Patent Foramen OvaleIMPORTNCT04686253
Internal Microstructure of Patent Foramen Ovale Related to Stroke
An observational study of Patent Foramen Ovale, run by China National Center for Cardiovascular Diseases at 2 sites in China.
Trial 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… Read more about this study
- Who is it for?
- Ages 16 to 65 years
- Conditions the study is for
- Patent Foramen Ovale
- What is being tested?
- not appliable
- How many people
- 1,200 participants
- Where
- 2 sitesChina
- Study dates
- 23 Dec 2020to 31 Dec 2028
- How long will I take part?
- 5 Years
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 to 65 years
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
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.
Who may be able to join
- Patients aged 16 to 65 years without any known vascular risk factor, including hypertension, hypercholesterolemia, diabetes mellitus, atrial fibrillation, smoking and obesity;
- Documented PFO with right-to-left shunt ≥ 20 micro-bubbles by c-TCD;
- Stroke group: history of ischemic stroke (based on brain magnetic resonance imaging) or TIA within 6 months without other identifiable causes (Phase1);
- Migraine group: history of migraine headaches more than one year without other identifiable causes (Phase2);
- Control group: incidental finding of PFO without neurological or systemic symptoms (Phase3).
Who cannot join
- Any identifiable cause of ischemic stroke/TIA or migraine other than PFO;
- History of stroke or TIA within the past one month;
- Presence of cardiac enlargement or dysfunction;
- Presence of coexisting cardiovascular structural malformations/diseases;
- Presence of carotid artery lesions or coronary artery disease;
- Presence of deep vein thrombosis or pulmonary embolism;
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- Presence of implanted cardiac devices;
- Evidence of hypercoagulable state;
- Allergic to contrast medium;
- Echocardiographic evidence of intra-cardiac thrombus, mass, tumor or vegetation;
- Active endocarditis or other infections.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
China2 sites, 2 recruiting
- Recruiting
Chaowu Yan
Beijing, Beijing Municipality, 100037
Chaowu Yan, PhD and MD, +861088398408, chaowuyan@163.com
Chaowu Yan, PhD and MD
- Recruiting
National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences,Fuwai Hospital
Beijing, Beijing Municipality, 100037
Chaowu Yan, PhD and MD
About this study
Official title: Internal Microstructure of Patent Foramen Ovale Related to Cryptogenic Stroke, Transient Ischemic Attack or Migraine
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.
- Conditions
- Patent Foramen Ovale
- Being tested
- not appliable
- Keywords
- patent foramen ovale, stroke, transient ischemic attack, migraine, microstructure
- Medical subject headings
- Foramen Ovale, Patent, Stroke, Ischemic Attack, Transient, Migraine Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
not appliableOther
not appliable
| Study group | Role | What they receive |
|---|---|---|
| PFO patients with CS or/and TIA | PFO patients with CS or/and TIA (transcatheter closure of PFO was performed). Receives: Other: not appliable | |
| PFO patients with migraine | PFO patients with migraine (transcatheter closure of PFO was performed). Receives: Other: not appliable | |
| PFO patients without symptom | PFO patients without symptom (5-year follow-up). Receives: Other: not appliable |
What is being measured
The primary outcome is the main question the study is designed to answer.
Adverse Events after evaluation of PFO internal microstructure
cryptogenic stroke, transient ischemic attack , migraine or systemic embolism
Measured: 5 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Dec 2020
- Study start23 Dec 2020
- Primary completion31 Dec 2028 (estimated)
- Study completion31 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Patent Foramen OvaleStudies of the same condition, open and under way.
- More trials run by China National Center for Cardiovascular DiseasesThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 1,200 participants (estimated)
- Target duration
- 5 Years
Sponsor and investigators
- Sponsor type
- Other government
- 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
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04686253
- Sponsor's protocol ID
- 2020-6
- Acronym
- IMPORT
- Status last verified
- Jul 2025
- First submitted
- 23 Dec 2020
- Last updated
- 22 Jul 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
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 36891906Yan 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 34032839Yan C, Li H, Wan L, Liu A, Yundan P, Wang C, Zhao Y, Wang L, Fang W. Association of incomplete device apposition with stroke recurrence after patent foramen ovale closure. Heart. 2026 Aug 7:heartjnl-2026-327956. doi: 10.1136/heartjnl-2026-327956. Online ahead of print.
PubMed 42567695
Study at a glance
From the registry record, last updated by the sponsor on 22 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Internal Microstructure of Patent Foramen Ovale Related to Cryptogenic Stroke, Transient Ischemic Attack or Migraine
- ClinicalTrials.gov ID
- NCT04686253
- Acronym / sponsor ID
- IMPORT / 2020-6
- Conditions
- Patent Foramen Ovale
- Keywords
- patent foramen ovale, stroke, transient ischemic attack, migraine, microstructure
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 1,200 participants (estimated)
- Lead sponsor
- China National Center for Cardiovascular DiseasesOther government
- Collaborators
- Beijing Anzhen Hospital, The Affiliated Hospital of Xuzhou Medical University, Tibet Autonomous Region People's Hospital, Beijing Tiantan Hospital, Xuanwu Hospital, Beijing
- Study start
- 23 Dec 2020 (actual)
- Primary completion
- 31 Dec 2028 (estimated)
- Study completion
- 31 Dec 2028 (estimated)
- First posted
- 28 Dec 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 5 Years
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| PFO patients with CS or/and TIA | – | Other: not appliablePFO patients with CS or/and TIA (transcatheter closure of PFO was performed). |
| PFO patients with migraine | – | Other: not appliablePFO patients with migraine (transcatheter closure of PFO was performed). |
| PFO patients without symptom | – | Other: not appliablePFO patients without symptom (5-year follow-up). |
Who may qualify
- Ages
- 16 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- 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.
Key inclusion criteria (5 listed)
- Patients aged 16 to 65 years without any known vascular risk factor, including hypertension, hypercholesterolemia, diabetes mellitus, atrial fibrillation, smoking and obesity;
- Documented PFO with right-to-left shunt ≥ 20 micro-bubbles by c-TCD;
- Stroke group: history of ischemic stroke (based on brain magnetic resonance imaging) or TIA within 6 months without other identifiable causes (Phase1);
- Migraine group: history of migraine headaches more than one year without other identifiable causes (Phase2);
- Control group: incidental finding of PFO without neurological or systemic symptoms (Phase3).
Key exclusion criteria (11 listed)
- Any identifiable cause of ischemic stroke/TIA or migraine other than PFO;
- History of stroke or TIA within the past one month;
- Presence of cardiac enlargement or dysfunction;
- Presence of coexisting cardiovascular structural malformations/diseases;
- Presence of carotid artery lesions or coronary artery disease;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| not appliablenot appliable | Other | PFO patients with CS or/and TIA, PFO patients with migraine, PFO patients without symptom |
Primary outcome
Adverse Events after evaluation of PFO internal microstructure
Time frame: 5 years
cryptogenic stroke, transient ischemic attack , migraine or systemic embolism
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Jul 2025.
- Results publication: PubMed 36891906Yan 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.
- Results publication: PubMed 34032839Yan 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.
- Derived from this study: PubMed 42567695Yan C, Li H, Wan L, Liu A, Yundan P, Wang C, Zhao Y, Wang L, Fang W. Association of incomplete device apposition with stroke recurrence after patent foramen ovale closure. Heart. 2026 Aug 7:heartjnl-2026-327956. doi: 10.1136/heartjnl-2026-327956. Online ahead of print.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Patent Foramen Ovale, run by China National Center for Cardiovascular Diseases at 2 sites in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 22 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Chaowu Yan, PhD and MD (+861088398408, chaowuyan@163.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Adverse Events after evaluation of PFO internal microstructure (time frame: 5 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04686253, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Jul 2025.