Initial clinical experience with the Coherex FlatStent™ and FlatStent™ EF PFO closure system for in-tunnel PFO closure: results of the Coherex-EU study

Long-term transesophageal echocardiography after patent foramen ovale closure by BioSTAR and Amplatzer patent foramen ovale occluders

OBJECTIVES

To compare transesophageal echocardiography (TOE) findings after patent foramen ovale (PFO) closure by BioSTAR (NMT Medical Inc, Boston, MA) and Amplatzer PFO occluders (Abbott Vascular, Plymouth, MN).

BACKGROUND

PFO closure with a biodegradable device represents an attractive alternative to permanent devices. Long-term effectiveness and morphology after biodegradation remain unknown.

METHODS

Between February 2008 and June 2014, 49 patients received BioSTAR and 48 Amplatzer PFO occluder. TOE was performed after closure, at 6 months and beyond 2 years.

RESULTS

PFO features were comparable between the groups. Immediate effective closure (<5 bubbles on Valsalva) was obtained in 96% by BioSTAR and 88% by Amplatzer PFO occluder (p = .16). Except for transient fever after BioSTAR (10.8 vs. 0%; p = .08), there was no adverse events. TOE at 6 months revealed comparable effective closure (93 vs. 89%; p = .74), all devices in correct position and no thrombus/pericardial effusion. In the BioSTAR group, a peri-device left-to-right color Doppler shunt was documented in one patient (2.2%), protrusion of the nitinol framework strut(s) into the atrial cavity in two patients (4.3%), and both events in one patient (2.2%). TOE beyond 2 years showed comparable effective closure (92 vs. 96%; p = 1.00) and again BioSTAR-associated peri-device left-to-right shunt and metal framework strut(s) protrusion. There was no stroke or peripheral embolization in either group while TIA was numerically greater in BioSTAR patients (6.8 vs. 2.5%; p = .61).

CONCLUSION

BioSTAR provided similar PFO closure rate as Amplatzer PFO occluder. As yet unreported BioSTAR-associated peri-device left-to-right shunt and metal framework strut(s) protrusion may have practical implications for further development of biodegradable devices.

Who benefits from percutaneous closure of patent foramen ovale vs medical therapy for stroke prevention? In-depth and updated meta-analysis of randomized trials

BACKGROUND

A few randomized clinical trials (RCT) and their meta-analyses have found patent foramen ovale closure (PFOC) to be beneficial in prevention of stroke compared to medical therapy. Whether the benefit is extended across all groups of patients remains unclear.

AIM

To evaluate the efficacy and safety of PFOC vs medical therapy in different groups of patients presenting with stroke, we performed this meta-analysis of RCTs.

METHODS

Electronic search of PubMed, EMBASE, Cochrane Central, CINAHL and ProQuest Central and manual search were performed from inception through September 2018 for RCTs. Ischemic stroke (IS), transient ischemic attack (TIA), a composite of IS, TIA and systemic embolism (SE), mortality, major bleeding, atrial fibrillation (AF) and procedural complications were the major outcomes. Random-effects model was used to perform analyses.

RESULTS

Meta-analysis of 6 RCTs including 3560 patients showed that the PFOC, compared to medical therapy reduced the risk of IS [odds ratio: 0.34; 95% confidence interval: 0.15-0.78; P = 0.01] and the composite of IS, TIA and SE [0.55 (0.32-0.93); P = 0.02] and increased the AF risk [4.79 (2.35-9.77); P < 0.0001]. No statistical difference was observed in the risk of TIA [0.86 (0.54-1.38); P = 0.54], mortality [0.74 (0.28-1.93); P = 0.53] and major bleeding [0.81 (0.42-1.56); P = 0.53] between two strategies. Subgroup analyses showed that compared to medical therapy, PFOC reduced the risk of stroke in persons who were males, ≤ 45 years of age and had large shunt or atrial septal aneurysm.

CONCLUSION

In certain groups of patients presenting with stroke, PFOC is beneficial in preventing future stroke compared to medical therapy.

PFO "angioplasty": The preparation of a very stiff and long tunnel for device closure

INTRODUCTION

Patent foramen ovale (PFO) closure is a widely performed procedure. Understanding the anatomy is mandatory in order to perform the procedure successfully. The degree of overlap between the septum primum and secundum is called the tunnel. In particular, long and stiff tunnels may prevent the correct positioning of devices that have a fixed distance between the right and left atrial discs.

PATIENTS AND METHODS

We evaluated retrospectively 361 patients with PFO closure between January 2012 and June 2014 in our institution and were treated due to previous history of ischemic stroke. By TEE, the overlap between septum primum and secundum is usually better seen on the bicaval view that is obtained at 75-90° midesophageal views. Tunnel length and PFO opening were measured. Twelve subjects (median age 35 years; range 30-58 years; three females) showed a long (median 22 mm; range 15-32 mm) and rigid tunnel (median opening 2 mm; range 1-4 mm).

RESULTS

Angioplasty of the tunnel was performed by using peripheral angioplasty balloons with a length ranging from 4 to 8 cm and a diameter between 8 and 12 mm. After angioplasty, the tunnel appeared shorter (12 mm; range 8-16 mm) and less rigid (median opening 8 mm; range 7-12 mm). The following devices were implanted: 25 mm Amplatzer PFO occluder in three patients; 25 mm Gore septal occluder in nine subjects. Median fluoroscopy time was 8 min (range 6-10 min). No complications occurred. At a median follow-up of 12 months (range 2-18 months), no problems occurred and all subjects but one (trivial residual shunting) showed a complete closure.

CONCLUSIONS

Angioplasty of a PFO rigid and stiff tunnel is a feasible and safe option. © 2016 Wiley Periodicals, Inc.

[Interventional closure of atrial septal defects, patent oval foramen and ventricular septal defects]

Percutaneous transcatheter closure techniques and devices for congenital intracardiac shunts have considerably improved; therefore, catheter closure is now the treatment of choice for atrial septal defects (ASD). This is technically feasible in more than 80% of patients with a secundum ASD and the success rate is higher than 99%. General anesthesia is as a rule unnecessary and the hospital stay is very short. A patent oval foramen (POF) is a potential cause of cryptogenic stroke and peripheral embolisms. The catheter occlusion has many advantages in comparison to lifelong anticoagulation therapy and for some patients it is the only therapeutic option. Randomized trials have shown that interventional closure leads to results which are comparable to drug therapy and for some occlusion systems even evidence of significant advantages compared to drug therapy was found. Even ventricular septal defects (VSD), including perimembraneous and post-myocardial infarction VSDs can be closed by catheter techniques with a high success rate.

Patent foramen ovale

Patent foramen ovale (PFO) is the most common congenital heart abnormality of fetal origin and is present in approximately ∼25% of the worldwide adult population. PFO is the consequence of failed closure of the foramen ovale, a normal structure that exists in the fetus to direct blood flow directly from the right to the left atrium, bypassing the pulmonary circulation. PFO has historically been associated with an increased risk of stroke, the mechanism of which has been attributed to the paradoxical embolism of venous thrombi that shunt through the PFO directly to the left atrium. However, several studies have failed to show an increased risk of stroke in asymptomatic patients with a PFO, and the risk of stroke recurrence is low in patients who have had a stroke that may be attributed to a PFO. With the advent of transoesophageal and transthoracic echocardiography, as well as transcranial Doppler, a PFO can be routinely detected in clinical practice. Medical treatment with either antiplatelet or anticoagulation therapy is recommended. At the current time, closure of the PFO by percutaneous interventional techniques does not appear to reduce the risk of stroke compared to conventional medical treatment, as shown by three large clinical trials. Considerable controversy remains regarding the optimal treatment strategy for patients with both cryptogenic stroke and PFO. This Primer discusses the epidemiology, mechanisms, pathophysiology, diagnosis, screening, management and effects on quality of life of PFO.

The Flatstent versus the conventional umbrella devices in the percutaneous closure of patent foramen ovale

BACKGROUND

Patent foramen ovale (PFO) has been associated with paradoxical embolism leading to stroke/transient ischemic attack, migraine, and neurological decompression sickness. In search for the optimal device that would achieve effective clinical closure with minimal complications, a better device selection based on PFO anatomy and improvements in device design is needed. The Flatstent is a new device designed to treat the highly prevalent long-tunnel PFOs from within, minimizing the amount of material left behind in an attempt to reduce device-related complications. The objective is to compare the safety and efficacy of the novel Flatstent versus the conventional umbrella devices in the transcatheter closure of PFO in a nonrandomized, retrospective, single-center study.

METHODS

Between March 2010 and March 2013, 88 patients underwent PFO closure at The Heart Hospital, London with either the novel Flatstent or one of the four conventionally used umbrella devices (GORE Helex Septal Occluder, Occlutech Figulla Flex, Biostar Septal Occluder, and Amplatzer PFO Occluder) depending on their PFO anatomy. Patients were then evaluated with contrast transthoracic echocardiography (TTE) and/or transoesophageal echocardiography (TOE) at 6 weeks and 1 year after the procedure. The residual shunt and complication rates between the Flatstent and umbrella devices were compared.

RESULTS

The Flatstent was used in 27 patients (30.7%), whereas 61 patients (69.3%) received one of the four umbrella devices. Primary efficacy point of clinical closure defined as grade 0 or grade 1; residual shunt was achieved in 81.3% in the Flatstent cohort and 80.3% in the umbrella device group at 6 weeks follow-up. At 1 year, the clinical closure rates reached 92.6 and 91.8%. There were two device embolizations, one in each cohort during the immediate postoperative period (<24 hrs), with successful retrieval. One patient in the umbrella device group developed transient atrial fibrillation, which was controlled medically. Event recurrence rate was 0% at 1 year.

CONCLUSION

No difference was found in closure or complication rates between the Flatstent and the umbrella devices. With appropriate preassessment of the PFO anatomy, the Flatstent works as a safe and effective method of treating the PFO from within the tunnel, especially in those with long-tunnel PFOs. Longer follow-up is needed to establish superiority.

Transcatheter patent foramen ovale closure versus medical therapy for cryptogenic stroke: a meta-analysis of randomized clinical trials

BACKGROUND

There is an association between cryptogenic stroke and patent foramen ovale (PFO). The optimal treatment strategy for secondary prevention remains unclear. The purpose of this study was to analyze aggregate data examining the safety and efficacy of transcatheter device closure versus standard medical therapy in patients with PFO and cryptogenic stroke.

METHODS

A search of published data identified 3 randomized clinical trials for inclusion. The primary outcome was a composite end-point of death, stroke and transient-ischemic attack (TIA). Pre-defined subgroup analysis was performed with respect to baseline characteristics including age, sex, atrial septal aneurysm and shunt size. Data was synthesized using a random effects model and results presented as hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

A cohort of 2,303 patients with a history of cryptogenic stroke and PFO were randomized to device closure (n = 1150) and medical therapy (n = 1153). Mean follow-up was 2.5 years. Transcatheter closure was not superior to medical therapy in the secondary prevention of stroke or TIA in intention-to-treat analysis (HR: 0.66, 95% CI: 0.43 to 1.01; p = 0.056). However, the results were statistically significant using per-protocol analysis (HR: 0.64, 95% CI: 0.41 to 0.98; p = 0.043). Males had significant benefit with device closure (HR: 0.48, 95% CI: 0.24 to 0.96; p = 0.038).

CONCLUSIONS

In this meta-analysis, using intention-to-treat analysis, transcatheter device closure of PFO was not superior to standard medical therapy in the secondary prevention of cryptogenic stroke. Transcatheter closure was superior using per-protocol analysis.