Transcatheter pulmonary valve implantation: will it replace surgical pulmonary valve replacement?

Update on Transcatheter Interventions in Adults with Congenital Heart Disease

The field of adult congenital interventions is unique in the world of cardiac catheterization, combining the structural concepts commonly employed in pediatric heart disease and applying them to adult patients, who are more amenable to device intervention as they no longer experience somatic growth. Rapid advances in the field have been made to match the growing population of adult patients with congenital heart disease, which currently surpasses the number of pediatric patients born with congenital heart disease. Many congenital defects, which once required surgical intervention or reoperation, can now be addressed via the transcatheter approach, minimizing the morbidity and mortality often encountered within adult congenital surgeries. In this paper, we aim to provide a focused review of the more common procedures that are utilized for the treatment of adult congenital heart disease patients in the catheterization laboratory, as examples of current practices in the United States, as well as emerging concepts and devices awaiting approval in the future.

Pediatric pulmonary valve replacements: Clinical challenges and emerging technologies

Congenital heart diseases (CHDs) frequently impact the right ventricular outflow tract, resulting in a significant incidence of pulmonary valve replacement in the pediatric population. While contemporary pediatric pulmonary valve replacements (PPVRs) allow satisfactory patient survival, their biocompatibility and durability remain suboptimal and repeat operations are commonplace, especially for very young patients. This places enormous physical, financial, and psychological burdens on patients and their parents, highlighting an urgent clinical need for better PPVRs. An important reason for the clinical failure of PPVRs is biofouling, which instigates various adverse biological responses such as thrombosis and infection, promoting research into various antifouling chemistries that may find utility in PPVR materials. Another significant contributor is the inevitability of somatic growth in pediatric patients, causing structural discrepancies between the patient and PPVR, stimulating the development of various growth-accommodating heart valve prototypes. This review offers an interdisciplinary perspective on these challenges by exploring clinical experiences, physiological understandings, and bioengineering technologies that may contribute to device development. It thus aims to provide an insight into the design requirements of next-generation PPVRs to advance clinical outcomes and promote patient quality of life.

Feasibility evaluation of the transapical saddle-shaped valved stent for transcatheter mitral valve implantation

Background and Aims of Study

Transcatheter mitral valve implantation (TMVI) is a promising and minimally invasive treatment for high‐risk mitral regurgitation. We aimed to investigate the feasibility of a novel self‐expanding valved stent for TMVI via apical access.

Methods

We designed a novel self‐expanding mitral valve stent system consisting of an atrial flange and saddle‐shaped ventricular body connected by two opposing anchors and two opposing extensions. During valve deployment, each anchor was controlled by a recurrent string. TMVI was performed in 10 pigs using the valve prosthesis through apical access to verify technical feasibility. Echocardiography and ventricular angiography were used to assess hemodynamic data and valve function. Surviving pigs were killed 4 weeks later to confirm stent deployment.

Results

Ten animals underwent TMVI using the novel mitral valve stent. Optimal valve deployment and accurate anatomical adjustments were obtained in nine animals. Implantation failed in one case, and the animal died 1 day later due to stent mismatch. After stent implantation, the hemodynamic parameters of the other animals were stable, and valve function was normal. The mean pressure across the mitral valve and left ventricular outflow tract were 2.98 ± 0.91 mmHg and 3.42 ± 0.66 mmHg, respectively. Macroscopic evaluation confirmed the stable and secure positioning of the stents. No obvious valve displacement, embolism, or paravalvular leakage was observed 4 weeks postvalve implantation.

Conclusions

This study demonstrated that the novel mitral valve is technically feasible in animals. However, the long‐term feasibility and durability of this valved stent must be improved and verified.

Early multicenter experience of a new balloon expandable MyVal transcatheter heart valve in dysfunctional stenosed right ventricular outflow tract conduits

Background :

Transcatheter pulmonary valve implantation (TPVI) is a surgical alternative for correcting dysfunctional right ventricular outflow tract conduits in previously operated patients. MyVal transcatheter heart valve (THV) (Meril Life Sciences, India), a new transcatheter valve designed for aortic position has not been used for TPVI.

Methods :

Patients with stenosed dysfunctional conduits from the right ventricle to pulmonary artery (RV-PA) were prestented after initial computed tomography and balloon interrogation before the implantation of MyVal. Size of MyVal was chosen based on the final diameter of the prestent. Procedural details and post-TPVI follow-up were analyzed.

Results :

Seven patients aged 17–60 years (median 26 years) had stenosed RV-PA conduits implanted 5–17 years (median 9 years) ago for tetralogy of Fallot in three, following Ross procedure in two, repair of pulmonary stenosis, and following PA debanding in one patient each. Prestenting improved the conduit diameter from 9.3 ± 2.8 mm to 20.8 ± 1.1 mm and relieved the gradient from 87.3 ± 31.7 mmHg (50–137 mmHg) to 12.7 ± 6.4 mmHg (5–20 mmHg). A 23 mm MyVal was implanted in all the seven patients successfully; one patient needed an additional 24.5 mm MyVal valve in valve implantation for residual regurgitation. The mean fluoroscopic time and dose area product were 38.7 ± 25.3 min and 66.917 ± 39.211Gray. cm2, respectively. At a median follow-up duration of 16 months (10–22 months), all patients were asymptomatic receiving dual antiplatelet therapy with no PR and the gradient was 12.5 ± 5.8 mmHg on echocardiography. Although one patient needed an additional valve-in-valve implantation, there were no valve-related adverse events.

Conclusions :

Early experience of TPVI with MyVal THV in prestented conduits is encouraging with procedural success in all patients and acceptable mid-term outcomes.

Transcatheter pulmonary valve replacement: a new polycarbonate urethane valve

OBJECTIVES

Transcatheter pulmonary valve replacement has become a valid treatment option for right ventricular outflow tract diseases. However, some limitations occur in patients with wide, compliant right ventricular outflow tracts that might be amenable to treatment with self-expanding valved protheses. An experimental ovine study was designed to evaluate a novel dip-coated, low-profile trileaflet polycarbonate urethane (PCU) heart valve mounted into a self-expandable nitinol stent.

METHODS

The PCU valves were produced by a dip-coating technique, mounted in a conical-shaped nitinol stent and provided with a leaflet thickness of 100-150 µm. The valved stents were implanted percutaneously via transfemoral access in 6 consecutive sheep divided into 2 groups. Three animals were followed up for 1 month and the remainder, for 6 months. Angiographic measurements and transthoracic echocardiography were performed before and after implantation and at the end of the 1- or 6-month observation period, respectively.

RESULTS

Orthotopic positioning of the valve was achieved in all animals. All except 1 had competent valves during the follow-up period. The peak-to-peak gradient across the PCU valved stents was 4.6 ± 1.0 mmHg after 1 month and 4.4 ± 2.3 mmHg after 6 months of follow-up. Macroscopic and microscopic post-mortem evaluation indicated good morphological and structural results. There were no stent fractures, leaflet calcification or thrombus formation.

CONCLUSIONS

This study demonstrates successful transcatheter pulmonary valve replacement with a novel dip-coated valved nitinol stent. The trileaflet PCU prostheses indicated good functional and biocompatible properties after a 6-month observation period.

German Heart Centre Munich-45 years of surgery in adults with congenital heart defects: from primary corrections of septal defects and coarctation to complex reoperations

Background

Our historical overview in the form of a cohort study aimed to describe the changes in the cardiac operations in adults with congenital heart disease (ACHD), over 45 years in the German Heart Centre in Munich.

Methods

The study population comprised all consecutive patients aged 18 or more, who underwent surgery for congenital heart disease (CHD) at the German Heart Centre Munich, between 1974 and 2018. Operations were coded according to the Adult Congenital Heart Surgery (ACHS) score. Two-tailed chi-square test was used for testing on differences in the frequency of procedural groups between the decades.

Results

During the examined 45-year period, 2,882 operations were performed on ACHD. The number of operations per year increased with a correlation coefficient r=0.533, P<0.001. Overall operative mortality was 3.2%. There was no significant difference in mortality over the decades. The percentage of primary CHD diagnosis being the indication for the operation was 99% in the 1970s and decreased significantly to 56% in the 2010s, P<0.001. There was a significant decrease in the relative frequency of atrial septal defect closures from 45% in the 1970s and 1980s to 9% in 2010s (P<0.001). Coarctation repair made up 15% of all operations in the 1970s, then dropped significantly to 1% in the 2010s (P<0.001). The percentage of reoperations increased significantly from 7% in the 1970s to 50% in 2010s (P<0.001).

Conclusions

The spectrum of cardiac surgery in ACHD changed significantly over the last 45 years, from primary repair of septal defects and coarctation of the aorta in the 1970s to complex reoperations in the 2010s.

Early Outcomes of Percutaneous Pulmonary Valve Implantation with Pulsta and Melody Valves: The First Report from Korea

Percutaneous pulmonary valve implantation (PPVI) is used to treat pulmonary stenosis (PS) or pulmonary regurgitation (PR). We described our experience with PPVI, specifically valve-in-valve transcatheter pulmonary valve replacement using the Melody valve and novel self-expandable systems using the Pulsta valve. We reviewed data from 42 patients undergoing PPVI. Twenty-nine patients had Melody valves in mostly bioprosthetic valves, valved conduits, and homografts in the pulmonary position. Following Melody valve implantation, the peak right ventricle-to-pulmonary artery gradient decreased from 51.3 ± 11.5 to 16.7 ± 3.3 mmHg and right ventricular systolic pressure fell from 70.0 ± 16.8 to 41.3 ± 17.8 mmHg. Thirteen patients with native right ventricular outflow tract (RVOT) lesions and homograft underwent PPVI with the new self-expandable Pulsta valve—a nitinol wire stent mounted with a trileaflet porcine pericardial valve. Following Pulsta valve implantation, cardiac magnetic resonance imaging showed a decreased PR fraction and that the right ventricular end-diastolic volume index decreased from 166.1 ± 11.9 to 123.6 ± 12.4 mL/m². There were no mortality, severe procedural morbidity, or valve-related complications. At the mean 14.2 month (4–57 months) follow-up, no patients had more than mild PR. PPVI using Melody and Pulsta valves was first shown to provide excellent early outcomes without serious adverse event in most patients with RVOT dysfunction in Korea.

Clinical outcomes of transcatheter versus surgical pulmonary valve replacement: a meta-analysis

Background

Transcatheter pulmonary valve replacement (TPVR) has currently been a well-established alternative operation method to surgical pulmonary valve replacement (SPVR) in patients with pulmonary valve dysfunction in the form of stenosis and/or regurgitation. We conducted a meta-analysis to evaluate the main clinical outcomes after TPVR and SPVR.

Methods

We systematically searched the references of relevant literatures from PubMed and the Cochrane Library published between January 2000 and December 2018 and followed The Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) for this study.

Results

Eleven studies with 4,364 patients were included in the study. Compared with SPVR, TPVR results in a significant decreased in-hospital mortality [odds ratio (OR): 0.18; 95% confidence interval (CI): 0.03-0.98] and mortality at the longest reported follow-up time point (OR: 0.43; 95% CI: 0.22-0.87), though 30-day mortality (OR: 0.38; 95% CI: 0.11-1.33) has no significant difference between groups. Days of hospital stay [(mean difference (MD): -4.38; 95% CI: -6.24--2.53] is shorter with TPVR than SPVR. Besides, rates of 30-day readmission (OR: 0.67; 95% CI: 0.50-0.91) and recurrent pulmonary regurgitation (OR: 0.17; 95% CI: 0.07-0.42) are lower with TPVR, whereas postprocedural infective endocarditis (IE) (OR: 4.56; 95% CI: 2.03-10.26) are higher with TPVR. SPVR carries a decreased risk of re-operation (OR: 2.19; 95% CI: 0.62-7.76) though without statistically significance.

Conclusions

In conclusion, TPVR is associated with a significantly decreased mortality, a shorter length of hospital-stay, a lower rate of 30-day readmission and recurrent pulmonary regurgitation as compared to SPVR throughout the follow-up duration, whereas SPVR results in a significantly lower rate of postprocedural IE than TPVR. In addition, SPVR carries a decreased risk of re-operation with statistically insignificance.

Current spectrum, challenges and new developments in the surgical care of adults with congenital heart disease

Today, more than two thirds of patients with congenital heart disease (CHD) are adults. Cardiac surgery plays an essential role in restoring and maintaining cardiac function, aside from evolving medical treatment and catheter-based interventions. The aim of the present publication was to describe the spectrum of operations performed on adults with CHD (ACHD) by reviewing current literature. Currently, surgery for ACHD is predominantly valve surgery, since valvular pathologies are often either a part of the basic heart defect or develop as sequelae of corrective or palliative surgery. Surgical techniques for valve repair, established in patients with acquired heart disease (non-ACHD), can often be transferred to ACHD. New valve substitutes may help to reduce the number of redo operations. Most of valve operations yield good results in terms of survival and quality of life, with the precondition that the ventricular function is preserved. Heart failure due to end-stage CHD is the most frequent cause of mortality in ACHD. However, surgical treatment by means of mechanical circulatory support (MCS) is still uncommon and the mortality exceeds the one following other operations in ACHD. Currently, different devices are used and new technical developments are in progress. However, there still is no ideal assist device available. Therefore, heart transplantation remains the only valid option for end-stage CHD. Despite higher early mortality following heart transplantation in ACHD compared to non-ACHD, the long-term survival compares favorably to non-ACHD. There is room for improvement by refining the indications, the time of listing, and the perioperative care of ACHD transplant patients. Sudden death is the second most frequent cause of mortality in ACHD. Ventricular tachycardia is the most frequent cause of sudden death followed by coronary artery anomaly. Due to the increasing awareness of physicians and the improved imaging techniques, coronary artery anomalies are coming more into the focus of cardiac surgeons. However, the reported experience is limited and it is currently difficult to provide a standardized and generally applicable recommendation for the indication and the adequate surgical technique. With the increasing age and complexity of ACHD, treatment of rhythm disturbances by surgical ablation, pacemaker or implantable cardioverter defibrillator (ICD) implantation and resynchronisation gains importance. A risk score specifically designed for surgery in ACHD is among the newest developments in predicting the outcome of surgical treatment of ACHD. This evidence-based score, derived from and validated with data from the Society of Thoracic Surgeons Congenital Heart Surgery Database, enables comparison of risk-adjusted performance of the whole spectrum of procedures performed in ACHD and helps in understanding the differences in surgical outcomes. The score is thus a powerful tool for quality control and quality improvement. In conclusion, new developments in surgery for ACHD are currently made with regard to valve surgery, which comprises more than half of all operations in ACHD and in treatment of end-stage CHD, which still yields high mortality and morbidity.

Pulmonary Valve Regurgitation: Neither Interventional Nor Surgery Fits All

Introduction: PV implantation is indicated for severe PV regurgitation after surgery for congenital heart defects, but debates accompany the following issues: timing of PV implantation; choice of the approach, percutaneous interventional vs. surgical PV implantation, and choice of the most suitable valve. Timing of pulmonary valve implantation: The presence of symptoms is class I evidence indication for PV implantation. In asymptomatic patients indication is agreed for any of the following criteria: PV regurgitation > 20%, indexed end-diastolic right ventricular volume > 120-150 ml/m2 BSA, and indexed end-systolic right ventricular volume > 80-90 ml/m2 BSA. Choice of the approach: percutaneous interventional vs. surgical: The choice of the approach depends upon the morphology and the size of the right ventricular outflow tract, the morphology and the size of the pulmonary arteries, the presence of residual intra-cardiac defects and the presence of extremely dilated right ventricle. Choice of the most suitable valve for surgical implantation: Biological valves are first choice in most of the reported studies. A relatively large size of the biological prosthesis presents the advantage of avoiding a right ventricular outflow tract obstruction, and also of allowing for future percutaneous valve-in-valve implantation. Alternatively, biological valved conduits can be implanted between the right ventricle and pulmonary artery, particularly when a reconstruction of the main pulmonary artery and/or its branches is required. Hybrid options: combination of interventional and surgical: Many progresses extended the implantation of a PV with combined hybrid interventional and surgical approaches. Major efforts have been made to overcome the current limits of percutaneous PV implantation, namely the excessive size of a dilated right ventricular outflow tract and the absence of a cylindrical geometry of the right ventricular outflow tract as a suitable landing for a percutaneous PV implantation. Conclusion: Despite tremendous progress obtained with modern technologies, and the endless fantasy of researchers trying to explore new forms of treatment, it is too early to say that either the interventional or the surgical approach to implant a PV can fit all patients with good long-term results.