Martin M. Brown

Endovascular versus surgical treatment in patients with carotid stenosis in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS): a randomised trial

Background: Percutaneous transluminal angioplasty and tenting (endovascular treatment) can be used to treat carotid stenosis, but risks and benefits are uncertain. We therefore compared endovascular treatment with conventional carotid surgery. Methods: In a multicentre clinical trial, we randomly assigned 504 patients with carotid stenosis to endovascular treatment (n=251) or carotid endarterectomy (n=253). For endovascular patients treated successfully, we used stents in 55 (26%) and balloon angioplasty alone in 158 (74%). An independent neurologist followed up patients. Analysis was by intention to treat. Findings: The rates of major outcome events within 30 days of first treatment did not differ significantly between endovascular treatment and surgery (6·4% vs 5·9%, respectively, for disabling stroke or death; 10·0% vs 9·9% for any stroke lasting more than 7 days, or death). Cranial neuropathy was reported in 22 (8·7%) surgery patients, but not after endovascular treatment (p<0·0001). Major groin or neck haematoma occurred less often after endovascular treatment than after surgery (three [1·2%] vs 17 [6·7%], p<0·0015). At 1 year after treatment, severe (70–99%) ipsilateral carotid stenosis was more usual after endovascular treatment (25 [14%] vs seven [4%], p<0·001). However, no substantial difference in the rate of ipsilateral stroke was noted with survival analysis up to 3 years after randomisation (adjusted hazard ratio=1·04, 95% CI 0·63–1·70, p=0·9). Interpretation: Endovascular treatment had similar major risks and effectiveness at prevention of stroke during 3 years compared with carotid surgery, but with wide CIs. Endovascular treatment had the advantage of avoiding minor complications.BACKGROUND Percutaneous transluminal angioplasty and stenting (endovascular treatment) can be used to treat carotid stenosis, but risks and benefits are uncertain. We therefore compared endovascular treatment with conventional carotid surgery. METHODS In a multicentre clinical trial, we randomly assigned 504 patients with carotid stenosis to endovascular treatment (n=251) or carotid endarterectomy (n=253). For endovascular patients treated successfully, we used stents in 55 (26%) and balloon angioplasty alone in 158 (74%). An independent neurologist followed up patients. Analysis was by intention to treat. FINDINGS The rates of major outcome events within 30 days of first treatment did not differ significantly between endovascular treatment and surgery (6.4% vs 5.9%, respectively, for disabling stroke or death; 10.0% vs 9.9% for any stroke lasting more than 7 days, or death). Cranial neuropathy was reported in 22 (8.7%) surgery patients, but not after endovascular treatment (p<0.0001). Major groin or neck haematoma occurred less often after endovascular treatment than after surgery (three [1.2%] vs 17 [6.7%], p<0.0015). At 1 year after treatment, severe (70-99%) ipsilateral carotid stenosis was more usual after endovascular treatment (25 [14%] vs seven [4%], p<0.001). However, no substantial difference in the rate of ipsilateral stroke was noted with survival analysis up to 3 years after randomisation (adjusted hazard ratio=1.04, 95% CI 0.63-1.70, p=0.9). INTERPRETATION Endovascular treatment had similar major risks and effectiveness at prevention of stroke during 3 years compared with carotid surgery, but with wide CIs. Endovascular treatment had the advantage of avoiding minor complications.

Short-term outcome after stenting versus endarterectomy for symptomatic carotid stenosis: a preplanned meta-analysis of individual patient data.

BACKGROUND Results from randomised controlled trials have shown a higher short-term risk of stroke associated with carotid stenting than with carotid endarterectomy for the treatment of symptomatic carotid stenosis. However, these trials were underpowered for investigation of whether carotid artery stenting might be a safe alternative to endarterectomy in specific patient subgroups. We therefore did a preplanned meta-analysis of individual patient data from three randomised controlled trials. METHODS Data from all 3433 patients with symptomatic carotid stenosis who were randomly assigned and analysed in the Endarterectomy versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S) trial, the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) trial, and the International Carotid Stenting Study (ICSS) were pooled and analysed with fixed-effect binomial regression models adjusted for source trial. The primary outcome event was any stroke or death. The intention-to-treat (ITT) analysis included all patients and outcome events occurring between randomisation and 120 days thereafter. The per-protocol (PP) analysis was restricted to patients receiving the allocated treatment and events occurring within 30 days after treatment. FINDINGS In the first 120 days after randomisation (ITT analysis), any stroke or death occurred significantly more often in the carotid stenting group (153 [8·9%] of 1725) than in the carotid endarterectomy group (99 [5·8%] of 1708, risk ratio [RR] 1·53, [95% CI 1·20-1·95], p=0·0006; absolute risk difference 3·2 [1·4-4·9]). Of all subgroup variables assessed, only age significantly modified the treatment effect: in patients younger than 70 years (median age), the estimated 120-day risk of stroke or death was 50 (5·8%) of 869 patients in the carotid stenting group and 48 (5·7%) of 843 in the carotid endarterectomy group (RR 1·00 [0·68-1·47]); in patients 70 years or older, the estimated risk with carotid stenting was twice that with carotid endarterectomy (103 [12·0%] of 856 vs 51 [5·9%] of 865, 2·04 [1·48-2·82], interaction p=0·0053, p=0·0014 for trend). In the PP analysis, risk estimates of stroke or death within 30 days of treatment among patients younger than 70 years were 43 (5·1%) of 851 patients in the stenting group and 37 (4·5%) of 821 in the endarterectomy group (1·11 [0·73-1·71]); in patients 70 years or older, the estimates were 87 (10·5%) of 828 patients and 36 (4·4%) of 824, respectively (2·41 [1·65-3·51]; categorical interaction p=0·0078, trend interaction p=0·0013]. INTERPRETATION Stenting for symptomatic carotid stenosis should be avoided in older patients (age ≥70 years), but might be as safe as endarterectomy in younger patients. FUNDING The Stroke Association.

The Microbleed Anatomical Rating Scale (MARS): Reliability of a tool to map brain microbleeds

Objective: Brain microbleeds on gradient-recalled echo (GRE) T2*-weighted MRI may be a useful biomarker for bleeding-prone small vessel diseases, with potential relevance for diagnosis, prognosis (especially for antithrombotic-related bleeding risk), and understanding mechanisms of symptoms, including cognitive impairment. To address these questions, it is necessary to reliably measure their presence and distribution in the brain. We designed and systematically validated the Microbleed Anatomical Rating Scale (MARS). We measured intrarater and interrater agreement for presence, number, and anatomical distribution of microbleeds using MARS across different MRI sequences and levels of observer experience. Methods: We studied a population of 301 unselected consecutive patients admitted to our stroke unit using 2 GRE T2*-weighted MRI sequences (echo time [TE] 40 and 26 ms). Two independent raters with different MRI rating expertise identified, counted, and anatomically categorized microbleeds. Results: At TE = 40 ms, agreement for microbleed presence in any brain location was good to very good (intrarater κ = 0.85 [95% confidence interval (CI) 0.77–0.93]; interrater κ = 0.68 [95% CI 0.58–0.78]). Good to very good agreement was reached for the presence of microbleeds in each anatomical region and in individual cerebral lobes. Intrarater and interrater reliability for the number of microbleeds was excellent (intraclass correlation coefficient [ICC] = 0.98 [95% CI 0.97–0.99] and ICC = 0.93 [0.91–0.94]). Very good interrater reliability was obtained at TE = 26 ms (κ = 0.87 [95% CI 0.61–1]) for definite microbleeds in any location. Conclusion: The Microbleed Anatomical Rating Scale has good intrarater and interrater reliability for the presence of definite microbleeds in all brain locations when applied to different MRI sequences and levels of observer experience.

Differentiation between different pathological cerebral embolic materials using transcranial Doppler in an in vitro model.

Background and Purpose The detection of circulating particulate cerebral emboli using transcranial Doppler ultrasonography has been recently reported. It has been suggested that this method might allow discrimination between different embolic materials; this would be very useful for selecting specific pharmacological treatment in individual patients. This study was designed to identify those parameters of the Doppler signal that might prove useful in discriminating between different types and sizes of particulate cerebral emboli. Methods An extracorporeal circuit filled with a saline/Tween solution and driven by a peristaltic pump was used. The tubing was placed in a skull in the position of the middle cerebral artery. Using transcranial Doppler ultrasound, flow was insonated via the transtemporal window. The following embolic materials of measured sizes (range of maximum dimension, 0.5-5.0 mm) were introduced into the circuit: thrombus (n=20), platelet-rich aggregates (n=15), atheromatous material (n=20), and fat (n=20). The Doppler signal was recorded during the passage of each embolus. Off-line analysis was performed to measure the maximum amplitude and duration of the signal. Results For all embolic materials there was a highly significant relation between embolus size and maximum amplitude of the Doppler signal. The closest correlation was obtained when the logarithm of maximum amplitude was used (for thrombi, r=0.74; for platelet, r=0.87; for atheroma, r=0.46; and for fat, r=0.68). The slope of the regression line differed for the different embolic materials and was significantly steeper for platelets than for atheroma (p< 0.01). Platelet emboli of maximum dimension ≤1.5 mm resulted in significantly lower maximum amplitude than similarly sized atheroma emboli (157 dB versus 206.7 dB, p<0.01). For larger emboli (>2 mm) there was little further increase in maximum amplitude with increases in embolus size. For all embolic materials there was a highly significant linear relation between embolus size and duration of the high-amplitude (>150 dB) signal (for thrombi, r=0.75; for platelet, r=0.90; for atheroma, r=0.77; and for fat, r=0.86). Conclusions Platelet emboli result in lower-amplitude signals, and therefore analysis of maximum amplitude may provide information on the type of embolic material. However, it may be difficult to determine whether a given signal is associated with a large platelet embolus or a small atheroma embolus. Duration of the high-amplitude signal will allow accurate estimation of the size of emboli, particularly where the emboli are all of the same material.

Safety and Efficacy of Endovascular Treatment of Carotid Artery Stenosis Compared With Carotid Endarterectomy: A Cochrane Systematic Review of the Randomized Evidence

Background and Purpose— Endovascular treatment of atherosclerotic carotid artery stenosis may be an alternative to surgical endarterectomy. To evaluate the safety and efficacy of endovascular techniques, we conducted a systematic review of randomized studies that compared endovascular treatment with surgery for carotid stenosis. Methods— We searched the Cochrane Stroke Group trials register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and Science Citation Index for randomized trials of carotid angioplasty and/or stenting compared with surgery. We also contacted researchers in the field and balloon catheter and stent manufacturers. Results— Five trials involving 1269 patients were included. Analysis of 30-day safety data found no significant difference in the odds of treatment-related death or any stroke (odds ratio [OR], endovascular surgery, 1.33; 95% confidence interval [CI], 0.86 to 2.04), death or disabling stroke (OR, 1.22; CI, 0.61 to 2.41), or death, any stroke, or myocardial infarction (OR, 1.04; CI, 0.69 to 1.57). At 1 year after randomization, there was no significant difference between the 2 treatments in the rate of any stroke or death (OR, 1.01; CI, 0.71 to 1.44). Endovascular treatment significantly reduced the risk of cranial nerve injury (OR, 0.13; CI, 0.06 to 0.25). There was substantial heterogeneity between the trials for 4 of the 5 outcomes. Conclusions— No significant difference in the major risks of treatment was found but the wide confidence intervals indicate that it is not possible to exclude a difference in favor of one treatment. Minor complication rates favor endovascular treatment. There is currently insufficient evidence to support a widespread change in clinical practice away from recommending carotid endarterectomy as the treatment of choice for suitable carotid artery stenosis. Patients suitable for carotid endarterectomy should only be offered stenting within the ongoing randomized trials of stenting versus surgery.

Triptans in migraine The risks of stroke, cardiovascular disease, and death in practice

Background: Triptans are widely used to treat migraine but have been associated with stroke, myocardial infarction (MI), and ischemic heart disease (IHD) in case reports. Objective: To estimate the incidence of stroke, cardiovascular events, and death in a migraine cohort, stratified by triptan prescription, and investigate whether the risk of these events was increased in those treated with triptans. Methods: Migraine patients and matched nonmigraine control subjects were identified from the General Practice Research Database. Computerized records were searched for triptan prescriptions, stroke, TIA, MI, IHD, death, arrhythmia, and confounding variables. Incidence rates were calculated and migraine groups compared with controls using a Cox model, adjusting for confounders. Results: Of 63,575 migraine patients, 13,664 were prescribed a triptan. There was no association between triptan prescription and stroke (hazard ratio [HR] 1.13; 95% CI 0.78, 1.65), MI (HR 0.93; 95% CI 0.60, 1.43), or other outcomes studied. The larger group of migraine patients not prescribed a triptan had an increased risk of stroke (HR 1.51; 95% CI 1.26, 1.82) and IHD (HR 1.35; 95% CI 1.18, 1.54) and a decreased risk of all-cause mortality (HR 0.72; 95% CI 0.65, 0.80). Conclusions: In general practice, triptan treatment in migraine does not increase the risk of stroke, MI, cardiovascular death, IHD, or mortality. Triptans are prescribed to those less at risk of these events.

International Carotid Stenting Study: Protocol for a Randomised Clinical Trial Comparing Carotid Stenting with Endarterectomy in Symptomatic Carotid Artery Stenosis

Background: Carotid stenting avoids general anaesthesia, cranial nerve injury and the discomforts of surgical treatment of carotid stenosis. A systematic review of the randomised trials showed no overall difference in the major risks of endovascular treatment for carotid stenosis compared with surgery, but the confidence intervals were wide and both methods carried a significant risk of stroke. The use of protection devices appears to improve the safety of endovascular treatment, but there are little randomised data available about long-term outcomes. We have therefore set up an international, multicentre, randomised, controlled, open, prospective clinical trial, namely the International Carotid Stenting Study (ICSS), also known as CAVATAS-2. The objectives of the ICSS are to compare the risks, benefits and cost-effectiveness of a treatment policy of referral for carotid stenting compared with referral for carotid endarterectomy. Methods: Centres are required to have a team with audited expertise in carotid endarterectomy and stenting procedures, including at least one neurologist or stroke physician, a surgeon and an interventionalist. Attendance at a carotid stenting training course is required. Centres with more limited experience can join the trial as probationary centres, but stenting must then be proctored by an experienced interventionalist. Symptomatic patients are included over the age of 40 years with atherosclerotic carotid stenosis, suitable for both stenting and surgery, and are randomised in equal proportions between carotid endarterectomy and stenting. Stents and other devices are chosen for use at the discretion of the interventionalists but must be approved by the devices committee. The protocol recommends that a cerebral protection system should be used whenever the operator thinks one can be safely deployed. The combination of aspirin and clopidogrel is recommended to cover stenting procedures. Standard or eversion endarterectomy is allowed using local or general anaesthesia, shunts or patches. All patients will receive best medical care. Patients will be followed up by neurologists at 30 days after treatment, 6 months after randomisation and then annually up to 5 years after randomisation. The primary outcome measure is the difference in the long-term rate of fatal or disabling stroke in any territory between patients randomised to stenting or surgery. Secondary outcome measures include any stroke, myocardial infarction or death within 30 days of treatment, treatment- related cranial nerve palsy or haematoma. Restenosis (>70%) on ultrasound follow-up, economic measures and quality of life will also be analysed. The sample size is estimated at 1,500 patients, which will provide 95% confidence intervals of ± 3.0 percentage points for the outcome measure of 30-day disabling stroke and death rate and ± 3.3 percentage points for the outcome measure of death or stroke during follow-up. The trial office monitors outcome events at individual centres and a rate of events above a given threshold triggers a blinded assessment of the events, submitted to the chairman of the data-monitoring committee. Conclusions: The ICSS protocol incorporates a number of novel features to ensure patient safety, including the concept of probationary centres, proctoring of inexperienced investigators and monitoring of individual centre results on an ongoing basis. The protocol is also designed to mirror routine clinical practice as far as possible, so that the results will be widely applicable and relevant to determining the place of carotid stenting in clinical practice in the future.

Angiotensin-Converting Enzyme Gene Deletion Polymorphism: A New Risk Factor for Lacunar Stroke but not Carotid Atheroma

BACKGROUND AND PURPOSE A deletion (D)/insertion (I) polymorphism in the angiotensin-converting enzyme gene has been associated with myocardial infarction. Its relations to both stroke and atheroma remain uncertain. We examined its role as a risk factor in patients with cerebrovascular disease and its relation to carotid atheroma. METHODS One hundred one patients with symptomatic carotid artery territory cerebral ischemia were compared with 137 age-matched control subjects. In the patient group, carotid atheroma was assessed by measurement of degree of carotid stenosis and intima-media thickness with high-resolution duplex ultrasound. The D/I polymorphism was examined using the polymerase chain reaction. RESULTS D:I allele frequency was 0.59:0.41 in case subjects and 0.48:0.52 in control subjects (P = .01). The DD genotype was more common in patients with cerebrovascular disease compared with control subjects (36/101 versus 30/137, P = .02). The DD genotype conferred a relative risk of any type of cerebrovascular disease of 1.98 (95% confidence interval [CI], 1.11 to 3.51; P = .02). However, this was largely due to a strong association in the 18 patients with lacunar stroke, in whom the D:I ratio was 0.75:0.25 (P = .0097 versus control subjects). The odds ratio for lacunar stroke associated with the DD genotype was 5.6 (95% CI, 2.0 to 15.7) and was still significant at 4.40 (95% CI, 1.45 to 12.6; P < .009) after controlling for other risk factors. There was no significant association between angiotensin-converting enzyme genotype and cerebrovascular disease due to large-vessel stenosis. There was no association between genotype and age, sex, smoking history, diabetes, or cholesterol level. CONCLUSIONS The deletion polymorphism in the angiotensin-converting enzyme gene is a new independent risk factor for lacunar stroke but is not a risk factor for stroke associated with carotid stenosis.

Comparison of Microembolism Detected by Transcranial Doppler and Neuropsychological Sequelae of Carotid Surgery and Percutaneous Transluminal Angioplasty

BACKGROUND AND PURPOSE Percutaneous transluminal angioplasty (PTA) is currently being assessed for the treatment of carotid stenosis. In comparison with carotid endarterectomy (CEA), there is evidence of an increased risk of cerebral microembolism during the procedure. We have sought evidence of any neuropsychological sequelae of carotid PTA and compared it with CEA to demonstrate the relative safety of the 2 treatment options. METHODS The neuropsychological outcomes after CEA and PTA were compared in 2 matched groups of patients with severe symptomatic carotid stenosis, 96% of whom had been randomized in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS), at a single center. Transcranial Doppler insonation of the middle cerebral artery was used to measure cerebral reactivity in response to carbon dioxide inhalation before treatment and then to detect microembolization of the ipsilateral cerebral hemisphere and measure changes in blood flow velocity during the procedures. The performance on a neuropsychological test battery administered before, 6 weeks after, and 6 months after the procedure was compared in 20 patients undergoing PTA and 26 having CEA. RESULTS At 6 weeks, 5 patients in each group showed a similar decline in neuropsychological performance; global measures showed no significant difference between the 2 procedures, despite a significantly higher incidence of microemboli during PTA. Both groups showed a marked reduction in anxiety after treatment. CONCLUSIONS The findings provide some reassurance that PTA is not associated with greater cerebral complications than CEA, despite the higher embolic load recorded by transcranial Doppler ultrasonography during angioplasty.

Long-term outcomes after stenting versus endarterectomy for treatment of symptomatic carotid stenosis : the International Carotid Stenting Study (ICSS) randomised trial

Summary Background Stenting is an alternative to endarterectomy for treatment of carotid artery stenosis, but long-term efficacy is uncertain. We report long-term data from the randomised International Carotid Stenting Study comparison of these treatments. Methods Patients with symptomatic carotid stenosis were randomly assigned 1:1 to open treatment with stenting or endarterectomy at 50 centres worldwide. Randomisation was computer generated centrally and allocated by telephone call or fax. Major outcomes were assessed by an independent endpoint committee unaware of treatment assignment. The primary endpoint was fatal or disabling stroke in any territory after randomisation to the end of follow-up. Analysis was by intention to treat ([ITT] all patients) and per protocol from 31 days after treatment (all patients in whom assigned treatment was completed). Functional ability was rated with the modified Rankin scale. This study is registered, number ISRCTN25337470. Findings 1713 patients were assigned to stenting (n=855) or endarterectomy (n=858) and followed up for a median of 4·2 years (IQR 3·0–5·2, maximum 10·0). Three patients withdrew immediately and, therefore, the ITT population comprised 1710 patients. The number of fatal or disabling strokes (52 vs 49) and cumulative 5-year risk did not differ significantly between the stenting and endarterectomy groups (6·4% vs 6·5%; hazard ratio [HR] 1·06, 95% CI 0·72–1·57, p=0·77). Any stroke was more frequent in the stenting group than in the endarterectomy group (119 vs 72 events; ITT population, 5-year cumulative risk 15·2% vs 9·4%, HR 1·71, 95% CI 1·28–2·30, p<0·001; per-protocol population, 5-year cumulative risk 8·9% vs 5·8%, 1·53, 1·02–2·31, p=0·04), but were mainly non-disabling strokes. The distribution of modified Rankin scale scores at 1 year, 5 years, or final follow-up did not differ significantly between treatment groups. Interpretation Long-term functional outcome and risk of fatal or disabling stroke are similar for stenting and endarterectomy for symptomatic carotid stenosis. Funding Medical Research Council, Stroke Association, Sanofi-Synthélabo, European Union.