The curative effect comparison of two kinds of therapeutic regimens on decreasing the relative intensity of microembolic signal in CLAIR trial

Abstract Background 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. Methods 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. Results 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. Conclusions Clopidogrel and aspirin more effectively decrease the MES intensity than aspirin alone in patients with large artery stenotic minor stroke or TIA.