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.
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
Cardiac source of embolism
Carotid stenosis caused by non-atherosclerotic disease e.g. dissection, fibromuscular disease or neck radiotherapy.
MRI contra-indications
Pregnancy
Parallel
IMPROVE Risk Model
Other interventionAll 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.
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.
Incidence of other cardiovascular ischemic symptoms (any stroke, myocardial infarction, TIA)
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.
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).
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.
Proportion of patients undergoing carotid revascularisation before application of the decision rule.
Process variables will be measured for the purpose of facilitating further implementation. These process variables are measured only in the intervention group.
Missing MRI or other required input data for application of the decision rule, recorded as the proportion of patients with incomplete data and documented reasons.
Process variables will be measured for the purpose of facilitating further implementation. These process variables are measured only in the intervention group.
Elective carotid revascularisation in low-risk patients according to the decision rule, assessed as the proportion of patients undergoing elective carotid endarterectomy or carotid artery stenting.
Process variables will be measured for the purpose of facilitating further implementation. These process variables are measured only in the intervention group.
Non-adherence to the risk-based recommendation, assessed as the proportion of patients with treatment decisions deviating from the decision rule.
Process variables will be measured for the purpose of facilitating further implementation. These process variables are measured only in the intervention group.
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Maastricht University Medical Center
Lead sponsor
Academisch Ziekenhuis Maastricht
Collaborator
Amsterdam UMC
Collaborator
UMC Utrecht
Collaborator
Haaglanden Medical Centre
Collaborator
Isala
Collaborator
Radboud University Medical Center
Collaborator
Zuyderland Medical Centre
Collaborator
Albert Schweitzer Hospital
Collaborator
Rijnstate Hospital
Collaborator
Erasmus Medical Center
Collaborator
