- •Stroke is associated with microembolic signal (MES).
- •2 MES size can be estimated by monitoring the intensity via transcranial doppler.
- •Clopidogrel and aspirin more effectively reduce MES intensity than aspirin alone.
- •MES intensity is an important parameter in TCD monitoring.
Microembolic signals (MESs) are direct markers of unstable large artery atherosclerotic plaques. In a previous study, we found that the number of MESs is associated with stroke recurrence and that clopidogrel plus aspirin more effectively reduce the number of MESs than does aspirin alone. Stroke recurrence is associated with not only the number of MESs but also the size of the MES, which can theoretically be estimated by monitoring the MES intensity via transcranial doppler (TCD). Thus, we compared the effects of clopidogrel and aspirin with aspirin alone on MES intensity using TCD.
We recruited 100 patients who experienced acute ischemic stroke or transient ischemic attack (TIA) within 7 days of symptom onset. All patients also had large artery stenosis in the cerebral or carotid arteries and the presence of MES as revealed by TCD. The patients were randomized to receive either aspirin or clopidogrel and aspirin for 7 days. MES monitoring was performed on days 2 and 7.
Intent-to-treat (ITT) analysis (46 patients in the dual therapy group, 52 patients in the monotherapy group) and per–protocol (PP) analysis (25 patients in the dual therapy group, 31 patients in the monotherapy group) were performed on 98 patients. The primary finding was that the MES intensity was dramatically reduced in the dual therapy group. ITT analysis of the dual therapy group revealed that the MES intensity was 8.04 (0–16) dB before treatment, 0.00 (0–17) dB on day 2, and 0.00 (0−12) dB on day 7 (P = 0.000). In the monotherapy group, the MES intensity was 9.00 (0−20) dB before treatment, 8.25 (0–17) dB on day 2, and 7.0 (0–18) dB on day 7 (P = 0.577). PP analysis revealed similar results. No severe hemorrhagic complications were detected. The two patients in this study who experienced stroke recurrence were in the monotherapy group.
Clopidogrel and aspirin more effectively decrease the MES intensity than aspirin alone in patients with large artery stenotic minor stroke or TIA.
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Published online: May 21, 2016
Accepted: May 20, 2016
Received in revised form: April 26, 2016
Received: January 13, 2016
© 2016 Published by Elsevier B.V.