The Swiss Patent Foramen Ovale (PFO) Consortium

Condition(s) targeted: Stroke; Transient Ischemic Attack

Intervention: Antithrombotic treatment (Drug); percutaneous device closure of PFO (Device)

Phase: N/A

Status: Recruiting

Sponsored by: University Hospital Inselspital, Berne

Official(s) and/or principal investigator(s):
Krassen Nedeltchev, MD, Principal Investigator, Affiliation: University of Bern and Triemli Municipal Hospital Zurich
Marcel Arnold, MD, Principal Investigator, Affiliation: University of Bern, Inselspital
Marie-Luise Mono, MD, Study Director, Affiliation: Dep. of Neurology, Bern University Hospital, Bern

Overall contact:
Krassen Nedeltchev, MD, Phone: +41444661729, Email: krassen.nedeltchev@triemli.stzh.ch

The prevalence of patent foramen ovale (PFO) is about 25% in the general population and approximately 40% in patients who have ischemic stroke of unknown cause (cryptogenic stroke). Given the large number of asymptomatic patients, no primary prevention is currently recommended. On the contrary, secondary prevention is a very important. Prospective studies have shown that antithrombotic treatment (ATT) with aspirin or warfarin appears to negate the risk of recurrent stroke associated with a PFO. Patients with spontaneous or large right-to-left shunts (RLS), those with a coinciding atrial septal aneurysm (ASA) or multiple ischemic events prior to the PFO diagnosis may still be at increased risk of stroke recurrence despite ATT. Percutaneous device closure (PDC) is a challenging alternative to ATT. Several studies reported 0% to 3. 4% annual recurrence rates of stroke or TIA in patients treated by PDC. To date, there is no data from randomized controlled trials (RCT) comparing the risk of stroke recurrence after PDC with that under ATT only. The results from ongoing RCTs are not to be awaited in the near future, mainly due to low enrolment and event rates. Alternative data-gathering strategies such as multicenter registries are needed to overcome the low recruitment rates. The aim of the present study is to compare the risk of recurrent stroke and TIA in patients with PFO and otherwise unexplained stroke who undergo PDC or receive ATT.

Official title: Secondary Stroke Prevention In Patients With Patent Foramen Ovale: The Swiss PFO Consortium

Study design: Cohort, Prospective

Primary outcome: proportion of patients free of any stroke (including fatal stroke) or TIA

Secondary outcome:

influence of gender, age, spontaneous or large shunt, coincidence of an atrial septum aneurysma

influence of competitive causes of stroke

frequency of residual shunt, (in)correct device position, need for implantation of second device and periprocedural complications

Detailed description: Background

Background: The prevalence of patent foramen ovale (PFO) is about 25% in the general population and approximately 40% in patients who have ischemic stroke of unknown cause (cryptogenic stroke). Given the large number of asymptomatic patients, no primary prevention is currently recommended. On the contrary, secondary prevention is a very important. Prospective studies have shown that antithrombotic treatment (ATT) with aspirin or warfarin appears to negate the risk of recurrent stroke associated with a PFO. Patients with spontaneous or large right-to-left shunts (RLS), those with a coinciding atrial septal aneurysm (ASA) or multiple ischemic events prior to the PFO diagnosis may still be at increased risk of stroke recurrence despite ATT. Percutaneous device closure (PDC) is a challenging alternative to ATT. Several studies reported 0% to 3. 4% annual recurrence rates of stroke or TIA in patients treated by PDC. To date, there is no data from randomized controlled trials (RCT) comparing the risk of stroke recurrence after PDC with that under ATT only. The results from ongoing RCTs are not to be awaited in the near future, mainly due to low enrolment and event rates. Even if RCTs are completed successfully, statistical differences may remain undetected with the planned sample sizes. Alternative data-gathering strategies such as multicenter registries are needed to overcome the low recruitment rates.

Objective

1) To compare the risk of recurrent stroke and TIA in patients aged ≤ 55 years with PFO and otherwise unexplained stroke who undergo PDC or receive ATT only; 2) To assess the etiological role of PFO for stroke/TIA in patients aged > 55 years; 3) To assess the risk of recurrent stroke/TIA in "high-risk" PFO patients (i. e. those with spontaneous (at rest) or large RLS, coinciding ASA, or multiple previous cerebrovascular events).

Methods

Multicenter prospective non-randomized study with scheduled 3-years follow-up of patients with PFO and ischemic stroke or TIA. Participating centers: Swiss University Hospitals of Basel, Bern, Geneva, Lausanne, and Zurich, the Cantonal Hospitals of Aarau and St. Gallen, the Triemli Municipal Hospital Zurich.

Minimum age: 18 Years. Maximum age: N/A. Gender(s): Both.

Criteria:

Inclusion Criteria:

- Age > 18 years

- Diagnosis of PFO established by transesophageal echocardiography (TEE)

- Ischemic stroke or transient ischemic attack within the previous 3 months

Exclusion Criteria

- Non-vascular origin of the neurological symptoms after brain imaging (CT scan or MRI)

- Comorbid condition that would interfere with the study

- Pregnancy

- History of intracranial bleeding, confirmed arterio-venous malformation, aneurysm or

uncontrolled coagulopathy

- Contraindications for TEE, echocardiographic or iodine contrast media

Krassen Nedeltchev, MD, Phone: +41444661729, Email: krassen.nedeltchev@triemli.stzh.ch

Department of Neurology, Bern University Hospital, Bern, Bern 3010, Switzerland; Recruiting
Marie-Luise Mono, Phone: +41316320743, Email: marie-luise.mono@insel.ch
Marcel Arnold, MD, Principal Investigator
Bernhard Meier, MD, Sub-Investigator
Marie-Luise Mono, MD, Sub-Investigator

Starting date: January 2009
Ending date: June 2015
Last updated: March 10, 2009