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RecruitingNCT04686253IMPORTUpdated Jul 22, 2025

Internal Microstructure of Patent Foramen Ovale Related to Stroke

An observational study in Patent Foramen Ovale, sponsored by China National Center for Cardiovascular Diseases. Recruiting at 2 sites in China. Open to participants aged 16 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-07-22.

Sponsored by China National Center for Cardiovascular Diseases · Observational

From the registry’s dates

  • Started Dec 2020; still recruiting 5 years 10 months later.
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
1,200
Ages
16 Years to 65 Years
Sex
All
01

Study summary

This study aims to (1) investigate the internal microstructure of patent foramen ovale related to cryptogenic stroke, transient ischemic attack or migraine and determine the effectiveness of transcatheter closure in these patients; (2) evaluate the microstructural features of asymptomatic patients with PFO and make a follow-up；(3) perform an untargeted metabolomics analysis using plasma samples from right atrium and left atrium and shunt provocative test was conducted;(4) collect the blood sample from PFO tunnel;(5) cardiac CTA was performed to evaluate the position and morphology of device.

Read the detailed description

Patent foramen ovale (PFO) is associated with a variety of pathological conditions, and it is presumed to be related to the occurrence of cryptogenic stroke (CS), transient ischemic attack (TIA) or migraine. In addition, the main hypothesized pathophysiologic mechanism is paradoxical embolization, namely microemboli or metabolites from the venous circulation to enter the systemic circulation. The morphological characteristics of PFO have the potential to predict risks and screen the appropriate candidates for transcatheter closure. The structure features for predicting risk included atrial septal aneurysm, a large right-left shunt, long-tunnel PFO and so on. However, the in-vivo internal microstructure of PFO is still unclear. The microstructural features might provide important information for better understanding the PFO and risk stratification.

The aim of this study is to (1) investigate the internal microstructure of patent foramen ovale related to cryptogenic stroke, transient ischemic attack or migraine and determine the effectiveness of transcatheter closure in these patients; (2) evaluate the microstructural features of asymptomatic patients with PFO and make a follow-up；(3) perform an untargeted metabolomics analysis using plasma samples from right atrium and left atrium and shunt provocative test was conducted;(4) collect the blood sample from PFO tunnel;(5) cardiac CTA was performed to evaluate the position and morphology of device.

This study will enroll subjects with PFO, and enrollment will be divided into three phases.

Phase 1: PFO patients with CS or/and TIA (transcatheter closure of PFO was performed). A minimum of 500 patients is reached.

Phase 2: PFO patients with migraine (transcatheter closure of PFO was performed). A minimum of 500 patients is reached.

Phase 3: PFO patients without symptom (5-year follow-up). A minimum of 200 patients is reached.

In addition, blood samples were obtained, including inferior vena cava, superior vena cava, right atrium, PFO-tunnel, left pulmonary artery, left atrium and left pulmonary vein. Then, another 20 ml blood sample was obtained from right atrium (near PFO) and injected into left atrium immediately. During a ten-minute waiting period, any symptom was recorded.

02

Conditions studied

  • Patent Foramen Ovale

Keywords

  • patent foramen ovale
  • stroke
  • transient ischemic attack
  • migraine
  • microstructure
03

In context

Foramen Ovale, Patent

136 studies on the registry are indexed under Foramen Ovale, Patent; 47 are open to participants now.

This study's planned enrollment of 1,200 is above the median of 254 across 59 observational studies indexed under Foramen Ovale, Patent.

Browse Foramen Ovale, Patent studies →

Lead sponsor

China National Center for Cardiovascular Diseases is the lead sponsor of 269 studies on the registry; 141 are open to participants now.

Browse China National Center for Cardiovascular Diseases studies →

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
16 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

This study will enroll subjects with PFO, and enrollment will be divided into three cohorts.

Cohort 1: PFO patients with CS or/and TIA (transcatheter closure of PFO was performed). A minimum of 100 patients is reached.

Cohort 2: PFO patients with migraine (transcatheter closure of PFO was performed). A minimum of 100 patients is reached.

Cohort 3: PFO patients without symptom (5-year follow-up). A minimum of 100 patients is reached.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Patients aged 16 to 65 years without any known vascular risk factor, including hypertension, hypercholesterolemia, diabetes mellitus, atrial fibrillation, smoking and obesity;
  2. Documented PFO with right-to-left shunt ≥ 20 micro-bubbles by c-TCD;
  3. Stroke group: history of ischemic stroke (based on brain magnetic resonance imaging) or within 6 months without other identifiable causes (Phase1);
  4. Migraine group: history of migraine headaches more than one year without other identifiable causes (Phase2);
  5. Control group: incidental finding of PFO without neurological or systemic symptoms (Phase3).

Exclusion criteria

Exclusion Criteria:

  1. Any identifiable cause of ischemic stroke/ or migraine other than PFO;
  2. History of stroke or TIA within the past one month;
  3. Presence of cardiac enlargement or dysfunction;
  4. Presence of coexisting cardiovascular structural malformations/diseases;
  5. Presence of carotid artery lesions or coronary artery disease;
  6. Presence of deep vein thrombosis or pulmonary embolism;
  7. Presence of implanted cardiac devices;
  8. Evidence of hypercoagulable state;
  9. Allergic to contrast medium;
  10. Echocardiographic evidence of intra-cardiac thrombus, mass, tumor or vegetation;
  11. Active endocarditis or other infections.
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

TIA (transient ischaemic attack)

A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.

Stroke symptoms need emergency care at once, even if they go away.

05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
1,200 participants (estimated)
Target follow-up
5 Years
Patient registry
Yes

Groups and cohorts

  • PFO patients with CS or/and TIA

    PFO patients with CS or/and TIA (transcatheter closure of PFO was performed).

    Other: not appliable

  • PFO patients with migraine

    PFO patients with migraine (transcatheter closure of PFO was performed).

    Other: not appliable

  • PFO patients without symptom

    PFO patients without symptom (5-year follow-up).

    Other: not appliable

Interventions

  • Othernot appliable

    not appliable

06

What researchers measure

Primary outcomes

  1. Adverse Events after evaluation of PFO internal microstructure

    cryptogenic stroke, transient ischemic attack , migraine or systemic embolism

    Time frame: 5 years

07

Study locations

2 of 2 sites recruiting
  • Chaowu Yan
    Beijing, Beijing Municipality 100037, China
    Recruiting
    • Chaowu Yan, PhD and MD · Contactchaowuyan@163.com · +861088398408
    • Chaowu Yan, PhD and MD · Principal investigator
  • National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences,Fuwai Hospital
    Beijing, Beijing Municipality 100037, China
    Recruiting
    • Chaowu Yan, PhD and MD · Contact
08

References and documents

Publications

  • Yan C, Li H, Wang C, Yu H, Guo T, Wan L, Yundan P, Wang L, Fang W. Frequency and Size of In Situ Thrombus Within Patent Foramen Ovale. Stroke. 2023 May;54(5):1205-1213. doi: 10.1161/STROKEAHA.122.041524. Epub 2023 Mar 9. PubMed 36891906 ↗
  • Yan C, Li H. Preliminary Investigation of In situ Thrombus Within Patent Foramen Ovale in Patients With and Without Stroke. JAMA. 2021 May 25;325(20):2116-2118. doi: 10.1001/jama.2021.4359. PubMed 34032839 ↗

Individual participant data

Plan to share: Undecided

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Started Dec 2020 (actual). Primary completion is estimated for Dec 2028, 96 months after the start.

How these figures are worked out, and which studies are left out of them.

Registered
Dec 23, 2020
First posted
Dec 28, 2020
StartActual
Dec 23, 2020
Primary completionEst.
Dec 31, 2028
CompletionEst.
Dec 31, 2028
Last update
Jul 22, 2025
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jul 22, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04686253
Lead sponsor
China National Center for Cardiovascular Diseases
Collaborators
Beijing Anzhen Hospital, The Affiliated Hospital of Xuzhou Medical University, Tibet Autonomous Region People's Hospital, Beijing Tiantan Hospital, Xuanwu Hospital, Beijing
Responsible party
Sponsor
First posted
Dec 28, 2020
Start date
Dec 23, 2020
Primary completion
Dec 31, 2028 (estimated)
Completion
Dec 31, 2028 (estimated)
Last update
Jul 22, 2025

Study contacts

Chaowu Yan, PhD and MD
Contact
chaowuyan@163.com
+861088398408

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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