The feasibility evaluation of transapical saddle-shaped valved stent for transcatheter mitral valve implantation

Background: Transcatheter mitral valve implantation (TMVI) is a promising and minimally invasive treatment for high-risk mitral regurgitation (MR). The purpose of this study was to investigate the feasibility of a novel self-expanding valved stent for transcatheter mitral valve implantation via apical access. Methods: A novel self-expanding mitral valved stent system was designed and fabricated for the in vivo evaluation. It is consists of an atrial flange and a saddle-shaped ventricular body connected by two opposing anchors and two opposing extensions. During the valve deployment, each anchor is controlled by a recurrent string. TMVI was performed in ten pigs using the valve prosthesis through the apical access to verify technical feasibility. Echocardiography and ventricular angiography were used to assess hemodynamic data and valve function. The surviving pigs were sacrificed four weeks later to confirm stent deployment. Results: Ten animals underwent transapical mitral valve implantation with the novel mitral valved stent. Optimal valve deployment and accurate anatomical adjustment were obtained in nine animals. Implantation failed in one case, and the animal died one day later due to stent mismatch. After stent implantation, the hemodynamic parameter of other animals was stable and valve function was normal. The mean pressure across the mitral valve and left ventricular outflow tract (LVOT) were 2.98±0.91mmHg and 3.42±0.66 mmHg, respectively. The macroscopic evaluation confirmed the stable and secure positioning of the stents in the mitral valve. No obvious valve displacement, embolism, and paravalvular leakage were observed four weeks after valve implantation. Conclusions: This study proved that the novel mitral valved valve stent is technically feasible in animals. This device features opposing anchors, opposing recurrent strings, and saddle-like ventricular portions, providing structural design details for reducing TMVI complications. However, the long-term feasibility and durability of this valved stent need to be improved and verified.

Lead Dependent Tricuspid Valve Dysfunction-Risk Factors, Improvement after Transvenous Lead Extraction and Long-Term Prognosis

Background: Lead-related tricuspid valve dysfunction (LDTVD) has not been studied in a large population and its management remains controversial. Methods: An analysis of the clinical data of 2678 patients undergoing transvenous lead extraction (TLE) in years 2008–2021 was conducted, with a separate group of 119 patients with LDTVD. Potential risk factors for LDTVD, improvement in valve function, and long-term prognosis after TLE were assessed. Results: LDTVD was diagnosed in 4.44% of patients referred for lead extraction due to different reasons. The most common mechanism of LDTVD was propping upward or clamping down the leaflet by the lead (85.71%). The probability of LDTVD was higher in female sex, patients with valvular heart disease, atrial fibrillation, heart failure, large right ventricle and high pulmonary artery systolic pressure, the presence of only pacing lead, and in case of collision of the lead with tricuspid valve and adhesion of the lead to the heart structures. The prognosis of patients with LDTVD was worse, however, patients with improved valve function after TLE showed a significantly better long-term survival. Conclusions: Lead dependent tricuspid valve dysfunction is a potentially serious condition that requires thorough diagnostics and thoughtful management. The risk factors for LDTVD are primarily related to the course of the lead and its adhesion to the heart structures. Improvement of tricuspid valve function after TLE is observed in 35.29% of patients Patients with LDTVD have a worse long-term survival, but the improvement in valve function following TLE contributes to a significant reduction in mortality.

Evolving Solutions in the Surgical Treatment of Isolated Pulmonary Valve Stenosis

Background: Surgical treatment of isolated pulmonary valve stenosis in infants and children has evolved over the years, shifting from the original exclusive aim at lowering right ventricle pressure to the current concomitant focus on preserving pulmonary valve function. In our study, we sought to analyze the effect of such evolving philosophy on long-term results. Methods: All consecutive patients treated in our center between July 1983 and March 2019 were included. Patients were categorized into 2 groups based on the introduction into treatment practice of sparing valve techniques (1995). Actuarial survival, freedom from reintervention on the right outflow tract, transvalvular mean pressure gradient decrease, and pulmonary valve function at follow-up were analyzed. Results: One hundred twenty-three patients operated before (Group I, n=81) or since (Group II, n=42) 1995 were enrolled in the study. Mean age and weight were 3.0 ± 0.36 years and 16.6 ± 1.7kg, respectively. Early mortality occurred exclusively in 3 patients of Group 1. Transvalvular mean pressure gradient decreased in the entire patient population (from 63.28 ± 12.9mmHg to 16.46 ± 7.9mmHg). At a mean follow-up interval of 4.9 ± 33 years, freedom from death was comparable, but freedom from right ventricular outflow tract reintervention was significantly greater in Group II. Although the transvalvular gradient remained stable over time in non-reoperated survivors (mean value of 16.46 ± 7.9mmHg), pulmonary valve function on 2D-Echo showed severe incompetence in 2 patients of Group I and just mild to moderate incompetence in 20 patients of Group II, with a significantly negative effect of unsuccessful preoperative pulmonary balloon valvuloplasty (14/20 vs 6/20, p=0.025) in the latter. Conclusion: Current pulmonary valve sparing techniques are associated with better results, particularly in terms of freedom from re-interventions and pulmonary valve function at follow-up. Balloon valvuloplasty prior to surgery may worsen operative results, promoting pulmonary insufficiency and therefore should probably be avoided in all patients in whom anatomical characteristics predict failure of percutaneous therapy.

Long-Term Outcome Up To 40 Years after Single Patch Repair of Complete Atrioventricular Septal Defect in Infancy or Childhood

Objectives Patients with repaired complete atrioventricular septal defect (CAVSD) represent an increasing portion of grown-ups with congenital heart disease. For repair of CAVSD, the single-patch technique has been employed first. This technique requires division of the bridging leaflets, thus, among other issues, long-term function of the atrioventricular valves is of particular concern. Methods Between 1978 and 2001, 100 consecutive patients with isolated CAVSD underwent single-patch repair in our institution. Hospital mortality was 11%. Primary endpoints were clinical status, atrioventricular valve function, and freedom from reoperation in long term. Follow-up was obtained contacting the patient and/or caregiver, and the referring cardiologist. Results Eighty-three patients were eligible for long-term follow-up (21.0 ± 8.7, mean ± standard deviation [21.5; 2.1–40.0, median; min–max] years after surgical repair). Actual long-term mortality was 3.4%. Quality of life (QoL; self- or caregiver-reported in patients with Down syndrome) was excellent or good in 81%, mild congestive heart failure was present in 16%, moderate in 3.6% as estimated by New York Heart Association classification. Echocardiography revealed normal systolic left ventricular function in all cases. Regurgitation of the right atrioventricular valve was mild in 48%, mild–moderate in 3.6%, and moderate in 1.2%. The left atrioventricular valve was mildly stenotic in 15% and mild to moderately stenotic in 2%; regurgitation was mild in 54%, mild to moderate in 13%, and moderate in 15% of patients. Freedom from left atrioventricular-valve-related reoperation was 95.3, 92.7, and 89.3% after 5, 10, and 30 years, respectively. Permanent pacemaker therapy, as an immediate result of CAVSD repair (n = 7) or as a result of late-onset sick sinus syndrome (n = 5), required up to six reoperations in single patients. Freedom from pacemaker-related reoperation was 91.4, 84.4, and 51.5% after 5, 10, and 30 years, respectively. Conclusion Up to 40 years after single-patch repair of CAVSD, clinical status and functional results are promising, particularly, in terms of atrioventricular valve function. Permanent pacemaker therapy results in a life-long need for surgical reinterventions.

Immediate Post-Procedural and Discharge Assessment of Mitral Valve Function Following Transcatheter Edge-to-Edge Mitral Valve Repair: Correlation and Association with Outcomes

The correlation between residual mitral regurgitation (rMR) grade or mitral valve pressure gradient (MVPG), at transcatheter edge-to-edge mitral valve repair (TEEMr) completion and at discharge, is unknown. Furthermore, there is disagreement regarding rMR grade or MVPG from which prognosis diverts. We retrospectively studied 82 patients that underwent TEEMr. We tested the correlation between rMR or MVPG and evaluated their association, with outcomes. Moderate or less rMR (rMR ≤ 2) at TEEMr completion was associated with improved survival, whereas mild or less rMR (rMR ≤ 1) was not. Patients with rMR ≤ 1 at discharge demonstrated a longer time of survival, of first heart failure hospitalization and of both. The correlation for both rMR grade (r = 0.5, p < 0.001) and MVPG (r = 0.51, p < 0.001), between TEEMr completion and discharge, was moderate. MR ≤ 2 at TMEER completion was the strongest predictor for survival (HR 0.08, p < 0.001) whereas rMR ≤ 1 at discharge was independently associated with a lower risk of the combined endpoint (HR 4.17, p = 0.012). MVPG was not associated with adverse events. We conclude that the assessments for rMR grade and MVPG, at the completion of TEEMr and at discharge, should be distinctly reported. Improved outcome is expected with rMR ≤ 2 at TEEMr completion and rMR ≤ 1 at discharge. Higher MVPG is not associated with unfavorable outcomes.

Impact of a structured patient education programme on early diagnosis of prosthetic pulmonary valve endocarditis

Background: Infective endocarditis is a major threat after prosthetic pulmonary valve replacement. Early diagnosis may improve outcomes. Methods: A structured patient education programme for prevention and early diagnosis of infective endocarditis was developed at our institution since 2016. Time delay between onset of symptoms of prosthetic pulmonary valve endocarditis and its diagnosis (defined as initiation of appropriate high-dose intravenous antibiotic treatment) was compared for patients presenting before (cohort 1) and after (cohort 2) initiation of the patient education programme. Results: Between 2008–2019, 26 patients (median age 24.9, range: 16.8–62.0 years, 73% male) were diagnosed with prosthetic pulmonary valve endocarditis, 13 patients (cohort 1) before (1.7 cases/year) and 13 patients (cohort 2) after June 2016 (3.7 cases/year). There were no differences in baseline characteristics or clinical presentation between the study cohorts. Overall, the median delay between onset of symptoms and diagnosis of infective endocarditis was 6 days (range: 0–133 days) with a significantly longer delay among patients in cohort 1, compared to cohort 2 (25 days, range: 5–133 days versus 3 days, range: 0–13 days, p < 0.0001). A delay of >7 days was documented in 11/13 patients (85%) in cohort 1 as compared to 1/13 (8%) in cohort 2 (p < 0.001). Need for urgent valve replacement or permanent deterioration of prosthetic valve function was higher in cohort 1, compared to cohort 2 (11/13, 85% versus 5/13, 39%; p = 0.041). Conclusions: Prosthetic pulmonary valve endocarditis is increasingly recognised. A structured patient education programme may improve early diagnosis and clinical outcomes.

Features of venous blood circulation and valve function in the lower extremities according to duplex scanning data and morphofunctional studies

Aim. To study the mechanisms of venous return and the functioning features of lower extremity venous valves in horizontal and vertical positions. Methods. The study, conducted from April 2019 to December 2020, included 100 people. The study participants were divided into 2 groups. The first group was represented by 44 patients (88 limbs) with varicose veins, whose venous system was examined by duplex ultrasound scanning during inpatient rehabilitation. The second (control) group consisted of 56 healthy individuals (92 limbs) without visible signs of venous pathology who underwent an outpatient examination of the venous system. The average age of the patients in the two groups was 49.22.4 and 51.11 years, respectively; women predominated in both groups. The qualitative and quantitative parameters of venous blood flow were studied in the study. Venous valvular insufficiency was assessed by using reflux duration and the Psatakis index. A morphometric study was conducted on 140 limbs of 48 human corpses, from which venous fragments were taken for biomechanical studies of the valves. The clinical characteristics of patients are presented by descriptive statistics, quantitative parameters are reported as the mean value (M) and standard deviation (SD). The differences were tested for significance by using the Student's t-test. Results. In the study, we introduced the concept of the valve index, the aspect ratio of the ellipse, the shape of which has a venous valve in cross-section. Duplex ultrasound scanning, as well as a morphofunctional examination of the valves, made it possible to establish that the valve index is significantly higher in the presence of signs of varicose veins, which indicates dilation and incipient varicose vein, which leads to valvular insufficiency. The elasticity index defined by us, as the indicator of change in the venous lumen size, measured by the ratio of its diameters, also significantly (p=0.034) differed in the studied groups: the elasticity index in the group of healthy people was 1.370.11, in the group of patients with varicose veins 1.560.17. The studied factors allowed us to develop a test that has an important prognostic value for the early diagnosis of varicose veins as well as the implementation of preventive health measures. Conclusion. The features of venous blood circulation and valve function studied in the study not only have prognostic value for the early diagnosis of varicose veins but are also of practical interest for developing methods of surgical correction of venous valvular insufficiency.

Detecting Aortic Valve Anomaly From Induced Murmurs: Insights From Computational Hemodynamic Models

Patients who receive transcatheter aortic valve replacement are at risk for leaflet thrombosis-related complications, and can benefit from continuous, longitudinal monitoring of the prosthesis. Conventional angiography modalities are expensive, hospital-centric and either invasive or employ potentially nephrotoxic contrast agents, which preclude their routine use. Heart sounds have been long recognized to contain valuable information about individual valve function, but the skill of auscultation is in decline due to its heavy reliance on the physician’s proficiency leading to poor diagnostic repeatability. This subjectivity in diagnosis can be alleviated using machine learning techniques for anomaly detection. We present a computational and data-driven proof-of-concept analysis of a novel, auscultation-based technique for monitoring aortic valve, which is practical, non-invasive, and non-toxic. However, the underlying mechanisms leading to physiological and pathological heart sounds are not well-understood, which hinders development of such a technique. We first address this by performing direct numerical simulations of the complex interactions between turbulent blood flow in a canonical ascending aorta model and dynamic valve motion in 29 cases with healthy and stenotic valves. Using the turbulent pressure fluctuations on the aorta lumen boundary, we model the propagation of heart sounds, as elastic waves, through the patient’s thorax. The heart sound may be recorded on the epidermal surface using a stethoscope/phonocardiograph. This approach allows us to correlate instantaneous hemodynamic phenomena and valve motion with the acoustic response. From this dataset we extract “acoustic signatures” of healthy and stenotic valves based on principal components of the recorded sound. These signatures are used to train a linear discriminant classifier by maximizing correlation between recorded heart sounds and valve status. We demonstrate that this classifier is capable of accurate prospective detection of anomalous valve function and that the principal component-based signatures capture prominent audible features of heart sounds, which have been historically used by physicians for diagnosis. Further development of such technology can enable inexpensive, safe and patient-centric at-home monitoring, and can extend beyond transcatheter valves to surgical as well as native valves.