Chronic Total Occlusion (CTO)NCT06917378
TRIO CTO (Taiwan Research Initiative on Coronary Total Occlusion)
An observational study of Chronic Total Occlusion (CTO), run by National Taiwan University Hospital at 3 sites in Taiwan.
Trial summary
Coronary chronic total occlusions (CTO) present a significant challenge in the field of interventional cardiology. These complex lesions, characterized by complete blockage of a coronary artery for a prolonged duration, often require specialized techniques and strategies to achieve successful revascularization. Read more about this study
- Who is it for?
- Ages 20 to 120 years
- Conditions the study is for
- Chronic Total Occlusion (CTO)
- What is being tested?
- Percutaneous coronary intervention of coronary chronic total occlusion
- Type of treatment
- Surgery or procedure
- How many people
- 5,000 participants
- Where
- 3 sitesTaiwan
- Study dates
- 15 Jan 2015to 31 Dec 2034
- 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 20 to 120 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: 1. Over 20 years old 2. Chronic total occlusion confirmed by coronary angiography, and noted for more than 3 months
Who may be able to join
- Over 20 years old
- Chronic total occlusion confirmed by coronary angiography, and noted for more than 3 months
Who cannot join
None listed.
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Taiwan3 sites, 3 recruiting
- Recruiting
Chang Gung Memorial Hospital
New Taipei City
Ying-Chang Tung, MD, +8863-3281200, cgmhswd@cgmh.org.tw
- Recruiting
National Taiwan University Hospital
Taipei
Chih-Fan Yeh, MD, PhD, +886223123456 ext. 262152, nicholas.yeh@gmail.com
- Recruiting
Taipei Veterans General Hospital
Taipei
Chun -Chin Chang, MD, PhD, +8862-28712121, ccchang16@vghtpe.gov.tw
About this study
Official title: The Multicenter Study to Evaluate Clinical and Angiographic Factors in Patients With Coronary Artery Chronic Total Occlusion in Taiwan
Coronary chronic total occlusions (CTO) present a significant challenge in the field of interventional cardiology. These complex lesions, characterized by complete blockage of a coronary artery for a prolonged duration, often require specialized techniques and strategies to achieve successful revascularization.
Read the detailed description
Using this consortium, we will establish a multicenter cohort to evaluate the clinical parameters, angiographic characteristics, interventional techniques, and clinical outcomes involved in coronary CTO intervention. 3 subprojects are listed here.
Subproject 1 intends to develop a novel algorithm integrating antegrade and retrograde scoring system to optimize the CTO intervention and determine the optimal timing for primary retrograde approach. Current algorithm for CTO intervention.
Subproject 2 aims to examine the strategies and outcomes of CTO involving bifurcations. Bifurcation CTO lesions present unique challenges due to their complex anatomy. Opening of the main vessel while preserving important branches is crucial for ensuring favorable long-term clinical prognosis. This subproject will investigate different strategies and devices employed in bifurcation CTO PCI to assess their efficacy and safety outcomes.
Subproject 3 investigates the treatment strategies for right coronary artery (RCA) CTOs with concomitant left main disease, which present a unique and intricate scenario, requiring careful consideration of revascularization strategies.
- Conditions
- Chronic Total Occlusion (CTO)
- Being tested
- Percutaneous coronary intervention of coronary chronic total occlusion
- Keywords
- CTO, Coronary Chronic Total Occlusion, Coronary artery disease, Coronary intervention, Collateral channel
- Medical subject headings
- Coronary Artery Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Percutaneous coronary intervention of coronary chronic total occlusionProcedure or surgery
Also called PCI to CTO
Coronary CTO was identified by coronary angiography, and its revascularization was attempted by either antegrade, retrograde or both approach.
| Study group | Role | What they receive |
|---|---|---|
| Successful CTO intervention | Successful CTO intervention, subgrouped by strategies, ex. antegrade or retrograde approach Receives: Procedure: Percutaneous coronary intervention of coronary chronic total occlusion | |
| Failed CTO intervention | Failed CTO intervention, subgrouped by strategies, ex. antegrade or retrograde approach Receives: Procedure: Percutaneous coronary intervention of coronary chronic total occlusion | |
| No CTO intervention | CTO was not intervened |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants with technical success of CTO revascularization
Successful CTO recanalization with <20% residual stenosis within the treated segment and restoration of Thrombolysis in Myocardial Infarction grade 3 antegrade flow, without side branch loss
Measured: 1 day
Number of participants with collateral channel tracking success
retrograde guidewire crossing the CC to reach the distal cap of CTO segment.
Measured: 1 day
Number of participants with major adverse cerebral cardiovascular events
Death, CV death, myocardial infarction, stroke, repeat revascularization
Measured: 5 years
Secondary outcomes (2)
Number of participants with periprocedural myocardial infarction
Confirmed by
Measured: 1 day
Number of participants with periprocedural complications
Periprocedural myocardial infarction, vessel perforation, stroke, urgent or emergent revascularization
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Apr 2025
- Study start15 Jan 2015
- Primary completion31 Dec 2034 (estimated)
- Study completion31 Dec 2034 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Chronic Total Occlusion (CTO)Studies of the same condition, open and under way.
- More trials run by National Taiwan University HospitalThe 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
- Case-control
- Time perspective
- Retrospective
- Enrolment
- 5,000 participants (estimated)
Sponsor and investigators
- Lead sponsor
- National Taiwan University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, National Taiwan University Clinical Trial Center, National Taiwan University Hospital
- Investigators
- Hsien-Li Kao, MD, Principal investigator, National Taiwan University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06917378
- Sponsor's protocol ID
- 202409095RINC
- Status last verified
- Jan 2025
- First submitted
- 24 Oct 2024
- Last updated
- 16 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Rossello X, Pujadas S, Serra A, Bajo E, Carreras F, Barros A, Cinca J, Pons-Llado G, Vaquerizo B. Assessment of Inducible Myocardial Ischemia, Quality of Life, and Functional Status After Successful Percutaneous Revascularization in Patients With Chronic Total Coronary Occlusion. Am J Cardiol. 2016 Mar 1;117(5):720-6. doi: 10.1016/j.amjcard.2015.12.001. Epub 2015 Dec 12.
PubMed 26747733Chen S, Karmpaliotis D, Redfors B, Shlofmitz E, Ben-Yehuda O, Crowley A, Mehdipoor G, Puskas JD, Kandzari DE, Banning AP, Morice MC, Taggart DP, Sabik JF 3rd, Serruys PW, Kappetein AP, Stone GW. Does an occluded RCA affect prognosis in patients undergoing PCI or CABG for left main coronary artery disease? Analysis from the EXCEL trial. EuroIntervention. 2019 Aug 9;15(6):e531-e538. doi: 10.4244/EIJ-D-19-00263.
PubMed 31186220Fefer P, Knudtson ML, Cheema AN, Galbraith PD, Osherov AB, Yalonetsky S, Gannot S, Samuel M, Weisbrod M, Bierstone D, Sparkes JD, Wright GA, Strauss BH. Current perspectives on coronary chronic total occlusions: the Canadian Multicenter Chronic Total Occlusions Registry. J Am Coll Cardiol. 2012 Mar 13;59(11):991-7. doi: 10.1016/j.jacc.2011.12.007.
PubMed 22402070Wu EB, Brilakis ES, Mashayekhi K, Tsuchikane E, Alaswad K, Araya M, Avran A, Azzalini L, Babunashvili AM, Bayani B, Behnes M, Bhindi R, Boudou N, Boukhris M, Bozinovic NZ, Bryniarski L, Bufe A, Buller CE, Burke MN, Buttner A, Cardoso P, Carlino M, Chen JY, Christiansen EH, Colombo A, Croce K, de Los Santos FD, de Martini T, Dens J, di Mario C, Dou K, Egred M, Elbarouni B, ElGuindy AM, Escaned J, Furkalo S, Gagnor A, Galassi AR, Garbo R, Gasparini G, Ge J, Ge L, Goel PK, Goktekin O, Gonzalo N, Grancini L, Hall A, Hanna Quesada FL, Hanratty C, Harb S, Harding SA, Hatem R, Henriques JPS, Hildick-Smith D, Hill JM, Hoye A, Jaber W, Jaffer FA, Jang Y, Jussila R, Kalnins A, Kalyanasundaram A, Kandzari DE, Kao HL, Karmpaliotis D, Kassem HH, Khatri J, Knaapen P, Kornowski R, Krestyaninov O, Kumar AVG, Lamelas PM, Lee SW, Lefevre T, Leung R, Li Y, Li Y, Lim ST, Lo S, Lombardi W, Maran A, McEntegart M, Moses J, Munawar M, Navarro A, Ngo HM, Nicholson W, Oksnes A, Olivecrona GK, Padilla L, Patel M, Pershad A, Postu M, Qian J, Quadros A, Rafeh NA, Ramunddal T, Prakasa Rao VS, Reifart N, Riley RF, Rinfret S, Saghatelyan M, Sianos G, Smith E, Spaedy A, Spratt J, Stone G, Strange JW, Tammam KO, Thompson CA, Toma A, Tremmel JA, Trinidad RS, Ungi I, Vo M, Vu VH, Walsh S, Werner G, Wojcik J, Wollmuth J, Xu B, Yamane M, Ybarra LF, Yeh RW, Zhang Q. Global Chronic Total Occlusion Crossing Algorithm: JACC State-of-the-Art Review. J Am Coll Cardiol. 2021 Aug 24;78(8):840-853. doi: 10.1016/j.jacc.2021.05.055.
PubMed 34412818Galassi AR, Werner GS, Boukhris M, Azzalini L, Mashayekhi K, Carlino M, Avran A, Konstantinidis NV, Grancini L, Bryniarski L, Garbo R, Bozinovic N, Gershlick AH, Rathore S, Di Mario C, Louvard Y, Reifart N, Sianos G. Percutaneous recanalisation of chronic total occlusions: 2019 consensus document from the EuroCTO Club. EuroIntervention. 2019 Jun 20;15(2):198-208. doi: 10.4244/EIJ-D-18-00826.
PubMed 30636678Huang CC, Lee CK, Meng SW, Hung CS, Chen YH, Lin MS, Yeh CF, Kao HL. Collateral Channel Size and Tortuosity Predict Retrograde Percutaneous Coronary Intervention Success for Chronic Total Occlusion. Circ Cardiovasc Interv. 2018 Jan;11(1):e005124. doi: 10.1161/CIRCINTERVENTIONS.117.005124.
PubMed 29311284
Study at a glance
From the registry record, last updated by the sponsor on 16 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Multicenter Study to Evaluate Clinical and Angiographic Factors in Patients With Coronary Artery Chronic Total Occlusion in Taiwan
- ClinicalTrials.gov ID
- NCT06917378
- Acronym / sponsor ID
- 202409095RINC
- Conditions
- Chronic Total Occlusion (CTO)
- Keywords
- CTO, Coronary Chronic Total Occlusion, Coronary artery disease, Coronary intervention, Collateral channel
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 5,000 participants (estimated)
- Lead sponsor
- National Taiwan University HospitalUniversity, hospital or other
- Collaborators
- Chang Gung Memorial Hospital, Taipei Veterans General Hospital, Taiwan
- Study start
- 15 Jan 2015 (actual)
- Primary completion
- 31 Dec 2034 (estimated)
- Study completion
- 31 Dec 2034 (estimated)
- First posted
- 8 Apr 2025 (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.
Coronary chronic total occlusions (CTO) present a significant challenge in the field of interventional cardiology. These complex lesions, characterized by complete blockage of a coronary artery for a prolonged duration, often require specialized techniques and strategies to achieve successful revascularization.
Detailed description
Using this consortium, we will establish a multicenter cohort to evaluate the clinical parameters, angiographic characteristics, interventional techniques, and clinical outcomes involved in coronary CTO intervention. 3 subprojects are listed here.
Subproject 1 intends to develop a novel algorithm integrating antegrade and retrograde scoring system to optimize the CTO intervention and determine the optimal timing for primary retrograde approach. Current algorithm for CTO intervention.
Subproject 2 aims to examine the strategies and outcomes of CTO involving bifurcations. Bifurcation CTO lesions present unique challenges due to their complex anatomy. Opening of the main vessel while preserving important branches is crucial for ensuring favorable long-term clinical prognosis. This subproject will investigate different strategies and devices employed in bifurcation CTO PCI to assess their efficacy and safety outcomes.
Subproject 3 investigates the treatment strategies for right coronary artery (RCA) CTOs with concomitant left main disease, which present a unique and intricate scenario, requiring careful consideration of revascularization strategies.
Study design
- Observational model
- Case-control
- Time perspective
- Retrospective
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Successful CTO intervention | – | Procedure: Percutaneous coronary intervention of coronary chronic total occlusionSuccessful CTO intervention, subgrouped by strategies, ex. antegrade or retrograde approach |
| Failed CTO intervention | – | Procedure: Percutaneous coronary intervention of coronary chronic total occlusionFailed CTO intervention, subgrouped by strategies, ex. antegrade or retrograde approach |
| No CTO intervention | – | –CTO was not intervened |
Who may qualify
- Ages
- 20 to 120 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- 1. Over 20 years old 2. Chronic total occlusion confirmed by coronary angiography, and noted for more than 3 months
Key inclusion criteria (2 listed)
- Over 20 years old
- Chronic total occlusion confirmed by coronary angiography, and noted for more than 3 months
Key exclusion criteria (0 listed)
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 |
|---|---|---|
| Percutaneous coronary intervention of coronary chronic total occlusionAlso: PCI to CTOCoronary CTO was identified by coronary angiography, and its revascularization was attempted by either antegrade, retrograde or both approach. | Procedure or surgery | Failed CTO intervention, Successful CTO intervention |
Primary outcome
Number of participants with technical success of CTO revascularization
Time frame: 1 day
Successful CTO recanalization with <20% residual stenosis within the treated segment and restoration of Thrombolysis in Myocardial Infarction grade 3 antegrade flow, without side branch loss
Number of participants with collateral channel tracking success
Time frame: 1 day
retrograde guidewire crossing the CC to reach the distal cap of CTO segment.
Number of participants with major adverse cerebral cardiovascular events
Time frame: 5 years
Death, CV death, myocardial infarction, stroke, repeat revascularization
2 secondary outcomes
Number of participants with periprocedural myocardial infarction
Time frame: 1 day
Number of participants with periprocedural complications
Time frame: 1 day
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 16 Oct 2026.
- Background: PubMed 26747733Rossello X, Pujadas S, Serra A, Bajo E, Carreras F, Barros A, Cinca J, Pons-Llado G, Vaquerizo B. Assessment of Inducible Myocardial Ischemia, Quality of Life, and Functional Status After Successful Percutaneous Revascularization in Patients With Chronic Total Coronary Occlusion. Am J Cardiol. 2016 Mar 1;117(5):720-6. doi: 10.1016/j.amjcard.2015.12.001. Epub 2015 Dec 12.
- Background: PubMed 31186220Chen S, Karmpaliotis D, Redfors B, Shlofmitz E, Ben-Yehuda O, Crowley A, Mehdipoor G, Puskas JD, Kandzari DE, Banning AP, Morice MC, Taggart DP, Sabik JF 3rd, Serruys PW, Kappetein AP, Stone GW. Does an occluded RCA affect prognosis in patients undergoing PCI or CABG for left main coronary artery disease? Analysis from the EXCEL trial. EuroIntervention. 2019 Aug 9;15(6):e531-e538. doi: 10.4244/EIJ-D-19-00263.
- Background: PubMed 22402070Fefer P, Knudtson ML, Cheema AN, Galbraith PD, Osherov AB, Yalonetsky S, Gannot S, Samuel M, Weisbrod M, Bierstone D, Sparkes JD, Wright GA, Strauss BH. Current perspectives on coronary chronic total occlusions: the Canadian Multicenter Chronic Total Occlusions Registry. J Am Coll Cardiol. 2012 Mar 13;59(11):991-7. doi: 10.1016/j.jacc.2011.12.007.
- Background: PubMed 34412818Wu EB, Brilakis ES, Mashayekhi K, Tsuchikane E, Alaswad K, Araya M, Avran A, Azzalini L, Babunashvili AM, Bayani B, Behnes M, Bhindi R, Boudou N, Boukhris M, Bozinovic NZ, Bryniarski L, Bufe A, Buller CE, Burke MN, Buttner A, Cardoso P, Carlino M, Chen JY, Christiansen EH, Colombo A, Croce K, de Los Santos FD, de Martini T, Dens J, di Mario C, Dou K, Egred M, Elbarouni B, ElGuindy AM, Escaned J, Furkalo S, Gagnor A, Galassi AR, Garbo R, Gasparini G, Ge J, Ge L, Goel PK, Goktekin O, Gonzalo N, Grancini L, Hall A, Hanna Quesada FL, Hanratty C, Harb S, Harding SA, Hatem R, Henriques JPS, Hildick-Smith D, Hill JM, Hoye A, Jaber W, Jaffer FA, Jang Y, Jussila R, Kalnins A, Kalyanasundaram A, Kandzari DE, Kao HL, Karmpaliotis D, Kassem HH, Khatri J, Knaapen P, Kornowski R, Krestyaninov O, Kumar AVG, Lamelas PM, Lee SW, Lefevre T, Leung R, Li Y, Li Y, Lim ST, Lo S, Lombardi W, Maran A, McEntegart M, Moses J, Munawar M, Navarro A, Ngo HM, Nicholson W, Oksnes A, Olivecrona GK, Padilla L, Patel M, Pershad A, Postu M, Qian J, Quadros A, Rafeh NA, Ramunddal T, Prakasa Rao VS, Reifart N, Riley RF, Rinfret S, Saghatelyan M, Sianos G, Smith E, Spaedy A, Spratt J, Stone G, Strange JW, Tammam KO, Thompson CA, Toma A, Tremmel JA, Trinidad RS, Ungi I, Vo M, Vu VH, Walsh S, Werner G, Wojcik J, Wollmuth J, Xu B, Yamane M, Ybarra LF, Yeh RW, Zhang Q. Global Chronic Total Occlusion Crossing Algorithm: JACC State-of-the-Art Review. J Am Coll Cardiol. 2021 Aug 24;78(8):840-853. doi: 10.1016/j.jacc.2021.05.055.
- Background: PubMed 30636678Galassi AR, Werner GS, Boukhris M, Azzalini L, Mashayekhi K, Carlino M, Avran A, Konstantinidis NV, Grancini L, Bryniarski L, Garbo R, Bozinovic N, Gershlick AH, Rathore S, Di Mario C, Louvard Y, Reifart N, Sianos G. Percutaneous recanalisation of chronic total occlusions: 2019 consensus document from the EuroCTO Club. EuroIntervention. 2019 Jun 20;15(2):198-208. doi: 10.4244/EIJ-D-18-00826.
- Background: PubMed 29311284Huang CC, Lee CK, Meng SW, Hung CS, Chen YH, Lin MS, Yeh CF, Kao HL. Collateral Channel Size and Tortuosity Predict Retrograde Percutaneous Coronary Intervention Success for Chronic Total Occlusion. Circ Cardiovasc Interv. 2018 Jan;11(1):e005124. doi: 10.1161/CIRCINTERVENTIONS.117.005124.
- Individual participant dataSharing planned: No
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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.
Hsien-Li Kao, MD principal investigator
National Taiwan University Hospital
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Chronic Total Occlusion (CTO), run by National Taiwan University Hospital at 3 sites in Taiwan.
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 2 inclusion and 0 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 16 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Taiwan. 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 Chih Fan Yeh (+8862-23123456 ext. 263912, nicholas.yeh@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of participants with technical success of CTO revascularization (time frame: 1 day). The study lists 3 primary outcomes in all. 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 NCT06917378, which also lists 6 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 16 Oct 2026.