Sumaira Macdonald

Multicenter evaluation of carotid artery stenting with a filter protection system

OBJECTIVES The aim of this study was to evaluate the feasibility and safety of carotid artery stenting (CAS) with a filter protection system. BACKGROUND Neurologic events linked to the embolization of particulate matter to the cerebral circulation may complicate CAS. Strategies designed to capture embolic particles during carotid intervention are being evaluated for their efficacy in reducing the risk of these events. METHODS Between September 1999 and July 2001, a total of 162 patients (164 hemispheres) underwent CAS with filter protection (NeuroShield, MedNova Ltd., Galway, Ireland) according to prospective protocols evaluating the filter system at three institutions. RESULTS Angiographic success was achieved in 162 of the procedures (99%) and filter placement was successful in 154 (94%) procedures. Carotid access was unsuccessful in two cases (1%) and filter placement in eight cases (5%). Of the latter, five procedures were completed with no protection and three were completed using alternative protection devices. On an intention-to-treat basis, the overall combined 30-day rate of all-stroke and death was 2% (four events: two minor strokes and two deaths). This includes one minor stroke in a patient with failed filter placement and CAS completed without protection. There was one cardiac arrhythmic death and one death from hyperperfusion-related intracerebral hemorrhage. There were no major embolic strokes. CONCLUSIONS Carotid artery stenting with filter protection is technically feasible and safe. Early clinical outcomes appear to be favorable and need to be confirmed in a larger comparative study.

Does Carotid Stent Cell Design Matter

Background and Purpose— Carotid stent cell design has recently been suggested to be a determinant of periprocedural and early postprocedural neurologic complications. We investigated the impact of closed- versus open-cell stent design on neurologic adverse events and mortality after carotid artery stenting. Methods— We studied 1684 consecutive patients (1010 asymptomatic, 674 symptomatic) from 10 European centers who underwent carotid artery stenting with either closed-cell (n=859, 51%) or open-cell (n=825, 49%) design stents. Rates of transient ischemic attack, stroke, and death on the day of the procedure (acute events) and from day 1 to day 30 after the procedure (subacute events) were analyzed (95% CIs). Results— Combined transient ischemic attack, stroke, or death rates, and stroke or death rates within 30 days of treatment were 6.1% (95% CI, 5.0 to 7.2) and 3.1% (95% CI, 2.3 to 3.9) for the closed-cell design versus 4.1% (95% CI, 3.2 to 5.0) and 2.4% (95% CI, 1.7 to 3.1) for the open-cell design stents (P=0.077, P=0.38), respectively, without significant differences in asymptomatic and symptomatic patients. By propensity-score–adjusted multivariable analysis, the open-cell carotid stent design was not associated with a differential risk for combined acute and subacute neurologic complications compared with closed-cell stents (adjusted odds ratio=0.84, P=0.53). When analyzed separately, the risk for acute events on the day of the procedure (adjusted odds ratio=0.83, P=0.57) and the risk for subacute events at days 1 to 30 (adjusted odds ratio=1.61, P=0.51) also were not significantly different between the groups. Conclusions— Current data do not support the superiority of a specific carotid stent cell design with respect to neurologic complications, stroke, and mortality risk.

Filter-Protected versus Unprotected Carotid Artery Stenting: A Randomised Trial

Background: Our aim was to determine whether filter protection reduces embolisation to the brain during carotid artery stenting (CAS). Methods: Thirty patients with symptomatic carotid artery stenosis ≧70% (North American Symptomatic Carotid Endarterectomy Trial) were randomly assigned to filter-protected or unprotected CAS. Diffusion-weighted magnetic resonance imaging (DWI) of the brain was performed before and at 3 time points after CAS. In a subset of patients, high-intensity transient signals on transcranial Doppler (TCD) were recorded with categorisation of emboli. Data were independently reviewed off-site. Results: There were no significant differences in mean age, proportion of octogenarians or presenting symptoms between the groups. On procedural DWI (1–3 and 24 h after stenting), there were 7/24 (29%) and 4/22 (18%) new lesions in protected and unprotected patients respectively (p = 0.38). At 30 days there were 9/33 (26%) and 4/33 (12%) lesions in protected and unprotected patients, respectively (p = 0.1). On TCD there were significantly more signals in total as well as particulate emboli during filter-protected CAS (426.5 and 251.3) than during unprotected CAS (165.2 and 92) – p = 0.01 and 0.03, respectively. Conclusions: Filter-protected CAS is associated with an increase in new lesions on DWI and significantly higher rates of total and particulate microembolisation on TCD than unprotected CAS. The clinical significance of these findings requires further study.

Pragmatic Minimum Reporting Standards for Endovascular Abdominal Aortic Aneurysm Repair

Jonathan R. Boyle, MD, FRCS1; Matt M. Thompson, MD, FRCS2; S. Rao Vallabhaneni, MD, FRCS, EBSQ-Vasc3; Rachael E. Bell, MS, FRCS4; John A. Brennan, MD, FRCS3; Tom F. Browne, FRCS5; Nicholas J. Cheshire, MD, FRCS6; Robert J. Hinchliffe, MD, FRCS2; Michael P. Jenkins, MS, FRCS, FEBVS6; Ian M. Loftus, MD, FRCS2; Sumaira Macdonald, FRCP, FRCR, PhD7; Mark J. McCarthy, PhD, FRCS8; Richard G. McWilliams, FRCR3; Robert A. Morgan, FRCR2; Olufemi A. Oshin, BEng, MRCS3; R. Mark Pemberton, MS, FRCS9; Woolagasen R. Pillay, FCS(SA), MMEDSc10; and Robert D. Sayers, MD, FRCS8 for the British Society of Endovascular Therapy

Carotid artery stenting: relationship between experience and complication rate

To investigate the evidence for the relationship between volume and outcome for carotid artery stenting. We performed a systematic review of the literature to examine the influence of experience and/or volume on outcome for carotid artery stenting. The primary search strategy was to identify studies presenting year-on-year data. The Pubmed, Embase, Medline and the Cochrane Collaboration databases were searched. Studies with over 100 interventions were included. The main outcome measure compared across studies was all stroke/death. Where possible, comparable data were pooled and analysed using meta-regression techniques. It was not possible to perform a standard systematic review and meta-analysis because of the lack of data from randomised studies. When redundant studies were excluded, four sizeable case series and one registry met the inclusion criteria. When the case series results were pooled, the χ2-test for trend demonstrated a significant reduction in the combined stroke and death rate over time. Meta-regression analysis of case series data allowed the setting of thresholds for ‘acceptable’ stroke/death rates. Where year-on-year data are available, published stroke and death rates for carotid artery stenting show improvements over time. While advances in technology and pharmacology may in part be responsible, temporal improvement in outcomes demonstrated in both early and contemporary time-frames together with the consistency of the results suggests the presence of a learning curve. In active carotid artery stenting units, it may take almost 2-years before the stroke/death rates fall below an arbitrary 5% threshold.

Characteristics of Ischemic Brain Lesions After Stenting or Endarterectomy for Symptomatic Carotid Artery Stenosis Results From the International Carotid Stenting Study–Magnetic Resonance Imaging Substudy

Background and Purpose— In a substudy of the International Carotid Stenting Study (ICSS), more patients had new ischemic brain lesions on diffusion-weighted magnetic resonance imaging (MRI) after stenting (CAS) than after endarterectomy (CEA). In the present analysis, we compared characteristics of diffusion-weighted MRI lesions. Methods— Number, individual and total volumes, and location of new diffusion-weighted MRI lesions were compared in patients with symptomatic carotid stenosis randomized to CAS (n=124) or CEA (n=107) in the ICSS-MRI substudy. Results— CAS patients had higher lesion numbers than CEA patients (1 lesion, 15% vs 8%; 2–5 lesions, 19% vs 5%; >5 lesions, 16% vs 4%). The overall risk ratio for the expected lesion count with CAS versus CEA was 8.8 (95% confidence interval, 4.4–17.5; P<0.0001) and significantly increased among patients with lower blood pressure at randomization, diabetes mellitus, stroke as the qualifying event, left-side stenosis, and if patients were treated at centers routinely using filter-type protection devices during CAS. Individual lesions were smaller in the CAS group than in the CEA group (P<0.0001). Total lesion volume per patient did not differ significantly. Lesions in the CAS group were more likely to occur in cortical areas and subjacent white matter supplied by leptomeningeal arteries than lesions in the CEA group (odds ratio, 4.2; 95% confidence interval, 1.7–10.2; P=0.002). Conclusions— Compared with patients undergoing CEA, patients treated with CAS had higher numbers of periprocedural ischemic brain lesions, and lesions were smaller and more likely to occur in cortical areas and subjacent white matter. These findings may reflect differences in underlying mechanisms of cerebral ischemia. Clinical Trial Registration— URL: http://www.isrctn.org. Unique identifier: ISRCTN25337470.

Status update and interim results from the asymptomatic carotid surgery trial-2 (ACST-2).

OBJECTIVES ACST-2 is currently the largest trial ever conducted to compare carotid artery stenting (CAS) with carotid endarterectomy (CEA) in patients with severe asymptomatic carotid stenosis requiring revascularization. METHODS Patients are entered into ACST-2 when revascularization is felt to be clearly indicated, when CEA and CAS are both possible, but where there is substantial uncertainty as to which is most appropriate. Trial surgeons and interventionalists are expected to use their usual techniques and CE-approved devices. We report baseline characteristics and blinded combined interim results for 30-day mortality and major morbidity for 986 patients in the ongoing trial up to September 2012. RESULTS A total of 986 patients (687 men, 299 women), mean age 68.7 years (SD ± 8.1) were randomized equally to CEA or CAS. Most (96%) had ipsilateral stenosis of 70-99% (median 80%) with contralateral stenoses of 50-99% in 30% and contralateral occlusion in 8%. Patients were on appropriate medical treatment. For 691 patients undergoing intervention with at least 1-month follow-up and Rankin scoring at 6 months for any stroke, the overall serious cardiovascular event rate of periprocedural (within 30 days) disabling stroke, fatal myocardial infarction, and death at 30 days was 1.0%. CONCLUSIONS Early ACST-2 results suggest contemporary carotid intervention for asymptomatic stenosis has a low risk of serious morbidity and mortality, on par with other recent trials. The trial continues to recruit, to monitor periprocedural events and all types of stroke, aiming to randomize up to 5,000 patients to determine any differential outcomes between interventions. CLINICAL TRIAL ISRCTN21144362.

Angioplasty or stenting in adult coarctation of the aorta? A retrospective single center analysis over a decade

AbstractFor over 11 years, endovascular treatment by angioplasty (PTA) alone or stenting of adult coarctation at a single center was evaluated. We retrospectively reviewed 28 consecutive patients (31 interventions), median age 25 years, treated between 1991 and 2002, 20 of whom had native coarctation. Thirteen patients had PTA alone (16 procedures) (10 “kissing balloon” angioplasty comprising 12 interventions, and 3 single balloon angioplasty comprising 4 interventions) and 15 patients were stented (15 procedures), including 6 secondary and 9 primary stents. There were no procedural or 30-day complications. For the whole group, the median follow-up was 6.6 years (range 1–10 years). In the PTA group, median follow-up was 9 years (range 3–10) and in the stenting group it was 3 years (range 1–5). There were 9 restenoses in the PTA group (6 after “kissing balloons” and 3 after single balloon) comprising 56% of the angioplasties (9/16 procedures). There was 1 restenosis in the stenting group diagnosed at computed tomography (CT). The patient was clinically well. For the whole group there were significant reductions in systolic blood pressure (BP) (p = 0.0003), diastolic BP (p = 0.004) and number of drugs per patient (p = 0.045) at latest follow-up post-treatment. Five patients discontinued therapy. Analysis of the groups revealed that the reduction of systolic and diastolic BP and number of drugs did not reach statistical significance in the PTA group but were significant in the stent group. The endovascular management of adult coarctation is safe. Stents may be more effective than PTA alone but longer-term follow-up of stents is required.

Ischemic Brain Lesions After Carotid Artery Stenting Increase Future Cerebrovascular Risk

Background Brain lesions on diffusion-weighted imaging (DWI) are frequently found after carotid artery stenting (CAS), but their clinical relevance remains unclear. Objectives This study sought to investigate whether periprocedural ischemic DWI lesions after CAS or carotid endarterectomy (CEA) are associated with an increased risk of recurrent cerebrovascular events. Methods In the magnetic resonance imaging (MRI) substudy of ICSS (International Carotid Stenting Study), 231 patients with symptomatic carotid stenosis were randomized to undergo CAS (n = 124) or CEA (n = 107). MRIs were performed 1 to 7 days before and 1 to 3 days after treatment. The primary outcome event was stroke or transient ischemic attack in any territory occurring between the post-treatment MRI and the end of follow-up. Time to occurrence of the primary outcome event was compared between patients with (DWI+) and without (DWI–) new DWI lesions on the post-treatment scan in the CAS and CEA groups separately. Results Median time of follow-up was 4.1 years (interquartile range: 3.0 to 5.2). In the CAS group, recurrent stroke or transient ischemic attack occurred more often among DWI+ patients (12 of 62) than among DWI– patients (6 of 62), with a cumulative 5-year incidence of 22.8% (standard error [SE]: 7.1%) and 8.8% (SE: 3.8%), respectively (unadjusted hazard ratio: 2.85; 95% confidence interval: 1.05 to 7.72; p = 0.04). In DWI+ and DWI– patients, 8 and 2 events, respectively, occurred within 6 months after treatment. In the CEA group, there was no difference in recurrent cerebrovascular events between DWI+ and DWI– patients. Conclusions Ischemic brain lesions discovered on DWI after CAS seem to be a marker of increased risk for recurrent cerebrovascular events. Patients with periprocedural DWI lesions might benefit from more aggressive and prolonged antiplatelet therapy after CAS. (A Randomised Comparison of the Risks, Benefits and Cost Effectiveness of Primary Carotid Stenting With Carotid Endarterectomy: International Carotid Stenting Study; ISRCTN25337470)

Predictors of Stroke, Myocardial Infarction or Death within 30 Days of Carotid Artery Stenting: Results from the International Carotid Stenting Study.

Objectives Stroke, myocardial infarction (MI), and death are complications of carotid artery stenting (CAS). The effect of baseline patient demographic factors, processes of care, and technical factors during CAS on the risk of stroke, MI, or death within 30 days of CAS in the International Carotid Stenting Study (ICSS) were investigated. Methods In ICSS, suitable patients with recently symptomatic carotid stenosis > 50% were randomly allocated to CAS or endarterectomy. Factors influencing the risk of stroke, MI, or death within 30 days of CAS were examined in a regression model for the 828 patients randomized to CAS in whom the procedure was initiated. Results Of the patients, 7.4% suffered stroke, MI, or death within 30 days of CAS. Independent predictors of risk were age (risk ratio [RR] 1.17 per 5 years of age, 95% CI 1.01–1.37), a right-sided procedure (RR 0.54, 95% CI 0.32–0.91), aspirin and clopidogrel in combination prior to CAS (compared with any other antiplatelet regimen, RR 0.59, 95% CI 0.36–0.98), smoking status, and the severity of index event. In patients in whom a stent was deployed, use of an open-cell stent conferred higher risk than use of a closed-cell stent (RR 1.92, 95% CI 1.11–3.33). Cerebral protection device (CPD) use did not modify the risk. Conclusions Selection of patients for CAS should take into account symptoms, age, and side of the procedure. The results favour the use of closed-cell stents. CPDs in ICSS did not protect against stroke.