Stroke due to late device thrombosis following successful percutaneous patent foramen ovale closure

Antithrombotic Therapy in Patients Undergoing Transcatheter Interventions for Structural Heart Disease

Contemporary evidence supports device-based transcatheter interventions for the management of patients with structural heart disease. These procedures, which include aortic valve implantation, mitral or tricuspid valve repair/implantation, left atrial appendage occlusion, and patent foramen ovale closure, profoundly differ with respect to clinical indications and procedural aspects. Yet, patients undergoing transcatheter cardiac interventions require antithrombotic therapy before, during, or after the procedure to prevent thromboembolic events. However, these therapies are associated with an increased risk of bleeding complications. To date, challenges and controversies exist regarding balancing the risk of thrombotic and bleeding complications in these patients such that the optimal antithrombotic regimens to adopt in each specific procedure is still unclear. In this review, we summarize current evidence on antithrombotic therapies for device-based transcatheter interventions targeting structural heart disease and emphasize the importance of a tailored approach in these patients.

Fabrication and characterization of chitosan nanoparticles and collagen-loaded polyurethane nanocomposite membrane coated with heparin for atrial septal defect (ASD) closure

Atrial septal defect (ASD) constitutes 30-40% of all congenital heart diseases in adults. The most common complications in the treatment of ASD are embolization of the device and thrombosis formation. In this research, an occluding patch was developed for ASD treatment using a well-known textile technology called electrospinning. For the first time, a cardiovascular occluding patch was fabricated using medical grade polyurethane (PU) loaded with bioactive agents namely chitosan nanoparticles (Cn) and collagen (Co) which is then coated with heparin (Hp). Fourier transform infrared spectrum showed characteristic vibrations of several active constituents and changes in the absorbance due to the inclusion of active ingredients in the patch. The contact angle analysis demonstrated no significant decrease in contact angle compared to the control and the composite patches. The structure of the electrospun nanocomposite (PUCnCoHp) was examined through scanning electron microscopy. A decrease in nanofiber diameter between control PU and PUCnCoHp nanocomposite was observed. Water uptake was found to be decreased for the PUCnCoHp nanocomposite against the control. The hemocompatibility properties of the PUCnCoHp ASD occluding patch was inferred through in vitro hemocompatibility tests like activated partial thromboplastin time (APTT), prothrombin time (PT) and hemolysis assay. It was found that the PT and APTT time was significantly prolonged for the fabricated PUCnCoHp ASD occluding patch compared to the control. Likewise, the hemolysis percentage was also decreased for the PUCnCoHp ASD patch against the control. In conclusion, the developed PUCnCoHp patch demonstrates potential properties to be used for ASD occlusion.

Initial use of the new GORE(®) septal occluder in patent foramen ovale closure: implantation and preliminary results

BACKGROUND

A number of devices are available for percutaneous closure of a clinically significant patent foramen ovale (PFO). The new GORE(®) septal occluder (GSO) is a nonself-centering device consisting of an expanded polytetrafluoroethylene tube supported by a frame of nitinol wire conforming into a double disk. This study reports the first clinical GSO implantation experience.

METHODS

GSO implantation in 20 consecutive patients is reported. Inclusion criteria were all patients referred with a significant PFO implicated in paradoxical embolism or transient right to left shunting causing desaturation. Procedures were performed under local anaesthesia and intracardiac echocardiography (ICE) in addition to fluoroscopy. Procedural data, acute and early closure rates were examined.

RESULTS

All patients underwent successful day-case device implantation. Eleven patients had previous stroke, five had transient ischemic attacks, two had a history suspicious of PFO-related desaturation, and two had a history suspicious of PFO-related peripheral thromboembolism. Acute closure rates on IVC injection bubble testing were 100% at implant and 100% (14/14) at 1 month. Average PFO balloon size was 8.0 ± 3.6(range 2.0-16.7) mm, mean fluoroscopic implantation time 3.0 ± 1.7(range 0.7-6.3) min, radiation dose 283 ± 340 (range 6-1,431) μGym(2), and total procedural time 34.8 ± 8.0 (range 22-53) min. 5 × 20 mm(2), 7 × 25 m(2), 8 × 30 mm(2) GSO devices were implanted, aiming for device size at least twice balloon PFO size. Cases included aneurysmal septums with up to 30 mm deviation and tunnels up to 12 mm long. Removal and repositioning of two devices was performed on two occasions after uncertainty about device locking. At 1 month follow-up, two patients had brief self-terminating episodes of suspected atrial fibrillation, all had normal resting ECGs. No thromboembolic/neurological events were reported.

CONCLUSIONS

The GSO can be implanted under local anaesthesia and ICE with low procedural and fluoroscopy times with high procedural success as a day case. No residual shunts were seen. This initial experience suggests that it is a safe and effective device for PFO closure.