The Association between Carotid Artery Atherosclerosis and Silent Brain Infarction: A Systematic Review and Meta-analysis

Abstract

Background Carotid atherosclerosis is responsible for ~20% of ischemic strokes, but it is unclear whether carotid disease is associated with the presence of downstream silent brain infarction (SBI). We performed a systematic review and meta-analysis to study the relationship between SBI and two separate manifestations of carotid atherosclerosis, carotid intima-media thickening (IMT) and luminal stenosis. Methods Ovid MEDLINE, Ovid Embase, and the Cochrane Library Database were searched with an additional search of references and citing articles of target studies. Articles were included if they reported an association between carotid IMT or stenosis and MRI-defined SBI, excluding SBIs found after carotid intervention. Results We pooled 7 studies of carotid IMT reporting on 1,469 subjects with SBI and 5,102 subjects without SBI. Subjects with SBI had a larger mean IMT compared to subjects without SBI (pooled standardized mean difference, 0.37; 95% CI, 0.23 to 0.51; P<0.0001). We pooled 11 studies of carotid stenosis reporting on 12,347 subjects (2,110 subjects with and 10,237 subjects without carotid stenosis). We found a higher prevalence of SBI among subjects with carotid stenosis (30.4 vs. 17.4%). Our pooled random-effects analysis showed a significant positive relationship between carotid stenosis and SBI (OR, 2.78; 95% CI, 2.19 to 3.52; P<0.0001). Conclusions Two forms of atherosclerotic disease, carotid IMT and stenosis, are both are significantly associated with SBI. This review highlights a lack of consistent definitions for carotid disease measures and little evidence evaluating SBI prevalence downstream from carotid stenosis.

Carotid Intima-Media Thickness and Silent Brain Infarctions in a Biracial Cohort: The Atherosclerosis Risk in Communities (ARIC) Study

“…19 Previous studies examining IMT and SBI in the general population have largely been limited to Asian or White study participants. 20 The Cardiovascular Health Study reported an incremental association between increasing quintiles of CCA-IMT and prevalence of SBI. 8 In contrast, an analysis from the Framingham Study reported no association between CCA-IMT and prevalent SBI after adjustment for stroke risk factors, but a significant association between SBI and IMT of the more atherogenic ICA.…”

Carotid stenosis – basing treatment on individual patients’ needs. Optimal medical therapy alone or accompanied by stenting or endarterectomy

“…Gupta et al [29] reported on a silent cerebral microemboli and an infarction prevalence of 18 % in adults over 60 years of age, with a twofold increased stroke risk. Finn et al [30] found a signifi cant association of ipsilateral silent cerebral microemboli and infarctions with both carotid stenosis and nonstenosing carotid intimamedia thickening. This is not always necessarily directly causal but may also be linked to the generalized elevated cardiovascular risk of concerned patients.…”

Silent cerebrovascular disease in hypertensive adults is frequent and age-dependent

“…Regarding the relationship between intra and extracerebral vascular lesions, a meta-analysis carried out based on 7 studies evaluating IMC thickness in 6,571 subjects, and on 11 studies, evaluating carotid stenosis in 12,347 subjects, revealed that both forms of carotid disease were signi icantly associated with the presence of silent cerebral infarction [28]. Another meta-analysis including 9 systematic reviews showed that ECAD was signi icantly associated with presence of WML, but could not demonstrate the relationship with cerebral atrophy due to lack of adequate studies [29].…”

“…Several studies have reported the impact of carotid plaques and the increase of IMC thickness in the prognosis of adverse vascular events [7][8][9]11,[28][29][30], which indicates the importance of considering these injuries in re inement of cardiovascular risk strati ication. The results of our study are in line with this opinion, especially in hypertensive patients in whom the treatment strategy involves the detection of target organ injury to de ine CVR and, accordingly, to impose the most appropriate treatment regimen.…”