Potential recruitment into a clinical trial of vascular secondary prevention medications in cerebral small vessel disease, based on concomitant medication use.

Background: Blood pressure-lowering medications, antiplatelet drugs and statins are often prescribed to asymptomatic patients with white matter hyperintensities (WMH). A clinical trial is needed, but potential trial participants would be excluded if they already had another indication to take the medication. It is likely that many patients with WMH would already have a recognised vascular-related indication for these drugs.We used data from the UK Biobank study to determine what proportion of people with WMH were not taking these drugs and would be potentially able to enter a clinical trial of antiplatelet drugs, statins, or BP-lowering medication.

Methods: We used the UK Biobank MRI sub-study of healthy volunteers aged 40-70 years as our cohort. We considered that WMH volumes in the top quartile (2.7-89 mls) were severe enough for a patient to be at risk of progression and be offered treatment. Such patients could also be included in a hypothetical clinical trial if there were no contraindications. Using the product licenses, we defined exclusion criteria for four hypothetical clinical trials of aspirin, clopidogrel, statins, and tight BP control. We then calculated what proportion of patients would still be eligible if these criteria were applied.

Results: 5794/23,179 patients had WMH in the top quartile. Of these, 4006/5794 69% (95% CI 68-70%) would be eligible for a trial of aspirin; with 81% (95% CI 80-82%) eligible for a trial of clopidogrel; 56% (95% CI 55-58%) of patients would be eligible to enter into a trial of a lower BP target, and 58% (95%CI 57-59%) would be able to enter a trial of a statin.

Conclusions: Over 80% of patients with WMH in the UK biobank would be eligible to enter a trial of an antiplatelet and just over half would be eligible to enter a trial of a statin or BP-lowering medication.