Efficacy of dual antiplatelet therapy in cerebrovascular disease as demonstrated by a decline in microembolic signals. A report of eight cases.

BACKGROUND

The presence of microembolic signals (MES) may indicate an increased risk of recurrent ischemic events in patients with stroke. The optimal management of such patients is uncertain. We report the effect of clopidogrel in addition to aspirin on the number of MES in a series of patients with ischemic stroke and transient ischemic attack (TIA) due to large-vessel disease.

METHODS

8 patients with either extracranial or intracranial artery stenosis were identified in 30-min MES studies by transcranial Doppler sonography as having MES. All patients were on antiplatelet therapy prior to baseline transcranial Doppler monitoring. The patients were subsequently treated with clopidogrel in addition to aspirin. Repeat MES studies were performed between day 3 and 7 with aspirin and clopidogrel.

RESULTS

All patients were Chinese. The median interval time from symptom onset to initial MES study was 7 days (range of 2-30). MES donor sites included 4 severely stenosed or occluded internal carotid arteries and 4 stenosed middle cerebral arteries. The median MES number at baseline was 8 (range 3-51). Repeat MES studies showed a significant decrease in MES (p = 0.012, Wilcoxon signed ranks test). 4 patients had complete cessation of MES and all patients showed a decline in MES. No patient had recurrent strokes or bleeding complications.

CONCLUSION

The rapid and significant decline of MES in our stroke and TIA patients suggests the possible efficacy of dual antiplatelet therapy with aspirin and clopidogrel in patients with MES and symptomatic large-artery occlusive disease. Randomized controlled trials should be conducted to confirm this preliminary observation.