Updated May 2026 · ClinicalTrials.gov

RECRUITINGPhase 4INTERVENTIONAL

BROKEN-SWEDEHEART- Optimized Pharmacological Treatment for Broken Heart (Takotsubo) Syndrome.

Q: What is the NCT04666454 clinical trial studying?

The aim of this study is to document an optimized pharmacologic treatment for patients with Takotsubo Syndrome. There is currently no published documentation in a large number of patients. The study is a Randomized Registry Clinical Trial and in total 1000 patients registered in SWEDEHEART will be included. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Q: Who can participate in NCT04666454?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

Q: How do I contact the trial site for NCT04666454?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Q: Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Q: Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

BROKEN-SWEDEHEART- Optimized Pharmacological Treatment for Broken Heart (Takotsubo) Syndrome. A Multinational, Multicentre, Registry-based, Open-label, Randomized Controlled Trial.

BROKEN-SWEDEHEART- Optimized Pharmacological Treatment for Broken Heart (Takotsubo) Syndrome. (NCT04666454) is a Phase 4 interventional studying Takotsubo Syndrome, sponsored by Vastra Gotaland Region. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

What Stage of Research Is This?

Phase 4 studies happen after a treatment has been approved by the FDA. They monitor long-term safety, real-world effectiveness, and any rare side effects that only emerge in larger populations over longer periods. Phase 4 results sometimes lead to label changes, additional warnings, or — rarely — withdrawal of approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

A target enrollment of 1,000 participants makes this a sizable late-stage trial. Studies in this range typically have enough power to detect clinically meaningful differences from a comparator and to characterize less-common side effects.

Who May Be Eligible (Plain English)

Who May Qualify: 1. Age ≥ 18 years. 2. A clinical diagnosis of TS (see definition 2.1), including an ejection fraction (EF) ˂ 50 % at baseline 3. Written willing to sign a consent form obtained Who Should NOT Join This Trial: 1. Previous randomization in the trial 2. Any concomitant condition resulting in a life expectancy of less than one month 3. Previously diagnosed left ventricular ejection fraction \<50% 4. Known cardiomyopathy (except previous Takotsubo syndrome) 5. Known hemodynamically significant valve disease (moderate or severe aortic/mitral regurgitation) or stenosis 6. Heart transplant or left ventricular assist device recipient 7. Most recent (within the most recent 3 months) haemoglobin ˂10 g/dL 8. Systolic blood pressure \<80 mm Hg at screening 9. Estimated glomerular filtration rate \<30 mL/min/1.73m2 10. Current dialysis 11. Pregnancy or of childbearing potential who is not sterilized or is not using a medically accepted form of contraception 12. Not suitable in the opinion of the investigator due to severe or terminal comorbidity with poor prognosis, or characteristics that may interfere with adherence to the trial protocol Specific exclusion criteria for Randomization 1 13. Any contra-indication for treatment with adenosine or dipyridamole (including AV-block II and III, sick-sinus syndrome in subjects who don´t have a functioning pacemaker, unstable angina, ongoing treatment with dipyridamole) 14. Severe asthma (defined as asthma requiring medium or high-dose inhaled corticosteroids combined with other long-acting medications) and severe Chronic Obstructive Pulmonary Disease (COPD), (defined as FEV-1 ˂ 50 %) 15. Ongoing treatment with dipyridamole 16. Declined participation in study 1 Specific exclusion criteria for Randomization 2 1. Any contra-indication for anticoagulant treatment. 2. Current indication for treatment with, anticoagulant or dual antiplatelet therapy 3. Declined participation in study 2 Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: 1. Age ≥ 18 years. 2. A clinical diagnosis of TS (see definition 2.1), including an ejection fraction (EF) ˂ 50 % at baseline 3. Written informed consent obtained Exclusion Criteria: 1. Previous randomization in the trial 2. Any concomitant condition resulting in a life expectancy of less than one month 3. Previously diagnosed left ventricular ejection fraction \<50% 4. Known cardiomyopathy (except previous Takotsubo syndrome) 5. Known hemodynamically significant valve disease (moderate or severe aortic/mitral regurgitation) or stenosis 6. Heart transplant or left ventricular assist device recipient 7. Most recent (within the most recent 3 months) haemoglobin ˂10 g/dL 8. Systolic blood pressure \<80 mm Hg at screening 9. Estimated glomerular filtration rate \<30 mL/min/1.73m2 10. Current dialysis 11. Pregnancy or of childbearing potential who is not sterilized or is not using a medically accepted form of contraception 12. Not suitable in the opinion of the investigator due to severe or terminal comorbidity with poor prognosis, or characteristics that may interfere with adherence to the trial protocol Specific exclusion criteria for Randomization 1 13. Any contra-indication for treatment with adenosine or dipyridamole (including AV-block II and III, sick-sinus syndrome in subjects who don´t have a functioning pacemaker, unstable angina, ongoing treatment with dipyridamole) 14. Severe asthma (defined as asthma requiring medium or high-dose inhaled corticosteroids combined with other long-acting medications) and severe Chronic Obstructive Pulmonary Disease (COPD), (defined as FEV-1 ˂ 50 %) 15. Ongoing treatment with dipyridamole 16. Declined participation in study 1 Specific exclusion criteria for Randomization 2 1. Any contra-indication for anticoagulant treatment. 2. Current indication for treatment with, anticoagulant or dual antiplatelet therapy 3. Declined participation in study 2

Treatments Being Tested

DRUG

Adenosine

Adenosine infusion 70 µg/kg/min for 3 hours.

DRUG

Dipyridamole 200 mg

200 mg b.i.d

DRUG

Apixaban 5 mg Oral Tablet

5mg b.i.d

OTHER

Care as recommended by the Taskforce on Takotsubo Syndrome of the Heart Failure Association of the European Society of Cardiology for takotsubo syndrome

This treatment will vary depending on local routines and the degree of adherence to the recommendations.

Locations (16)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Aarhus Universitetshospital

Aarhus, Denmark

Rigshospitalet

Copenhagen, Denmark

Oslo University Hospital

Oslo, Norway

Östersund Sjukhus

Östersund, Jämtland Härjedalen, Sweden

Region Jönköpings Län

Jönköping, Region Jönköping, Sweden

Norra Älvsborgs länssjukhus

Trollhättan, Västra Götalands Region, Sweden

Region Dalarna

Falun, Sweden

Sahlgrenska University Hospital, Department of Cardiology

Gothenburg, Sweden

Skaraborg Hospital

Gothenburg, Sweden

Region Skane Helsingborg Hospital

Helsingborg, Sweden

Region Oestergoetland

Linköping, Sweden

Region Skane - Skanes Universitetssjukhus

Lund, Sweden

Region Orebro lan

Örebro, Sweden

Danderyds Hospital, Department of Cardiology

Stockholm, Sweden

Karolinska University Hospital, Huddinge, Department of Cardiology

Stockholm, Sweden

Umeå University Hospital, Department of Cardiology

Umeå, Sweden

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT04666454), the sponsor (Vastra Gotaland Region), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT04666454 clinical trial studying?

The aim of this study is to document an optimized pharmacologic treatment for patients with Takotsubo Syndrome. There is currently no published documentation in a large number of patients. The study is a Randomized Registry Clinical Trial and in total 1000 patients registered in SWEDEHEART will be included. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT04666454?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT04666454?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT04666454. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT04666454. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.