The Risk of Ischemic Events Increased in Patients with Asymptomatic Carotid Stenosis with Decreased Cerebrovascular Reserve

Abstract

Identifying high-risk patients with asymptomatic carotid stenosis (ACS) is necessary regardless of whether intensive medical therapy or aggressive treatment is applied. In order to assess the relationship between cerebrovascular reserve (CVR) measured by perfusion CT with inhalation of CO and the risk of ischemic events in ACS, this long-term follow-up study was conducted. Forty-five patients with ACS who underwent the examination of CVR measured by perfusion CT with inhalation of CO were collected and followed-up for at least 5 years. The primary end point was the occurrence of ipsilateral cerebral ischemic events. HRs and their 95% CI were calculated by Kaplan-Meier survival analysis and Cox regression models. The mean follow-up time was 68.7±10.7 months (40.0-84.0 months). 13 (28.9%) ipsilateral ischemic events were observed. The annual risk of ipsilateral ischemic events was 4.8%. Kaplan-Meier survival analysis and univariate Cox regression analysis indicated that patients with less CVR experienced more ischemic events (p=0.006 and p=0.013, respectively), which was confirmed by multiple Cox regression analysis (p=0.012). CVR measured by perfusion CT may potentially be the factor which can predict the risk of ipsilateral ischemic events in patients with ACS. Multidisciplinary management is necessary for these high-risk patients.

Brain imaging biomarkers of carotid artery disease

“…CT perfusion (CTP) is a well-studied and straightforward method for assessing cerebrovascular reserve. Studies have shown that asymptomatic patients with carotid artery stenosis who have abnormal cerebrovascular reserve on CTP are more likely to develop ipsilateral ischemic events (32). In addition, studies have found that hemodynamic changes on CTP can be reversed with carotid artery stenting in both symptomatic and asymptomatic patients (Figure 1) (33)(34)(35).…”

A narrative review of the pathophysiology of ischemic stroke in carotid plaques: a distinction versus a compromise between hemodynamic and embolic mechanism

“…Webster et al and Yonas et al also showed in Xe-CT studies an association between a decreased CVR and risk of stroke in patients with severe carotid stenosis (38,39). These results were corroborated by two other studies using CT perfusion and doppler ultrasound (40,41). A meta-analysis has identified an increased OEF as an independent predictor of stroke in carotid stenosis or occlusion (42).…”

Prevalence of High-risk Plaques and Risk of Stroke in Patients With Asymptomatic Carotid Stenosis

“…In the subgroup of studies focusing on participants with severe stenosis only (9 cohorts with 2128 participants; mean follow-up period, 2.8 years; range, 1.4-6.5 years), the incidence of ipsilateral ischemic cerebrovascular events was 3.7 events per 100 person-years (95% CI, 1.9-6.0 events per 100 person-years). The incidence of ipsilateral ischemic cerebrovascular events was also higher in patients with high-risk features (7.3 events per 100 person-years; 95% CI, 2.0-15.0 events per 100 person-years) (Figure 1) than in those without high-risk features (1.7 events per 100 person-years; 95% CI, 0.6-3.3 events per 100 person-years) (eFigure 18 in the Supplement), with an OR of 3.2 (95% CI, 1.7-5.9; I 2 = 39.6%) (Table 3).…”

“…The incidence of ipsilateral ischemic events was higher in patients with high-risk features (4.3 events per 100 person-years; 95% CI, 2.5-6.5 events per 100 person-years) (Figure 1; eFigure 17 in the Supplement) than in those without high-risk features (1.2 events per 100 person-years; 95% CI, 0.6-1.8 events per 100 person-years) (eFigure 18 in the Supplement), with a corresponding OR of 3.0 (95% CI, 2.1-4.3; I 2 = 48.8%) (Figure 2). This association between the presence of high-risk plaque and the risk of ipsilateral ischemic cerebrovascular events was also observed in pooling data from the 7 studies that reported adjusted HRs (pooled HR, 3.0; 95% CI, 1.8-4.2; I 2 = 0%) (eFigure 2 in the Supplement).…”