Microembolic signals in transcranial Doppler and the functional outcome of patients with acute ischemic stroke: a meta-analysis.
Microembolic signals (MES) detected by transcranial Doppler ultrasonography (TCD) reflect ongoing cerebral embolization and may serve as a marker of stroke instability. However, the association between MES and functional outcomes in patients with acute ischemic stroke (AIS) remains uncertain. This meta-analysis aimed to evaluate the prognostic significance of MES for poor functional outcomes after AIS.
PubMed, Embase, Web of Science, Wanfang Data, and CNKI databases were searched for cohort studies comparing functional outcomes between AIS patients with and without MES. The primary outcome was poor functional outcome, defined as a modified Rankin Scale score of 3-6 during follow-up. Odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using a random-effects model accounting for the influence of potential heterogeneity.
Thirteen cohort studies involving 1,777 patients with AIS were included, of whom 361 (20.3%) had detectable MES. Overall, MES was associated with a significantly increased risk of poor functional outcome (OR: 2.85, 95% CI: 2.16-3.75; p < 0.001) with no significant heterogeneity (I 2 = 0%). Subgroup analyses demonstrated consistent results across prospective and retrospective studies, and the observed association was not significantly influenced by patient age, sex distribution, endovascular treatment status, TCD monitoring duration, analytical model, or study quality (all p for subgroup difference > 0.05). MES was associated with poor functional outcomes at discharge (OR: 3.60), 14 days (OR: 2.69), and 90 days (OR: 3.15).
MES detected by TCD are associated with an increased risk of poor functional outcome in patients with AIS. However, their independent and incremental prognostic value beyond established clinical and imaging predictors requires further confirmation.
The review protocol was prospectively registered in PROSPERO (CRD420261425262).
PubMed, Embase, Web of Science, Wanfang Data, and CNKI databases were searched for cohort studies comparing functional outcomes between AIS patients with and without MES. The primary outcome was poor functional outcome, defined as a modified Rankin Scale score of 3-6 during follow-up. Odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using a random-effects model accounting for the influence of potential heterogeneity.
Thirteen cohort studies involving 1,777 patients with AIS were included, of whom 361 (20.3%) had detectable MES. Overall, MES was associated with a significantly increased risk of poor functional outcome (OR: 2.85, 95% CI: 2.16-3.75; p < 0.001) with no significant heterogeneity (I 2 = 0%). Subgroup analyses demonstrated consistent results across prospective and retrospective studies, and the observed association was not significantly influenced by patient age, sex distribution, endovascular treatment status, TCD monitoring duration, analytical model, or study quality (all p for subgroup difference > 0.05). MES was associated with poor functional outcomes at discharge (OR: 3.60), 14 days (OR: 2.69), and 90 days (OR: 3.15).
MES detected by TCD are associated with an increased risk of poor functional outcome in patients with AIS. However, their independent and incremental prognostic value beyond established clinical and imaging predictors requires further confirmation.
The review protocol was prospectively registered in PROSPERO (CRD420261425262).