Association of Left Vertebral Artery Hypoplasia with Posterior Circulation Stroke and the Functional Outcome of Patients with Atrial Fibrillation–Related Cardioembolic Stroke

Abstract

BACKGROUND AND PURPOSE:A cardiogenic embolus could reach the posterior circulation through the right vertebral artery because of a relatively larger diameter in cases of left vertebral artery hypoplasia. Hence, we investigated whether left vertebral artery hypoplasia is associated with cardiac embolisms with atrial fibrillation in the posterior circulation and its functional outcomes. MATERIALS AND METHODS:In this monocentric retrospective study, patients with acute cardioembolic stroke with atrial fibrillation were enrolled and underwent CT or neck MRA, which visualized the aortic arch and subclavian arteries. The laterality and size of vertebral artery hypoplasia were recorded. Posterior circulation stroke, basilar artery occlusion, and the functional outcomes after 3 months were investigated.RESULTS: This study included 407 patients; the patients with left vertebral artery hypoplasia experienced a higher rate of posterior circulation stroke (19 versus 73; 42.2% versus 20.2%; P ¼ .001) and basilar artery occlusion (5 versus 10; 11.1% versus 2.8%; P ¼ .005) than the patients without left vertebral artery hypoplasia. Multivariate analysis revealed that left vertebral artery hypoplasia showed an association with lower odds of achieving a good functional outcome 3 months after the stroke (OR ¼ 0.4; 95% CI, 0.2-0.9; P ¼ .027). CONCLUSIONS:Patients with cardioembolic stroke and left vertebral artery hypoplasia had posterior circulation stroke, basilar artery occlusion, and poor functional outcomes after 3 months.ABBREVIATIONS: PICAI ¼ posterior inferior cerebellar artery infarction; VA ¼ vertebral artery; VAH ¼ vertebral artery hypoplasia A natomic variations in the posterior circulation are common, particularly in the vertebral arteries (VAs). 1 Congenital vertebral artery hypoplasia (VAH) is present in 1.9%-26.5% of the population. It is associated with posterior circulation ischemic stroke due to stenosis in the hypoplastic segment and the resultant ipsilateral cerebellar hypoperfusion. [2][3][4][5] It is uncertain whether VAH influences cardioembolic stroke in the posterior circulation.Although conflicting results exist, previous studies have reported that cardiogenic cerebral embolisms have a right-sided propensity in acute stroke. 6,7 This is because the innominate artery, which supplies the right VA and right common carotid artery, has the largest caliber and travels superior and parallel to the direction of the ascending aorta. 6,7 Patients with left VAH have a right VA with a relatively larger diameter. On the basis of this evidence, we assumed that cardiogenic emboli might reach the right VA more often than the left VA. We hypothesized that the patients with cardiogenic stroke with left VAH may be have posterior circulation stroke, basilar artery occlusion, and less functional independence after 3 months. MATERIALS AND METHODSWe assessed all patients with stroke admitted to the Stroke Center at single tertiary referral hospital, Seoul, South Korea, between January 1, 2017, and August 31, 2020. The patients ...

The association between vertebral artery hypoplasia and fetal‐type variants of the posterior cerebral artery with imaging findings among patients with posterior circulation stroke: A single‐center cross‐sectional study

“…Nonetheless, it is believed that BAH predisposes patients to atherosclerosis in the PC, ultimately causing ischemia in this system. 9,30 A more detailed analysis revealed that fetal origin was evident in almost 60% of the patients, with complete unilateral origin on the right side being the most common type observed, accounting for nearly 25% of the cases. Other types were observed in less than 10% of patients.…”

“…Many studies have shown that BAH is associated with PC stroke; however, no exact explanation has been offered. Nonetheless, it is believed that BAH predisposes patients to atherosclerosis in the PC, ultimately causing ischemia in this system 9,30 …”

The prevalence, clinical characteristics, and brain MRI changes in intracranial artery hypoplasia: a retrospective single-center cross-sectional study

“…It can be concluded that cerebral artery hypoplasia may be considered as an additional risk factor to the conventional vascular risk factors for subtle brain ischemia, symptomatic complaints, and recurrent stroke. 3,4,12 Cerebral artery hypoplasia was hypothesized either independently or in association with cardiovascular risk factors to produce clinical symptoms. Decreased vessel lumen may independently produce regional hypoperfusion.…”

“…While VAH was firstly considered as a non-dangerous anatomic variant, recent studies have associated its presence with increased predisposition for posterior circulation stroke, especially involving the posterior inferior cerebellar artery and lateral medullary infarcts, and when accompanied with other atherosclerotic risk factors. [2][3][4] Unilateral VAH may be associated with ipsilateral atherosclerosis of VA, relative hypoperfusion in ipsilateral PICA, and increased risk of contralateral cardioemboli whereas bilateral VAH may present with the involvement of multiple bilateral vascular teritories. 4 The most common types of anatomical variation in the circle of Willis includes hypoplasia of one or both of posterior communicating arteries (34-68%), hypoplasia of A1 segment of anterior cerebral artery (4-10%), absence of anterior communicating artery (12-21%), persistent fetal origin of posterior cerebral artery (4-26%), and infundibular dilatation of posterior communicating artery (7-15%).…”

“…[2][3][4] Unilateral VAH may be associated with ipsilateral atherosclerosis of VA, relative hypoperfusion in ipsilateral PICA, and increased risk of contralateral cardioemboli whereas bilateral VAH may present with the involvement of multiple bilateral vascular teritories. 4 The most common types of anatomical variation in the circle of Willis includes hypoplasia of one or both of posterior communicating arteries (34-68%), hypoplasia of A1 segment of anterior cerebral artery (4-10%), absence of anterior communicating artery (12-21%), persistent fetal origin of posterior cerebral artery (4-26%), and infundibular dilatation of posterior communicating artery (7-15%). Anterior cerebral artery hypoplasia variant of the circle of Willis is uncommon, with a frequency of 1-13% in another study.…”