October

Alterra Adaptive Prestent and SAPIEN 3 THV for Congenital Pulmonic Valve Dysfunction: An Early Feasibility Study. Shahanavaz S, Balzer D, Babaliaros V, Kim D, Dimas V, Veeram Reddy SR, Leipsic J, Blanke P, Shirali G, Parthiban A, Gorelick J, Zahn EM.JACC Cardiovasc Interv. 2020 Nov 9;13(21):2510-2524. doi: 10.1016/j.jcin.2020.06.039. Epub 2020 Oct 14.PMID: 33069657   Take Home Points: The Alterra Adaptive Prestent is a self- expanding Nitinol device, partially covered with expanded polytetrafluoroethylene, that serves as a landing zone for implantation of the SAPIEN 3 THV The screening process is comprehensive, including MRI and contrast-enhanced CTA, as well as virtual and physical simulation in patient-specific models. There was 100% successful device and valve implantation at the index catheterization, and no THV dysfunction nor RVOT reinterventions at 6-month follow-up. Commentary from Dr. Arash Salavitabar (Ann Arbor MI, USA), catheterization section editor of Pediatric Cardiology Journal Watch: The authors reports on this early feasibility study designed to determine the safety and functionality of the Alterra Adaptive Prestent in patients with dysfunctional right ventricular outflow tracts (RVOT) or pulmonary valves (PV). The Alterra Adaptive Prestent is a self- expanding Nitinol device, partially covered with expanded polytetrafluoroethylene, in a self-sheathed delivery system. This serves as a landing zone for implantation of the SAPIEN 3 THV. The primary outcome was a 5-item, nonhierarchical composite measure of post-procedural device success and the secondary outcome was a 3-item composite measure of freedom from valve dysfunction at 30 days and 6 months. Patients considered suitable candidates for implantation had proximal and distal landing zone diameters of 27-38 mm and a minimum of 35 mm from contractile tissue to lowest pulmonary artery (PA) takeoff immediately before Alterra Adaptive Prestent insertion. Patients were first evaluated by cMRI and 2D phase contrast MRA, and if met initial criteria for valve implantation, were followed with contrast-enhanced CTA. Perimeter plots of each patient’s RVOT (Figure B), in both systole and diastole, were created and analyzed in relation to the diameter and perimeter of the unconstrained device. Virtual implants were then performed, followed by 3D printed models at peak systole and diastole for each patient (Figures C and D) Over nearly 10 months, 4 investigational sites performed this study on 15 patients, out of 29 patients initially screened, with a median age of 29 years and most common underlying cardiac anatomy of tetralogy of Fallot. Anatomic unsuitability was the primary reason for exclusion. All patients met the composite endpoints of device success. There were no major adverse events through 180 day follow-up, including no deaths, RVOT reintervention, device embolism, endocarditis, or coronary compression. No THV dysfunction nor RVOT reinterventions were reported at 6 months. All patients had trivial-to-mild PR and median RVOT Doppler gradient of 9mmHg. There were several adverse events, including likely TV chordal rupture, self-limited transient ventricular tachycardia, and small pericardial effusion. One patient had an incidental thrombus noted by TTE attached to the inflow of the Alterra Adaptive Prestent and without valve-related thrombus, however the RVOT gradient continued to increase (mildly so) over the following 6 months. Echocardiography showed prominent native valve leaflet tissue that was not entirely captured by the Alterra Prestent, resulting in in-folding of the native leaflet proximal to the Alterra Prestent, causing subvalvular obstruction. Adjustments were made to the pre-procedural imaging to prevent similar episodes from occurring. Another patient had progressive RVOT obstruction secondary to an acute angulation of the RVOT causing the inferomedial aspect of the Alterra Adaptive Prestent to project into the RVOT. This early feasibility study demonstrates the importance of patient-specific pre-procedural imaging and simulation, as well as the thoughtful determination of the interactions between the present and the dynamic, heterogeneous RVOTs in this patient population. The relatively high screening acceptance rate, procedural success rate, and freedom of valve dysfunction at 6-month follow-up make the Alterra Adaptive Prestent a promising and attractive option for patients with dysfunctional RVOTs based on this preliminary experience.

Long-term outcome of perimembranous VSD closure using the Nit-Occlud® Lê VSD coil system. Kozlik-Feldmann R, Lorber A, Sievert H, Ewert P, Jux C, Müller GC, Dalla Pozza R, Yigitbasi M, Schranz D, Lindinger A, Galal O, Meinertz T. Clin Res Cardiol. 2020 Oct 31. doi: 10.1007/s00392-020-01750-6. Online ahead of print. PMID: 33128576   Take Home Points: In carefully selected patients the Nit-Occlud Le VSD coil may offer an effective option for closure of aneurysmal perimembranous VSDs. There appears to be a low risk of damage to the conduction system but a relatively high risk of other complications (hemolysis, device embolization, and tricuspid valve injury). Commentary from Dr. Konstantin Averin (Edmonton), catheterization section editor of Pediatric Cardiology Journal Watch: Percutaneous closure of ventricular septal defects (VSD) – especially of the perimembranous type (pmVSD) - fell out of favor in the early 2000s due to a relatively high (6%) incidence of complete atrioventricular block. However, with new devices and techniques this approach is slowly regaining favor. The Nit-Occlud Le VSD coil has a reinforced coil configuration with Dacron fibers (Figure 1) and is designed for closure of aneurysmal pmVSDs up to 8mm in diameter. The authors present data from a prospective, multicenter, non-randomized clinical trial of the VSD coil. From October 2006 to June 2011 94 patients with VSDs were screened in 6 tertiary centers in Germany and Israel; 6 were excluded as they had muscular VSDs. The median age was 8 (2-65) years, weight 26.7 (10-109) kg. Device implant was technically successful in 85 (96.6%). The immediate closure rate was 67.2% but increased to 96.4% at 12 month and 98.7% at 5 year follow up. During the procedure there were 5 adverse events (2 device embolizations, 1 episode of severe hemolysis requiring implant of a second device, and arterial access site complications). There were 3 serious adverse events during the follow up period - 2 patients developed hemodynamically significant tricuspid valve regurgitation requiring surgical repair and 1 developed a large vegetation requiring device explant. Minor hemolysis was seen in 8 patients (9.4%) but resolved in all without further intervention. There were no episodes of 2nd or 3rd degree heart block or post-procedure coil embolization. In carefully selected patients the Nit-Occlud Le VSD coil may offer an effective option for closure of aneurysmal perimembranous VSDs. There appears to be a low risk of damage to the conduction system but a relatively high risk of other complications (hemolysis, device embolization, and tricuspid valve injury) which may improve as operator experience with the device grows. The authors acknowledge that they did not meet their enrollment goals due to a change in the legal environment in the course of the study. FIGURE 1 Close-up image of the Nit Occlud® Lê VSD coil. The device configures as larger left-sided cone with reinforced and Dacron fibered distal coil loops and a smaller right-side cone that configures over the left cone.