Acute Myocardial Infarction Type 1Tropo-FragmNCT04465591
TROPOnin FRAGMentation in Myocardial Injury Study
An observational study of Acute Myocardial Infarction Type 1 and Myocardial Injury, run by University of Turku at 2 sites in 2 countries.
Trial summary
Troponin T (TnT) is a part of the troponin protein complex that principally exists in cardiac and skeletal muscle cells and is widely used as diagnostic biomarker for myocardial injury and, thus, myocardial infarction (MI). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Acute Myocardial Infarction Type 1, Myocardial Injury
- What is being tested?
- troponin T fragmentation test
- How many people
- 1,500 participants
- Where
- 2 sitesin 2 countries
- Study dates
- 2 Apr 2020to 31 Dec 2028
- How long will I take part?
- 1 Year
- 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients are prospectively recruited from the Heart Center, Department of Medicine and Kidney Center of the study hospital. All patients aged 18 years are eligible.
Who may be able to join
- Troponin T fragmentation sample collected from a recruited patient.
Who cannot join
- Age <18
Trial locations and contacts
2 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
2 sites in 2 countries
Finland1 site, 1 recruiting
- Recruiting
Turku University Hospital, Heart Center
Turku, Southwest Finland, 20521
Juhani KE Airaksinen, MD, PhD, +358 2 313 1079, juhani.airaksinen@tyks.fi
Samuli Jaakkola, MD, PhD, +358 2 3138 025, samuli.jaakkola@tyks.fi
Switzerland1 site, 1 recruiting
- Enrolling by invitation
University Hospital Zurich
Zurich, 8091 Zurich
About this study
Official title: Troponin T Fragmentation in the Assessment of Myocardial Injury Study
Troponin T (TnT) is a part of the troponin protein complex that principally exists in cardiac and skeletal muscle cells and is widely used as diagnostic biomarker for myocardial injury and, thus, myocardial infarction (MI). Elevated TnT levels can, however, be observed in the presence of other clinical conditions such as heart failure, sepsis and kidney failure and the contemporary high-sensitivity TnT test may yield false positive results when performing diagnostics for suspected MI in these patients.
Recent data have demonstrated that in the presence of MI, TnT gradually undergoes fragmentation into smaller fragments. It has been suggested that in the presence of e.g. chronic kidney disease or physical exercise the released TnT is predominantly in the form of smaller fragments.
However, the clinical significance of TnT fragmentation is unknown and, thus, we sought to investigate the prevalence of fragmentation of TnT in different patient cohorts.
Read the detailed description
Modern cardiac troponin T (cTnT) tests are highly sensitive in diagnosing AMI and myocardial damage. Atrial fibrillation and many non-cardiac conditions and even strenuous exercise are associated with elevated cTnT levels which are problematic to clinicians and may lead to redundant use of diagnostic coronary angiography or "overdiagnosis" of ACS in the emergency room workup.
The cardiac troponin (cTn) complex is part of the thin filaments of myocardium. Small part (approximately 5% of total content) of troponins are cytosolic. These smaller cytosolic fragments may more easily traverse across cell membranes that have become leaky for some reason but not irreversibly damaged. Only cytoplasmic forms of troponin are contained in the subcellular blebs which lyse upon early cTn release into the circulation. Bleb formation may explain how troponin can appear in blood in the absence of cell necrosis. Still many aspects of their intramyocardial degradation, their tissue release, and their degradation within and elimination from the human circulation are still incompletely understood.
In the early hours of AMI, troponin is found in its full-size complex, but the complexed cTnT degrades in a time-dependent pattern after the first hours. Small molecular weight troponin fragments originating from the cytoplasm may traverse across leaky cell membranes not completely damaged in various conditions without irreversible myocardial cell necrosis.
Commercial cTnT test detects all these fragments and may thus lead to false diagnosis of AMI. At present, there is limited information based on small studies using complicated gel filtration chromatography and Western blotting showing cTnT fragmentation in later phases of AMI and in renal failure. These time-consuming analytical methods are, however, not suitable for clinical purposes in the emergency room.
ANALYTICAL METHODS In this study we test a novel sensitive time-resolved immunofluorometric assay, which has been developed at the biotechnology unit of the Department Biochemistry, University of Turku, which enables us to measure cTnT from blood samples in its intact or only slightly fragmented form. Thus, we can exclude the highly fragmented short forms of cTnT from the analysis. This selectivity can be achieved with specific capture and tracer antibodies that bind to carefully chosen epitopes located closer to the opposite ends of the cTnT molecule. In the assay one of the antibodies is attached to a surface and acts as an antigen capturing antibody. The capture-antigen pair can be detected with tracer antibody, thus forming capture-antigen-tracer complex. In our case this tracer antibody has been labeled with europium chelates which provide sensitive detection by time-resolved fluorometry.
The aim of Tropo-Fragment study is to use the described preliminary assay format in the clinical studies to evaluate:
- TnT fragmentation and its time course in STEMI and NSTEMI
- TnT fragmentation in renal failure, sepsis, strenuous exercise, stroke, atrial fibrillation, takotsubo, myocarditis and healthy subjects
- TnT fragmentation after heart interventions ( cardiac surgery, TAVI operations. catheter ablation of atrial fibrillation, PCI)
- Being tested
- troponin T fragmentation test
- Keywords
- Troponin, myocardial injury, myocardial infarction
- Medical subject headings
- Myocardial Infarction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
troponin T fragmentation testDiagnostic test
laboratory test from blood sample
| Study group | Role | What they receive |
|---|---|---|
| Myocardial infarction | Recruited patients with STEMI or NSTEMI and elevated Troponin T Receives: Diagnostic Test: troponin T fragmentation test | |
| Myocardial injury | Recruited patients with myocardial injury based on elevated Troponin T and associated with renal failure, severe infection, strenouos exercise, atrial fibrillation, myocarditis, takotsubo cardiomyopathy or other similar conditions.
Patients undergoing interventions konow to cause troponin elevations, e.g. heart surgery, TAVI operations, catheter ablation of atrial fibrillation, PCI. Receives: Diagnostic Test: troponin T fragmentation test |
What is being measured
The primary outcome is the main question the study is designed to answer.
The fragmentation rate of Troponin T
The proportion of fragmented Troponin T in patient cohort.
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jul 2020
- Study start2 Apr 2020
- Primary completion30 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 (5)Papers the sponsor has linked to this study.
- Other trials for Acute Myocardial Infarction Type 1Studies of the same condition, open and under way.
- 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
- Cross-sectional
- Enrolment
- 1,500 participants (estimated)
- Target duration
- 1 Year
Sponsor and investigators
- Lead sponsor
- University of Turku
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Juhani Airaksinen, University of Turku
- Investigators
- Juhani K Airaksinen, MD, PhD, Principal investigator, University of Turku
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04465591
- Sponsor's protocol ID
- T29/2020
- Acronym
- Tropo-Fragm
- Status last verified
- May 2026
- First submitted
- 7 Jul 2020
- Last updated
- 8 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Airaksinen KEJ, Teppo K, Lehto J, Vasankari T, Salonen S, Haataja S, Tuominen T, Junes H, Varonen S, Paana T, Jaakkola S, Kiviniemi T, Wittfooth S. Composition of Troponin Release After Elective On-Pump and Off-Pump Cardiac Surgery. J Am Heart Assoc. 2026 Aug 28:e051842. doi: 10.1161/JAHA.126.051842. Online ahead of print.
PubMed 42663617Aalto R, Lahtinen A, Airaksinen KEJ, Vasankari T, Hellman T, Koskimaki L, Wittfooth S. Design and Analytical Evaluation of an Immunoassay for Long Forms of Cardiac Troponin T. J Appl Lab Med. 2026 Jan 5;11(1):36-47. doi: 10.1093/jalm/jfaf143.
PubMed 41025697Airaksinen JKE, Tuominen T, Paana T, Hellman T, Vasankari T, Salonen S, Junes H, Linko-Parvinen A, Pallari HM, Strandberg M, Teppo K, Jaakkola S, Wittfooth S. Novel troponin fragmentation assay to discriminate between Takotsubo syndrome and acute myocardial infarction. Eur Heart J Acute Cardiovasc Care. 2024 Dec 3;13(11):782-788. doi: 10.1093/ehjacc/zuae115.
PubMed 39422200Salonen SM, Tuominen TJK, Raiko KIS, Vasankari T, Aalto R, Hellman TA, Lahtinen SE, Soukka T, Airaksinen KEJ, Wittfooth ST. Highly Sensitive Immunoassay for Long Forms of Cardiac Troponin T Using Upconversion Luminescence. Clin Chem. 2024 Aug 1;70(8):1037-1045. doi: 10.1093/clinchem/hvae075.
PubMed 38888909Airaksinen KEJ, Aalto R, Hellman T, Vasankari T, Lahtinen A, Wittfooth S. Novel Troponin Fragmentation Assay to Discriminate Between Troponin Elevations in Acute Myocardial Infarction and End-Stage Renal Disease. Circulation. 2022 Nov;146(18):1408-1410. doi: 10.1161/CIRCULATIONAHA.122.060845. Epub 2022 Oct 31. No abstract available.
PubMed 36315607
Study at a glance
From the registry record, last updated by the sponsor on 8 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Troponin T Fragmentation in the Assessment of Myocardial Injury Study
- ClinicalTrials.gov ID
- NCT04465591
- Acronym / sponsor ID
- Tropo-Fragm / T29/2020
- Keywords
- Troponin, myocardial injury, myocardial infarction
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 1,500 participants (estimated)
- Lead sponsor
- University of TurkuUniversity, hospital or other
- Study start
- 2 Apr 2020 (actual)
- Primary completion
- 30 Dec 2028 (estimated)
- Study completion
- 31 Dec 2028 (estimated)
- First posted
- 10 Jul 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.
Troponin T (TnT) is a part of the troponin protein complex that principally exists in cardiac and skeletal muscle cells and is widely used as diagnostic biomarker for myocardial injury and, thus, myocardial infarction (MI). Elevated TnT levels can, however, be observed in the presence of other clinical conditions such as heart failure, sepsis and kidney failure and the contemporary high-sensitivity TnT test may yield false positive results when performing diagnostics for suspected MI in these patients.
Recent data have demonstrated that in the presence of MI, TnT gradually undergoes fragmentation into smaller fragments. It has been suggested that in the presence of e.g. chronic kidney disease or physical exercise the released TnT is predominantly in the form of smaller fragments.
However, the clinical significance of TnT fragmentation is unknown and, thus, we sought to investigate the prevalence of fragmentation of TnT in different patient cohorts.
Detailed description
Modern cardiac troponin T (cTnT) tests are highly sensitive in diagnosing AMI and myocardial damage. Atrial fibrillation and many non-cardiac conditions and even strenuous exercise are associated with elevated cTnT levels which are problematic to clinicians and may lead to redundant use of diagnostic coronary angiography or "overdiagnosis" of ACS in the emergency room workup.
The cardiac troponin (cTn) complex is part of the thin filaments of myocardium. Small part (approximately 5% of total content) of troponins are cytosolic. These smaller cytosolic fragments may more easily traverse across cell membranes that have become leaky for some reason but not irreversibly damaged. Only cytoplasmic forms of troponin are contained in the subcellular blebs which lyse upon early cTn release into the circulation. Bleb formation may explain how troponin can appear in blood in the absence of cell necrosis. Still many aspects of their intramyocardial degradation, their tissue release, and their degradation within and elimination from the human circulation are still incompletely understood.
In the early hours of AMI, troponin is found in its full-size complex, but the complexed cTnT degrades in a time-dependent pattern after the first hours. Small molecular weight troponin fragments originating from the cytoplasm may traverse across leaky cell membranes not completely damaged in various conditions without irreversible myocardial cell necrosis.
Commercial cTnT test detects all these fragments and may thus lead to false diagnosis of AMI. At present, there is limited information based on small studies using complicated gel filtration chromatography and Western blotting showing cTnT fragmentation in later phases of AMI and in renal failure. These time-consuming analytical methods are, however, not suitable for clinical purposes in the emergency room.
ANALYTICAL METHODS In this study we test a novel sensitive time-resolved immunofluorometric assay, which has been developed at the biotechnology unit of the Department Biochemistry, University of Turku, which enables us to measure cTnT from blood samples in its intact or only slightly fragmented form. Thus, we can exclude the highly fragmented short forms of cTnT from the analysis. This selectivity can be achieved with specific capture and tracer antibodies that bind to carefully chosen epitopes located closer to the opposite ends of the cTnT molecule. In the assay one of the antibodies is attached to a surface and acts as an antigen capturing antibody. The capture-antigen pair can be detected with tracer antibody, thus forming capture-antigen-tracer complex. In our case this tracer antibody has been labeled with europium chelates which provide sensitive detection by time-resolved fluorometry.
The aim of Tropo-Fragment study is to use the described preliminary assay format in the clinical studies to evaluate:
- TnT fragmentation and its time course in STEMI and NSTEMI
- TnT fragmentation in renal failure, sepsis, strenuous exercise, stroke, atrial fibrillation, takotsubo, myocarditis and healthy subjects
- TnT fragmentation after heart interventions ( cardiac surgery, TAVI operations. catheter ablation of atrial fibrillation, PCI)
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Target follow-up
- 1 Year
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Myocardial infarction | – | Diagnostic Test: troponin T fragmentation testRecruited patients with STEMI or NSTEMI and elevated Troponin T |
| Myocardial injury | – | Diagnostic Test: troponin T fragmentation testRecruited patients with myocardial injury based on elevated Troponin T and associated with renal failure, severe infection, strenouos exercise, atrial fibrillation, myocarditis, takotsubo cardiomyopathy or other similar conditions. Patients undergoing interventions konow to cause troponin elevations, e.g. heart surgery, TAVI operations, catheter ablation of atrial fibrillation, PCI. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients are prospectively recruited from the Heart Center, Department of Medicine and Kidney Center of the study hospital. All patients aged 18 years are eligible.
Key inclusion criteria (1 listed)
- Troponin T fragmentation sample collected from a recruited patient.
Key exclusion criteria (1 listed)
- Age <18
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 |
|---|---|---|
| troponin T fragmentation testlaboratory test from blood sample | Diagnostic test | Myocardial infarction, Myocardial injury |
Primary outcome
The fragmentation rate of Troponin T
Time frame: Baseline
The proportion of fragmented Troponin T in patient cohort.
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 8 May 2026.
- Derived from this study: PubMed 42663617Airaksinen KEJ, Teppo K, Lehto J, Vasankari T, Salonen S, Haataja S, Tuominen T, Junes H, Varonen S, Paana T, Jaakkola S, Kiviniemi T, Wittfooth S. Composition of Troponin Release After Elective On-Pump and Off-Pump Cardiac Surgery. J Am Heart Assoc. 2026 Aug 28:e051842. doi: 10.1161/JAHA.126.051842. Online ahead of print.
- Derived from this study: PubMed 41025697Aalto R, Lahtinen A, Airaksinen KEJ, Vasankari T, Hellman T, Koskimaki L, Wittfooth S. Design and Analytical Evaluation of an Immunoassay for Long Forms of Cardiac Troponin T. J Appl Lab Med. 2026 Jan 5;11(1):36-47. doi: 10.1093/jalm/jfaf143.
- Derived from this study: PubMed 39422200Airaksinen JKE, Tuominen T, Paana T, Hellman T, Vasankari T, Salonen S, Junes H, Linko-Parvinen A, Pallari HM, Strandberg M, Teppo K, Jaakkola S, Wittfooth S. Novel troponin fragmentation assay to discriminate between Takotsubo syndrome and acute myocardial infarction. Eur Heart J Acute Cardiovasc Care. 2024 Dec 3;13(11):782-788. doi: 10.1093/ehjacc/zuae115.
- Derived from this study: PubMed 38888909Salonen SM, Tuominen TJK, Raiko KIS, Vasankari T, Aalto R, Hellman TA, Lahtinen SE, Soukka T, Airaksinen KEJ, Wittfooth ST. Highly Sensitive Immunoassay for Long Forms of Cardiac Troponin T Using Upconversion Luminescence. Clin Chem. 2024 Aug 1;70(8):1037-1045. doi: 10.1093/clinchem/hvae075.
- Derived from this study: PubMed 36315607Airaksinen KEJ, Aalto R, Hellman T, Vasankari T, Lahtinen A, Wittfooth S. Novel Troponin Fragmentation Assay to Discriminate Between Troponin Elevations in Acute Myocardial Infarction and End-Stage Renal Disease. Circulation. 2022 Nov;146(18):1408-1410. doi: 10.1161/CIRCULATIONAHA.122.060845. Epub 2022 Oct 31. No abstract available.
- 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.
Juhani K Airaksinen, MD, PhD principal investigator
University of Turku
2 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Acute Myocardial Infarction Type 1 and Myocardial Injury, run by University of Turku at 2 sites in 2 countries.
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 1 inclusion and 1 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 8 May 2026. 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 Finland, Switzerland. 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 Juhani K Airaksinen, MD, PhD (+358 2 3131005, juhani.airaksinen@tyks.fi), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The fragmentation rate of Troponin T (time frame: Baseline). 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 NCT04465591, which also lists 5 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 8 May 2026.