Risk Factors for Early Recurrent Cerebral Ischemia Before Treatment of Symptomatic Carotid Stenosis

Revacept, an Inhibitor of Platelet Adhesion in Symptomatic Carotid Stenosis: A Multicenter Randomized Phase II Trial

BACKGROUND

Patients with symptomatic internal carotid artery (ICA) stenosis are at high risk of recurrent ischemic stroke and require early interventional treatment and antiplatelet therapy. Increased bleeding rates might counterbalance the periprocedural efficacy of intensified platelet inhibition. We aim to investigate, whether Revacept, a competitive antagonist of glycoprotein VI, adjunct to standard antiplatelet therapy reduces the occurrence of ischemic lesions in patients with symptomatic ICA stenosis.

METHODS

International, multicenter (16 sites), 3-arm, randomized (1:1:1), double-blind, and placebo-controlled study with parallel groups, including patients with symptomatic ICA stenosis. A single infusion over 20 minutes of either placebo, 40 mg or 120 mg Revacept in addition to guideline-conform antiplatelet therapy was evaluated with regard to the exploratory efficacy end point: Number of new ischemic lesions on diffusion-weighted magnetic resonance imaging after treatment initiation. Main clinical outcome was the combined safety and efficacy end point including any stroke or death, transient ischemic attack, myocardial infarction, coronary intervention, and bleeding complications during follow-up.

RESULTS

Out of 160 randomized patients, 158 patients (68±10.1 years, 24% female) received study medication (51 patients placebo, 54 patients 40 mg Revacept and 53 patients 120 mg Revacept) and were followed for 11.2±2.3 months. A total of 1.16 (95% CI, 0.88-1.53)/1.05 (95% CI, 0.78-1.42; P=0.629)/0.63 (95% CI, 0.43-0.93) new diffusion-weighted magnetic resonance imaging lesions per patient were detected in the placebo/40 mg/120 mg Revacept groups, without statistical evidence of a difference. A reduction of the combined safety and efficacy end point during the study period was observed in patients who received 120 mg (HR, 0.46 [95% CI, 0.21-0.99]; P=0.047), but not 40 mg Revacept compared with placebo (HR, 0.72 [95% CI, 0.37-1.42]; P=0.343).

CONCLUSIONS

Revacept 120 mg reduced the combined safety and efficacy end point in patients with symptomatic ICA stenosis.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique Identifier: NCT01645306.

Computed Tomography Perfusion Imaging Quality Affected by Different Input Arteries in Patients of Internal Carotid Artery Stenosis

BACKGROUND The aim of this study was to explore the influence of different input arteries on the parameters of computed tomography (CT) perfusion imaging for patients with different degree of stenosis of internal carotid artery (ICA). MATERIAL AND METHODS Forty patients were enrolled in the present study and divided into mild, moderate, severe stenosis and occlusion groups respectively with each 10 patients in each group. In reconstruction of cerebral CT perfusion (CTP) images, each raw perfusion image was reconstructed 3 times based on different reference input artery, including bilateral middle cerebral artery (MCA) and basilar arteries (BA). Region of interest (ROI) was drawn in the central territories of bilateral anterior cerebral artery, middle cerebral artery and posterior cerebral artery. And regional cerebral blood flow (rCBF) regional cerebral blood volume (rCBV), mean transit time (MTT), time to peak (TTP) and delay time (DT) were obtained from those ROI corresponding perfusion images. RESULTS In patients with mild and moderate ICA stenosis, there was no significant difference of perfusion parameters based on different input arteries (P>0.05). However, in severe ICA stenosis and occlusion CBF, MTT, and DT were significant different in affect side of the MCA group compared to the others (P<0.05). CONCLUSIONS Large intracranial artery can be selected as the input artery for patients with mild to moderate ICA stenosis, while for patients with severe stenosis and occlusion of ICA, the contra lateral middle cerebral artery or basilar artery would be better choice.

Silent brain infarcts on diffusion-weighted imaging after carotid revascularisation: A surrogate outcome measure for procedural stroke? A systematic review and meta-analysis

Aim

To investigate whether lesions on diffusion-weighted imaging (DWI+) after carotid artery stenting (CAS) or endarterectomy (CEA) might provide a surrogate outcome measure for procedural stroke.

Materials and Methods

Systematic MedLine® database search with selection of all studies published up to the end of 2016 in which DWI scans were obtained before and within seven days after CAS or CEA. The correlation between the underlying log odds of stroke and of DWI+ across all treatment groups (i.e. CAS or CEA groups) from included studies was estimated using a bivariate random effects logistic regression model. Relative risks of DWI+ and stroke in studies comparing CAS vs. CEA were estimated using fixed-effect Mantel-Haenszel models.

Results

We included data of 4871 CAS and 2099 CEA procedures (85 studies). Across all treatment groups (CAS and CEA), the log odds for DWI+ was significantly associated with the log odds for clinically manifest stroke (correlation coefficient 0.61 (95% CI 0.27 to 0.87), p = 0.0012). Across all carotid artery stenting groups, the correlation coefficient was 0.19 (p = 0.074). There were too few CEA groups to reliably estimate a correlation coefficient in this subset alone. In 19 studies comparing CAS vs. CEA, the relative risks (95% confidence intervals) of DWI+ and stroke were 3.83 (3.17-4.63, p < 0.00001) and 2.38 (1.44-3.94, p = 0.0007), respectively.

Discussion

This systematic meta-analysis demonstrates a correlation between the occurrence of silent brain infarcts on diffusion-weighted imaging and the risk of clinically manifest stroke in carotid revascularisation procedures.

Conclusion

Our findings strengthen the evidence base for the use of DWI as a surrogate outcome measure for procedural stroke in carotid revascularisation procedures. Further randomised studies comparing treatment effects on DWI lesions and clinical stroke are needed to fully establish surrogacy.

Time is brain: an update

The '6-month' threshold for treating symptomatic patients is obsolete. There is compelling evidence that the highest-risk period for stroke (after suffering a transient ischemic attack) is the first 2 weeks, especially the first few days, and that carotid endarterectomy (CEA) confers maximal benefit when performed early. Despite well-documented anxieties, there is increasing evidence that CEA can be performed safely within the first 7 days after onset of symptoms, although risks may be higher when performed within 48 h. The role for carotid artery stenting in the hyperacute period remains uncertain. Centers performing carotid artery stenting within 14 days of symptom onset with risks equivalent to CEA should be encouraged to continue and help others to achieve similar outcomes. For the majority, however, CEA will probably remain the safer option. 'Best medical therapy' and risk factor modification should be started as soon as a transient ischemic attack is suspected, while the early introduction of dual antiplatelet therapy may reduce recurrent events prior to CEA, without increasing perioperative bleeding complications.

Proton magnetic resonance spectroscopy in patients with symptomatic unilateral internal carotid artery / middle cerebral artery stenosis or occlusion

PURPOSE

To explore the value of proton magnetic resonance spectroscopy imaging ((1)H-MRSI) in patients with stenosis or occlusion of the internal carotid artery (ICA) / middle cerebral artery (MCA).

MATERIALS AND METHODS

Fifty noninfarcted patients with stenosis or occlusion of unilateral ICA/MCA were included in our study. In the meantime, 25 patients with cerebral infarction and 25 healthy control subjects were enrolled. All patients and healthy control subjects underwent (1)H-MRSI. Cerebral metabolic changes were studied in the noninfarcted patients and compared with the infarcted patients as well as healthy control subjects.

RESULTS

In 50 noninfarcted patients N-acetylaspartate (NAA) decreased and choline increased in the ischemic hemisphere compared with the contralateral side and control subjects. Lactate peaks were observed in 12 patients. The metabolic changes were relatively slight but were associated with metabolic disruption in infarcted patients. There were relationships between metabolic abnormalities and neurological status of the noninfarcted patients.

CONCLUSION

(1)H-MRSI can demonstrate abnormal metabolic changes in cerebral tissues with no infarction, while with ICA/MCA may show stenosis or occlusion at an early stage, which may help guide treatment decisions and preoperative evaluation.

Cervical carotid pseudoaneurysm: A carotid artery stenting complication

Background:

As carotid artery stenting becomes increasingly used, more complications are likely to occur. We present a case of Staphylococcus septicemia and pseudoaneurysm arising in the neck portion of the carotid artery after stenting.

Case Description:

A 51-year-old man was admitted with mild left hemiparesis. CT and MRI showed right hemisphere ischemia. Duplex Scan and MRA showed bilateral severe stenosis of the carotid arteries in the neck. A percutaneous angioplasty with stenting of the left carotid artery was performed. Two weeks after the procedure, he developed fever and swelling in the right leg and shoulder. An abscess, near where the groin had been punctured for the angioplasty was surgically drained. Blood samples were positive for S. aureus. After treatment the patient complained of a painful bulky pulsatile left cervical mass. Duplex scan and MRA showed a pseudoaneurysm of the left carotid artery. We excised the pseudoaneurysm and rebuilt the carotid artery with a saphenous vein graft. The postoperative period was uneventful, and the MRA revealed a patent saphenous graft.

Conclusion:

Mycotic pseudoaneurysm of the carotid artery is a rare complication of percutaneous angioplasty and stenting. Surgical treatment with saphenous vein graft is the treatment of choice.

The importance of early carotid endarterectomy in symptomatic patients

INTRODUCTION

Early carotid endarterectomy (CEA) in symptomatic patients may prevent repeat cerebral events. This study investigates the relationship between waiting time for CEA and the incidence of repeat cerebral events prior to surgery in symptomatic patients.

PATIENTS AND METHODS

A prospective database of consecutive patients undergoing CEA between January 2002 and December 2006 was reviewed. Repeat event rates prior to surgery were calculated using Kaplan-Meier analysis and predictive factors identified using Cox regression analysis.

RESULTS

A total of 118 patients underwent CEA for non-disabling stroke, TIA and amaurosis fugax. Repeat cerebral events occurred in 34 of 118 (29%) patients at a median 51 days (range, 2-360 days) after the first event. The estimated risk of repeat events was 2% at 7 days and 9% at 1 month after first event (Kaplan-Meier survival analysis). Age (HR 1.059; 95% CI 1.014-1.106; P = 0.009] was identified as a predictor of repeat events. Patients underwent surgery at median 97 days (range, 7-621 days) after the first event. Eleven of 60 (18%) patients waiting < or = 97 days for surgery and 23 of 58 (40%) patients waiting > 97 days had repeat events. (P = 0.011, chi-squared test).

CONCLUSIONS

Delays in surgery should be reduced in order to minimise repeat cerebral events in patients with symptomatic carotid stenosis, particularly in the elderly population.