflet excursion from 1.9 ± 0.2 to 2.3 ± 0.2cm (p&lt;0.001), posterior leaflet excursion from 1.6±0.2to1.9 ± 0.2cm (p&lt;0.001). Mitral valve areas increased from 0.8 ± 0.1 to1.7 ± 0.2cm²(p&lt;0.001). Both leaflet excursion increased significantly with the increase in mitral valve area till the area reached a value of about 1.5 cm2, after which any further increase in mitral valve area was not associated with any further increase in leaflet excursion.Conclusion: PTMC is associated with immediate significant changes in mitral valve morphology in terms of splitting of fused mitral commissures, increased leaflets excursion and splitting of the subvalvular structures. Post PTMC leaflet excursion increases significantly with the increase in mitral valve area till the area reaches a value of about 1.5 cm2 after which any further increase in mitral valve area is not associated with any further increase in leaflet excursion.Cardiovasc. j. 2017; 10(1): 3-7

Regional Changes in Leaflet Coaptation Dynamics After Total Tricuspid Reconstruction

Stentless porcine extracellular matrix tricuspid tube grafts were developed for tricuspid valve reconstruction. The purpose of this study was to conduct an echocardiographic assessment of the performance of native and tube graft leaflets in an acute porcine model. Fourteen 65-kg pigs were randomly assigned to tube graft (n= 7) or control with native valve preservation (n= 7). Epicardial echocardiography was performed at baseline after sternotomy, after valve operation, and after hemodynamic stabilization. No baseline differences were found (p > 0.05). All valves were competent with only a mild central regurgitant jet in two tube grafts and two native valves. Tube graft valves were compared with native valves. Anterior-septal leaflet coaptation length (18 ± 6 mm versus 6 ± 1 mm, p < 0.0005), coaptation height (20 ± 9 mm versus 9 ± 4 mm, p < 0.005), and anterior leaflet length (31± 1 mm versus 22 ± 2 mm, p < 0.00005) were all significantly larger in the tube graft valves. The billowing index (0.8 ± 0.1 versus 0.9 ± 0.1, p > 0.05) and tenting height (5 ± 1 mm versus 4 ± 2 mm, p > 0.1) were not significantly different. Leaflet excursion angles for both leaflets were not significantly different between the native and tube graft valves (p > 0.1). In a porcine experimental model, a competent tricuspid valve was constructed using extracellular matrix tube graft material. Coaptation geometry was significantly different from native valves with an increased coaptation zone because of excessive leaflet tissue in the tube graft valves. The tube graft tended to prolapse into the atrium, but it did not compromise the motion and competence of the leaflets.

Bioprosthetic Mitral Valve Leaflet Thrombosis, Novel Oral Anticoagulants a Potential Solution for a Sticky Problem

A 52-year-old female presented with NYHA class III dyspnoea on a background of a previous bioprosthetic mitral valve replacement. This was inserted five years previously for severe mitral regurgitation secondary to anthracycline cardiomyopathy. The patient had declined a mechanical valve prosthesis. Transoesophageal echocardiography demonstrated restricted leaflet motion, and confirmed severe stenosis of the bioprosthetic mitral valve with a mean gradient of 12 mmHg across the valve. Coronary angiogram did not reveal significant coronary disease and after heart team discussion the patient was referred for a re-do mechanical mitral valve replacement. Whilst awaiting surgery apixaban was prescribed for a deep vein thrombosis and co-existent paroxysmal atrial fibrillation. A repeat transoesophageal echocardiogram performed on table pre-sternotomy two months later revealed normal bioprosthetic valve function with appropriate leaflet excursion and a mean gradient of 3 mmHg across the valve. The patient's symptoms had improved during the anticoagulation period. Bioprosthetic valve leaflet thrombosis (BVLT) has been reported post transcatheter and surgical bioprosthetic aortic valve replacements. This clinical vignette highlights the importance of recognising BVLT in the months and years post implantation. The case also demonstrates a potential role for novel oral anticoagulants in treating this condition. Future studies are required to determine risk factors for BVLT and optimal treatment methods.

Relation of Aortic Valve Morphologic Characteristics to Aortic Valve Insufficiency and Residual Stenosis in Children With Congenital Aortic Stenosis Undergoing Balloon Valvuloplasty

Aortic valve morphology has been invoked as intrinsic to outcomes of balloon aortic valvuloplasty (BAV) for congenital aortic valve stenosis. We sought to use aortic valve morphologic features to discriminate between valves that respond favorably or unfavorably to BAV, using aortic insufficiency (AI) as the primary outcome. All patients who underwent BAV at 2 large-volume pediatric centers from 2007 to 2014 were reviewed. Morphologic features assessed on pre-BAV echo included valve pattern (unicuspid, functional bicuspid, and true bicuspid), leaflet fusion length, leaflet excursion angle, and aortic valve opening area and on post-BAV echo included leaflet versus commissural tear. Primary end point was increase in AI (AI+) of ≥2°. Eighty-nine patients (median age 0.2years) were included in the study (39 unicuspid, 41 functional bicuspid, and 9 true bicuspid valves). Unicuspid valves had a lower opening area (p <0.01) and greater fusion length (p= 0.01) compared with functional and true bicuspid valves. Valve gradient pre-BAV and post-BAV were not different among valve patterns. Of the 16 patients (18%) with AI+, 14 had leaflet tears (odds ratio 13.9, 3.8 to 50). True bicuspid valves had the highest rate (33%) of AI+. On multivariate analysis, leaflet tears were associated with AI+, with larger opening area pre-BAV and lower fusion length pre-BAV. AI+ was associated with larger pre-BAV opening area. Gradient relief was associated with reduced angle of excursion. Valve morphology influences outcomes after BAV. Valves with lesser fusion and larger valve openings have higher rates of leaflet tears which in turn are associated with AI.

Mitral stenosis and hypertrophic obstructive cardiomyopathy: An unusual combination

ObjectiveSystolic anterior motion of mitral valve (MV) leaflets is a main pathophysiologic feature of left ventricular outflow tract (LVOT) obstruction in hypertrophic obstructive cardiomyopathy. Thus, restricted leaflet motion that occurs with MV stenosis might be expected to minimize outflow tract obstruction related to systolic anterior motion. MethodsFrom January 1993 through February 2015, we performed MV replacement and septal myectomy in 12 patients with mitral stenosis and hypertrophic obstructive cardiomyopathy at Mayo Clinic Hospital in Rochester, Minn. Preoperative data, echocardiographic images, operative records, and postoperative outcomes were reviewed. ResultsMean (standard deviation) age was 70 (7.6) years. Preoperative mean (standard deviation) maximal LVOT pressure gradient was 75.0 (35.0) mm Hg; MV gradient was 13.7 (2.8) mm Hg. From echocardiographic images, 4 mechanisms of outflow tract obstruction were identified: systolic anterior motion without severe limitation in MV leaflet excursion, severe limitation in MV leaflet mobility with systolic anterior motion at the tip of the MV anterior leaflet, septal encroachment toward the LVOT, and MV displacement toward the LVOT by calcification. Mitral valve replacement and extended septal myectomy relieved outflow gradients in all patients, with no death or serious morbidity. ConclusionsPatients with mitral stenosis and hypertrophic obstructive cardiomyopathy have multiple LVOT obstruction mechanisms, and MV replacement may not be adequate treatment. We favor septal myectomy and MV replacement in this complex subset of hypertrophic obstructive cardiomyopathy.

Functional and Biomechanical Performance of Stentless Extracellular Matrix Tricuspid Tube Graft: An Acute Experimental Porcine Evaluation

Stentless porcine extracellular matrix tricuspid tubular valves have been developed for tricuspid valve reconstruction. The purpose of this study was to compare biomechanical and functional performance of native and tube graft valves in an acute porcine model. Twenty-two 65-kg pigs were randomized to tube graft or control with native valve preservation. Anterior papillary muscle force was measured with a dedicated force transducer. Microtip pressure catheters were placed in the right atrium and ventricle. Leaflet motion and three-dimensional valve geometry were evaluated using 13 sonomicrometry crystals: six in the tricuspid annulus, one on each leaflet free edge, one on each papillary muscle tip, and one in the right ventricular apex. No regurgitation and no significant differences in intracavitary pressures, annular motion, or leaflet excursion angles were observed after tube graft implantation (p > 0.05). Compared with the native valve, the tricuspid annulus, leaflet orifice area, annular diameters, and the septal segment of the annulus were significantly smaller in the tube graft group (p < 0.05). Maximum anterior papillary muscle force was significantly lower in the tube graft group (p < 0.005). The implantation technique led to an annular circumferential downsizing of 20% ± 17%. An extracellular matrix tube graft implanted in the tricuspid position produces a competent valve with physiologic performance that, despite downsizing, makes the tube graft an attractive alternative to valve replacement. The downsizing of the implantation should be considered when planning tube graft size and may be potentially beneficial by relieving tension on the repaired tissue, thereby increasing durability.

Effect of Subvalvular Changes on Mitral Valve Leaflets Excursion after Percutaneous Transvenous Mitral Commissurotomy

Background: Aim of our study was to predict the effect of subvalvular changes on mitral valve leaflets excursion in a patient with mitral stenosis following percutaneous trans-venous mitral commissurotomy.Methods: Total of 60 patients of severe mitral stenosis were enrolled in the study. Transthoracic echocardiography was done on the day before percutaneous trans-venous mitral commissurotomy and 24-48 hours after percutaneous trans-venous mitral commissurotomy. Subvalvular area, anterior and posterior leaflets excursion were recorded.Results: Following percutaneous trans-venous mitral commissurotomy there were significant increase in anterior leaflet excursion from 1.8 ± 0.2 to 2.2 ± 0.2cm (p=&lt;0.001), posterior leaflet excursion from 1.5±0.2to1.8 ± 0.2cm (p&lt;0.001) . Subvalvular splitting areas was from 0.8 ± 0.2 to1.2 ± 0.2cm²(p=&lt;0.001). Pulmonary arterial systolic pressure and left atrial diameter were significantly reduced respectively 55.6 ± 19.5 vs. 31.6 ± 9.5 mmHg,(p &lt; 0.001) and 4.3 ± 0.6 cm vs. 3.8 ± 0.6 cm (p &lt; 0.001). Post percutaneous trans-venous mitral commissurotomy subvalvular splitting area was found to be the predictor of increased excursion of both anterior and posterior mitral leaflets.Conclusion: percutaneous trans-venous mitral commissurotomy is associated with immediate significant changes in mitral valve morphology in terms of splitting of fused mitral commissures, increased valve leaflets excursion and splitting of the subvalvular structures. Post percutaneous trans-venous mitral commissurotomy subvalvular splitting area was found to be the predictor of increased excursion of both anterior and posterior mitral leaflets.Cardiovasc. j. 2015; 8(1): 8-12