Comparing PFO Outcomes of the Occlutech Flex II PFO Occluder to Standard of Care PFO Occlusion (OCCLUFLEX)

Prospective Randomized Multi-center Controlled Clinical Investigation Comparing Patent Foramen Ovale (PFO) Outcomes of the Occlutech Flex II PFO Occluder to Standard of Care PFO Occlusion

The objective of this study is to investigate whether percutaneous PFO closure with the Occlutech Flex II PFO Occluder is non-inferior to the AMPLATZER™ PFO Occluder and Gore® Cardioform Septal Occluder in closure of the PFO, prevention of recurrent embolic stroke, and device/procedure related Serious Adverse Events (SAE).

Study Overview

• Status: Active, not recruiting
• Conditions: Stroke; Patent Foramen Ovale; PFO
• Intervention / Treatment: Device: Investigational PFO Closure Device; Device: Standard of Care PFO Closure Device

• Study Type: Interventional
• Enrollment (Estimated): 450
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Edmonton, Alberta, Canada
      • University of Alberta Mazankowski Heart Institute
  • British Columbia
    • Vancouver, British Columbia, Canada
      • Vancouver General Hospital
  • Ontario
    • Ottawa, Ontario, Canada, K1Y 4W7
      • Ottawa Heart Institute
    • Toronto, Ontario, Canada
      • Toronto General Hospital
  • Quebec
    • Montreal, Quebec, Canada
      • Centre hospitalier de l'Université de Montréal (CHUM)
    • Montreal, Quebec, Canada
      • Institut de Cardiologie de Montreal
• Denmark
  • Aarhus, Denmark
    • Aarhus University Hospital
  • Copenhagen, Denmark, 2100
    • Rigshospitalet Copenhagen
• Finland
  • Helsinki, Finland
    • Heart and Lung Center, Helsinki University Hospital
• France
  • La Tronche, France, 38700
    • Chu Grenoble Alpes
  • Massy, France, 91300
    • Hôpital Privé Jacques Cartier
  • Toulouse, France, 31400
    • CHU TOULOUSE Rangueil
• Germany
  • Frankfurt, Germany, 60389
    • CardioVasculäre Centrum Frankfurt
  • Heidelberg, Germany
    • Universitätsklinik Heidelberg
  • Lübeck, Germany, 23538
    • University Heart Center Lübeck
  • Free and Hanseatic City of Hamburg
    • Hamburg, Free and Hanseatic City of Hamburg, Germany, 20246
      • Universitaetsklinikum Hamburg-Eppendorf
    • Hamburg, Free and Hanseatic City of Hamburg, Germany, 22763
      • Asklepios Klinik Altona Hamburg
• Netherlands
  • Amsterdam, Netherlands
    • Amsterdam University Medical Center
  • Rotterdam, Netherlands
    • Erasmus University Medical Centre
• United Kingdom
  • Belfast, United Kingdom
    • Royal Victoria Hospital
  • East Sussex
    • Brighton, East Sussex, United Kingdom
      • University Hospitals Sussex
• United States
  • Arizona
    • Phoenix, Arizona, United States, 85016
      • Arizona Cardiovascular Research Center
  • California
    • Stanford, California, United States, 94305
      • Stanford University Medical Center
    • Thousand Oaks, California, United States, 91360
      • Los Robles Medical Center
  • Colorado
    • Lakewood, Colorado, United States, 80228
      • Colorado Heart and Vascular PC / St. Anthony Hospital
    • Littleton, Colorado, United States, 80120
      • South Denver Cardiology Associates
  • District of Columbia
    • Washington D.C., District of Columbia, United States, 20010
      • Medstar Washington Hospital Center
  • Illinois
    • Chicago, Illinois, United States, 60612
      • Rush University Medical Center
    • Peoria, Illinois, United States, 61637
      • OSF Saint Francis Medical Center
  • Kentucky
    • Louisville, Kentucky, United States, 40202
      • University of Louisville
  • Maine
    • Portland, Maine, United States, 04102
      • MaineHealth
  • Massachusetts
    • Boston, Massachusetts, United States, 02215
      • Beth Israel Deaconess Medical Center
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital
    • Boston, Massachusetts, United States, 02111
      • Tufts New England Medical Center
    • Springfield, Massachusetts, United States, 01199
      • Baystate Medical Center
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • University of Michigan
  • Minnesota
    • Duluth, Minnesota, United States, 55804
      • Essentia Health
  • Nebraska
    • Omaha, Nebraska, United States, 68198
      • University of Nebraska Medical Center
  • New Jersey
    • Paramus, New Jersey, United States, 07652
      • The Valley Hospital
  • Ohio
    • Cleveland, Ohio, United States, 44106
      • University Hospitals Cleveland Medical Center
    • Columbus, Ohio, United States, 43210
      • The Ohio State University
    • Columbus, Ohio, United States, 43214
      • Ohio Health Research Institute
  • Oklahoma
    • Oklahoma City, Oklahoma, United States, 73120
      • Oklahoma Heart Hospital
  • Oregon
    • Portland, Oregon, United States, 97239
      • Oregon Health & Science University
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15213
      • UPMC Presbyterian
  • Tennessee
    • Nashville, Tennessee, United States, 37232
      • Vanderbilt Medical Center
  • Texas
    • Houston, Texas, United States, 77030
      • University of Texas Health Science Center at Houston
    • Houston, Texas, United States, 77004
      • HCA Houston Healthcare Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria: Subjects with a PFO and cryptogenic stroke:

• PFO defined as visualization of microbubbles (during Trans Esophageal Echo (TEE)) in the left atrium within three cardiac cycles of right atrial opacification at rest and/or with Valsalva.
• Cryptogenic stroke defined as a stroke of unknown cause.
• Stroke defined as an acute focal neurological deficit, presumed to be due to focal ischemia, and either:
• Symptoms persisting ≥24 hours OR
• Symptoms persisting <24 hours with Magnetic Resonance Imaging (MRI) or Computer Tomography (CT) findings of a new, neuroanatomically relevant, cerebral infarct.

Exclusion Criteria:

• Age < 18 years
• Myocardial Infarction (MI) or unstable angina within 6 months.
• Severe mitral valve stenosis, severe aortic valve stenosis, or severe regurgitation.
• Left Ventricle Ejection Fraction (LVEF) <35%.
• Uncontrolled hypertension or diabetes mellitus despite medications.
• Subjects contraindicated for aspirin or clopidogrel.
• Presence of other comorbid conditions, or other medical, social, or psychological conditions that, in the investigator's opinion, could limit the subject's ability to participate in the clinical trial or to comply with follow up requirements, or impact the scientific soundness of the clinical trial results.
• Qualifying stroke with Modified Rankin score >3.
• Anatomy in which the device would interfere with intracardiac or vascular structures.
• Life expectancy < 2 years.
• Participation in another clinical study that can interfere with the results of this study
• Exclusion for patients with known causes of ischemic stroke:
• Atrial fibrillation/atrial flutter (chronic or intermittent).
• Left Ventricle (LV) aneurysm, intracardiac thrombus, or tumor.
• Mitral or aortic valve vegetation or prosthesis.
• Aortic arch plaques protruding >4 mm into the lumen.
• Atherosclerosis or arteriopathy of intra- or extracranial vessels with >50% diameter stenosis in the artery supplying the infarcted territory.
• Another cause of right-to-left shunting (e.g., an Atrial Septal Defect (ASD) or a fenestrated atrial septum).
• Presence of an arterial hypercoagulable state.
• Lacunar infarct probably due to intrinsic small vessel as the qualifying event, defined as an ischemic stroke in the distribution of a single, small deep penetrating vessel in a patient with any of the following:
• A history of hypertension (except in the first week post stroke).
• A history of diabetes mellitus.
• Age ≥50 years.
• MRI or CT with leukoaraiosis greater than symmetric, well-defined periventricular caps, or bands (European Task Force on Age-Related White Matter Changes rating scale score >0).
• Arterial dissection as the qualifying event.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Investigational PFO Closure Device; PFO closure with the study Occlutech Flex II PFO device.	Device: Investigational PFO Closure Device; Occlutech Flex II PFO Closure Device
Active Comparator: Standard of Care PFO Closure Device; PFO closure with either of the standard of care PFO occlusion devices; Amplatzer PFO Occluder or the Gore Cardioform PFO Occluder.	Device: Standard of Care PFO Closure Device; Amplatzer PFO Occluder and Gore Cardioform PFO Occluder

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Effective Closure Rate of PFO	Twelve Months

Secondary Outcome Measures

Outcome Measure	Time Frame
Non-Fatal Recurrent Stroke	Enrollment to 12 Months

Other Outcome Measures

Outcome Measure	Time Frame
Safety: Device and Procedure Related Serious Adverse Events	Enrollment to Twelve Months, Annually thereafter.

Collaborators and Investigators

• Sponsor: Occlutech International AB
• Investigators: Study Chair: David Thaler, MD, PhD, FAHA, Tufts Medical Center and Tufts University School of Medicine; Study Chair: Steven Yakubov, MD, FACC, MSCAI, OhioHealth Heart & Vascular

Study record dates

Study Major Dates

• Study Start (Actual): May 9, 2022
• Primary Completion (Actual): November 30, 2025
• Study Completion (Estimated): November 1, 2029

Study Registration Dates

• First Submitted: September 24, 2021
• First Submitted That Met QC Criteria: September 24, 2021
• First Posted (Actual): October 6, 2021

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 21, 2026
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Heart Diseases; Congenital Abnormalities; Cardiovascular Abnormalities; Heart Defects, Congenital; Heart Septal Defects, Atrial; Heart Septal Defects; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Stroke; Foramen Ovale, Patent
• Other Study ID Numbers: OCC2021_02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No