Robert A. Taylor

Is the ABCD Score Useful for Risk Stratification of Patients With Acute Transient Ischemic Attack

Background and Purpose— A 6-point scoring system (ABCD) was described recently for stratifying risk after transient ischemic attack (TIA). This score incorporates age (A), blood pressure (B), clinical features (C), and duration (D) of TIA. A score <4 reportedly indicates minimal short-term stroke risk. We evaluated this scoring system in an independent population. Methods— This was a prospective study of TIA patients (diagnosed by a neurologist using the classic <24-hour definition) hospitalized <48 hours from symptom onset. The primary outcome assessment consisted of dichotomization of patients into 2 groups. The high-risk group included patients with stroke or death within 90 days, ≥50% stenosis in a relevant artery, or a cardioembolic source warranting anticoagulation. All others were classified as low risk. Findings on diffusion-weighted MRI (DWI) were also evaluated when performed and patients classified as DWI+ or DWI−. Results— Over 3 years, 117 patients were enrolled. Median time from symptom onset to enrollment was 25.2 hours (interquartile range 19.8 to 30.2). Overall, 26 patients (22%) were classified as high risk, including 2 strokes, 2 deaths, 15 with ≥50% stenosis, and 10 with cardioembolic source. The frequency of high-risk patients increased with ABCD score (0 to 1 13%; 2 8%; 3 17%; 4 27%; 5 26%; 6 30%; P for trend=0.11). ABCD scores in the 2 patients with stroke were 3 and 6. Of those who underwent MRI, 15 of 61 (25%) were DWI+, but this correlated poorly with ABCD score (0 to 1 17%; 2 10%; 3 36%; 4 24%; 5 13%; 6 60%; P for trend=0.24). Conclusions— Although the ABCD score has some predictive value, patients with a score <4 still have a substantial probability of having a high-risk cause of cerebral ischemia or radiographic evidence of acute infarction despite transient symptoms.

Involvement of skeletal muscle in dialysis-associated systemic fibrosis (nephrogenic fibrosing dermopathy)

Nephrogenic fibrosing dermopathy (NFD), a newly recognized scleroderma‐like disease, was originally described as a purely cutaneous disorder. More widespread involvement, including fibrosis of pulmonary and cardiac tissues, has been documented only recently, and it has been suggested that a more appropriate designation is dialysis‐associated systemic fibrosis. We report five cases of this novel disorder, spanning a spectrum of primarily skin to primarily muscle involvement. Clinical, radiological, electrophysiological, and pathological studies revealed moderate to severe fibrosis of striated muscles. All patients had end‐stage renal failure on chronic dialysis, subacute to chronic hardening of the skin and muscles, restriction of limb movements with joint contractures, but normal to only mildly weak muscle strength. Limitation of movements was caused predominantly by skin tightness and induration, and by joint contractures rather than muscle weakness. Computerized tomography showed fibrosis of the fascia and muscles in the most severely affected patients, and electromyography showed mild to severe myopathic changes. Histopathology of affected muscles revealed a spectrum of mild to severe fibrosis, degenerating fibers, and chronic inflammatory cells. These results further support the contention that NFD is not a purely cutaneous disease, but is part of a larger systemic fibrotic process that may involve muscles. Muscle Nerve, 2004

Comparison of Primary Angioplasty With Stent Placement for Treating Symptomatic Intracranial Atherosclerotic Diseases A Multicenter Study

Background and Purpose— We sought to compare the clinical outcomes between primary angioplasty and stent placement for symptomatic intracranial atherosclerosis. Methods— We retrospectively analyzed the clinical and angiographic data of 190 patients treated with 95 primary angioplasty procedures and 98 intracranial stent placements (total of 193 procedures) in 3 tertiary care centers. Stroke and combined stroke and/or death were identified as primary clinical end points during the periprocedural and follow-up period of 5 years. The rates of significant postoperative residual stenosis (≥50% of greater stenosis immediately after the procedure) and binary restenosis (≥50% stenosis at follow-up angiography within 3 years) were also compared. The comparative analysis was performed after adjusting for age, sex, and center. Results— Fourteen procedures in the angioplasty-treated group (15%) and 4 in the stent-treated group (4.1%) had significant postoperative residual stenosis (relative risk [RR]=2.8, 95% CI, 0.85 to 9.5, P=0.09, for the adjusted model). There were 3 periprocedural deaths (1.5%), 1 in the angioplasty group (1.1%) and 2 in the stent-treated group (2.0%) and 14 periprocedural strokes (7.3%), 7 periprocedural strokes in each group (7.4% and 7.1%, respectively; hazard ratio=1.1; 95% CI, 0.57 to 1.9, P=0.85). Angiographic follow-up was available for 134 procedures (66 angioplasty-treated and 68 stent-treated cases). Forty-eight procedures (36.1%) had evidence of binary restenosis (25 of 66 angioplasties, 23 of 68 stents, P=0.85). Binary restenosis-free survival at 12 months was 68% for the angioplasty-treated group and 64% for the stent-treated group. There was no difference in follow-up survival (stroke, or stroke and/or death) between the angioplasty-treated and the stent-treated groups (hazard ratio=0.54; 95% CI, 0.11 to 2.5, P=0.44 and hazard ratio=0.50; 95%, CI 0.17 to 1.5, P=0.22, respectively, after adjusting for age, sex, and center). The stroke- and/or death-free survival at 2 years for the angioplasty-treated group and the stent-treated group was 92±4% and 89±5%, respectively. Conclusions— Stent treatment for intracranial atherosclerosis may lower the rate of significant postoperative residual stenosis compared with primary angioplasty alone. No benefit of stent placement over primary angioplasty in reducing stroke or stroke and/or death could be identified in this study.

Intracranial atherosclerotic disease: An update

The consensus conference on intracranial atherosclerosis provides a comprehensive review of the existing literature relevant to the epidemiology, diagnosis, prevention, and treatment of intracranial atherosclerosis, and identifies principles of management and research priorities. Patients who have suffered a stroke or transient ischemic attack attributed to stenosis (50–99%) of a major intracranial artery face a 12 to 14% risk for subsequent stroke during the 2‐year period after the initial ischemic event, despite treatment with antithrombotic medications. The annual risk for subsequent stroke may exceed 20% in high‐risk groups. In patients with intracranial atherosclerotic disease, short‐term and long‐term anticoagulation is not superior to antiplatelet treatment. Overall, the subgroup analyses from randomized trials provide evidence about benefit of aggressive atherogenic risk factor management. Intracranial angioplasty with or without stent placement has evolved as a therapeutic option for patients with symptomatic intracranial atherosclerotic disease, particularly those with high‐grade stenosis with recurrent ischemic symptoms, medication failure, or both. A multicenter randomized trial is currently under way to compare stent placement with intense medical management for patients with high‐grade symptomatic intracranial atherosclerotic disease. Ann Neurol 2009;66:730–738

Lipoprotein-Associated Phospholipase A2 and C-Reactive Protein for Risk-Stratification of Patients With TIA

Background and Purpose— Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a marker of unstable atherosclerotic plaque, and is predictive of both primary and secondary stroke in population-based studies. Methods— We conducted a prospective study of patients with acute TIA who presented to the ED. Clinical risk scoring using the ABCD2 score was determined and Lp-PLA2 mass (LpPLA2-M) and activity (LpPLA2-A) and high-sensitivity C-reactive protein (CRP) were measured. The primary outcome measure was a composite end point consisting of stroke or death within 90 days or identification of a high-risk stroke mechanism requiring specific early intervention (defined as ≥50% stenosis in a vessel referable to symptoms or a cardioembolic source warranting anticoagulation). Results— The composite outcome end point occurred in 41/167 (25%) patients. LpPLA2-M levels were higher in end point–positive compared to –negative patients (mean, 192±48 ng/mL versus 175±44 ng/mL, P=0.04). LpPLA2-A levels showed similar results (geometric mean, 132 nmol/min/mL, 95% CI 119 to 146 versus 114 nmol/min/mL, 95% CI 108 to 121, P=0.01). There was no relationship between CRP and outcome (P=0.82). Subgroup analysis showed that both LpPLA2-M (P=0.04) and LpPLA2-A (P=0.06) but not CRP (P=0.36) were elevated in patients with >50% stenosis. In multivariate analysis using cut-off points defined by the top quartile of each marker, predictors of outcome included LpPLA2-A (OR 3.75, 95% CI 1.58 to 8.86, P=0.003) and ABCD2 score (OR 1.30 per point, 95% CI 0.97 to 1.75, P=0.08). Conclusion— Many patients with TIA have a high-risk mechanism (large vessel stenosis or cardioembolism) or will experience stroke/death within 90 days. In contrast to CRP, both Lp-PLA2 mass and activity were associated with this composite end point, and LpPLA2-A appears to provide additional prognostic information beyond the ABCD2 clinical risk score alone.

Improvement in Cerebral Hemodynamics After Carotid Angioplasty

BACKGROUND AND PURPOSE Carotid percutaneous transluminal angioplasty ( PTA) may offer an alternative treatment to carotid endarterectomy. However, in contrast to carotid endarterectomy, which has been shown to normalize impaired cerebral hemodynamics, the effects of carotid PTA are unknown. Therefore, we prospectively studied the effect of carotid PTA on both perioperative and postoperative cerebral hemodynamics. METHODS Eleven patients undergoing carotid PTA for symptomatic carotid artery stenosis were prospectively studied. Transcranial Doppler recordings from the ipsilateral middle cerebral artery (MCA) were performed during the procedure. In addition, MCA blood flow velocity and CO2 reactivity were determined before PTA and at 2 days, 1 month, and 6 months after procedure. The results were compared with those in 11 similar patients undergoing carotid endarterectomy in whom measurements were performed before and 1 month after the operation. RESULTS During carotid PTA, in 2 of 11 patients during passage of the balloon catheter through the stenosis, MCA blood flow velocity fell transiently. In 6 of 11 patients there was a reduction in flow velocity (>50%) during balloon deflation, but this lasted only a few seconds. After the procedure there was a significant improvement in ipsilateral hypercapnic reactivity: preoperative value, 59.8+/-42.2% (mean+/-SD); 2 days, 77.9+/-31.4%; 1 month, 88.7+/-45.0%; 6 months, 89.8+/-33.9%; and (ANOVA P=.003) preoperative value versus 1 month, P<.02; versus 6 months, P<.02. In all cases in which reactivity was significantly impaired preoperatively, it returned to the normal range. Pulsatility index also increased significantly: preoperative value, 0.827+/-0.251 (mean+/-SD); 2 days, 0.992+/-0.262 (P=.002). Contralateral MCA hypercapnic reactivity also improved after carotid PTA. There was a similar improvement in ipsilateral hypercapnic reactivity after carotid endarterectomy. CONCLUSIONS Carotid PTA results in a normalization of impaired hemodynamics, as assessed by CO2 reactivity. The degree of improvement is similar to that seen after carotid endarterectomy.

The Safety and Efficacy of Thrombolysis for Strokes After Cardiac Catheterization

OBJECTIVES The purpose of this study was to systematically compare clinical outcomes of patients treated with thrombolysis with those without treatment in a multi-year, multicenter cohort of strokes after cardiac catheterization. BACKGROUND Ischemic strokes after cardiac catheterization procedures, although uncommon, lead to the morbidity and mortality of thousands of patients each year. Despite the availability of Food and Drug Administration-approved thrombolytic therapy for acute ischemic stroke since 1996, thrombolysis remains unestablished in the setting of cardiac catheterization, owing to unique concerns regarding safety and efficacy. METHODS Consecutive cases of ischemic stroke after cardiac catheterization were abstracted retrospectively and reviewed by clinicians at 7 major North American academic centers with acute stroke teams. Safety and efficacy outcome measures were pre-defined. RESULTS A total of 66 cases of ischemic strokes after cardiac catheterization were identified over 3 to 4 years; 12 (18%) were treated with thrombolysis, consisting of 7 intravenous and 5 intra-arterial recombinant tissue plasminogen activator cases. Improvement in stroke symptoms, as measured by the primary efficacy measure of median change in National Institutes of Health Stroke Scale score from baseline to 24 h, was greater in treated versus nontreated cases (p < 0.001). Additional secondary measures of efficacy also showed better outcomes in the treated group. There were no significant differences in bleeding events, defined as symptomatic intracerebral hemorrhage, hemopericardium, or other systemic bleeding resulting in hemodynamic instability or blood transfusions. Mortality rates were also similar. CONCLUSIONS Thrombolysis might improve early outcomes after post-catheterization strokes and seems safe in this context. Emergent cerebral revascularization should be a routine consideration.

A Comparison of Computed Tomography Perfusion-Guided and Time-Guided Endovascular Treatments for Patients With Acute Ischemic Stroke

Background and Purpose— The role of CT perfusion (CT-P) imaging for the selection of patients with acute ischemic stroke who may benefit from endovascular treatment is not defined. The objective of this study was to determine whether CT-P-guided endovascular treatment improves clinical outcomes compared with standard endovascular treatment based on the time interval between symptom onset and presentation and noncontrast cranial CT imaging. Methods— A retrospective study was performed comparing the clinical characteristics, complications, and clinical outcomes of patients with acute ischemic stroke who were treated using endovascular modalities based on either CT-P imaging (CT-P-guided) or time interval between symptom onset and presentation and absence of intracerebral hemorrhage or extensive ischemic changes on noncontrast cranial CT scan (time-guided). Results— The rates of partial and complete recanalization were similar between the CT-P- and time-guided treatment groups (n=61 [88%] versus n=103 [81%]; P=0.52) regardless of whether they received intravenous recombinant tissue plasminogen activator before endovascular treatment. Comparing the CT-P-guided with the time-guided patients, favorable discharge outcome (modified Rankin Scale 0 to 2) was observed in 23 (32%) versus 41 (33%) of the patients, respectively (P=0.9). In-hospital mortality was observed in 15 (21%) of CT-P- and 29 (23%) of time-guided patients (P=0.74). Conclusion— CT-P-guided endovascular treatment did not increase the rate of short-term favorable outcomes among patients with acute ischemic stroke. Prospective studies are required to validate the CT-P criteria and protocols currently in use before incorporating CT-P as a routine modality for patient selection for endovascular treatment.

Risk factors for in-stent restenosis after vertebral ostium stenting.

Purpose: To determine whether vascular risk factors, underlying vessel diameter, and/or the type of stent affect restenosis rates for vertebral ostium stents. Methods: A single-center retrospective analysis was conducted of 44 patients (31 men; mean age 61 years, range 32–81) who underwent stenting of 48 ostial lesions in the vertebral arteries between 1999 and 2005. Only patients who underwent angiographic follow-up were included in the analysis. Cox regression analysis was utilized for risk factor association with binary restenosis (≥50% versus <50%). Stent types and stent categories were compared for differences in binary restenosis rates and lumen gain at follow-up angiography. Results: Twenty-three (48%) of 48 lesions had ≥50% stenosis at a mean follow-up of 7.7 months. Cigarette smoking was associated with higher binary restenosis rates (p=0.025), while hypertension, diabetes, hyperlipidemia, history of neck radiation, and known coronary artery and/or peripheral vascular disease were not. Reduced binary restenosis rates and improved lumen gain were seen in cobalt chromium balloon-expandable stents compared to non-cobalt chromium stents (p=0.002 and p=0.002, respectively), stainless steel balloon-expandable stents (p=0.005 and p=0.005), and the S670 stent (p=0.069 and p=0.069). The size of stent used was not associated with risk of restenosis (p=0.756). Conclusions: Cobalt chromium stents were associated with reduced restenosis, while smoking was associated with increased restenosis risk.

Consensus Conference on Intracranial Atherosclerotic Disease: Rationale, Methodology, and Results

The consensus conference on intracranial atherosclerotic disease (ICAD) identifies principles of management, and research priorities in various aspects upon which leading experts can agree (using “Delphi” method). ICAD is more prevalent in Asian, Hispanic, and African‐American populations. Patients who have had a stroke or transient ischemic attack (TIA) attributed to stenosis (50‐99%) of a major intracranial artery face a 12‐14% risk of subsequent stroke during the 2‐year period after the initial ischemic event, despite treatment with antithrombotic medications. The annual risk of subsequent stroke may exceed 20% in high‐risk groups. The medical treatment of patients with symptomatic ICAD is directed toward: 1. Prevention of intraluminal thrombo‐embolism, 2. plaque stabilization and regression, and 3. management of atherogenic risk factors. In patients with ICAD, short‐term and long‐term anticoagulation (compared with aspirin) have not shown to be beneficial. The current guidelines recommend that aspirin monotherapy, the combination of aspirin and extended release dipyridamole, and clopidogrel monotherapy (rather than oral anticoagulants) are all acceptable options in patients with non‐cardioembolic ischemic stroke and TIA. Overall, the subgroup analysis from randomized trials provides evidence about benefit of aggressive atherogenic risk factor management among patients with ICAD. Intracranial angioplasty with or without stent placement has evolved as a therapeutic option for patients with symptomatic ICAD, particularly those with high‐grade stenosis with recurrent ischemic symptoms and/or medication failure. A matched comparison between medical‐treated patients in the Warfarin Aspirin Symptomatic Intracranial Disease (WASID) study and stent‐treated patients in the National Institutes of Health intracranial stent registry concluded that stent placement may offer benefit in patients with 70‐99% stenosis. The 5‐year, multicenter, prospective, randomized Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis study supported by the National Institutes of Health is currently comparing stent placement with intense medical management with intense medical management alone in patients with high‐grade symptomatic intracranial stenosis. The proceedings of the consensus conference provide a template for standardizing management of patients with ICAD and determining research priorities.