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Carotid Artery Stenosis SymptomaticIMPROVENCT07556887

Clinical Impact of Using IMPROVE to Select Patients for Carotid Revascularisation

A study testing IMPROVE Risk Model in people with Carotid Artery Stenosis Symptomatic and Ischemic Cerebral Infarction, run by Maastricht University Medical Center at 10 sites in Netherlands.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

Narrowing of the carotid artery due to atherosclerosis with an unstable plaque can cause a stroke. Patients with carotid artery disease who have had a TIA or minor stroke and are at high risk of another stroke are often treated with surgery or stenting to remove the plaque. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
IMPROVE Risk Model
Could I receive a placebo?
No, everyone receives an active treatment
How many people
613 participants
Where
10 sitesNetherlands
Study dates
31 Mar 2026to 31 Aug 2031
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

  • Mentally competent
  • 18 years or older
  • Recent (<30 days) stroke (modified Rankin scale ≤3) or TIA
  • Ipsilateral 30-99% atheromatous stenosis at the carotid bifurcation assessed using non-invasive imaging according to NASCET criteria
  • Life expectancy >5 years
  • Patient and stenosis are suitable for carotid revascularisation
  • Patient is agreeable to randomisation and willing to accept either IMPROVE-based or CAU-based selection method for carotid revascularisation

Who cannot join

  • Cardiac source of embolism
  • Carotid stenosis caused by non-atherosclerotic disease e.g. dissection, fibromuscular disease or neck radiotherapy.
  • MRI contra-indications
  • Pregnancy

Trial locations and contacts

10 sites in 1 country. Contact the study team or a site near you to ask about taking part.

M. Eline Kooi, Prof. dr. contact

+31 43 387 4911

improve.trial@mumc.nl

Robin M.M. Pleumeekers, MSc. contact

+31 43 387 7622

robin.pleumeekers@mumc.nl

10 sites in 1 country

Netherlands10 sites, 10 recruiting

  • Amsterdam UMC

    Amsterdam, North Holland, 1105 AZ

    Paul Nederkoorn, Dr., p.j.nederkoorn@amsterdamumc.nl

    Not yet recruiting

  • Rijnstate

    Arnhem, Gelderland, 6800 TA

    Sarah Vermeer, Dr., SVermeer@rijnstate.nl

    Michelle Simons, MCMSimons@Rijnstate.nl

    Not yet recruiting

  • Albert Schweitzer Ziekenhuis

    Dordrecht, South Holland, 3300 AK

    Henk Kerkhoff, Dr., H.Kerkhoff@asz.nl

    Not yet recruiting

  • Zuyderland

    Heerlen, Limburg, 6419 PC

    Tobien Schreuder, Drs., t.schreuder@zuyderland.nl

    Sandra Liedekerken, Drs., s.liedekerken@zuyderland.nl

    Not yet recruiting

  • Maastricht University

    Maastricht, Limburg, 6229 ER

    Robin Pleumeekers, MSc., +31 43 387 7622, robin.pleumeekers@mumc.nl

    Juul Bierens, MSc., juul.bierens@maastrichtuniversity.nl

    Recruiting

  • Radboud UMC

    Nijmegen, Gelderland, 6525 GA

    Floris Schreuder, Dr., floris.schreuder@radboudumc.nl

    Not yet recruiting

  • Erasmus MC

    Rotterdam, South Holland, 3000 CA

    Daniel Bos, Dr., d.bos@erasmusmc.nl

    Dianne Van Dam-Nolen, Dr., h.nolen@erasmusmc.nl

    Not yet recruiting

  • Haaglanden MC

    The Hague, South Holland, 2501 CK

    Korné Jellema, Dr., k.jellema@haaglandenmc.nl

    Not yet recruiting

  • Utrecht UMC

    Utrecht, Utrecht, 3584 CX

    Gert Jan De Borst, Prof. dr., g.j.deborst-2@umcutrecht.nl

    Not yet recruiting

  • Isala

    Zwolle, Overijssel, 8025 AB

    Clemens Kersten, Dr., c.j.b.a.kersten@isala.nl

    Not yet recruiting

Other trials in Netherlands

About this study

Official title: Clinical Impact of the Use of IMPROVE for Selection of Patients for Carotid Revascularisation: a Randomized Controlled Multicentre Non-inferiority Trial in Symptomatic Patients With 30-99% Carotid Stenosis

Narrowing of the carotid artery due to atherosclerosis with an unstable plaque can cause a stroke. Patients with carotid artery disease who have had a TIA or minor stroke and are at high risk of another stroke are often treated with surgery or stenting to remove the plaque. For lower-risk patients, medication alone is the better option, as surgery also carries risks. A new decision method, based on MRI detection of unstable plaques (IMPROVE), can better assess stroke risk and help determine which patients do or do not need surgery. We are investigating whether this method is at least as effective as the standard approach, which mainly considers the degree of narrowing. We expect that this new method will help reduce strokes and lower healthcare costs.

Patients will be followed for several years to compare which method is better for health and costs.

Read the detailed description

SUMMARY:

Stroke is the 2nd leading global cause of death and disability. Rupture of a vulnerable carotid plaque causes ~20% of ischemic strokes. Symptomatic patients with carotid stenosis may benefit from surgical removal of the plaque or stenting (revascularisation) to prevent recurrent stroke, but this carries risks. Current patient selection for revascularisation is suboptimal, largely based on stenosis degree without considering plaque vulnerability. Improving risk prediction is therefore crucial and has been formally recognized as a key priority in the Dutch Society for Vascular Surgery's Knowledge Agenda (2022): "How can we better identify patients with carotid stenosis who would or would not benefit from revascularisation?" Presence of intraplaque haemorrhage (IPH) on MRI is one of the most powerful imaging biomarkers of plaque vulnerability and a superior predictor of stroke compared to traditional clinical factors, including degree of stenosis. The recently developed "Individualized MRI- Based Stroke Prediction Score Using Plaque Vulnerability for Symptomatic Carotid Artery Disease Patients" (IMPROVE) clinical prediction model integrates both IPH on MRI and clinical risk factors to calculate ipsilateral ischemic stroke risk. This model has demonstrated significantly improved predictive performance over existing scores. A recent decision-analytic study investigated the impact of the use of IMPROVE to select patients with high stroke risk for revascularisation plus OMT (medication and lifestyle advice) and low-risk patients for OMT (optimized medical therapy)-only. This decision-analytic study showed that implementation of the IMPROVE decision rule for revascularisation selection can lead to 35% less ipsilateral strokes and perioperative strokes and deaths and a lifetime cost reduction of €6101 per patient, equating to an annual reduction in societal healthcare costs of €18 million in the Netherlands alone.

Rationale: Patient selection for carotid revascularisation to prevent recurrent strokes could be optimised by providing clinicians and patients the IMPROVE score for shared decision-making. Objective: The primary objective is to investigate the clinical impact and the cost-effectiveness of the individualised MRI-based IMPROVE decision rule compared to care as usual (CAU) in the selection of TIA and non-disabling stroke patients with 30-99% carotid stenosis for revascularisation.

Study design: Multicentre, randomized controlled non-inferiority trial. Study population: Patients with a recent TIA or minor ischemic stroke and ipsilateral 30-99% carotid stenosis according to NASCET criteria.

Intervention: For patients that are randomised to the IMPROVE arm, the IMPROVE risk score will be provided as additional information for clinical decision-making on patient stratification for carotid revascularisation plus OMT versus OMT-only. A revascularization procedure in combination with OMT will be advised for patients at high ipsilateral stroke risk (≥10% within 3 years) according to the IMPROVE score, while OMT- only (medication and lifestyle advice) is advised to patients with lower risk scores.

Comparator: Patients randomised for the control arm (care-as-usual (CAU)) will be selected for revascularisation based on the guidelines for carotid interventions from the European Society for Vascular Surgery. It advises to consider revascularisation for TIA and stroke patients with ≥50% carotid stenosis. Patients with 30-49% stenosis are treated by OMT-only (medication and lifestyle advice). Plaque vulnerability is not taken into account for patient selection in current clinical care in the Netherlands.

Main study parameters/endpoints: Primary: Composite of any stroke or death within 44 days after randomisation or ipsilateral ischemic stroke at any time during subsequent 3-5 years follow up. Secondary: a.o. QALYs, number of revascularization procedures, costs.

Being tested
IMPROVE Risk Model
Keywords
Carotid Artery Stenosis, Transient Ischemic Attack, Ischemic Stroke, Atherosclerosis, Plaque Rupture, Revascularisation, Carotid Endarterectomy, Carotid Artery Stenting, Magnetic Resonance Imaging, Stroke Risk Prediction, Intraplaque hemorrhage, Clinical Decision Support, Randomized Controlled Mulitcentre Trial, Cost-Effectiveness Analysis, Optimal Medical Therapy
Medical subject headings
Ischemic Stroke, Atherosclerosis, Stroke, Ischemic Attack, Transient, Carotid Artery Diseases, Carotid Stenosis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • IMPROVE Risk ModelOther

    Also called IMPROVE Rule, IMPROVE Decision Rule, IMPROVE Risk Score, IMPROVE Stroke Risk Model

    All patients are screened in routine care for stenosis. The stroke risk is assessed using IMPROVE, incorporating plaque vulnerability (intraplaque haemorrhage (IPH) on MRI), stenosis degree, ischemic event type (ocular vs. cerebral), age and sex. The practitioner and patient discuss treatment options in shared decision making based on this risk score. Patients above the risk threshold (≥10% ipsilateral stroke risk within 3 years) receive a recommendation for revascularisation, those below an advice for OMT-only. The 10% threshold resulted in the largest stroke reduction in the decision analytic study. ~53% of the patients need an extra MRI. In ~47% an MRI is unnecessary since, based on the other risk factors, the stroke risk is already high or low and the MRI result does not affect the risk category.

Study groups in NCT07556887
Study groupRoleWhat they receive
Care As Usual (CAU)No interventionCAU follows Dutch FMS guidelines, recommending revascularisation for symptomatic patients with ≥50% stenosis and OMT-only for 30-49%. Guidelines suggest risk models like CAR score but lack treatment guidance.
Intervention (IMPROVE) Arm:ExperimentalIMPROVE recommends revascularisation + OMT for patients with ≥10% 3-year ipsilateral stroke risk according to the IMPROVE-score and OMT-only for those with lower than 10% risk.
Receives: Other: IMPROVE Risk Model

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. The primary outcome of the study is the composite of any stroke or death within 44 days after randomisation or ipsilateral ischemic stroke at any time during subsequent follow-up.

    The perioperative period for the primary endpoint is defined as 44 days after randomisation for both study arms, rather than (the frequently defined) 30 days after carotid revascularisation. This approach avoids bias that would arise if the perioperative window were limited only to patients undergoing revascularisation. By using a fixed 44-day period after randomisation, carotid revascularisation can take place up to two weeks after randomisation without affecting the primary outcome definition, ensuring a fair comparison between treatment arms. The endpoint includes any stroke, including haemorrhagic stroke, as well as death occurring within this period.

    Measured: any strokes/deaths: from randomisation (day 1) until day 44. Ipsilateral ischemic strokes: from randomisation (day 1) through completion of follow-up (36 up to 60 months).

Secondary outcomes (9)

  1. Incidence of other cardiovascular ischemic symptoms (any stroke, myocardial infarction, TIA)

    Measured: From randomisation (Day 1) through completion of follow-up (36 up to 60 months).

  2. Functional outcome (mRS)

    The modified Rankin Scale (mRS) is a measure used to assess a patients functional outcome after a stroke. It is an observational scale in which patients are classified into seven categories according to their functional status. A score of "0" corresponds to no symptoms, and a score of "6" corresponds to death.

    Measured: At day 44 and 3 years after randomisation.

  3. The iMTA (Institute for Medical Technology Assessment) Productivity Cost Questionnaire (iPCQ)

    The goal of the iMTA Productivity Cost Questionnaire (iPCQ) is to measure productivity losses due to health problems for use in economic evaluations and health economic studies.

    Outcomes are reported in (working) days/hours or efficiency loss and there is no fixed total score. Higher values indicate worse productivity loss (e.g. more days absent due to illness or more symptoms during work).

    Measured: From baseline follow-up visit through completion of follow-up (36 up to 60 months).

  4. Quality of life (EQ-5D-5L: EuroQol [Quality of Life-5 dimensions-5 levels]) questionnaire

    The descriptive system comprises 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: no problems (=0) up to extreme problems (=5). The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. This decision results in a 1-digit number that expresses the level selected for that dimension. The digits for the five dimensions can be combined into a 5-digit number that describes the patient's health state (Dutch value set).

    The EQ VAS (virtual analogue scale) records the patient's self-rated health on a vertical visual analogue scale where the endpoints are labelled 'The best health you can imagine' = 100 and 'The worst health you can imagine' = 0. The VAS can be used as a quantitative measure of health outcome that reflects the patient's own judgement.

    Measured: From baseline follow-up visit through completion of follow-up (36 up to 60 months).

  5. The iMTA Medical Consumption Questionnaire (iMCQ)

    The iMCQ collects data on medical resource use so that direct healthcare costs can be calculated.

    Assesses healthcare utilization (e.g., visits, hospitalizations, medication use). Outcomes are reported as frequencies/volumes and there is no fixed total score. Higher volumes/frequenties indicate more healthcare use (and therefore higher costs).

    Measured: From baseline follow-up visit through completion of follow-up (36 up to 60 months).

  6. Number of hospitalizations

    Measured: From randomisation (Day 1) through completion of follow-up (36 up to 60 months).

  7. Number of carotid revascularisation procedures

    The number of carotid revascularisations (carotid endarterectomy (CEA) and stenting) will be determined.

    Measured: From randomisation (Day 1) through completion of follow-up (36 up to 60 months).

  8. Incremental cost-effectiveness ratio

    Measured: From randomisation (Day 1) through completion of follow-up (36 up to 60 months).

  9. Perioperative complications

    Measured: From randomisation (Day 1) through completion of follow-up (36 up to 60 months).

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted29 Apr 2026
  2. Study start31 Mar 2026
  3. Primary completion31 Aug 2028 (estimated)
  4. Study completion31 Aug 2031 (estimated)

Resources

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
Diagnosis
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
613 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07556887
Sponsor's protocol ID
NL-010345
Acronym
IMPROVE
Status last verified
May 2026
First submitted
18 Feb 2026
Last updated
15 May 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Data will not be publicly available but can be obtained from the principal investigator upon reasonable request.

Publications

  • Bierens J, Ament SMC, Truijman MTB, de Borst GJ, Nederkoorn PJ, Bos D, Joore MA, Postma AA, Kooi ME, van Oostenbrugge RJ, Smits LJM; IMPROVE Investigators. Plaque Magnetic Resonance Imaging Based Decision Rule for the Selection of Symptomatic Patients for Carotid Revascularisation: Clinician Perspectives on Acceptability and Implementation Barriers in the Netherlands. Eur J Vasc Endovasc Surg. 2026 Jan;71(1):5-11. doi: 10.1016/j.ejvs.2025.08.022. Epub 2025 Sep 9.

    PubMed 40930395

  • Nies KPH, Smits LJM, van Kuijk SMJ, Hosseini AA, van Dam-Nolen DHK, Kwee RM, Kurosaki Y, Rupert I, Nederkoorn PJ, de Jong PA, Bos D, Yamagata S, Auer DP, Schindler A, Saam T, van Oostenbrugge RJ, Kooi ME. Individualized MRI-Based Stroke Prediction Score Using Plaque Vulnerability for Symptomatic Carotid Artery Disease Patients (IMPROVE). Stroke. 2025 Aug;56(8):2068-2078. doi: 10.1161/STROKEAHA.124.050020. Epub 2025 May 8.

    PubMed 40336502

Questions about this trial

What is this clinical trial studying?

A study testing IMPROVE Risk Model in people with Carotid Artery Stenosis Symptomatic and Ischemic Cerebral Infarction, run by Maastricht University Medical Center at 10 sites in Netherlands.

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 7 inclusion and 4 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 15 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 10 sites in Netherlands. 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 M. Eline Kooi, Prof. dr. (+31 43 387 4911, improve.trial@mumc.nl), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

The primary outcome of the study is the composite of any stroke or death within 44 days after randomisation or ipsilateral ischemic stroke at any time during subsequent follow-up. (time frame: any strokes/deaths: from randomisation (day 1) until day 44. Ipsilateral ischemic strokes: from randomisation (day 1) through completion of follow-up (36 up to 60 months).). 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 NCT07556887, which also lists 2 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 15 May 2026.

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