Optimizing PFO Assessment in Cryptogenic Stroke

Understanding what caused a stroke is key to potentially preventing the next one. But in up to one-third1 of ischemic strokes, no clear source is identified—leaving physicians and patients with unanswered questions about the risk of recurrence.  

PFO is a common contributor in cryptogenic stroke 

While not always causative, its presence can be clinically meaningful in the right context, making accurate detection a critical step on the path forward. 

A patent foramen ovale (PFO) is present in a significant portion of cryptogenic stroke cases—up to 40%–50%.2 

A Coordinated Imaging Strategy

For heart and brain teams, accurate assessment relies on both the selection of appropriate tests and the way those tests are performed and interpreted together.

Clinical guidelines support a stepwise, multimodality approach to PFO assessment—one that brings together complementary tools for a comprehensive evaluation3,4: 

  • Transthoracic echocardiography (TTE) typically serves as the starting point: accessible, non-invasive, and well-suited for initial evaluation.
  • Transesophageal echocardiography (TEE) builds on that foundation, offering greater sensitivity and detailed anatomical insight when more clarity is needed.
  • Transcranial Doppler (TCD) adds a highly sensitive, functional perspective, detecting and quantifying right-to-left shunting, even in smaller or more transient cases. 

Together, these modalities form a coordinated pathway, each contributing unique benefits that can provide a more complete and reliable understanding of whether a PFO is present and clinically meaningful. 

Technique is key for bubble study quality

Bubble studies have long been a standard tool for identifying PFOs, but their reliability is a matter of technique. Strong studies are built on fundamentals: effective patient coaching for the Valsalva maneuver, robust microbubble generation, and precise timing of contrast injection and imaging.  

When these elements come together, diagnostic confidence improves—particularly in initial assessments.5 Early bubble appearance in the left atrium suggests an intracardiac shunt, while delayed appearance may point to alternative sources such as pulmonary shunting. The number of bubbles observed can also help characterize shunt significance.6  

  1. Cryptogenic stroke or stroke of unknown cause. American Stroke Association. Accessed May 19, 2026. https://www.stroke.org/en/about-stroke/types-of-stroke/cryptogenic-stroke
  2. Mojadidi MK, Zaman MO, Elgendy IY, et al. Cryptogenic stroke and patent foramen ovale. J Am Coll Cardiol. 2018;71(9):1035-1043. doi:10.1016/j.jacc.2017.12.059 
  3. Messé SR, Gronseth GS, Kent DM, et al. Practice advisory update summary: patent foramen ovale and secondary stroke prevention: report of the guideline subcommittee of the American Academy of Neurology. Neurology. 2020;94(20):876-885. doi:10.1212/WNL.0000000000009443 
  4. Kleindorfer DO, Towfighi A, Chaturvedi S, et al. 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline from the American Heart Association/American Stroke Association. Stroke. 2021;52(7):e364-e467. doi:10.1161/STR.0000000000000375 
  5. Waggoner AD, Ehler D, Adams D, et al. Guidelines for the cardiac sonographer in the performance of contrast echocardiography: recommendations of the American Society of Echocardiography council on cardiac sonography. J Am Soc Echocardiogr. 2001;14(5):417-420. doi:10.1067/mje.2001.113817 
  6. Davison P, Clift PF, Steeds RP. The role of echocardiography in diagnosis, monitoring closure and post-procedural assessment of patent foramen ovale. Eur J Echocardiogr. 2010;11(10):i27-i34. doi:10.1093/ejechocard/jeq120
IFU Consult instructions

Refer to Instructions for Use at eifu.goremedical.com for a complete description of all applicable indications, warnings, precautions and contraindications for the markets where this product is available. RXOnly

INDICATIONS FOR USE IN THE U.S.: The GORE® CARDIOFORM Septal Occluder is a permanently implanted device indicated for the percutaneous, transcatheter closure of the following defects of the atrial septum: ostium secundum atrial septal defects (ASDs); patent foramen ovale (PFO) to reduce the risk of recurrent ischemic stroke in patients, predominantly between the ages of 18 and 60 years, who have had a cryptogenic stroke due to a presumed paradoxical embolism, as determined by a neurologist and cardiologist following an evaluation to exclude known causes of ischemic stroke.

INDICATIONS FOR USE IN CANADA: The GORE® CARDIOFORM Septal Occluder is a permanently implanted device indicated for the percutaneous, transcatheter closure of atrial septal defects (ASDs), such as ostium secundum and patent foramen ovale.

CONTRAINDICATIONS: The GORE® CARDIOFORM Septal Occluder is contraindicated for use in patients: unable to take antiplatelet or anticoagulant medications such as aspirin, heparin or warfarin; with anatomy where the GORE® CARDIOFORM Septal Occluder size or position would interfere with other intracardiac or intravascular structures, such as cardiac valves or pulmonary veins; with active endocarditis, or other infections producing bacteremia, or patients with known sepsis within one month of planned implantation, or any other infection that cannot be treated successfully prior to device placement; with known intracardiac thrombi. 

26CR1048-EN01 MAT-0708-1