Outcomes of transcatheter pulmonary SAPIEN 3 valve implantation: an international registry.

BACKGROUND AND AIMS: Transcatheter pulmonary valve implantation (TPVI) is indicated to treat right-ventricular outflow tract (RVOT) dysfunction related to congenital heart disease (CHD). Outcomes of TPVI with the SAPIEN 3 valve that are insufficiently documented were investigated in the EUROPULMS3 registry of SAPIEN 3-TPVI. METHODS: Patient-related, procedural, and follow-up outcome data were retrospectively assessed in this observational cohort from 35 centres in 15 countries. RESULTS: Data for 840 consecutive patients treated in 2014-2021 at a median age of 29.2 (19.0-41.6) years were obtained. The most common diagnosis was conotruncal defect (70.5%), with a native or patched RVOT in 50.7% of all patients. Valve sizes were 20, 23, 26, and 29 mm in 0.4%, 25.5%, 32.1%, and 42.0% of patients, respectively. Valve implantation was successful in 98.5% [95% confidence interval (CI), 97.4%-99.2%] of patients. Median follow-up was 20.3 (7.1-38.4) months. Eight patients experienced infective endocarditis; 11 required pulmonary valve replacement, with a lower incidence for larger valves (P = .009), and four experienced pulmonary valve thrombosis, including one who died and three who recovered with anticoagulation. Cumulative incidences (95%CI) 1, 3, and 6 years after TPVI were as follows: infective endocarditis, 0.5% (0.0%-1.0%), 0.9% (0.2%-1.6%), and 3.8% (0.0%-8.4%); pulmonary valve replacement, 0.4% (0.0%-0.8%), 1.3% (0.2%-2.4%), and 8.0% (1.2%-14.8%); and pulmonary valve thrombosis, 0.4% (0.0%-0.9%), 0.7% (0.0%-1.3%), and 0.7% (0.0%-1.3%), respectively. CONCLUSIONS: Outcomes of SAPIEN 3 TPVI were favourable in patients with CHD, half of whom had native or patched RVOTs.

Feasibility and Diagnostic Value of Recording Smartwatch Electrocardiograms in Neonates and Children.

OBJECTIVE: The objective of this study was to evaluate the agreement of smartwatch-derived single-lead electrocardiogram (ECG) recordings with 12-lead ECGs for diagnosing electrocardiographic abnormalities. STUDY DESIGN: A 12-lead ECG and an ECG using Apple Watch were obtained in 110 children (aged 1 week to 16 years) with normal (n = 75) or abnormal (n = 35) 12-lead ECGs (atrioventricular block [7], supraventricular tachycardia [SVT] {5}, bundle branch block [12], ventricular preexcitation [6], long QT [5]). In children aged <6 years, the ECG recording was performed with the active participation of an adult who applied the neonate or child's finger to the crown of the watch. In older children, tracings were obtained after brief teaching without adult guidance. All 12-lead ECGs were independently evaluated by 2 blinded cardiologists. Apple Watch ECGs were independently evaluated by another blinded cardiologist. RESULTS: In 109 children (99.1%), the smartwatch tracing was of sufficient quality for evaluation. Smartwatch tracings were 84% sensitive and 100% specific for the detection of an abnormal ECG. All 75 normal tracings were correctly identified. Of the 35 children with abnormalities on 12-lead ECGs, 5 (14%) were missed, most often because of baseline wander and artifacts. Rhythm disorders (atrioventricular block or SVT) and bundle branch blocks were correctly detected in most cases (11 of 12 and 11 of 12, respectively); preexcitation and long QT was detected in 4 of 6 and 4 of 5, respectively. CONCLUSION: Smartwatch ECGs recorded with parental assistance in children aged up to 6 years and independently in older children have the potential to detect clinically relevant conditions.

Electrophysiological study prior to planned pulmonary valve replacement in patients with repaired tetralogy of Fallot.

AIM: Ventricular arrhythmias (VAs) are the most common cause of death in patients with repaired Tetralogy of Fallot (rTOF). However, risk stratifying remains challenging. We examined outcomes following programmed ventricular stimulation (PVS) with or without subsequent ablation in patients with rTOF planned for pulmonary valve replacement (PVR). METHODS: We included all consecutive patients with rTOF referred to our institution from 2010 to 2018 aged ≥18 years for PVR. Right ventricular (RV) voltage maps were acquired and PVS was performed from two different sites at baseline, and if non-inducible under isoproterenol. Catheter and/or surgical ablation was performed when patients were inducible or when slow conduction was present in anatomical isthmuses (AIs). Postablation PVS was undertaken to guide implantable cardioverter-defibrillator (ICD) implantation. RESULTS: Seventy-seven patients (36.2 ± 14.3 years old, 71% male) were included. Eighteen were inducible. In 28 patients (17 inducible, 11 non-inducible but with slow conduction) ablation was performed. Five had catheter ablation, surgical cryoablation in 9, both techniques in 14. ICDs were implanted in five patients. During a follow-up of 74 ± 40 months, no sudden cardiac death occurred. Three patients experienced sustained VAs, all were inducible during the initial EP study. Two of them had an ICD (low ejection fraction for one and important risk factor for arrhythmia for the second). No VAs were reported in the non-inducible group (p < .001). CONCLUSION: Preoperative EPS can help identifying patients with rTOF at risk for VAs, providing an opportunity for targeted ablation and may improve decision-making regarding ICD implantation.

Using a smartwatch to record an electrocardiogram in the pediatric population.

The accuracy of smartwatch ECG recordings in adults has been demonstrated primarily in the automated diagnosis of atrial fibrillation. While the detection of atrial fibrillation is a priority among adults given the arrhythmia's prevalence and actionable ramifications, the potential value of smartwatch ECG recordings in children differs considerably. In this case series, we will describe some examples of smartwatch ECGs recorded in children, highlighting the feasibility and potential indications of this technology in the pediatric population.

Edge to edge repair using a MitraClip for severe tricuspid valve regurgitation after a Mustard operation.

A 48-year-old who underwent a Mustard operation in 1972 followed by a second cardiac intervention in 1996 for pulmonary venous baffle enlargement and residual baffle leak closure, complicated by recurrent atrial flutter, was admitted to our institution for severe systemic atrio-ventricular valve regurgitation (SAVVR) associated with severely impaired systemic right ventricular (RV) function. After careful preoperative anatomic assessment including three-dimensional transesophageal echocardiography (3DTEE) to define the clipping strategy and computed tomography to optimize the transvenous baffle puncture site, the intervention was performed under general anesthesia, fluoroscopic, and 3DTEE guidance. One XTR MitraClip was successfully implanted, achieving a significant reduction in regurgitation and immediate clinical improvement. The transbaffle puncture was closed using an 8 mm atrial septal defect (ASD) device without residual shunt or obstruction of the venous baffle. Post-operative clinical evaluation showed immediate improvement in the NYHA functional class (from III to II), but the patient presented with recurrent flutter at 1 week after the procedure, which was successfully treated by catheter ablation with another transbaffle approach next to the ASD device. Clinical improvement was maintained at 1- and 6-month follow-up with significant reduction in SAVVR, reduced systemic RV volumes and improved RV ejection fraction. This case demonstrates the feasibility of percutaneous treatment of systemic SAVV in patients with systemic RV after atrial redirection.

Nit-Occlud atrial septal defect occluder device: Histological characterisation of the healing process.

We describe the healing process following transcatheter implantation of the Nit-Occlud ASD-R occluder (PFM medical, Cologne, Germany) for atrial septal defect closure in a sheep model with histological confirmation of neotissue formation covering the device.

Cardiovascular events in perimembranous ventricular septal defect with left ventricular volume overload: a French prospective cohort study (FRANCISCO).

The long-term prospective multi-centre nationwide (French) observational study FRANCISCO will provide new information on perimembranous ventricular septal defect with left ventricular overload but no pulmonary hypertension in children older than 1 year. Outcomes will be compared according to treatment strategy (watchful waiting, surgical closure, or percutaneous closure) and anatomic features of the defect. The results are expected to provide additional guidance about the optimal treatment of this specific population, which is unclear at present. BACKGROUND: The management of paediatric isolated perimembranous ventricular septal defect (pmVSD) with left ventricle (LV) volume overload but no pulmonary arterial hypertension (PAH) remains controversial. Three therapeutic approaches are considered: watchful waiting, surgical closure, and percutaneous closure. We aim to investigate the long-term outcomes of these patients according to anatomic pmVSD characteristics and treatment strategy. METHODS: The Filiale de Cardiologie Pediatrique et Congénitale (FCPC) designed the FRANCISCO registry, a long-term prospective nationwide multi-centre observational cohort study sponsored by the French Society of Cardiology, which enrolled, over 2 years (2018­2020), patients older than 1 year who had isolated pmVSD with LV volume overload. Prevalent complications related to pmVSD at baseline were exclusion criteria. Clinical, echocardiographic, and functional data will be collected at inclusion then after 1, 5, and 10 years. A core lab will analyse all baseline echocardiographic data to depict anatomical pmVSD features. The primary outcome is the 5-year incidence of cardiovascular events (infective endocarditis, sub-aortic stenosis, aortic regurgitation, right ventricular outflow tract stenosis, tricuspid regurgitation, PAH, arrhythmia, stroke, haemolysis, heart failure, or death from a cardiovascular event). We plan to enrol 200 patients, given the 10% estimated 5-year incidence of cardiovascular events with a 95% confidence interval of ±5%. Associations linking anatomical pmVSD features and treatment strategy to the incidence of complications will be assessed. CONCLUSIONS: The FRANSCICO study will provide the long-term incidence of complications in patients older than 1 year with pmVSD and LV volume overload. The results are expected to improve guidance for treatment decisions.

Comparison of Two Percutaneous Atrial Septal Defect Occluders for Device Healing and Nickel Release in a Chronic Porcine Model.

AIMS: To investigate the healing process and nickel release of the Hyperion occluder (Comed BV, Netherlands), as compared to the Amplatzer septal occluder (ASO) (St. Jude Medical Inc., St. Paul, MN, USA) in a chronic swine model. BACKGROUND: Some long-term complications occurring after percutaneous atrial septal defect (ASD) closure may be partially associated with an inappropriate healing of the device and increased nickel release. There is no direct comparative study of different occluders for healing and nickel release. METHODS: After percutaneous ASD creation, 12 pigs were implanted with 15 mm Hyperion (n = 6) and 15 mm ASO (n = 6) devices. After 1 month (n = 3 for each device) and 3 months (n = 3 for each device) of follow-up, device explantation was performed and healing was assessed using histopathological workup. Systemic and tissular nickel release was performed. RESULTS: Implantation was successful in 100% without complications. Device coverage was observed as early as 1 month after implantation and was almost complete after 3 months. A granulation tissue with a predominantly mononuclear inflammatory reaction was observed in contact with nitinol wires while an inflammatory reaction was seen in contact with textile fibers. We found no statistically significant difference between the 2 devices whether for histological grading scores or systemic nickel release, regardless to follow-up duration. CONCLUSIONS: In this preclinical study, we demonstrated that Amplatzer septal occluder and Hyperion occluder were not significantly different for device healing and nickel release processes.

First Case of Q Fever Endocarditis Involving the Melody® Transcatheter Pulmonary Valve in an Afebrile Child.

In this article we report the first case of Q fever endocarditis in a 13 years old child with a percutaneous pulmonary Melody® valve. The patient had a new onset of Melody valve dysfunction associated with the combination of hepatosplenomegaly and pancytopenia but was afebrile. Although blood cultures were negative, we have further investigated in the direction of infective endocarditis by performing PCR detection and the serology of C. burnetii which were positive. A combination antibiotic therapy with doxycycline and hydroxychloroquine was started with good clinical evolution. Our case emphasizes the fact that any Melody valvular dysfuntion should be considered as a potential infective endocarditis despite the absence of typical bacterial features.

Left Atrial Appendage Closure in Patients with Atrial Fibrillation and Previous Intracerebral Hemorrhage.

BACKGROUND: Percutaneous left atrial appendage closure (LAAC) may be considered in patients with atrial fibrillation and contraindication for long-term anticoagulation. This study aimed to assess the safety and efficacy of LAAC followed by single antiplatelet therapy in patients with atrial fibrillation and previous spontaneous intracerebral hemorrhage (ICH). METHODS: In this explorative, prospective, single-center study, consecutive patients who underwent LAAC because of previous spontaneous ICH over a period of 4 years were analyzed. Risks of ischemic strokes and hemorrhagic complications were estimated using the CHA2DS2-VASc and HAS-BLED scores, respectively. Single antiplatelet therapy was given for at least 6 months post implantation. Clinical follow-up included cardiological evaluations at 1, 3, 6, and 12 months, and neurological evaluations at 3 and 12 months. RESULTS: A total of 46 patients underwent LAAC with a mean follow-up of 12 ± 7 months. The observed annual rate of ischemic stroke was 4.35% compared with an expected rate of 7.23% according to the mean risk of the population based on CHA2DS2-VASc score, which translated into a 40% risk reduction. The observed annual rate of major bleeding was 4.35% compared with an expected rate of 8.05% according to the mean risk of the population based on HAS-BLED score, which translated into a 46% risk reduction. CONCLUSIONS: LAAC followed by single antiplatelet therapy is feasible as an alternative to oral anticoagulation in high-risk patients with previous ICH, with an acceptable periprocedural risk. Longer follow-up in a larger number of patients will be needed to establish the effectiveness of LAAC relative to direct oral anticoagulants.

Dilatable pulmonary artery band: Safety and efficacy of balloon dilatation.

OBJECTIVES: Review early and midterm results of dilatable pulmonary artery band (PAB). BACKGROUND: PAB is performed in various conditions: as a transient stage before ventricular septal defect (VSD) closure, as a palliative procedure for multiple VSD or to prepare the left ventricle (LV) before switch or double switch operations in transposition of the great artery (TGA) or congenitally corrected transposition of great arteries (CCTGA). METHODS: All children with dilatation of PAB were reviewed. Reason for PAB and for cardiac catheterization, hemodynamics, and outcomes were analyzed. RESULTS: Between 2002 and 2014, 28 patients were identified. Reason for interventional dilatation of the PAB was supra systemic right ventricular (RV) pressure in four patients, aortic recoarctation in one patient, cyanosis in seven patients, RV failure in one patient, suprasystemic LV pressure in two CCTGA patients and spontaneous closure of VSD in other patients. All patients underwent successful balloon dilatation using high (n = 21) or low pressure balloons with a mean diameter of 12 mm. 23 Patients had no further interventions. Five patients had reintervention: one needed two dilatations of PAB and four had surgery (one double switch, one vicious pulmonary artery (PA) band removal, one in a context of severe RV dysfunction with tricuspid regurgitation, and one for VSD closure). One patient died of RV failure following surgery. CONCLUSION: Balloon dilatation of dilatable PAB carries good results with achievement of hemodynamic aim in most of the cases and definitive treatment in the majority of patients. Careful and sequential dilatation with shunt measurement is mandatory in patients with significantly residual VSD. © 2016 Wiley Periodicals, Inc.

A new percutaneous pulmonary valve implantation technique for complex right ventricular outflow tracts: the "folded melody valve".

OBJECTIVES: This article sought to describe a new modification of the Melody valve that allows percutaneous pulmonary valve implantation (PPVI) in complex outflow tracts. BACKGROUND: PPVI has been validated as a valuable therapeutic option for the management of patients with dysfunctional right ventricular outflow tracts (RVOT). However, complex and unfavourable RVOT anatomy continue to limit the indications for PPVI. METHODS: Between April 2012 and November 2013, PPVI was performed in 10 patients (mean age = 16, 3 ± 5 years old) using a new modification of the Melody® valve consisting in a manual shortening of the Melody by folding the two extremities of the stent. We reviewed the results of this technique. RESULTS: Indications were short RVOT in three patients, prevention of retrosternal compression in two patients, bioprosthetic valves in four and coronary arteries proximity in one. No complication occurred during procedures. All patients had excellent hemodynamic results [mean post PPVI RV-PA gradient was 14 ± 6 mm Hg, three patients had trivial pulmonary regurgitation (PR) and the remaining had no PR]. After a mean follow-up of 11 months (range 5-21 months), no patient had reintervention. No valve dysfunction or stent fractures were observed. CONCLUSION: The "Folded valve technique" is a safe modification of the Melody valve. By shortening the valve, this technique allowed PPVI in short and complex RVOTs with vulnerable neighborhood.

Adverse remodelling in tetralogy of Fallot: From risk factors to imaging analysis and future perspectives.

Although contemporary outcomes of initial surgical repair of tetralogy of Fallot (TOF) are excellent, the survival of adult patients remains significantly lower than that of the normal population due to the high incidence of heart failure, ventricular arrhythmias, and sudden cardiac death. The underlying mechanisms are only partially understood but involve an adverse biventricular response, so-called remodelling, to key stressors such as right ventricular (RV) pressure-and/or volume-overload, myocardial fibrosis, and electro-mechanical dyssynchrony. In this review, we explore risk factors and mechanisms of biventricular remodelling, from histological to electro-mechanical aspects, and the role of imaging in their assessment. We discuss unsolved challenges and future directions to better understand and treat the long-term sequelae of this complex congenital heart disease.

Role and Applications of Experimental Animal Models of Fontan Circulation.

Over the last four decades, the Fontan operation has been the treatment of choice for children born with complex congenital heart diseases and a single-ventricle physiology. However, therapeutic options remain limited and despite ongoing improvements in initial surgical repair, patients still experience a multiplicity of cardiovascular complications. The causes for cardiovascular failure are multifactorial and include systemic ventricular dysfunction, pulmonary vascular resistance, atrioventricular valve regurgitation, arrhythmia, development of collaterals, protein-losing enteropathy, hepatic dysfunction, and plastic bronchitis, among others. The mechanisms leading to these late complications remain to be fully elucidated. Experimental animal models have been developed as preclinical steps that enable a better understanding of the underlying pathophysiology. They furthermore play a key role in the evaluation of the efficacy and safety of new medical devices prior to their use in human clinical studies. However, these experimental models have several limitations. In this review, we aim to provide an overview of the evolution and progress of the various types of experimental animal models used in the Fontan procedure published to date in the literature. A special focus is placed on experimental studies performed on animal models of the Fontan procedure with or without mechanical circulatory support as well as a description of their impact in the evolution of the Fontan design. We also highlight the contribution of animal models to our understanding of the pathophysiology and assess forthcoming developments that may improve the contribution of animal models for the testing of new therapeutic solutions.

Risk of infective endocarditis after hybrid melody mitral valve replacement in infants: the French experience.

OBJECTIVES: Surgical management of mitral valve disease is challenging in infants <1 year old. We aimed at reviewing the French experience with Melody mitral valve replacement in critically ill infants. METHODS: A retrospective cohort study reporting the French experience with Melody mitral valve replacement. RESULTS: Seven symptomatic infants [complete atrioventricular septal defect (n = 4, Down syndrome: n = 3), hammock valve (n = 3)] underwent Melody mitral valve replacement [age: 3 months (28 days to 8 months), weight: 4.3 kg (3.2-6.4 kg)] because of severe mitral valve regurgitation (6) or mixed valve disease (1) and 14 mm (11-16 mm) mitral valve annulus. In 2 patients whose valve was felt irreparable, Melody mitral valve replacement was performed straightaway. The others underwent 2 (1-3) previous attempts of valve repair; 3 were on extracorporeal membrane oxygenation. Melody mitral valve replacement led to competent valve and low gradient [3 mmHg, (1-4 mmHg)]. One patient died 3 days post-implant from extracorporeal membrane oxygenation-related stroke. Of the 6 discharged home patients, 3 (50%) were readmitted for a definite diagnosis (1) or high suspicion (2) of infective endocarditis, of which 2 died. Over the follow-up, 1 underwent balloon expansions of the valve at 9- and 16-months post-implant, and mechanical mitral valve replacement at 2 years; another is currently planned for transcatheter Melody valve dilation. CONCLUSIONS: Melody mitral valve replacement may be considered in selected infants with small mitral valve annulus as an alternative to mechanical mitral valve replacement. Our experience highlights a high-risk of late infective endocarditis that deserves further consideration.

From Crafoord's End-to-End Anastomosis Approach to Percutaneous Interventions: Coarctation of the Aorta Management Strategies and Reinterventions.

First described in 1760 by the anatomist Morgagni, coarctation of the aorta (CoA) is a congenital heart defect characterized by narrowing the aorta, typically distal to the left subclavian artery. It accounts for approximately 5-8% of all congenital heart diseases, with an incidence estimated at 4 per 10,000 live births. In 1944, the Swedish surgeon Clarence Crafoord achieved the first successful surgical CoA repair by performing an aortic end-to-end anastomosis on two patients aged 12 and 27 years old. Presently, the most prevalent techniques for surgical repair, particularly in infants and neonates with isolated coarctation, involve resection with end-to-end anastomosis (EEA) and the modified Crafoord technique (extended resection with end-to-end anastomosis (EEEA)). Subclavian flap aortoplasty (SCAP) is an alternative surgical option for CoA repair in patients under two years of age. In cases where the stenosis extends beyond resection and end-to-end anastomosis feasibility, patch aortoplasty (PP) employing a prosthetic patch can augment the stenotic region, especially for older patients. Despite advances in pediatric cardiology and cardiac surgery, recoarctation remains a significant concern after surgical or interventional repair. This comprehensive review aims to provide a thorough analysis of coarctation management, covering the pioneering techniques introduced by Crafoord using end-to-end anastomosis and now extending to the contemporary era marked by percutaneous interventions as well as the recoarctation rate associated with each type.

Outcomes Following Closure of Secundum Atrial Septal Defect in Children ≤ 15 kg in a French Tertiary Centre.

Secundum atrial septal defects (sASDs) are common congenital cardiac defects mostly treated using a transcatheter approach. However, small children (<15 kg) are still undergoing surgical sASD closure in many centres. Although both options have been proved to have excellent results in children, comparative data of the two techniques are missing for patients ≤ 15 kg. The medical records of children ≤ 15 kg who underwent sASD surgical (group A) and transcatheter (group B) closure between 2010 and 2023 were reviewed retrospectively. Twenty-five children in group A and twenty-two in group B were included (mean weight 8.9 kg in group A and 10.3 kg in group B). The main indications for closure were right heart enlargement and failure to thrive. Major complications occurred in two patients in group A and none in group B. Minor complications occurred in eight patients in group A and one in group B. At last follow-up, symptoms resolved completely or improved significantly for all infants, with the exception of failure to thrive in the sub-population of children with extra-cardiac comorbidities. sASD closure can be performed safely in symptomatic infants ≤ 15 kg, even in the presence of comorbidity, and should not be postponed. However, in patients with extra-cardiac comorbidities, the only indication of growth retardation must be carefully evaluated.

Multicentre experience with Optimus balloon-expandable cobalt-chromium stents in congenital heart disease interventions.

OBJECTIVES: To evaluate bare-metal Optimus and polytetrafluoroethylene (PTFE)-covered Optimus-CVS balloon-expandable, cobalt-chromium, hybrid cell-designed stents in congenital heart disease (CHD) interventions. METHODS: Retrospective multicentre review of patients with CHD receiving Optimus stents. Stent mechanical behaviour, clinical indications and outcomes were assessed. RESULTS: 183 stents (49.2% XXL/15-ZIG, 33.3% XL/12-ZIG, 17.5% L/9-ZIG) were implanted (98.9% success rate, 2.3% serious procedural complication rate) in 170 patients (57.6% men, 64.1% adults), median age 23.6 years (IQR, 15.2-39.2) and weight 63.5 kg (IQR, 47-75.7). Indications were right ventricular outflow tract stand-alone stenting or before revalvulation (62.4%), aortic coarctation treatment (15.3%), Fontan-circuit fenestration closure (12.4%) and miscellaneous (10%). 86/170 (50.6%) patients had PTFE-covered stenting (50% prophylactic). In 86/170 (50.6%) patients with stenotic lesions, median percentage of achieved stent expansion was 93.4% (IQR, 85.5%-97.7%), median gradient decreased from 28 mm Hg (IQR, 19-41) to 5 mm Hg (IQR, 1-9) (p<0.001), median vessel diameters increased from 13 mm (IQR, 7.9-17) to 18.9 mm (IQR, 15.2-22) (p<0.001) and percentage of vessel expansion was 45.2% (IQR, 19.8%-91.3%). In 30/36 (83.3%) patients with graft, median dilation of 2 mm (IQR, 2-5) above nominal diameter was achieved. Median stent shortening was 10.9% (IQR, 6.1-15.1) and was associated only with expansion diameter (OR: 0.66, 95% CI: 0.38 to 0.93). No clinically relevant fracture, stent embolisation or dysfunction occurred on a median follow-up of 9 (IQR, 4-14) months. CONCLUSIONS: Optimus stents are effective tools for transcatheter treatment of simple and complex CHD. Optimus stents' reliable mechanical behaviour and particular covering design can promote widespread use.

Assessment of Nit-Occlud atrial septal defect occluder device healing process using micro-computed tomography imaging.

After percutaneous implantation of a cardiac occluder, a complex healing process leads to the device coverage within several months. An incomplete device coverage increases the risk of device related complications such as thrombosis or endocarditis. We aimed to assess the device coverage process of atrial septal defect (ASD) occluders in a chronic sheep model using micro-computed tomography (micro-CT). After percutaneous creation of an ASD, 8 ewes were implanted with a 16-mm Nit-Occlud ASD-R occluder (PFM medical, Cologne, Germany) and were followed for 1 month (N = 3) and 3 months (N = 5). After heart explant, the device coverage was assessed using micro-CT (resolution of 41.7 µm) and was compared to histological analysis. The micro-CT image reconstruction was performed in 2D and 3D allowing measurement of the coverage thickness and surface for each device. Macroscopic assessment of devices showed that the coverage was complete for the left-side disk in all cases. Yet incomplete coverage of the right-side disk was observed in 5 of the 8 cases. 2D and 3D micro-CT analysis allowed an accurate evaluation of device coverage of each disk and was overall well correlated to histology sections. Surface calculation from micro-CT images of the 8 cases showed that the median surface of coverage was 93±8% for the left-side disk and 55±31% for the right-side disk. The assessment of tissue reactions, including endothelialisation, after implantation of an ASD occluder can rely on in vitro micro-CT analysis. The translation to clinical practice is challenging but the potential for individual follow-up is shown, to avoid thrombotic or infective complications.