Severe spontaneous carotid artery dissection and multiple aneurysmal dilatations. A case report

Echocardiographic evaluation in subjects with α1-Antitrypsin deficiency

BACKGROUND

α1-Antitrypsin (AAT) deficiency (AATD) is a genetic condition associated with early-onset panacinar emphysema and, less often, vascular disease. Recently, abnormal elastic properties of ascending aortic wall were described in ZZ genotype AATD subjects who incidentally showed an increased left ventricular mass.

MATERIALS AND METHODS

To evaluate biventricular dimensions, valvular apparatus, systolic and diastolic function, 33 AATD subjects with ZZ genotype and 33 healthy subjects matched for age and sex underwent a complete echocardiographic assessment.

RESULTS

Compared to controls, AATD subjects showed increased left ventricular mass (160 ± 59 g vs. 121 ± 70 g, P < 0.001), a higher incidence of left and right ventricular diastolic dysfunction (30% vs. 16%, P < 0.001 and 45% vs. 20%, P < 0.001, respectively) and mitral valve prolapse (35% vs. 6%, P < 0.001). In contrast, there was no difference between the two groups in diameters and systolic function of both ventricles and in the ejection fraction of left ventricle. The functions of aortic and tricuspidal valves were also similar.

CONCLUSIONS

In the presence of greater left ventricular mass, a significantly higher incidence of left and right ventricular diastolic dysfunction and mitral valve prolapse occurs in AATD subjects (ZZ genotype). These findings strongly suggest an abnormal remodelling process in cardiac tissue in AATD.

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.

Protease Inhibitors in Spontaneous Cervical Artery Dissections

Background and Purpose— Observations in patients with arterial aneurysms, fibromuscular dysplasia, and spontaneous cervical artery dissection (sCAD) indicate that protease inhibitor deficiency might boost the enzymatic destruction of arterial tissue and increase the risk of these arterial wall diseases. Here we present the first large investigation of the protease inhibitor hypothesis in patients with sCAD.

Methods— Eighty patients with sCAD were compared with 80 age- and sex-matched healthy individuals. α 1 -antitrypsin (α 1 -AT) and α 2 -macroglobulin (α 2 -MG) levels, and α 1 -AT genotypes were assessed and compared between groups.

Results— α 1 -AT and α 2 -MG levels as well as α 1 -AT genotypes did not differ significantly between patients and controls. The frequency of Z alleles in the patient group was higher than in the control group and than in other cohorts from Europe; however, the difference remained nonsignificant. All patients with Z alleles had internal carotid artery dissections.

Conclusions— Overall, this data does not support the hypothesis that protease inhibitor levels or α 1 -AT genotypes play an important role in the etiology of sCAD. The present data does not exclude that the Pi-Z allele might have an influence on subgroups of sCAD, such as internal carotid artery dissections.

Pathogenesis of spontaneous cervico-cerebral artery dissection. A hypothesis and a review of the literature

The pathogenesis of spontaneous cervico-cerebral artery dissection remains speculative due to the rarity of histopathological observations, which often correspond to late stage lesions. Transposition of theoretic data from experimental models, study of pathologies with morphological lesions of the same type, and review of some clinical cases, suggest a sequence for the pathological events leading to arterial dissection. Arterial dysplasia, aneurysms and dissections could all result from vascular remodeling in response to endothelial injury. It induces morphologic changes of the internal elastic lamina, smooth muscle cell proliferation, various matrix abnormalities involving the fibrillary components or their enzymatic regulation, arterial wall neoangiogenesis and dissection. Endothelial dysfunction could so play a key role in the imbalance between arterial degenerative and reparative processes and the initiation of cervico-cerebral artery dissection.

Levels of alpha1-antitrypsin in plasma and risk of spontaneous cervical artery dissections: a case-control study

BACKGROUND AND PURPOSE

Abnormalities of dermal connective tissue have been detected in patients with spontaneous cervical artery dissections (sCAD), suggesting an underlying structural defect of the arterial wall. Alpha1-antitrypsin (A1-AT) is a circulating serine proteinase inhibitor of proteolytic enzymes that helps to maintain the integrity of elastic and collagen fibers.

METHODS

To test the hypothesis that moderate deficiency of A1-AT may be a risk factor for sCAD, 22 cases with sCAD and 113 controls were included in the study.

RESULTS

Patients with sCAD had significantly mean lower levels of A1-AT compared with controls (116.0+/-24.9 versus 141.1+/-31.7 mg/dL; P<0.01). Low levels of A1-AT (<90 mg/dL) were more frequently observed in patients with sCAD compared with controls (27.3% versus 2.7%; P<0.001). A positive correlation between age and plasma levels of A1-AT was found (r=0.22; P<0.01). A1-AT levels were not affected by sex or vascular risk factors, including smoking habit. On multivariate analysis, A1-AT <90 mg/dL was associated with sCAD independently of age, sex, or vascular risk factors (odds ratio, 17.7; 95% confidence interval, 2.9 to 105.6).

CONCLUSIONS

Low plasma levels of A1-AT may be a risk factor for sCAD.

Carotid artery dissection

Among the large variety of cerebrovascular syndromes, carotid artery dissections remain often under-recognized. Many patients present with minor or transient symptoms, some with local pain only, and some are asymptomatic. A useful rule is that the coincidence of any local pain in neck or face with an ipsilateral Horner's syndrome preceding transient or persistent retinal or cerebral ischemic symptoms should alert physicians--notably those treating emergencies--to rule out an underlying dissection of the ipsilateral carotid artery. In most cases the extracranial part of the carotid artery is affected; therefore, this review will focus on this main subgroup of patients. We review the pathological anatomy, as well as possible underlying causes, clinical features, diagnostic tools, differential diagnosis, treatment options, and outcome data.

[Cervical artery dissection: recent data physiopathologic hypotheses]

INTRODUCTION

Cervicocranial arterial dissection is a major cause of cerebral infarction in young subjects. Traumatic and infectious factors are frequently suspected to be at the origin of cervicocranial artery dissection. However, they are usually too minor or too common to explain the vessel wall split-off. Underlying arteriopathy predisposing to dissections is therefore often suspected.

CURRENT KNOWLEDGE AND KEY POINTS

The hypothesis of an underlying arteriopathy is based in certain cases on either the discovery of hereditary connective tissue disorders (or secondary signs of these diseases) or their frequent association with vascular and cardiac morphological abnormalities, thus suggesting extracellular matrix abnormalities. Current histological and biochemical data do not suggest the existence of a unique form of the disease but rather indicate the presence of various matrix abnormalities that could involve one of the fibrillar components or its enzymatic regulation.

FUTURE PROSPECTS AND PROJECTS

Classification of dissections according to the various vascular wall alterations would therefore permit to better define recurrence and familial risks and to improve overall management of the patients.

Fibromuscular dysplasia of the internal carotid artery associated with alpha1-antitrypsin deficiency

OBJECTIVE

A deficiency of alpha1-antitrypsin has been implicated in the development of various disorders affecting medium-sized arteries, including intracranial aneurysms, cervicocephalic arterial dissections, and fibromuscular dysplasia (FMD). We performed alpha1-antitrypsin phenotyping in three consecutive patients who underwent bypass surgery for FMD of the extracranial internal carotid artery to test the hypothesis that alpha1-antitrypsin deficiency is a genetic risk factor for the development of FMD.

METHODS

The study population consisted of three women (aged 37, 49, and 53 years, respectively) who had bilateral internal carotid artery stenosis caused by FMD. The indications for surgery included ocular or cerebral ischemic symptoms in two patients and progressive stenosis in one patient. The diagnosis of FMD was confirmed by histological examination of the resected segment of artery. The alpha1-antitrypsin phenotype was determined by isoelectric focusing in polyacrylamide gels.

RESULTS

Two of the three patients had a heterozygous alpha1-antitrypsin deficiency (PiMZ phenotype). Pathological examination of the resected arterial segment showed typical medial FMD with focal intimal fibroplasia in both patients with the PiMZ phenotype.

CONCLUSION

These findings suggest that a heterozygous alpha1-antitrypsin deficiency may be a genetic risk factor for the development of FMD of the internal carotid artery.

Internal carotid artery dissection: an update

Carotid artery dissection is a major cause of cerebral infarction in the young. The extracranial portion of the internal carotid artery is much more frequently involved than the intracranial portion. In up to 20% of cases it is bilateral or associated with vertebral artery dissection. It is mainly characterised by local signs such as headache or facial pain, Horner's syndrome, lower cranial nerve palsies and pulsatile tinnitus, followed a few hours or days later by signs of cerebral or retinal ischemia. Ultrasound investigations show signs of distal stenosis or occlusion, highly suggestive of dissection, but the best diagnostic tool is presently the association of magnetic resonance imaging (MRI) and MR angiography which tend to replace intra-arterial angiography. The prognosis is highly variable: excellent in cases limited to local signs, but very poor leading to death or major sequelae in about 15% of cases. Various treatments have been suggested but no controlled trial has ever been performed in this condition. Heparin in the acute stage followed by warfarin or aspirin for 3 to 6 months is most commonly used.