Spontaneous and Endothelial-Independent Vasodilation Are Impaired in Patients With Spontaneous Carotid Dissection

Long-Term Course of Circulating Elastin, Collagen Type I, and Collagen Type III in Patients with Spontaneous Cervical Artery Dissection: a Prospective Multicenter Study

An impaired integrity of vascular elements and the extracellular matrix (ECM) has been discussed to play a critical role in the pathophysiology of spontaneous cervical artery dissection (sCAD). This study aimed to explore the temporal course of circulating elastin, collagen type I, and collagen type III in patients with sCAD and evaluated their eligibility as diagnostic biomarkers. Patients with sCAD were prospectively enrolled in four German stroke centers. Blood samples were collected at baseline (acute phase), at day 10 ± 3 (subacute phase), and after 6 ± 1 months (chronic phase). Patients with acute ischemic stroke not related to sCAD, healthy probands, and patients undergoing thromboendarterectomy of the carotid artery served as control groups. Serum levels of elastin and collagen types I and III were determined by ELISAs. Fifty-seven patients with sCAD were enrolled. Compared to all three control groups, patients with sCAD had significantly lower levels of elastin and collagen type III at baseline and after 6 months. Compared to healthy probands, patients with sCAD showed similar collagen type I levels at baseline and in the subacute phase, but significantly increased levels after 6 months. As serum levels of elastin, collagen types I and III were not elevated in the acute phase, they do not appear eligible as biomarkers for the diagnosis of sCAD. Persisting low serum levels of elastin and collagen type III towards the chronic phase of sCAD strengthens the hypothesis of a subtle, in most cases clinically inapparent affection of the ECM in patients with sCAD.

Coronary endothelial function and spontaneous coronary artery dissection

Objectives:

To investigate the role of endothelial function in patients with previous spontaneous coronary artery dissection.

Background:

Mechanisms underlying spontaneous coronary artery dissection, including a possible contribution from endothelial dysfunction, remain poorly understood.

Methods:

This was a single center, retrospective study of patients with a prior spontaneous coronary artery dissection episode who underwent invasive endothelial function testing in the cardiac catheterization laboratory for evaluation of recurrent chest pain. Coronary epicardial and microvascular responses to acetylcholine, adenosine, and nitroglycerine were assessed. Findings were compared to a reference group of normal controls ( n=232).

Results:

A total of 10 patients with prior angiographically confirmed spontaneous coronary artery dissection were referred for coronary endothelial function testing. The median coronary flow reserve was 2.8 (interquartile range (IQR) 2.3, 3.6). The median change in coronary diameter with acetylcholine was −0.9% (IQR −23.9, 4.2). The median increase in peak coronary blood flow following acetylcholine administration was 91.4% (IQR 9.1, 105.7), which was similar to the response observed in a reference group of patients (median age 51 years, 96% women) from our laboratory with normal microvascular responses to acetylcholine: 107.4% (IQR 75.5, 165.7; P=0.20). Four patients (40%) had an abnormal microvascular response to acetylcholine, with less than a 50% increase in coronary blood flow, and all but one patient had left anterior descending artery or multivessel spontaneous coronary artery dissection.

Conclusion:

Coronary epicardial and microvascular vasomotor dysfunction is not a predominant feature of spontaneous coronary artery dissection. Endothelial dysfunction is not implicated as the principal underlying mechanism.

Impaired Brachial Flow-Mediated Dilatation May Predict Symptomatic Intracranial Arterial Dissections

BACKGROUND AND PURPOSE

Spontaneous intracranial arterial dissections are characterized by the sudden disruption of the internal elastic lamina in the intracranial arteries. The purpose of our retrospective study was to investigate whether patients with nontraumatic intracranial arterial dissections had normal endothelial function.

METHODS

The study included symptomatic patients with nontraumatic intracranial arterial dissections who underwent an endothelial function test. Controls were selected from headache patients matched for sex and age. Endothelial function was assessed using flow-mediated dilatation. We investigated patients' ankle brachial index and pulse wave velocity to determine the degree of atherosclerosis. Patient characteristics, brachial flow-mediated dilatation, ankle brachial index, and pulse wave velocity were compared between the 2 groups.

RESULTS

During the study period, there were 22 patients with nontraumatic intracranial arterial dissections matched with 22 controls. Clinical characteristics were compared between the groups. Although there were no significant differences in ankle brachial index or pulse wave velocity between the 2 groups, patients with intracranial arterial dissections had lower flow-mediated dilatation values than controls (median flow-mediated dilatation, 3.95% in dissection patients versus 7.3% in controls, P = .0035). Brachial flow-mediated dilatation was impaired in symptomatic patients with nontraumatic intracranial arterial dissections despite the normal ankle brachial index and pulse wave velocity.

CONCLUSIONS

Impaired brachial flow-mediated dilatation is a probable predictor of intracranial arterial dissections.

Association Between Migraine and Cervical Artery Dissection: The Italian Project on Stroke in Young Adults

Importance

Although sparse observational studies have suggested a link between migraine and cervical artery dissection (CEAD), any association between the 2 disorders is still unconfirmed. This lack of a definitive conclusion might have implications in understanding the pathogenesis of both conditions and the complex relationship between migraine and ischemic stroke (IS).

Objective

To investigate whether a history of migraine and its subtypes is associated with the occurrence of CEAD.

Design, Setting, and Participants

A prospective cohort study of consecutive patients aged 18 to 45 years with first-ever acute ischemic stroke enrolled in the multicenter Italian Project on Stroke in Young Adults was conducted between January 1, 2000, and June 30, 2015. In a case-control design, the study assessed whether the frequency of migraine and its subtypes (presence or absence of an aura) differs between patients whose IS was due to CEAD (CEAD IS) and those whose IS was due to a cause other than CEAD (non-CEAD IS) and compared the characteristics of patients with CEAD IS with and without migraine.

Main Outcomes and Measures

Frequency of migraine and its subtypes in patients with CEAD IS vs non-CEAD IS.

Results

Of the 2485 patients (mean [SD] age, 36.8 [7.1] years; women, 1163 [46.8%]) included in the registry, 334 (13.4%) had CEAD IS and 2151 (86.6%) had non-CEAD IS. Migraine was more common in the CEAD IS group (103 [30.8%] vs 525 [24.4%], P = .01), and the difference was mainly due to migraine without aura (80 [24.0%] vs 335 [15.6%], P < .001). Compared with migraine with aura, migraine without aura was independently associated with CEAD IS (OR, 1.74; 95% CI, 1.30-2.33). The strength of this association was higher in men (OR, 1.99; 95% CI, 1.31-3.04) and in patients 39.0 years or younger (OR, 1.82; 95% CI, 1.22-2.71). The risk factor profile was similar in migrainous and non-migrainous patients with CEAD IS (eg, hypertension, 20 [19.4%] vs 57 [24.7%], P = .29; diabetes, 1 [1.0%] vs 3 [1.3%], P > .99).

Conclusions and Relevance

In patients with IS aged 18 to 45 years, migraine, especially migraine without aura, is consistently associated with CEAD. This finding suggests common features and warrants further analyses to elucidate the underlying biologic mechanisms.

Current optimal assessment and management of carotid and vertebral spontaneous and traumatic dissection

Dissection of the internal carotid or vertebral artery has been recognized as a cause of stroke in young patients. It is disproportionate in its representation as a cause of stroke in this age group. Intimal tears, intramural hematomas, and dissection aneurysms may be the result of trauma or may occur spontaneously. Spontaneous dissection may be the result of inherent arterial weakness or in association with other predisposing factors. Clinical diagnosis is often difficult, but increased awareness and a range of modern investigations such as computerized tomography or magnetic resonance imaging may aid in diagnosis. Management options include antiplatelet therapy, anticoagulation, thrombolysis, and surgical or endovascular procedures. Prognosis is variable, and dissection may be asymptomatic but may lead to profound neurological deficit and death.

Cervical carotid artery dissection: current review of diagnosis and treatment

Carotid artery dissection is a cause of stroke, especially in young and middle-aged patients. A dissection occurs when there is an intimal tear or rupture of the vasa vasorum, leading to an intramural hematoma, which is thought to result from trauma or can occur spontaneously, and is likely multifactorial, involving environmental and intrinsic factors. The clinical diagnosis of carotid artery dissection can be challenging, with common presentations including pain, partial Horner syndrome, cranial nerve palsies, or cerebral ischemia. With the use of noninvasive imaging, including magnetic resonance and computed tomography angiography, the diagnosis of carotid dissection has increased in frequency. Treatment options include thrombolysis, antiplatelet or anticoagulation therapy, endovascular or surgical interventions. The choice of appropriate therapy remains controversial as most carotid dissections heal on their own and there are no randomized trials to compare treatment options.

Wall stress of the cervical carotid artery in patients with carotid dissection: a case-control study

Spontaneous internal carotid artery (ICA) dissection (sICAD) results from an intimal tear located around the distal carotid sinus. The mechanisms causing the tear are unknown. This case-control study tested the hypotheses that head movements increase the wall stress in the cervical ICA and that the stress increase is greater in patients with sICAD than in controls. Five patients with unilateral, recanalized, left sICAD and five matched controls were investigated before and after maximal head rotation to the left and neck hyperextension after 45° head rotation to the left. The anatomy of the extracranial carotid arteries was assessed by magnetic resonance imaging and used to create finite element models of the right ICA. Wall stress increased after head movements. Increases above the 80th and 90th percentile were located at the intimal side of the artery wall from 7.4 mm below to 10 mm above the cranial edge of the carotid sinus, i.e., at the same location as histologically confirmed tears in patients with sICAD. Wall stress increase did not differ between patients and controls. The present findings suggest that wall stress increases at the intimal side of the artery wall surrounding the distal edge of the carotid bulb after head movements may be important for the development of carotid dissection. The lack of wall stress difference between the two groups indicates that the carotid arteries of patients with carotid dissection have either distinct functional or anatomical properties or endured unusually heavy wall stresses to initiate dissection.

Cervical artery dissection

Spontaneous and traumatic cervical artery dissection is a common cause of stroke in the young. It generally carries an excellent prognosis if treatment is initiated early. Antiplatelet therapy may be as effective as or safer than warfarin, although no randomized prospective studies have addressed the issue of optimal medical therapy. Rarely, endovascular therapy may be indicated for the treatment of ruptured aneurysms or to prevent recurrent ischemia.

Cervical-artery dissections: predisposing factors, diagnosis, and outcome

Cervical-artery dissection (CAD) is a major cause of cerebral ischaemia in young adults and can lead to various clinical symptoms, some of which are benign (eg, headache, neck pain, Horner's syndrome, and cranial-nerve palsy), but most patients have a stroke or transient ischaemic attack. In addition to trauma to the neck, other risk factors have been suggested, such as infection, migraine, hyperhomocysteinaemia, and the 677TT genotype of the 5,10-methylenetetrahydrofolate reductase gene (MTHFR 677TT), although evidence is sparse. An underlying arteriopathy, which could in part be genetically determined, is believed to have a role in the development of CAD. Importantly, both research on and optimum management of CAD strongly rely on diagnostic accuracy. Although the functional outcome of CAD is good in most patients, socioprofessional effects can be important. Incidence of the disorder in the general population is underestimated. Mortality and short-term recurrence rates are low but possibly also underestimated. Further research is warranted to improve our understanding of the underlying pathophysiology, to assess the long-term outcome, and ultimately to provide treatment and prevention strategies.

Vasomotion in Multiple Spontaneous Cervical Artery Dissections

Background and Purpose— The etiology of spontaneous cervical artery dissection (sCAD) is still unknown, even though an underlying arteriopathy impairing vasomotion has often been suspected. This study was undertaken to investigate: (1) spontaneous, (2) endothelial-dependent, and (3) endothelial-independent vasodilation in patients with multiple sCAD.

Methods— In 19 consecutive patients with multiple carotid or vertebral artery dissections high-resolution ultrasound was used to assess spontaneous and endothelial-independent dilations (isosorbide dinitrate-mediated) in the common carotid, vertebral and brachial arteries, and endothelial-dependent dilation (flow-mediated arterial dilation) in the brachial arteries alone. The same parameters were measured in 19 healthy subjects matched for age, sex, and height (controls). Ultrasound studies were performed by one investigator, and off-line analysis by another investigator who was blinded to the clinical data and study status (patient or control).

Results— Spontaneous and endothelial-independent dilations were significantly impaired in the carotid ( P =0.0006 and P <0.0001, respectively) and vertebral arteries ( P =0.0121 and P =0.0047, respectively) of patients as compared with controls, whereas no statistically significant differences were found in the brachial arteries; conversely, endothelial-dependent dilation of the brachial arteries was significantly lower in patients as compared with controls ( P <0.0001).

Conclusions— Patients with multiple sCADs have a significantly impaired vasomotion, which may predispose to dissection.