Cardiac Resynchronisation Therapy (CRT)EFFECT-CRTNCT07084467
A Study Testing a New Heart Scan Method to Improve Pacemaker Treatment for Heart Failure
A study testing EF1 guided CRT optimisation in people with Cardiac Resynchronisation Therapy (CRT) and Heart Failure, run by King's College London at 1 site in United Kingdom.
Trial summary
Cardiac resynchronization therapy (CRT) is a device treatment for patients with heart failure which cannot be managed by medications alone. CRT can help the heart contract more efficiently and improve the pumping function. However, many patients do not benefit from this treatment. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cardiac Resynchronisation Therapy (CRT), Heart Failure
- What is being tested?
- EF1 guided CRT optimisation
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 400 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 1 Aug 2025to 31 Jul 2030
- Phase
- Interventional
- 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
Who may be able to join
- Age 18 years or older
- On optimal medical therapy for heart failure
- Meets standard guideline criteria for CRT (including conduction system pacing), specifically:
- NYHA class II to IV
- Left ventricular ejection fraction (EF) ≤ 35%
- QRS duration > 130 ms
Who cannot join
- Co-morbidities likely to reduce life expectancy to less than 6 months
- Major cardiovascular event within the past 6 weeks
- More than mild aortic stenosis
- Receiving continuous or intermittent infusion therapy for heart failure
- Poor ultrasound acoustic window preventing adequate imaging
- Unable to give informed consent
- Currently participating in another interventional study
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Phil Chowienczyk, PhD contact
About this study
Official title: Evaluation of First-Phase Ejection Fraction to Guide Cardiac Resynchronization Therapy - A Randomised Controlled Trial
Cardiac resynchronization therapy (CRT) is a device treatment for patients with heart failure which cannot be managed by medications alone. CRT can help the heart contract more efficiently and improve the pumping function. However, many patients do not benefit from this treatment. Therefore, a better selection tool will help us to determine the most suitable patients to receive this treatment. A new measure of pumping function of the heart called: first-phase ejection fraction or EF1 has been shown a good tool to select suitable patients for CRT. EF1 is a sensitive measurement of heart function and can be easily measured by echocardiography (an ultrasound heart scan).
The purpose of this study is to examine whether this new measurement (EF1) can predict outcomes and response to CRT treatment.
- Being tested
- EF1 guided CRT optimisation, Standard of Care (SOC)
- Medical subject headings
- Heart Failure
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
EF1 guided CRT optimisationOther
In the EF1-guided optimisation group, the settings of the CRT device are adjusted to maximise early heart pumping efficiency, measured by a parameter called first-phase ejection fraction (EF1). Depending on the patient's heart rhythm, either the timing between heart chambers (AV or VV delay) is adjusted in small steps. The device setting that gives the best EF1 reading is chosen to help improve the heart's response to CRT.
Standard of Care (SOC)Other
This group will receive standard of care for their health condition and CRT management.
| Study group | Role | What they receive |
|---|---|---|
| Standard of Care | Active comparator | Not described Receives: Other: Standard of Care (SOC) |
| EF1 optimisation | Experimental | Not described Receives: Other: EF1 guided CRT optimisation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Volumetric response of left ventricle
This will be defined as a reduction in left ventricular end-systolic volume by more than 15% at following CRT implantation comparing to before CRT implantation on echocardiogram.
Measured: 6 months post CRT implantation or 6 months post CRT optimisation
Secondary outcomes (1)
Hospitalization for heart failure or all-cause death
This composite endpoint will be collected over the entire duration of follow-up in the trial when the last patient randomized has reached 36 months of follow-up post CRT implantation.
Measured: From enrollment to 36 months post CRT implantation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jul 2025
- Study start1 Aug 2025 (estimated)
- Primary completion31 Jul 2030 (estimated)
- Study completion31 Jul 2030 (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 Cardiac Resynchronisation Therapy (CRT)Studies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- King's College London
- Sponsor type
- University, hospital or other
- Collaborators
- Guy's and St Thomas' NHS Foundation Trust, The Leeds Teaching Hospitals NHS Trust, King's College Hospital NHS Trust, Barts & The London NHS Trust
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07084467
- Sponsor's protocol ID
- 25/LO/0562
- Acronym
- EFFECT-CRT
- Status last verified
- Jun 2025
- First submitted
- 16 Jul 2025
- Last updated
- 3 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Gu H, Li Y, Fok H, Simpson J, Kentish JC, Shah AM, Chowienczyk PJ. Reduced First-Phase Ejection Fraction and Sustained Myocardial Wall Stress in Hypertensive Patients With Diastolic Dysfunction: A Manifestation of Impaired Shortening Deactivation That Links Systolic to Diastolic Dysfunction and Preserves Systolic Ejection Fraction. Hypertension. 2017 Apr;69(4):633-640. doi: 10.1161/HYPERTENSIONAHA.116.08545. Epub 2017 Feb 21.
PubMed 28223475Gu H, Sidhu BS, Fang L, Webb J, Jackson T, Claridge S, Einarsen E, Razavi R, Papageorgiou N, Chow A, Bhattacharyya S, Chowienczyk P, Rinaldi CA. First-Phase Ejection Fraction Predicts Response to Cardiac Resynchronization Therapy and Adverse Outcomes. JACC Cardiovasc Imaging. 2021 Dec;14(12):2275-2285. doi: 10.1016/j.jcmg.2021.05.007.
PubMed 34886993Gu H, Cirillo C, Nabeebaccus AA, Sun Z, Fang L, Xie Y, Demir O, Desai N, He L, Lu Q, Nakou E, O'Gallagher K, Tountas C, Marvaki A, Monaghan M, Perera D, Pericao A, Ryan M, Sinclair H, Stylianidis V, Victor K, Wang B, Wang J, Wang R, Wu C, Yang Y, Yuan H, Zhang D, Zhang Y, Faconti L, Papachristidis A, Zhang L, Carr-White G, Shah AM, Xie M, Chowienczyk P. First-Phase Ejection Fraction, a Measure of Preclinical Heart Failure, Is Strongly Associated With Increased Mortality in Patients With COVID-19. Hypertension. 2021 Jun;77(6):2014-2022. doi: 10.1161/HYPERTENSIONAHA.121.17099. Epub 2021 May 10.
PubMed 33966447Bing R, Gu H, Chin C, Fang L, White A, Everett RJ, Spath NB, Park E, Jenkins WS, Shah AS, Mills NL, Flapan AD, Chambers JB, Newby DE, Chowienczyk P, Dweck MR. Determinants and prognostic value of echocardiographic first-phase ejection fraction in aortic stenosis. Heart. 2020 Aug;106(16):1236-1243. doi: 10.1136/heartjnl-2020-316684. Epub 2020 Apr 28.
PubMed 32345658Gu H, Saeed S, Boguslavskyi A, Carr-White G, Chambers JB, Chowienczyk P. First-Phase Ejection Fraction Is a Powerful Predictor of Adverse Events in Asymptomatic Patients With Aortic Stenosis and Preserved Total Ejection Fraction. JACC Cardiovasc Imaging. 2019 Jan;12(1):52-63. doi: 10.1016/j.jcmg.2018.08.037. Epub 2018 Nov 15.
PubMed 30448118Yancy CW, Jessup M, Bozkurt B, Butler J, Casey DE Jr, Colvin MM, Drazner MH, Filippatos GS, Fonarow GC, Givertz MM, Hollenberg SM, Lindenfeld J, Masoudi FA, McBride PE, Peterson PN, Stevenson LW, Westlake C. 2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Failure Society of America. Circulation. 2017 Aug 8;136(6):e137-e161. doi: 10.1161/CIR.0000000000000509. Epub 2017 Apr 28. No abstract available.
PubMed 28455343
Study at a glance
From the registry record, last updated by the sponsor on 3 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of First-Phase Ejection Fraction to Guide Cardiac Resynchronization Therapy - A Randomised Controlled Trial
- ClinicalTrials.gov ID
- NCT07084467
- Acronym / sponsor ID
- EFFECT-CRT / 25/LO/0562
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- King's College LondonUniversity, hospital or other
- Collaborators
- Guy's and St Thomas' NHS Foundation Trust, The Leeds Teaching Hospitals NHS Trust, King's College Hospital NHS Trust, Barts & The London NHS Trust
- Study start
- 1 Aug 2025 (estimated)
- Primary completion
- 31 Jul 2030 (estimated)
- Study completion
- 31 Jul 2030 (estimated)
- First posted
- 24 Jul 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.
Cardiac resynchronization therapy (CRT) is a device treatment for patients with heart failure which cannot be managed by medications alone. CRT can help the heart contract more efficiently and improve the pumping function. However, many patients do not benefit from this treatment. Therefore, a better selection tool will help us to determine the most suitable patients to receive this treatment. A new measure of pumping function of the heart called: first-phase ejection fraction or EF1 has been shown a good tool to select suitable patients for CRT. EF1 is a sensitive measurement of heart function and can be easily measured by echocardiography (an ultrasound heart scan).
The purpose of this study is to examine whether this new measurement (EF1) can predict outcomes and response to CRT treatment.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Standard of Care | Active comparator | Other: Standard of Care (SOC) |
| EF1 optimisation | Experimental | Other: EF1 guided CRT optimisation |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age 18 years or older
- On optimal medical therapy for heart failure
- Meets standard guideline criteria for CRT (including conduction system pacing), specifically:
Key exclusion criteria (7 listed)
- Co-morbidities likely to reduce life expectancy to less than 6 months
- Major cardiovascular event within the past 6 weeks
- More than mild aortic stenosis
- Receiving continuous or intermittent infusion therapy for heart failure
- Poor ultrasound acoustic window preventing adequate imaging
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 |
|---|---|---|
| EF1 guided CRT optimisationIn the EF1-guided optimisation group, the settings of the CRT device are adjusted to maximise early heart pumping efficiency, measured by a parameter called first-phase ejection fraction (EF1). Depending on the patient's heart rhythm, either the timing between heart chambers (AV or VV delay) is adjusted in small steps. The device setting that gives the best EF1 reading is chosen to help improve the heart's response to CRT. | Other | EF1 optimisation |
| Standard of Care (SOC)This group will receive standard of care for their health condition and CRT management. | Other | Standard of Care |
Primary outcome
Volumetric response of left ventricle
Time frame: 6 months post CRT implantation or 6 months post CRT optimisation
This will be defined as a reduction in left ventricular end-systolic volume by more than 15% at following CRT implantation comparing to before CRT implantation on echocardiogram.
1 secondary outcome
Hospitalization for heart failure or all-cause death
Time frame: From enrollment to 36 months post CRT implantation
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 3 Aug 2025.
- Results publication: PubMed 28223475Gu H, Li Y, Fok H, Simpson J, Kentish JC, Shah AM, Chowienczyk PJ. Reduced First-Phase Ejection Fraction and Sustained Myocardial Wall Stress in Hypertensive Patients With Diastolic Dysfunction: A Manifestation of Impaired Shortening Deactivation That Links Systolic to Diastolic Dysfunction and Preserves Systolic Ejection Fraction. Hypertension. 2017 Apr;69(4):633-640. doi: 10.1161/HYPERTENSIONAHA.116.08545. Epub 2017 Feb 21.
- Results publication: PubMed 34886993Gu H, Sidhu BS, Fang L, Webb J, Jackson T, Claridge S, Einarsen E, Razavi R, Papageorgiou N, Chow A, Bhattacharyya S, Chowienczyk P, Rinaldi CA. First-Phase Ejection Fraction Predicts Response to Cardiac Resynchronization Therapy and Adverse Outcomes. JACC Cardiovasc Imaging. 2021 Dec;14(12):2275-2285. doi: 10.1016/j.jcmg.2021.05.007.
- Results publication: PubMed 33966447Gu H, Cirillo C, Nabeebaccus AA, Sun Z, Fang L, Xie Y, Demir O, Desai N, He L, Lu Q, Nakou E, O'Gallagher K, Tountas C, Marvaki A, Monaghan M, Perera D, Pericao A, Ryan M, Sinclair H, Stylianidis V, Victor K, Wang B, Wang J, Wang R, Wu C, Yang Y, Yuan H, Zhang D, Zhang Y, Faconti L, Papachristidis A, Zhang L, Carr-White G, Shah AM, Xie M, Chowienczyk P. First-Phase Ejection Fraction, a Measure of Preclinical Heart Failure, Is Strongly Associated With Increased Mortality in Patients With COVID-19. Hypertension. 2021 Jun;77(6):2014-2022. doi: 10.1161/HYPERTENSIONAHA.121.17099. Epub 2021 May 10.
- Results publication: PubMed 32345658Bing R, Gu H, Chin C, Fang L, White A, Everett RJ, Spath NB, Park E, Jenkins WS, Shah AS, Mills NL, Flapan AD, Chambers JB, Newby DE, Chowienczyk P, Dweck MR. Determinants and prognostic value of echocardiographic first-phase ejection fraction in aortic stenosis. Heart. 2020 Aug;106(16):1236-1243. doi: 10.1136/heartjnl-2020-316684. Epub 2020 Apr 28.
- Results publication: PubMed 30448118Gu H, Saeed S, Boguslavskyi A, Carr-White G, Chambers JB, Chowienczyk P. First-Phase Ejection Fraction Is a Powerful Predictor of Adverse Events in Asymptomatic Patients With Aortic Stenosis and Preserved Total Ejection Fraction. JACC Cardiovasc Imaging. 2019 Jan;12(1):52-63. doi: 10.1016/j.jcmg.2018.08.037. Epub 2018 Nov 15.
- Results publication: PubMed 28455343Yancy CW, Jessup M, Bozkurt B, Butler J, Casey DE Jr, Colvin MM, Drazner MH, Filippatos GS, Fonarow GC, Givertz MM, Hollenberg SM, Lindenfeld J, Masoudi FA, McBride PE, Peterson PN, Stevenson LW, Westlake C. 2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Failure Society of America. Circulation. 2017 Aug 8;136(6):e137-e161. doi: 10.1161/CIR.0000000000000509. Epub 2017 Apr 28. No abstract available.
- 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.
Phil Chowienczyk, PhD contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing EF1 guided CRT optimisation in people with Cardiac Resynchronisation Therapy (CRT) and Heart Failure, run by King's College London at 1 site in United Kingdom.
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 6 inclusion and 7 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: opening soon, as of the sponsor's last update on 3 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. 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 Haotian Gu, PhD (+44(0)2071884700, haotian.gu@kcl.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Volumetric response of left ventricle (time frame: 6 months post CRT implantation or 6 months post CRT optimisation). 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 NCT07084467, 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 3 Aug 2025.