Endothelial Dysfunction, Distensibility and Intima-media Thickness and Aetiology of Stroke

Peripheral vascular function in stroke: systematic review and meta-analysis

Peripheral vascular dysfunction, measured as flow-mediated dilation (FMD), is present across all phases of stroke recovery and elevates the risk for recurrent cardiovascular events. The objective of this systematic review and meta-analysis was to characterize baseline FMD in individuals' poststroke, with consideration for each phase of stroke recovery. Three databases (PubMed, CINAHL, and Embase) were searched between January 1, 2000 and October 12, 2023 for studies that examined baseline FMD in stroke. Three reviewers conducted abstract and full-text screening, data extraction, and quality assessment. A random effects model was used to estimate FMD across studies. Meta-regression was used to examine the impact of age and time since stroke (acute, subacute, chronic) on FMD. Twenty-eight studies with ischemic and hemorrhagic stroke were included. Descriptive statistics for the demographics and FMD values of each study are presented. For the meta-analysis, average estimate FMD was 3.9% (95% CI: 2.5-5.3%). We report a large amount of heterogeneity (Cochrane's Q P value <0.001, and I2 = 99.6%). Differences in average age and the time poststroke between studies were not significantly associated with differences in FMD values. Despite the large heterogeneity for FMD values across studies, our primary finding suggests that FMD remains impaired across all phases of stroke.NEW & NOTEWORTHY This systematic review and meta-analysis offers invaluable insight into poststroke vascular function. Despite the inherent heterogeneity among the 28 studies analyzed, we report that peripheral vascular dysfunction, as quantified by flow-mediated dilation, exists across all stages of stroke recovery. This finding underscores the importance for interventions that focus on improving vascular health and secondary stroke prevention.

Using Ultrasound and Inflammation to Improve Prediction of Ischemic Stroke: A Secondary Analysis of the Multi-Ethnic Study of Atherosclerosis

INTRODUCTION

Current ischemic stroke risk prediction is primarily based on clinical factors, rather than imaging or laboratory markers. We examined the relationship between baseline ultrasound and inflammation measurements and subsequent primary ischemic stroke risk.

METHODS

In this secondary analysis of the Multi-Ethnic Study of Atherosclerosis (MESA), the primary outcome is the incident ischemic stroke during follow-up. The predictor variables are 9 carotid ultrasound-derived measurements and 6 serum inflammation measurements from the baseline study visit. We fit Cox regression models to the outcome of ischemic stroke. The baseline model included patient age, hypertension, diabetes, total cholesterol, smoking, and systolic blood pressure. Goodness-of-fit statistics were assessed to compare the baseline model to a model with ultrasound and inflammation predictor variables that remained significant when added to the baseline model.

RESULTS

We included 5,918 participants. The primary outcome of ischemic stroke was seen in 105 patients with a mean follow-up time of 7.7 years. In the Cox models, we found that carotid distensibility (CD), carotid stenosis (CS), and serum interleukin-6 (IL-6) were associated with incident stroke. Adding tertiles of CD, IL-6, and categories of CS to a baseline model that included traditional clinical vascular risk factors resulted in a better model fit than traditional risk factors alone as indicated by goodness-of-fit statistics.

CONCLUSIONS

In a multiethnic cohort of patients without cerebrovascular disease at baseline, we found that CD, CS, and IL-6 helped predict the occurrence of primary ischemic stroke. Future research could evaluate if these basic ultrasound and serum measurements have implications for primary prevention efforts or clinical trial inclusion criteria.

Endothelial dysfunction is an independent risk factor for stroke patients irrespective of the presence of patent foramen ovale

BACKGROUND

Paradoxical embolization through the patent foramen ovale (PFO) is the major cause of most cryptogenic stroke cases. However, the presence of PFO may simply be an incidental finding in these patients, and endothelial dysfunction may be the underlying reason of ischemic stroke. The aim of this study was to compare the endothelial function of cryptogenic stroke patients according to the presence of PFO.

METHODS

Sixty consecutive patients with cryptogenic stroke referred for transesophageal echocardiography (TEE) and 39 consecutive nonstroke patients referred for TEE examination because of suspected PFO were included in the study. Endothelial functions were assessed by brachial artery ultrasonography. PFO was diagnosed by the presence of right-to-left passage of contrast bubbles during TEE. Stroke and nonstroke patients were further subdivided into two groups according to the presence of PFO.

RESULTS

Stroke patients had significantly lower flow-mediated dilation (FMD) values than nonstroke patients (8.36 ± 4.38 % vs. 12.57 ± 4.90 %, p < 0.001). The stroke patients with PFO had significantly lower FMD measures than nonstroke patients with PFO (6.60 ± 3.98 % vs. 10.84 ± 4.40 %, p = 0.001). Similarly, cryptogenic stroke patients without PFO had significantly lower FMD measures than nonstroke patients without PFO (9.90 ± 4.18 % vs. 14.22 ± 4.88, p = 0.002). Logistic regression analysis showed FMD as an independent predictor of cryptogenic stroke when adjusted by age, sex, and presence of PFO (odds ratio: 0.809, 95 % confidence interval: 0.719-0.911, p < 0.001). An FMD value of  11.30 % or lower predicted cryptogenic stroke with a sensitivity of 78.3 %, a specificity of 66.7 %, and positive and negative predictive values of 78.3 and 66.7 %, respectively.

CONCLUSION

Endothelial dysfunction seems to play a more important role than PFO in the underlying mechanism of cryptogenic stroke.

Impaired brachial flow-mediated dilation is a predictor of a new-onset vascular event after stroke

BACKGROUND AND OBJECTIVE

Brachial arterial flow-mediated dilation (FMD) is associated with an increased risk of vascular events. Our aim was to investigate the relationship between FMD measured in the acute phase of ischemic stroke and a new major adverse vascular event in a consecutive cohort of patients followed up for 48 months after an acute first-ever stroke.

METHODS

We measured FMD in 120 consecutive patients with acute ischemic stroke using high-resolution ultrasonography. FMD was calculated as the relationship between the basal diameter of the brachial artery before and after transient vascular occlusion. Intima-media thickness, extracranial carotid atherosclerosis, stroke severity National Institute of Health Stroke Scale, and modified Rankin Scale at 3 months were also evaluated. A vascular event was defined as any of the following: vascular disease (VD) death, nonfatal myocardial infarction (MI), nonfatal recurrent stroke (RS), claudication or peripheral arterial thrombosis (PVD), angioplasty or cardiac bypass graft surgery.

RESULTS

There were 34 new major adverse vascular events in 32 of 120 patients (26.7%): 21 (61.8%) RS, 5 (14.7%) VD death, 5 (14.7%) MI, and 3 (8.8%) PVD. The presence of carotid artery plaque (81.3 vs. 46%; p < 0.0001), atrial fibrillation (37.5 vs. 14.8%; p = 0.007) and FMD (5.30 ± 7.48 vs. 10.54 ± 7.02; p = 0.001) were associated with new-onset vascular events. FMD ≤4.5% was an independent predictor of new-onset vascular events (hazards ratio 3.48; 95% confidence interval 1.26-9.63; p = 0.01).

CONCLUSIONS

FMD is an independent predictor for a new-onset vascular event after first-ever ischemic stroke.

Systemic vascular function, measured with forearm flow mediated dilatation, in acute and stable cerebrovascular disease: a case-control study

Background

Acute ischaemic stroke is associated with alteration in systemic markers of vascular function. We measured forearm vascular function (using forearm flow mediated dilatation) to clarify whether recent acute ischaemic stroke/TIA is associated with impaired systemic vascular function.

Methods

Prospective case control study enrolling 17 patients with recent acute ischaemic stroke/TIA and 17 sex matched controls with stroke more than two years previously. Forearm vascular function was measured using flow medicated dilatation (FMD).

Results

Flow mediated dilatation was 6.0 ± 1.1% in acute stroke/TIA patients and 4.7 ± 1.0% among control subjects (p = 0.18). The mean paired difference in FMD between subjects with recent acute stroke and controls was 1.25% (95% CI -0.65, 3.14; p = 0.18). Endothelium independent dilatation was measured in six pairs of participants and was similar in acute stroke/TIA patients (22.6 ± 4.3%) and control subjects (19.1 ± 2.6%; p = 0.43).

Conclusions

Despite the small size of this study, these data indicate that recent acute stroke is not necessarily associated with a clinically important reduction in FMD.