Citations

Background: The management of asymptomatic high-grade carotid stenosis remains challenging, particularly in identifying individuals at highest risk for hypoperfusion-related stroke. Impaired cerebrovascular reactivity (CVR) has emerged as a potential predictor of future cerebrovascular events. Objective: To perform a systematic review and meta-analysis to quantify the association between impaired CVR and the risk of ipsilateral ischemic stroke or TIA in patients with asymptomatic high-grade carotid stenosis/occlusion. Methods: A systematic literature search of PubMed, Embase and Scopus was conducted from inception till July 2025. Eligible studies included asymptomatic patients with ≥70% carotid stenosis or occlusion who underwent CVR assessment and reported ipsilateral ischemic stroke or TIA outcomes. Pooled relative risks (RR) with 95% confidence intervals (CIs) were calculated using a random-effects model. Forest plots were generated, and heterogeneity was assessed using the chi-square test and the I 2 statistic. Results: Six prospective observational studies including a total of 361 patients with asymptomatic high-grade carotid stenosis/occlusion (mean age 70.4 years; 73.6% male; 71.2% with hypertension; 28.6% with diabetes; 29.6% current or former smokers) were included in the analysis. Of these, 120 patients had impaired CVR and 241 had preserved CVR. Transcranial Doppler (TCD) was the most frequently used modality to assess CVR, with acetazolamide or CO 2 as the vasodilatory stimulus. Following CVR assessment, patients were monitored for a weighted mean follow-up of 26.2 months (range: 21.5 to 42.5 months). The incidence of ipsilateral ischemic stroke or TIA was 14.2% in patients with impaired CVR versus 2.1% in those with preserved CVR (RR 3.98; 95% CI 1.62–9.76; P = 0.003; Figure 1). When limited to ipsilateral ischemic stroke alone, the incidence was 21.4% in the impaired CVR group compared to 4.3% in the preserved CVR group (RR 3.35; 95% CI 1.54–7.25; P = 0.002; Figure 2). Conclusions: Impaired CVR is associated with a 3- to 4-fold increased risk of ipsilateral ischemic stroke or TIA in patients with high-grade carotid stenosis/occlusion. CVR assessment may help stratify risk and guide individualized management in this population.

Background: Intracranial atherosclerosis (ICAS) is a common stroke cause, with a recurrent stroke risk of up to 18% per year despite treatment advances. Although lipid-lowering therapies reduce cardiovascular events, their effect on stroke risk in ICAS remains unclear. Objective: To perform a systematic review and meta-analysis assessing the efficacy of lipid-lowering therapies in improving stroke outcomes among patients with ICAS. Methods: A systematic search of PubMed, Embase, Web of Science, Cochrane, and other databases was conducted from inception to November 2023. Eligible studies compared lipid-lowering therapies (Statins and PCSK9i) to standard care or placebo in patients with ICAS. The primary outcome was the incidence of stroke. Pooled relative risks (RR) with 95% confidence intervals (CI) were calculated using a random-effects model, and forest plots were constructed. Chi-square and I 2 statistics were used to assess heterogeneity. Results: Seven observational studies and two randomized controlled trials involving 1,902 ICAS patients were included. Of these, 801 received lipid-lowering therapy, and 1,101 received standard care or placebo. The weighted mean follow-up was 17.6 months (IQR 9.75-25.5). The weighted mean age was 63.7 years (range 55-68) for the lipid-lowering group and 64.0 years (range 50-66) for controls. Females comprised 42% of both groups. Hypertension was present in 74% of the intervention group and 71% of controls. A history of stroke was reported in 32% of the intervention group and 29% of controls. The weighted mean baseline LDL level was 105 mg/dL in the intervention group and 107 mg/dL in controls. The weighted mean change in LDL pre- and post-treatment in the intervention group was -47.18 mg/dL, compared to -12.39 mg/dL in controls. The incidence of ischemic stroke was 5.0% (40/801) in the lipid-lowering group versus 13.0% (143/1,101) in controls (RR 0.40; 95% CI 0.24-0.64; P<0.001, Figure 1a). Subgroup analysis of studies comparing statin versus no statin treatment showed an RR of 0.40 (95% CI 0.30-0.92; P<0.05, Figure 1b). Another subgroup analysis comparing PCSK9 inhibitors and statins versus statins only found an RR of 0.44; 95% CI 0.20-0.96; P<0.05, Figure 1c). Conclusions: Lipid-lowering therapies significantly reduce the risk of ischemic stroke in patients with intracranial atherosclerosis. The addition of PCSK9 inhibitors to statins appears to provide added stroke risk reduction.