Matrix Metalloproteinase Levels in Cervical and Intracranial Carotid Dolichoarteriopathies

Internal Carotid Artery Angle Variations are Poorly Explained by Vascular Risk Factors: The Northern Manhattan Study

OBJECTIVES

The internal carotid artery (ICA) angle of origin may contribute to atherogenesis by altered hemodynamics. We aim to determine the contribution of vascular risk factors and arterial wall changes to ICA angle variations.

METHODS

We analyzed 1,065 stroke-free participants from the population-based Northern Manhattan Study who underwent B-mode ultrasound (mean age 68.7±8.9 years; 59% women). ICA angle was estimated at the intersection between the common carotid artery and the ICA center line projections. Narrower external angles translating into greater carotid bifurcation bending were considered unfavorable. Linear regression models were fitted to assess the relationship between ICA angle and demographics, vascular risk factors, and arterial wall changes including carotid intima-media thickness (cIMT) and plaque presence.

RESULTS

ICA angles were narrower on the left compared to the right side (153±15.4 degrees versus 161.4±12.7 degrees, p<0.01). Mean cIMT was 0.9±0.1 mm and 54.3% had at least one plaque. ICA angle was not associated with cIMT or plaque presence. Unfavorable left and right ICA angles were associated with advanced age (per 10-year increase β=-1.6; p=0.01, and -1.3; p=0.03, respectively) and being Black participant (β=-4.6; p<0.01 and -2.9; p=0.04, respectively), while unfavorable left ICA angle was associated with being female (β=-2.8; p=0.03) and increased diastolic blood pressure (per 10 mmHg increase β=-2.1; p<0.01). Overall, studied factors explained less than 10% of the variance in ICA angle (left R2=0.07; right R2=0.05).

CONCLUSION

Only a small portion of ICA angle variation were explained by demographics, vascular risk factors and arterial wall changes. Whether ICA angle is determined by other environmental or genetic factors, and is an independent risk factor for atherogenesis, requires further investigation.

Systemic Arterial Correlates of Cervical Carotid Artery Tortuosity : The Northern Manhattan Study

INTRODUCTION

The association between cervical internal carotid artery (cICA) tortuosity and atherosclerosis is a matter of debate. Additionally, some genetic syndromes characterized by connective tissue remodeling are associated with arterial tortuosity, raising the possibility that cICA tortuosity may not only be atherosclerotic. In this study, we hypothesized that cICA tortuosity is not associated with imaging biomarkers of atherosclerosis.

METHODS

The Northern Manhattan Study (NOMAS) was a prospective, multiethnic cohort of stroke-free individuals who underwent brain MRA, carotid ultrasound and transthoracic echocardiogram from 2003-2008. The cICA tortuosity was scored in each carotid as 0 = no tortuosity, 1 = tortuosity <90°, 2 = tortuosity ≥90°. A summary cICA tortuosity score (possible range 0-4) was created by adding up the tortuosity score from each carotid. Participants were assessed for atherosclerotic markers by using B‑mode carotid sonography and transthoracic echocardiography.

RESULTS

Of 558 participants 178 (31.9%) had any cervical ICA tortuosity (tortuosity score >0). The cICA tortuosity score was higher in women and was associated with diastolic and systolic blood pressures and height (all P < 0.05). In models adjusted for demographics and risk factors, only the association with diastolic blood pressure remained significant (β = 0.002, P = 0.02). Similarly, cICA tortuosity was associated with larger aortic root diameter (B = 1.03 ± 0.36, P = 0.004) but not with other markers of carotid or aortic atherosclerosis.

CONCLUSION

Cervical ICA tortuosity is associated with a higher diastolic blood pressure and larger aortic root diameter but not with other measures of atherosclerosis. Determining the risks of vascular events associated with this non-atherosclerotic phenotype may help for a better risk stratification for individuals with cICA tortuosity.

Dolichoectasia: a brain arterial disease with an elusive treatment

INTRODUCTION

Dolichoectasia is a form of brain large artery disease associated with a high risk of mortality and morbidity. Progressive enlargement of arterial size is a predictor of mortality, but there are no specific treatments for arresting or slowing down dilatation. Additionally, dilated brain arteries can cause flow stagnation, which can trigger thrombosis and cause stroke. Pathology and genetic studies indicate a possible role for increased matrix metalloproteinase activation in arterial dilatation and thus in the pathophysiology of dolichoectasia. Therefore, therapeutic interventions aimed at slowing down arterial dilatation and preventing thrombosis could hypothetically play a role in treating patients with dolichoectasia.

METHODS

We present four patients with dolichoectasia that exemplify therapeutic challenges worth discussing in the context of the current literature. Two patients were treated off-label with doxycycline (based on its antiMMP properties) and with apixaban, one patient was put on warfarin and later switched to aspirin, and the fourth patient underwent endovascular treatment.

RESULTS

We report four cases, all men 50 years or older. Of the two patients treated with doxycycline, we noted a slowdown of the basilar artery (BA) growth, but the BA continued to grow in the other patient. Of the two patients who received apixaban, none had a subsequent stroke in 5 and 4 years of follow-up, respectively. One patient was admitted with a fatal BA thrombosis and rupture, and pathological examination of the brain arteries demonstrated advanced arterial wall degeneration but no atherosclerosis.

DISCUSSION

These cases exemplify the challenges of treating people with dolichoectasia and highlight the need for better evidence regarding the best possible treatment for this population.

Metalloproteinases and their inhibitors in neurological disease

Matrix metalloproteinases (MMPs) are a group of endopeptidases that degrade the extracellular matrix and are responsible for many physiological and pathological processes. We aim to review the MMP inhibition from a clinical perspective and its possible therapeutic use in the future. MMPs play a role in various neurodegenerative and cerebrovascular diseases such as large artery atherosclerosis and ischemic stroke; for example, MMPs increase blood-brain barrier permeability favoring neuroinflammation. Synthetic MMPs inhibitors have been tested mostly in oncological trials and failed to demonstrate efficacy; some of them were discontinued because of the severe adverse reactions. Tetracyclines, in submicrobial doses, act as an MMP inhibitor, although tetracyclines have not yet been proven effective in several neurological conditions in which they were tested against placebo; it is uncertain whether there may be a use for tetracyclines in cerebrovascular disease, as a neuroprotective agent or in dolichoectasia.

Matrix metalloproteinase-2 and matrix metalloproteinase-9 serum levels in patients with vertebrobasilar dolichoectasia with and without stroke: case-control study

PURPOSE

To describe the differences in the serum levels of MMP-2 and MMP-9 of patients with vertebrobasilar dolichoectasia (VBD) with and without acute stroke.

METHODS

Case-control study. From an outpatient clinic, we recruited 14 controls and 19 patients with VBD. We also recruited 33 patients with stroke from two emergency departments, 14 without VBD (S/-VBD) and 19 with VBD (S/ + VBD). All the patients underwent serum MMP-2 and MMP-9 measurements and a non-contrast CT scan. Two investigators assessed the intracranial vertebral arteries (VA) and the basilar artery (BA) at the mid-pons. Diagnosis of VBD was made if the BA diameter was ≥ 4.5 mm.

RESULTS

The mean age of the 66 patients studied was 57.6 + 16.0 years, 41% female. In the 33 patients with stroke, the median NIHSS was 8 (range 15); there were no differences in the NIHSS scores between both groups with stroke. Median MMP-2 levels were lower in the S/-VBD when compared to controls. Median MMP-9 serum levels were higher in both groups with VBD when compared to controls and the S/-VDB group. Both groups with stroke exhibited higher MMP-9 serum levels than controls but were not statistically different from those found in patients with VBD. Serum levels of MMP-9 were significantly correlated with the diameters of the BA (r = 0.344, p = 0.01) and the left VA (r = 0.305, p = 0.05).

CONCLUSION

This study found that high serum levels of MMP-9 are associated with VBD independently of stroke and correlated with the degree of VBD.

MMP-9, Vertebrobasilar Ectasia and Vertebral Artery Dominance in Vertigo or Dizziness Patients With Vascular Risk Factors

Background and Purpose: Although vertebrobasilar ectasia (VBE) is diagnosed with increasing frequency, it is not clear whether this is because of altered hemodynamics caused by the effects of matrix metalloproteinases (MMPs) and/or vertebral artery dominance (VAD). Therefore, we investigate the relationship between plasma levels of MMPs and VBE in patients with vertigo or dizziness who also have vascular risk factors, in order to determine whether high levels of MMPs in VBE are independent of VAD.

Methods: We prospectively studied 285 patients with vertigo or dizziness and at least one vascular risk factor. Plasma levels of MMPs, tissue inhibitor of metalloproteinases (TIMPs) and cathepsin L were measured. Subjects were classified as VBE-negative or VBE-positive, who were further classified based on the presence of VAD with magnetic resonance angiography. Acute ischemic stroke was screened by diffusion-weighted imaging, generally after bedside evaluation and the drawing of blood samples. Receiver operating characteristic (ROC) curves were applied to evaluate the utility of these potential biomarkers in predicting risk for ischemic stroke.

Results: The prevalence of VBE in patients with vertigo or dizziness was 16.5%. Of the 82 patients with ischemic stroke, 14 strokes involved the cortex or subcortex. MMP-9 levels were significantly higher in the VBE-positive group than in the VBE-negative group (P = 0.022). There was a significant difference in the risk of posterior circulation ischemic stroke between the VBE-positive group and the VBE-negative group (P = 0.002). Levels of MMP-2 and cathepsin L tended to be higher in the VBE-negative group (P = 0.054, P = 0.060, respectively). Compared with the non-VAD subgroup, levels of MMP-2,−3,−9, TIMP-1,−2, and cathepsin L were similar in the VAD subgroup. ROC analysis showed that MMP-9 predicted risk for ischemic stroke (AUC = 0.582, 95%CI, 0.510–0.654, P = 0.030).

Conclusions: MMP-9 was associated with VBE and independent of VAD. High levels of MMP-9 may predict risk for ischemic stroke in patients with vertigo or dizziness who also have vascular risk factors.

Extensive intracranial arterial dolichoectasia involving distal branches of intracranial arteries: two cases report and review of the literature

With the rapid development of noninvasive angiography techniques such as Magnetic Resonance Angiography (MRA) and Computer Tomography Angiography (CTA), more and more patients with intracranial arterial dolichoectasia (IADE) have been found, and clinical studies on this kind of vascular abnormity have become hot subjects in neurology. We presented two young patients with IADE extensively involving the branches of intracranial arteries, which were different from patients described in other articles. A young male patient was diagnosed with IADE after examination on admission, and further detailed examination revealed that the patient had osteropathia striata. Another young woman had an arterial malformation that mainly affected the distal branch of the intracranial artery. These two cases give us another perspective to look into IADE.

Two-dimensional speckle-tracking echocardiographic evaluation of the longitudinal deformation of the left ventricular myocardium in patients with severe coronary artery tortuosity

PURPOSE

Coronary artery tortuosity (CAT) is an anatomical condition in which epicardial coronary arteries have abnormal curves or spiral courses. Although correlated with higher rates of positive stress test, its effects on the myocardial function remain to be clearly defined.

METHODS

We included in this cross-sectional study and evaluated with 2D speckle-tracking echocardiography 40 consecutive patients admitted to our hospital for selective coronary angiography which showed severe CAT without significant epicardial coronary artery stenosis, and 40 consecutive subjects matched for age, hypertension, and diabetes in whom selective coronary angiography showed neither CAT nor significant epicardial coronary artery stenosis.

RESULTS

Systolic strain, strain rate, and early and late diastolic strain rates were not significantly different between the 2 groups, even after adjustment for potential confounding variables.

CONCLUSION

The 2D speckle-tracking echocardiography-derived indices of longitudinal deformation of the left ventricular myocardium were not significantly different between the patients with severe CAT and controls.

Wandering carotid arteries: Reciprocating change between normal and retropharyngeal positions on serial CT studies

Positional change in the retropharyngeal carotid artery, a rare phenomenon over time, is even rarer in previous reports, and it is important to be aware of this before any neck surgical procedure. A woman in her 50s underwent an anterior maxillectomy for upper gingival cancer, without neck dissection. The patient had medical histories of diabetes mellitus and liver dysfunction, with unremarkable family histories. Serial neck contrast-enhanced computed tomography for detecting locoregional recurrence had been performed as a follow-up during 4 years. A radiological course of moving carotid arteries in serial computed tomography studies showed reciprocating positional changes (wandering) between normal and retropharyngeal regions. There was no locoregional recurrence of the gingival cancer. This is the first case to describe a so-rare presentation of wandering carotid arteries. It is important for clinicians to be aware of a wandering carotid artery to avoid potentially fatal complications.

Current Understanding of Dolichoarteriopathies of the Internal Carotid Artery: A Review

Dolichoarteriopathies of the internal carotid artery (DICAs) are not uncommon, and although several studies have investigated DICAs, several questions regarding the etiology and best management course for DICAs remain unanswered. It is also difficult to correlate the occurrence of DICAs with the onset of clinical symptoms. Therefore, we surveyed the literature in PubMed and performed a review of DICAs to offer a comprehensive picture of our understanding of DICAs. We found that DICAs can be classified into three types, specifically tortuous, coiling and kinking, and are not associated with atherosclerotic risk factors. Cerebral hemodynamic changes are mainly associated with the degree of bending of DICAs. DICAs can result in symptoms of the brain and eyes due to insufficient blood supply and can co-occur with a pulsatile cervical mass, a pharyngeal bulge and pulsation. The diagnostic tools for the assessment of DICAs include Doppler ultrasonography, computed tomography angiography (CTA), magnetic resonance angiography (MRA) and digital subtraction angiography (DSA), and although DSA remains the gold standard, Doppler ultrasonography is a convenient method that provides useful data for the morphological evaluation of DICAs. CTA and MRA are efficient methods for detecting the morphology of the cervical segment of DICAs. Some DICAs should be treated surgically based on certain indications, and several methods, including correcting the bending or shortening of DICAs, have been developed for the treatment of DICAs. The appropriate treatment of DICAs results in good outcomes and is associated with low morbidity and mortality rates. However, despite the success of surgical reconstruction, an appropriate therapeutic treatment remains a subject of numerous debates due to the lack of multicentric, randomized, prospective studies.