Prognostic Role of Preoperative Tricuspid Annular Plane Systolic Excursion (TAPSE) in Mitral Valve Replacement (MVR) for Rheumatic Mitral Stenosis Patients

Tricuspid annular plane systolic excursion has been proposed as a simple and reproducible parameter for quantitative assessment of the right ventricular ejection fraction. The prognostic importance of preoperative TAPSE in patients with mitral valve replacement for rheumatic mitral stenosis patients is still under focused. Therefore, the objective of the study was to predict the outcome after MVR in rheumatic mitral stenosis patients in relation to preoperative TAPSE. This comparative cross-sectional study was conducted at the Department of Cardiac Surgery, National Heart Foundation Hospital and Research Institute. A total of 72 patients of rheumatic mitral stenosis patients who underwent mitral valve replacement were included in the study. They were divided into two groups: Group A and B. Group A included 36 patients with TAPSE 0.05) except for the preoperative TAPSE. Mean TAPSE of Group A was 13.17 (±1.40) and Group B was 18.61 (±1.57), the difference was statistically significant (p 0.05). Among the postoperative complications, including postoperative atrial fibrillation was higher in Group A (30.56%) than Group B (11.11%), mean ventilation time was higher in Group A (27.78%) than Group B (5.56%), length of intensive care was higher in Group A (33.33%) than Group B (11.12%), and hospital stay was higher in Group A (25.0%) than Group B (5.56%), (p < 0.05). Higher preoperative TASPE could be used as a prognostic tool for MVR in rheumatic mitral stenosis patients in our settings.

In-Hospital Outcomes in Minimally Invasive Mitral Valve Surgery: First Results in a Brazilian Single Center

Introduction: Treatments for cardiovascular diseases have increasingly evolved with the tendency to offer minimally invasive or transcatheter procedures instead of conventional sternotomy surgery. In this context, we highlight minimally invasive mitral valve surgery (MIMVS), which has been shown to be an increasingly solid option with some superior results when compared to the conventional technique: better pain control, shorter hospital stays, shorter recovery time, shorter readmission rate in the first postoperative year, better aesthetic results, and lower overall cost. Aim: This study aims to evaluate the stages of MIMVS, by primary mitral valve consultation, in our service and compare these results with data from the literature. Methods: All electronic medical records of patients who underwent MIMVS for primary mitral valve injury in the Encore Hospital from January 2020 to February 2023 were analyzed. Tabulation and statistical analysis were performed using the Microsoft Excel® program. Quantitative variables were presented as means, standard deviations. Results: 46 patients were enrolled in our study (Age: 59.1 ± 12.4 years old;60.8% Female, BMI: 26 ± 4.4 Kg/m2, Low risk STS score: 82.6%). The observed 30-day mortality was 2.1%, plastic rate of 23.9%, blood transfusion rate of 41.3%, length of stay in an intensive care bed (ICB) of 3.3 ± 3.3 days and hospital stay of 6.4 ± 5.1 days. Conclusions: We noticed that the MIMVS results carried out in our service agree with data from national and international literature with approximately 1.3 days more hospitalization in ICB.

Importance of concomitant functional mitral regurgitation on survival in severe aortic stenosis patients undergoing aortic valve replacement

BACKGROUND Mitral regurgitation(MR)is commonly seen in patients with severe aortic stenosis(AS)undergoing aortic valve replacement(AVR).But the long-term implications of MR in AS are unknown.AIM To investigate MR’s impact on survival of patients undergoing surgical AVR for severe AS.METHODS Of the 740 consecutive patients with severe AS evaluated between 1993 and 2003,287 underwent AVR forming the study cohort.They were followed up to death or till the end of 2019.Chart reviews were performed for clinical,echocardiographic,and therapeutic data.MR was graded on a 1-4 scale.Mortality data was obtained from chart review and the Social Security Death Index.Survival was analyzed as a function of degree of MR.RESULTS The mean age of the severe AS patients who had AVR(n=287)was 72±13 years,46%women.Over up to 26 years of follow up,there were 201(70%)deaths,giving deep insights into the determinants of survival of severe AS who had AVR.The 5,10 and 20 years survival rates were 75%,45%and 25%respectively.Presence of MR was associated with higher mortality in a graded fashion(P=0.0003).MR was significantly associated with lower left ventricular(LV)ejection fraction and larger LV size.Impact of MR on mortality was partially mediated through lower LV ejection fraction and larger LV size.By Cox regression,MR,lower ejection fraction(EF)and larger LV end-systolic dimension were independent predictors of higher mortality(χ^(2)=33.2).CONCLUSION Presence of greater than 2+MR in patients with severe AS is independently associated with reduced survival in surgically managed patients,an effect incremental to reduced EF and larger LV size.We suggest that aortic valve intervention should be considered in severe AS patients when>2+MR occurs irrespective of EF or symptoms.

Mitral Valve Abnormalities during Hypertrophic Cardiomyopathy: Study on a Cohort in Dakar

INTRODUCTION: Mitral valve abnormalities in hypertrophic cardiomyopathy (HCM) are becoming increasingly well defined, and their role in intra-ventricular obstruction is well defined. The aim of this study was to evaluate mitral valve abnormalities in patients with HCM. PATIENTS AND METHODS: We conducted a descriptive cross-sectional study from May 1 to July 1, 2022 in the Cardiology Department of Aristide Le Dantec Hospital. All patients with HCM aged at least 18 years old were included. The parameters studied concerned mainly the mitral valvular apparatus (papillary muscles abnormalities, leaflet length, mitral insufficiency). RESULTS: A total of 10 patients were included. Mean age was 58.3. On Doppler echocardiography, mean interventricular septal thickness was 20.6 mm. The mean maximum intra-ventricular gradient was 21.06 mmHg. Two patients had significant intraventricular obstruction. The mean length of the anterior mitral valve leaflet was 28.7 ± 3.55 mm, with extremes of 22 and 33 mm. The posterior mitral leaflet averaged 14.8 ± 3.16 mm. Nine (9) out of 10 patients had an elongated anterior valve leaflet. Elongation of the posterior leaflet was noted in 6 patients. With regard to papillary muscle position, 6 patients had an anterolateral ascending pillary muscle. These patients had a mean intra-ventricular gradient of 25 mmHg, compared with 16.5 mmHg in the others cases. We found no direct insertion on the mitral valve. Mitral insufficiency was noted in 9 patients, including 5 with mild insufficiency and 4 with moderate one. CONCLUSION: Mitral valve abnormalities in HCM appear to be frequent. They should be analyzed for a better diagnostic and therapeutic approach.

Chronic ischemic mitral valve regurgitation and surgical perspectives

Chronic ischemic mitral valve regurgitation is a result of disturbed left ventricular geometry secondary to myocardial ischemia in the absence of intrinsic mitral valve pathology. It is a common complication after myocardial infarction, and patients who have ischemic mitral regurgitation(IMR) have a worse prognosis compared to patients who have ischemic heart disease alone, and this is directly related to the severity of IMR. Medical therapy has limited efficacy, and surgical options including various repair techniques and valve replacement had been tried with variable success. Still there is intense debate among surgeons whether to interfere with moderate degree IMR at the time of coronary artery revascularization.

A novel case of transcatheter mitral valve-in-valve replacement using Mi-thos^TM system

Transcatheter mitral valve replacement(TMVR)has become an alternative to surgical mitral valve replacement for the treatment of patients with severe mitral insufficiency(MI)who are at very high or prohibitive surgical risk.[1]Because of impaired left ventricular dysfunction and previous cardiac surgery,some aged patients with degenerated bioprosthetic mitral valve and mitral regurgitation were refused to redo surgery.[2]Increasing demand are required for minimally invasive treatment of these patients.Hundreds of patients worldwide have been treated with a transcatheter mitral valve-in-ring or valve-in-valve procedure using transcatheter aortic valve.[3]However,rare case of transcatheter mitral valve-in-valve/ring replacement using transcatheter mitral valve system was reported.Here,we reported a successfully case of transcatheter mitral“valve-in-valve”replacement for the treatment of bioprosthetic mitral valve degeneration and severe regurgitation with domestic Mithos^TM valve.

Surgical management of moderate ischemic mitral valve regurgitation: Where do we stand?

Ischemic mitral regurgitation(IMR) represents a common complication after myocardial infarction. The valve is anatomically normal and the incompetence is the result of papillary muscles displacement and annular dilatation, causing leaflets tethering. Functionally the leaflets present a restricted systolic motion due to tethering forces that displaces the coaptation surface toward the left ventricle apex. The patients present poor left ventricular function at the time of surgery and the severity of the mitral regurgitation increases the risk of mortality. Currently there is general agreement to treat surgically severe IMR nevertheless strong evidences for patient with moderate insufficiency remains poor and proper treatment debated. The most effectivesurgical approach for the treatment of IMR remains debated. Some authors demonstrated that coronary artery bypass graft(CABG) alone is beneficial in patients with IMR. Conversely, in most patients, moderate IMR will persist or worsen after CABG alone which translate in higher long-term mortality as a function of residual mitral regurgitation severity. A probable reason for this unclear surgical management of functional MR is due to the contemporary suboptimal results of reparative techniques. The standard surgical treatment of chronic IMR is CABG associated with undersized annuloplasty using complete ring. Though, the recurrence of mitral regurgitation remains high(】 30%) because of continous left ventricle remodeling. To get better long term results, in the last decade, several subvalvular procedures in adjunct to mitral anuloplasty have been developed. Among them, surgical papillary muscle relocation represents the most appreciated option capable to restore normal left ventricle geometry. In the next future new preoperative predictors of increased mitral regurgitation recurrence are certainly needed to find an individual time period of treatment in each patient with moderate IMR.

The first two cases of transcatheter mitral valve repair with ARTO system in Asia

BACKGROUND:MAVERIC(Mitral Valve Repair Clinical Trial)validates the safety and effi cacy of the ARTO system.We here report the fi rst two successful cases of utilizing the ARTO system in patients with symptomatic heart failure(HF)with functional mitral regurgitation(FMR)in Asia.METHODS:Two patients,aged 70 and 63,had severe HF with FMR.Transesophageal echocardiography confirmed that the left ventricular ejection fractions were less than 50%with severe mitral regurgitation(MR)in both patients.Optimizing drug treatment could not mitigate their symptoms.Therefore,we used the ARTO system to repair the mitral valve for these patients on March 5 and 6,2019,respectively.RESULTS:Mitral valve repairs using the ARTO system were successfully performed under general anaesthesia for these two patients.MR was decreased immediately after the procedures in both patients.The 30-day and 3-month transthoracic echocardiography(TTE)revealed a moderate to severe MR in both patients,and the New York Heart Association(NYHA)scales were also partially improved.CONCLUSION:The first two cases in Asia indicate that the ARTO system is feasible for patients with heart failure with FMR,and the patient selection appears to be crucial.

Role of real-time three-dimensional transesophageal echocardiography in mitral valve repair

Background and objective Pre-operative assessment of mitral valve (MV) anatomy is essential to surgical design in patients undergoing MV repair.Although 2-dimensional (2D) echocardiography provides precise information regarding MV anatomy,RT-3D TEE could increase the understanding of MV apparatus and individual scallop identification.We aimed to investigate the value of RT- 3DTEE in MV repair.Methods RT-3DTEE was performed in six patients with mitral valve prolapse (MVP) by using Philips 1E33 with X7-2t probe.Preoperative RT-3DTEE studies were compared with surgical findings in patients undergoing surgical mitral valve repair,and quantitative evaluation was performed by QLab 6.0 software before and after surgical mitral valve repair.Results RT- 3DTEE could display dynamic morphology of MV,the location of prolapse,and spatial relation to the surrounding tissue.It could provide surgical views of the valves and the valvular apparatus.These results were consistent with surgical findings.The quantitative evaluation before and after surgical MV repair indicated that anterolateral to posteromedial diameter of annulus,anterior to posterior diameter of annulus,perimeter of annulus,and area of annulus in projection plane were significantly smaller after operation compared with those before operation (P【0.05).The length of posterior leaflet,the area of anterior and posterior leaflet,the maximal prolapse height,the volume of leaflet prolapse and the length of coaptation in projection plane were significantly reduced after operation (P【0. 05).Conclusion RT-3DTEE is a unique new modality for rapid and accurate evaluation ofmitral valve prolapse and mitral valve repair.

Echocardiographic Monitoring of Cardiac Parameters after Mitral Valve Replacement with the Preservation of Subvalvular Structures

To date many monitoring techniques have been used to determine the efficacy of surgical correction of mitral valve disease. The most common non-invasive method in use is echocardiography which can assess the myocardial and mitral valve function changes after mitral valve replacement procedures. In this study, we investigated the five-year follow-up echocardiographic results of 143 patients undergoing mitral valve replacement with preservation of subvalvular apparatus to analyze the recovery of myocardial and mitral valve functions.

Noninvasive Assessment of Cardiac Index with Transesophageal Echocardiography in Patients Undergoing Mitral Valve Replacement: A Comparison between Determinations at the Mitral Valve and the Ascending Aorta

Methods: Sixteen patients with American Society of Anesthesiologists status (ASA) II-III, age ≤ 70 yr, male or female, preoperatively NYHA II-III and EF ≥ 45%, scheduled for mitral valve replacement (MVR) were studied. Complete intravenous general anesthesia was used for induction and anesthesia maintenance. After anesthesia induction we put the TEE probe into the esophagus. The cardiac index was determined at three periods following MVR: T1 30 minutes later following cessation of bypass, T2 60 minutes after cessation of bypass, T3 90 minutes after cessation of bypass. Statistical analysis was made with the Bland and Altman method. Results: Ninety-six measurements were compared. The cardiac index values at the level of prosthesis mitral valve (CIMV) ranged from 1.3 to 5.5 L·min-1·m-2 (mean 2.6 ± 0.9). The Values of cardiac index at aortic valve (CIAA) ranged from 2.7 to8.8 L·min-1·m-2 (mean 4.9 ± 1.7). Bias was -2.3 L·min-1·m-2 and limits of agreement -5.6 to 1.0 L·min-1·m-2. Conclusion: During mitral valve replacement, doubtful correlations were observed between values of cardiac index at the mitral valve and the ascending aorta using TEE.

Should mitral valve prolapse be considered as one of the risk factors for open angle glaucoma? A preliminary observation

AIM:To assess the incidence of mitral valve prolapse in patients with newly diagnosed primary open angle glaucoma.METHODS:The study included 12 patients without any other comorbidities or taking any general or local medications.Each patient underwent a full ophthalmological examination with visual field assessment and optical computed tomography of the macula and optic nerve head.Carotid Doppler ultrasound was performed to exclude impaired blood flow in this region and transthoracic echocardiography with assessment of the function and morphology of the heart valves.RESULTS:In the study group,mitral valve prolapse was found in seven patients(58.3%),while mitral valve regurgitation in 11 patients(91.7%).One case of normal pressure glaucoma and four cases of juvenile glaucoma were diagnosed.There were also other risk factors for glaucoma:myopia(58.3%),migraine headaches(41.7%),a positive family history of glaucoma(16.7%).CONCLUSION:Mitral valve prolapse could be indicated as a new risk factor for glaucoma.It seems reasonable to conduct screening tests for glaucoma in patients with mitral valve prolapse in the course of echocardiography.

A rare case of mitral valve dissection and aortic-left ventricular tunnel associated with possible autoimmune vasculitis

We report a very rare case of mitral valve dissection and aorticleft ventricular tunnel caused by possible autoimmune vasculitis.We suspected Behcet’s disease in this patient.There was no obvious clinical evidence of infective endocarditis.Echocardiography is the diagnostic tool of choice to recognize valvular dysfunction,related pathology and possible complications.The patient may require immunosuppressive therapy due to the high likelihood of recurrence perioperation period.

Early Results of Mitral Valve Replacement in Severe Pulmonary Artery Hypertension—An Institutional Prospective Study

Introduction: In patients undergoing surgery for mitral valve replacement (MVR) for valvular heart disease, pulmonary artery hypertension (PAH) has been considered a major risk factor. In this prospective study, we have studied the early hemodynamic changes and post-operative outcomes of MVR among patients with severe PAH. Methods: 68 consecutive patients who underwent mitral valve replacement for severe rheumatic mitral valve disease with severe PAH (pulmonary artery pressure (PAP) > 50 mmHg) were studied prospectively for immediate postoperative hemodynamics and outcomes. The mean age of the patients was 32.1 years. 32 (47.05%) patients had mitral stenosis, 13 (19.11%) had mitral regurgitation and 23 (33.82%) had mixed lesions. Patients were divided into two groups based on preoperative pulmonary artery pressures. In 56 patients (82.35%, group I) PAP was sub-systemic or systemic, with a mean of 58.4 mmHg. Twelve patients (17.65%, group II) had supra-systemic PAP with a mean of 82.4 mmHg. Results: After mitral valve replacement, the PAP and pulmonary vascular resistance (PVR) decreased significantly in group I to near normal levels. In group II also the PAP and PVR decreased significantly but significant residual PAH remained. Operative mortality was 3.5% in group I and 16.6% in group II. Conclusions: MVR is safe and effective at the presence of severe PAH as long as the PAP is below or equal to systemic pressures. With suprasystemic PAP, MVR carries a high risk of mortality and the patient continues to have severe PAH in the postoperative period.

Evaluation of mitral chordae tendineae length using four-dimensional computed

BACKGROUND Mitral valvuloplasty using artificial chordae tendineae represents an effective surgical approach for treating mitral regurgitation.Achieving precise measurements of artificial chordae tendineae length(CL)is an important factor in the procedure;however,no objective index currently exists to facilitate this measurement.Therefore,preoperative assessment of CL is critical for surgical planning and support.Four-dimensional x-ray micro-computed tomography(4D-CT)may be useful for accurate CL measurement considering that it allows for dynamic three-dimensional(3D)evaluation compared to that with transthoracic echocardiography,a conventional inspection method.AIM To investigate the behavior and length of mitral chordae tendineae during systole using 4D-CT.METHODS Eleven adults aged>70 years without mitral valve disease were evaluated.A 64-slice CT scanner was used to capture 20 phases in the cardiac cycle in electrocardiographic synchronization.The length of the primary chordae tendineae was measured from early systole to early diastole using the 3D image.The primary chordae tendineae originating from the anterior papillary muscle and attached to the A1-2 region and those from the posterior papillary muscle and attached to the A2-3 region were designated as cA and cP,respectively.The behavior and maximum lengths[cA(ma),cP(max)]were compared,and the correlation with body surface area(BSA)was evaluated.RESULTS In all cases,the mitral anterior leaflet chordae tendineae could be measured.In most cases,the cA and cP chordae tendineae could be measured visually.The mean cA(max)and cP(max)were 20.2 mm±1.95 mm and 23.5 mm±4.06 mm,respectively.cP(max)was significantly longer.The correlation coefficients(r)with BSA were 0.60 and 0.78 for cA(max)and cP(max),respectively.Both cA and cP exhibited constant variation in CL during systole,with a maximum 1.16-fold increase in cA and a 1.23-fold increase in cP from early to mid-systole.For cP,CL reached a plateau at 15%and remained elongated until end-systole,whereas for cA,after peaking at 15%,CL shortened slightly and then moved toward its peak again as end-systole approached.CONCLUSION The study suggests that 4D-CT is a valuable tool for accurate measurement of both the length and behavior of chordae tendineae within the anterior leaflet of the mitral valve.

An Investigation of Regional Variations in the Biaxial Mechanical Properties of Porcine Mitral Valve

Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,posterior leaflet,chordae tendineae,and papillary muscles,which all work in harmony.The material properties alteration on the leaflet causes MV malfunction,and leading to valve diseases such as regurgitation and stenosis.The alteration may be caused by several factors such as calcification,genetic disorders,and infection,which usually have an influence to the mechanical properties,and thus affecting the mechanical behavior of MV.In consequence,some of the patients need MV replacement or repair to restore the normal function of MV.The important point for succeeding such a medical treatment depends on the technique,design,and material used in the treatment shall help rebuild the normal mechanical environment and behavior of MV.Therefore,the mechanical and materials characteristics of MV become a magnetism to explore.In this study,we present an integrated experimental and mathematical constitutive study base in collagen distribution aiming at the mechanical property differences in various region on MV.Methods and materials Both the size and composition of porcine valves are similar to human’s,so the porcine heart valve is often being used in experimental research.Mitral valve was isolated from fresh eight porcine hearts(250-500 gr),and perfused in PBS solution to maintain moist.Anterior and posterior leaflets were separated and dissected into 4 part(two 8~*8 mm rough zone and two clear zone samples)and 2 part(8~*8 mm belly and edge of the clear zone)respectively.Tracking markers(glass bean)were stickled on specimen with superglue(cyanoacrylate adhesive).Then,the specimen was mounted onto biaxial tester machine(CeIIScale,Biotester),and the tests are run by force control.During mechanical test,the specimen is immersed into PBS solution in physiological temperature(37℃).Every test procedure contains 8 preconditioning cycles and 8 loading cycles.The mechanical behavior was determined from the relationship between first Piola-Kirchoff stress and stretch.Constitutive model was reconstructed and material parameters were fitted from biaxial tensile result.Histological analyses were performed in the specimen before and after test.First,a piece of the specimen was cut and immersed in fixation solution(4%paraformaldehyde),then it was dehydrated in graded alcohol solution,and next embedding in paraffin wax block.Paraffin block was then cut and stained with VVG and Picro-sirius red.The collagen fibril orientation was observed from those histological results.Results The experimental results of the clear zone of MV’s first Piola-Kirchhoff stress and stretch curve are similar to those of the recent study from others,while result of the rough zone shows a different trend.This can be explained by differences in collagen distribution between clear zone and rough zone of MV.Our result thus allows for a refinement of computational models for more accurately predicting MV condition,where tissue heterogeneity plays an important role in the MV function.

Transfemoral aortic valve implantation in the case of pre-existing mitral prosthesis and pure aortic regurgitation: A case report

BACKGROUND Transcatheter aortic valve replacement(TAVR)is recommended in patients with severe aortic stenosis who have high surgical risk.However,in the pre-existing mechanical mitral valve prosthesis and natural pure aortic regurgitation,TAVR is relatively contraindicated.In this report,we described one case of TAVR with native aortic regurgitation in the presence of mechanical mitral valve prosthesis.CASE SUMMARY A 64-year-old man with a medical history of mitral valve replacement had severe dyspnea and was symptomatic even at rest for 3 mo.His echocardiography showed severe native pure aortic regurgitation.His euroscore was 15.A TAVR procedure with an evolut R was planned.A 34 mm evolut R was placed by transesophageal echocardiography.The mitral prosthesis was functioning normally,and mild-moderate paravalvular leakage was evident by transesophageal echocardiography.The patient recovered without any complication.At 1 mo follow up,the patient was well,and no paravalvular leakage was noted.CONCLUSION TAVR for pure aortic regurgitation in the presence of prosthetic mitral valve can be a safe procedure.

Detection of Mitral Valve Diseases by Bicoherence Analysis of Heart Sound Signals

The analysis of 10 normal and 51 mitral valve pathology making a total of 61 heart sound signals that were obtained with Littmann 4100 Digital Stethoscope were conducted in this study.Following the recorded sound signals were denoised by using wavelet filters,the signals were applied bicoherence analysis that is an high order spectral analysis method.It has been demonstrated that varieties of mitral valve pathology could be determined by three-dimensional surfaces of bicoherence and maximum bicoherence values.

Feasibility and short-term outcomes of transcatheter valve-in-valve implantation for failed aortic and mitral bioprosthesis-a single-center experience

Objectives Transcatheter valve-in-valve （VIV） implantation for failed bioprostheses has become an alternative to open surgery in those deemed high risk. The purpose of this study was to evaluate the effectiveness and outcomes of this emerging procedure. Methods Fourty VIV procedures were performed in 38 consecutive patients （mean age 70 ± 14 years and mean Logistic EuroScore 23.6 ± 15.5%） with severe aortic （n = 19） or mitral （n = 21） bioprosthetic valve dysfunction between 2014 and 2017. Bioprosthetic failure was secondary to stenosis in 11 （27.5%）, regurgitation in 19 （47.5%）, and combined in 10 （25.0%） bioprostheses. Clinical, echocardiographic, and procedural profiles were characterized, and the short-term results of the study patients were reported. Results Successful transfemoral （n = 15）, trans-subclavian （n = 1）, or transapical （n = 3） aortic VIV using either balloon-expandable valves （Edwards Sapien XT, n = 7） or self-expandable valves （Medtronic CoreValve, n = 12）; and transapical （n = 21） mitral VIV using either Edwards Sapien XT （n = 15） or me-chanically expandable valves （Boston Scientific Lotus, n = 6） were accomplished in all 40 VIV procedures. Implantation was successful with immediate restoration of satisfactory valve function in all patients. Five patients （13.2%） died at a median follow up of 9.3 months. Most of the 33 patients alive were in good functional status with good prosthetic valve performance. Conclusions Transcatheter VIV implantation is a feasible and safe option for the management of bioprosthetic valve failure. It may offer a less invasive alternative for those high-risk patients needing repeat valve replacement.

Transcatheter mitral valve implantation using a novel system:preclinical results

Background This preclinical study in sheep sought to demonstrate the initial safety and feasibility of a novel transcatheter mitral valve system(Mi-thos valve)composed of a self-expanding frame and a bovine pericardial tissue bioprosthesis.Methods The valve was implanted in 26 sheep using a transapical approach for short-and long-term evaluation.The technical feasibility,safety,durability,and valve function were evaluated during and 6 months after the procedure using intracardiac and transthoracic echocardiography,multisliced computed tomography,histological analysis,and electron microscopy.Results The success rate of valve implantation was 100%,and the immediate survival rate after surgery was 84%.Five animals died within 90 min after the development of the prosthetic valve due to an acute left ventricular outflow tract obstruction(n=2)and sudden intraoperative ventricular fibrillation(n=3).Twelve animals died within 1 month due to acute left heart dysfunction.Mild(n=5)and moderate(n=2)paravalvular leakage occurred in seven animals,and two moderate PVL animals died of chronic heart failure within three months.Multimodality imaging studies of the remaining seven animals showed excellent function and alignment of the valves,with no coronary artery obstruction,no left ventricular outflow tract obstruction,no severe transvalvular gradients and no paravalvular leakage.Macroscopic evaluation demonstrated stable,secure positioning of the valve,with full endothelialization of the valve leaflets without injury to the ventricular or atrial walls.Histological and electron microscopic examinations at six months showed no obvious macro-or microcalcification in the leaflets.Conclusions Preclinical studies indicate that transcatheter implantation of the Mi-thos valve is technically safe and feasible.The durability,functionality,and lack of leaflet calcification were all verified in animal experiments.The information from these preclinical studies will be applied to patient selection criteria and the first-in-human studies.