Cardiovasc Intervent Radiol DOI 10.1007/s00270-014-1000-4 CLINICAL INVESTIGATION Carotid Stenting with Distal Protection in High-Surgical-Risk Patients: One-Year Results of the ASTI Trial Marc Bosiers • Dierk Scheinert • Klaus Mathias • Ralf Langhoff • Harald Mudra • Juan Diaz-Cartelle Received: 27 March 2014 / Accepted: 25 August 2014 Ó Springer Science+Business Media New York and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) 2014 Abstract Purpose This prospective, multicenter, nonrandomized study evaluated the periprocedural and 1-year outcomes in high-surgical-risk patients with carotid artery stenosis treated with the Adapt Carotid Stent plus FilterWire EZ distal protection catheter (Boston Scientific Corporation, Natick, MA) Materials and Methods The study enrolled 100 patients (32 symptomatic, 63 asymptomatic, unknown) at high risk for carotid endarterectomy due to prespecified K Mathias Klinikum Dortmund GmbH, Beurhausstrasse 40, 44137 Dortmund, Germany e-mail: k.mathias@asklepios.com anatomical criteria and/or medical comorbidities Thirtyday and 1-year follow-up included clinical evaluation, carotid duplex ultrasound, and independent neurologic and NIH stroke scale assessments One-year endpoints included the composite rate of major adverse events (MAE), defined as death, stroke, and myocardial infarction (MI) and the rates of late ipsilateral stroke (31–365 days), target lesion revascularization, and in-stent restenosis Results Of the 100 enrolled patients, technical success was achieved in 90.9 % (90/99) The 30-day MAE rate (5.1 %) consisted of major stroke (2.0 %) and minor stroke (3.1 %); no deaths or MIs occurred The 1-year MAE rate (12.2 %) consisted of death, MI, and stroke rates of 4.4, 3.3, and 8.9 %, respectively Late ipsilateral stroke (31–365 days) rate was 1.1 % Symptomatic patients had higher rates of death (11.1 vs 1.7 %) and MI (7.4 vs 1.7 %), but lower rates of major (7.4 vs 10.0 %) and minor stroke (0.0 vs 6.7 %), compared with asymptomatic patients Conclusion Results through year postprocedure demonstrated that carotid artery stenting with Adapt Carotid Stent and FilterWire EZ is safe and effective in high-risksurgical patients R Langhoff Sankt Gertrauden-Krankenhaus, Paretzer Str 12, 10713 Berlin, Germany e-mail: ralf.langhoff@sankt-gertrauden.de Keywords Carotid artery stenosis Á Carotid stent Á Carotid endarterectomy Á High risk Á Symptomatic Á Asymptomatic H Mudra Klinikum Neuperlach, Oskar Maria Graf Ring 51, 81737 Munich, Germany e-mail: haraldmudra@aol.com Introduction J Diaz-Cartelle Boston Scientific Corporation, One Boston Scientific Place, Natick, MA 01760, USA e-mail: juan.diazcartelle@bostonscientific.com Carotid artery stenting (CAS) is accepted as an alternative stroke prevention therapy to traditional surgery (carotid endarterectomy [CEA]), when conducted by an experienced operator and support team, in patients with suitable M Bosiers (&) Department of Vascular Surgery, A.Z Sint-Blasius, Kroonveldlaan 50, 9200 Dendermonde, Belgium e-mail: marc.bosiers@telenet.be D Scheinert Center for Vascular Medicine-Angiology and Vascular Surgery, Park Hospital, Struămpellstrasse 41, Leipzig, Germany e-mail: dierk.scheinert@gmx.de 123 M Bosiers et al.: ASTI One-Year Results anatomy who are at increased risk of surgical complications [1–10] Periprocedural and long-term clinical evidence from the SAPPHIRE [11] and CREST [12] randomized trials, as well as numerous registries [4, 6, 7, 13–24] and meta-analyses [5, 10, 25, 26], support ‘‘equipoise’’ for CAS and CEA in high-surgical-risk patients The investigators in the Adapt Monorail Carotid Stent System: A Postmarket Clinical Follow-up Study (ASTI) evaluated the safety and efficacy of the Adapt Carotid Stent System (Boston Scientific Corporation, Natick, MA) plus FilterWireEZ embolic protection device (Boston Scientific Corporation, Natick, MA), a stent system designed to improve carotid stenting outcomes in high-surgical-risk patients We now report results up to 1-year postprocedure Materials and Methods The ASTI Trial was a nonrandomized, multicenter, prospective, open-label study conducted in accordance with Good Clinical Practice and the Declaration of Helsinki regarding investigation in humans The trial was registered on the National Institutes of Health website (Clinicaltrials.gov, Identifier NCT01133327) Patient Selection and Study Centers Eleven study centers in Germany, Belgium, and Spain participated in the study after receiving approval from their local institutional or human ethical review boards To be eligible for enrollment, patients were required to be at high risk for CEA due to anatomic (e.g., previous neck surgery or CEA) or comorbid conditions (e.g., recent MI, severe congestive heart failure, or left ventricle ejection fraction \30 %), in accordance with the Adapt Stent System directions for use High-risk populations have been defined in previous studies of CAS [4, 13, 14, 17, 27] Symptomatic patients were required to have C50 % stenosis and asymptomatic patients were required to have C80 % stenosis of the common or internal carotid artery or the bifurcation by angiography Each patient underwent bilateral carotid and intracranial angiography (digital subtraction angiography [DSA], magnetic resonance angiography [MRA], or computed tomography angiography [CTA] could be used preprocedure, but intraprocedural DSA was used to confirm eligibility) A neurological assessment, including the NIH Stroke Scale (NIHSS) [28], was administered by a physician or other health professional (independent of the treating investigator) within days prior to the procedure The NIHSS was to be completed by a certified individual A reference vessel diameter of C4.0 and B9.0 mm at the target lesion and written informed consent were also 123 necessary for inclusion Patients with severely tortuous lesions, target vessel occlusions, or lesions in the ostium of the common carotid artery were excluded from the trial A complete listing of eligibility criteria is shown in Table A patient was considered enrolled at the time placement of the FilterWire EZ was attempted Device Description CAS procedures were performed with the Adapt Stent System and FilterWire EZ distal emboli protection system (Fig 1) The FilterWire EZ is a 190- or 300-cm monorail, 0.014-in., filter-type distal emboli protection guidewire The FilterWire EZ System includes a 0.014-in steerable guidewire with spring coil tip and filter bag, delivery sheath, and retrieval sheath It is sized for 3.5–5.5-mmdiameter vessels The deployed filter (110-lm pore size) is intended to contain embolic material during stenting procedures and this material is removed along with the filter Table Major eligibility criteria Inclusion criteria • Patients at high risk for adverse events from carotid endarterectomy due to anatomic or comorbid conditions and either - Have neurological symptoms and C50 % stenosis by angiography (DSA) OR - Are asymptomatic and have C80 % stenosis by angiography (DSA) • Target lesion in the common carotid artery, internal carotid artery, or carotid bifurcation • Reference vessel diameter of target lesion C4.0 and B9.0 mm • Patient willingness and ability to comply with all follow-up requirements • Written informed consent Exclusion criteria • Contraindication to anticoagulant and/or antiplatelet therapy or to percutaneous transluminal angioplasty (PTA) • Severe vascular tortuosity or anatomy that would preclude the safe introduction of a guide catheter, sheath, embolic protection system, or stent system • Uncorrected bleeding disorder • Lesion in the ostium of the common carotid artery • Occlusion in the target vessel • Evidence of intraluminal thrombus • Known sensitivity to nickel-titanium or previous lifethreatening reaction to contrast medium • Previous stent placement in the target vessel • Evolving stroke or intracranial hemorrhage • Intracranial hemorrhage or brain surgery within the last 12 months M Bosiers et al.: ASTI One-Year Results Fig The AdaptTM MonorailTM Carotid Stent and FilterWireEZTM—photograph of the Adapt Monorail Carotid Stent (left) and the FilterWire EZ distal embolic protection device (right) (Images Ó 2014 Boston Scientific Corporation or its affiliates All rights reserved Used with permission of Boston Scientific Corporation) The Adapt Stent System consists of a closed-cell, selfexpanding, nitinol stent configured as an open nitinol sheet (Fig 1), rolled in a cylindrical fashion that self-expands to accommodate vessel diameters between and mm The stent has radiopaque markers at the proximal and distal ends and is premounted on a sheathed percutaneous monorail delivery system Stents of 21-, 32-, and 40-mm lengths were used in the study hospital discharge, and at 30-day and 1-year follow-up visits Procedure and Follow-Up Carotid duplex ultrasound was performed on all patients prior to enrollment, prior to hospital discharge, and at 30-day and 1-year follow-up visits Medications, including pre- and post-procedure anticoagulants/antiplatelets, were administered consistent with local clinical practice Intravenous heparin was recommended to achieve an activated clotting time of C275 s throughout the procedure General anesthesia and use of medications with potential sedative effects was not recommended during the procedure Femoral access was used in all patients DSA was performed immediately before treatment to confirm the degree of stenosis The FilterWire EZ System and Adapt Stent System were introduced via a guide catheter or introducer sheath After the FilterWire EZ wire was advanced past the lesion, the delivery sheath was retracted to deploy the filter distal to the lesion The Adapt Stent delivery system was advanced and the stent deployed across the target lesion under fluoroscopic guidance After stent deployment, balloon post-dilatation was performed at the operator’s discretion (it was done in 98 % of procedures) The FilterWire EZ filter and wire were retrieved by advancing the retrieval sheath past the stent and then pulling the wire/filter back until the filter was constrained in the sheath The wire and sheath were then retracted together Ipsilateral carotid and intracranial angiography was performed immediately after treatment Neurologic status was monitored throughout the procedure Independent neurologic and NIHSS assessments were performed by NIHSS-certified staff on all patients prior to Endpoints and Definitions The primary endpoint was the composite rate of all major adverse events (MAE), including Clinical Events Committee (CEC)-adjudicated death, stroke, and myocardial infarction (MI), through 30-day follow-up Stroke was defined as a new focal neurological deficit of presumed vascular origin persisting more than 24 h with a neuroimaging study not indicative of a different etiology; it included patients presenting with clinical signs and symptoms suggestive of subarachnoid hemorrhage, intracerebral hemorrhage, or cerebral infarction A major stroke was a stroke causing a deficit that was present after days and increased the patient’s NIHSS by at least points A minor stroke caused a deficit that lasted [24 h, but did not meet the definition of major stroke A transient ischemic accident (TIA) was a focal ischemic neurological deficit of abrupt onset that resolved in less than 24 h Secondary analyses assessed the components of the primary endpoint (death, stroke, MI) individually System technical success was defined as the successful placement and retrieval of the FilterWire EZ and successful deployment of the Adapt Carotid Stent System into the target carotid artery, with core-lab-confirmed residual stenosis of B30 % Other endpoints evaluated included (1) target lesion revascularization (TLR), defined as any surgical or percutaneous attempt to revascularize the target lesion after initial treatment when the diameter restenosis was either C50 % with symptoms related to the target lesion or C80 % with no symptoms related to the target lesion; (2) late ipsilateral stroke, defined as any ipsilateral stroke occurring between 30 and 365 days postprocedure; (3) stent thrombosis, defined as angiographically confirmed thrombus within the stent; and (4) in-stent restenosis, defined as target lesion diameter stenosis of C50 %, as measured by duplex ultrasound after the index procedure All in-stent restenosis and stent thrombosis events were confirmed by independent ultrasound (VasCore, Massachusetts General Hospital, Boston, MA, USA) and 123 M Bosiers et al.: ASTI One-Year Results Table Baseline patient characteristics N = 100 patients 95 % CI Age (years) 71.3 ± 8.6 (100) [69.6–72.9] Male gender (%) 64.0 % (64/100) [53.8–73.4 %] Current or previous smoker 51 % (51/100) Diabetes mellitus (%) 40.0 % (40/100) [30.3–50.3 %] History of hypertension requiring medication 88.0 % (88/100) [80.0–93.6 %] History of hyperlipidemia requiring medication 85.0 % (85/100) [76.5–91.4 %] History of peripheral vascular disease/claudication 26.0 % (26/100) [17.7–35.7 %] History of carotid atherosclerosis 42.0 % (42/100) [32.2–52.3 %] History of transient ischemic accident 20.0 % (20/100) [12.7–29.2 %] History of stroke 23.0 % (23/100) [15.2–32.5 %] History of coronary artery disease History of congestive heart failure 38.0 % (38/100) 8.0 % (8/100) [28.5–48.3 %] [3.5–15.2 %] Previous myocardial infarction 16.0 % (16/100) [9.4–24.7 %] Previous carotid endarterectomy 10.0 % (10/100) [4.9–17.6 %] Previous CABG surgery 17.0 % (17/100) [10.2–25.8 %] Previous percutaneous coronary intervention 14.0 % (14/100) [7.9–22.4 %] Numbers are % (Count/Sample Size) or mean ± SD (N) (min, max) The CI for proportions is based on the exact binomial distribution and for continuous variables is Mean ± 1.96*Standard Error CABG coronary artery bypass grafting, CI confidence interval Results characteristics are reported in Table Just under twothirds of patients (63.0 % [63/100]) were asymptomatic, with site-reported carotid stenosis of C80 % A total of 23.0 % of patients had experienced a previous stroke and 20.0 % had a previous TIA All treated lesions were in the common carotid artery, and the mean preprocedure diameter stenosis was 75.5 ± 10.7 % (Table 3) All patients were on antiplatelet/anticoagulant medication at the time of the procedure: typically heparin, acetylsalicylic acid, and clopidogrel Antiplatelet/anticoagulant treatment continued for a mean (±SD) of 302 ± 126 days, with 82 % of patients treated for at least year Among the 99 patients who received both the Adapt Carotid Stent and the FilterWire EZ protection device, system technical success was 90.9 % (90/99) One patient received the Adapt Carotid Stent, but not the FilterWireEZ embolic protection device, and thus was not evaluable for system technical success Eight of the technical failures were due to postprocedure stenosis [30 %, and procedure was designated a technical failure because the stent was deployed in an unintended location This deployment was not considered a device malfunction, and the patient had no associated adverse events Baseline and Procedural Characteristics 30-Day and 1-Year Outcomes Between June 2010 and April 2011, a total of 100 patients were enrolled in the ASTI trial Baseline patient characteristics are reported in Table and procedural Antiplatelet and/or anticoagulant medications, most commonly acetylsalicylic acid and clopidogrel, were used by 97.8 % of patients at the 30-day follow-up and 96.4 % at angiographic core labs (Beth Israel Deaconess Medical Center, Boston, MA, USA), respectively All cases of death, stroke, MI, TIA, TLR, and stent thrombosis were adjudicated by the CEC Statistical Methods All statistical analyses were performed using SAS version 9.1 or above (SAS Institute, Inc., Cary, North Carolina) The event rate of the primary endpoint was estimated based on CEC-adjudication of individual MAE events, including stroke, death, and MI through 30 days postprocedure, and was displayed as a binomial proportion with its exact binomial two-sided 95 % confidence interval All enrolled patients who experienced a MAE on or before 30 days postprocedure or were free of MAE and followed through 23 days postprocedure were included in the analysis Secondary analyses at 30 days and year were also provided as binomial proportions with their exact twosided 95 % confidence intervals 123 M Bosiers et al.: ASTI One-Year Results Table Procedural characteristics and outcomes N = 100 patients 95 % CI Length of procedure (min) 47.5 ± 22.8 (99) [43.0–52.0] Pre-stent balloon angioplasty 49.0 % (49/100) [38.9–59.2 %] Post-stent dilatation 98.0 % (98/100) [91.5–99.4 %] System technical success 90.9 % (90/99) [83.4–95.8 %] Reference vessel diameter (mm) 5.1 ± 0.9 (100) [4.9–5.2] Minimum lumen diameter (mm) 1.2 ± 0.5 (100) [1.1–1.3] Percent diameter stenosis (%) 75.5 ± 10.7 (100) [73.4–77.6] Reference vessel diameter (mm) Minimum lumen diameter (mm) 5.1 ± 0.9 (100) [4.9–5.2] 3.6 ± 0.6 (99) [3.4–3.7] Percent diameter stenosis (%) 28.3 ± 13.9 (99) [25.6–31.0] Pre-procedure Post-procedure Numbers are % (Count/Sample Size) or mean ± SD (N) (min, max) The CI for proportions is based on the Exact Binomial Distribution and for continuous variables is Mean ± 1.96*Standard Error year Ninety eight patients were evaluable for MAE at 30 days (i.e., an MAE or follow-up of at least 23 days; one patient withdrew from the study and one had unknown MAE status as of 30 days) At the 30-day primary endpoint, the composite rate of CEC-adjudicated MAEs of 5.1 % (5/98) was driven entirely by the stroke rate; no deaths or MIs occurred within this time interval (Table 4) Two of the five strokes were considered major and both were ipsilateral and hemorrhagic (Table 4); one occurred in the immediate postoperative period and the other 30 days after the index procedure and was probably related to a hypertensive episode All three of the minor strokes were ischemic and ipsilateral (Table 4; Fig 2) No TLRs or instances of in-stent restenosis occurred within 30 days postprocedure; however, one patient experienced a stent thrombosis at the time of the procedure By 1-year postprocedure, the composite rate of CECadjudicated MAEs was 12.2 % (11/90) (Table 4) and involved death (4.4 %), stroke (8.9 %), and non-Q-wave MI (3.3 %) Five of the strokes were considered major, with three ischemic (one ipsilateral) and two hemorrhagic and ipsilateral The composite rate of stroke and death was 11.1 % (Table 4) The late ipsilateral stroke rate was 1.1 % at year and stent thrombosis occurred in 1.2 % (Table 4) TIA occurred in 3.5 % (3/86 patients; 95 % CI 0.7, 9.9 %) No TLR or in-stent stenosis occurred at 1-year postprocedure Among the symptomatic and asymptomatic subgroups, the 30-day rate of MAE, driven only by the stroke rate, was 6.5 % in asymptomatic subjects (4/62) and 3.2 % in symptomatic subjects (1/31) Although the overall MAE rates in symptomatic and asymptomatic subjects were similar by 1-year postprocedure (Fig 3), the individual rates of death (11.1 % [3/27] vs 1.7 % [1/60]) and MI (7.4 % [2/27] vs 1.7 % [1/60]) were higher in symptomatic subjects (several subjects had multiple events) Also, though the rate of 12-month stroke was slightly lower in symptomatic subjects compared to asymptomatic subjects (7.4 % [2/27] vs 10.0 % [6/60]), the strokes that occurred among symptomatic subjects were both major (7.4 % [2/27]; one was ischemic and one was hemorrhagic), while only of the strokes (a total of subjects had strokes, subject had strokes) in the asymptomatic group were major (5.0 % [3/60]; ischemic and one hemorrhagic) (Fig 4) The composite rate of stroke and death at 1-year postprocedure was similar between the symptomatic (11.1 %, 3/27 patients) and the asymptomatic patients (11.7 %, 7/60 patients) Nine subjects had a total of 13 serious adverse events which were assessed by the site investigator as related to the procedure These 13 events were reported as cerebrovascular accident (2), carotid artery thrombosis, intracranial hemorrhage, partial seizures (focal epilepsy), reversible posterior leukoencephalopathy syndrome, transient ischaemic attack, femoral artery stenosis, hematoma, contrast media reaction, vascular procedure complication, psychotic disorder, and catheter site hematoma All but two of these events (intracranial hemorrhage and psychotic disorder) had resolved by the end of the study The intracranial hemorrhage and the carotid artery thrombosis event occurred concomitantly in one patient on the day of the procedure The hemorrhage was considered ‘‘not recovered/not resolved’’ at the time of the patient’s death from unknown causes approximately months later The ‘‘psychotic disorder’’ event occurred on the day of the procedure and was considered recovering/resolving at study end; this patient also experienced the focal epilepsy event approximately weeks postprocedure Discussion The periprocedural (30-day) and 1-year outcomes of the multicenter, prospective ASTI trial demonstrate that CAS with the Adapt Carotid Stent System and the FilterWireEZ is safe and effective for the treatment of carotid artery disease in symptomatic and asymptomatic patients who are poor candidates for CEA Use of the Adapt System with FilterWireEZ was associated with a high rate of technical success (90.9 %), with acceptable rates of 30-day (5.1 %) and 1-year (12.2 %) MAEs, as well as serious adverse events related to the CAS procedure (9.1 %) Although these results are specific to one stent/embolic protection 123 M Bosiers et al.: ASTI One-Year Results Table Clinical outcomes at 30 days and 12 months 30 days 12 months a (N = 90b) (N = 98 ) Event rate Death, stroke, myocardial infarction (MI) Death Neurologic death Cardiac death Non-neurologic/non-cardiac death Stroke Major Ischemic 95 % CI Event rate 95 % CI 5.1 % (5/98) [1.7–11.5 %] 12.2 % (11/90) [6.3–20.8 %] 0.0 % (0/98) [0.0–3.7 %] 4.4 % (4/90) [1.2–11.0 %] 0.0 % (0/98) 0.0 % (0/98) [0.0–3.7 %] [0.0–3.7 %] 2.2 % (2/90) 1.1 % (1/90) [0.3–7.8 %] [0.0–6.0 %] 0.0 % (0/98) [0.0–3.7 %] 1.1 % (1/90) [0.0–6.0 %] 5.1 % (5/98) [1.7–11.5 %] 8.9 % (8/90) [3.9–16.8 %] 2.0 % (2/98) [0.2–7.2 %] 5.6 % (5/90) [1.8–12.5 %] [0.7–9.4 %] 0.0 % (0/98) [0.0–3.7 %] 3.3 % (3/90) Ipsilateral 0.0 % (0/98) [0.0–3.7 %] 1.1 % (1/90) [0.0–6.0 %] Contralateral 0.0 % (0/98) [0.0–3.7 %] 2.2 % (2/90) [0.3–7.8 %] Hemorrhagic Ipsilateral Contralateral Minor Ischemic 2.0 % (2/98) [0.2–7.2 %] 2.2 % (2/90) [0.3–7.8 %] 2.0 % (2/98) [0.2–7.2 %] 2.2 % (2/90) [0.3–7.8 %] 0.0 % (0/98) [0.0–3.7 %] 0.0 % (0/90) [0.0–4.0 %] 3.1 % (3/98) [0.6–8.7 %] 4.4 % (4/90) [1.2–11.0 %] [1.2–11.0 %] 3.1 % (3/98) [0.6–8.7 %] 4.4 % (4/90) Ipsilateral 3.1 % (3/98) [0.6–8.7 %] 3.3 % (3/90) [0.7–9.4 %] Contralateral 0.0 % (0/98) [0.0–3.7 %] 1.1 % (1/90) [0.0–6.0 %] Hemorrhagic Ipsilateral 0.0 % (0/98) 0.0 % (0/98) [0.0–3.7 %] [0.0–3.7 %] 0.0 % (0/90) 0.0 % (0/90) [0.0–4.0 %] [0.0–4.0 %] Contralateral 0.0 % (0/98) [0.0–3.7 %] 0.0 % (0/90) [0.0–4.0 %] NA NA 1.1 % (1/90) [0.0–6.0 %] Late ipsilateral stroke (31–365 days) 1-year stroke and death Myocardial infarction Non-Q-wave NA NA 11.1 % (10/90) [5.5–19.5 %] 0.0 % (0/98) [0.0–3.7 %] 3.3 % (3/90) [0.7–9.4 %] 0.0 % (0/98) [0.0–3.7 %] 3.3 % (3/90) [0.7–9.4 %] Target lesion revascularization 0.0 % (0/98) [0.0–3.7 %] 0.0 % (0/86) [0.0–4.2 %] In-stent restenosis 0.0 % (0/98) [0.0–3.7 %] 0.0 % (0/86) [0.0–4.2 %] Stent thrombosis 1.0 % (1/98) [0.0–5.6 %] 1.2 % (1/86) [0.0–6.3 %] Numbers are % (count/sample size) a 98 patients were evaluable for MAE at 30 days (i.e., follow-up of at least 23 days or follow-up less than 23 days with an MAE) b 90 patients were evaluable for MAE at year (i.e., follow-up of at least 335 days or follow-up less than 335 days with an MAE) system, these favorable clinical outcomes add to the existing support for CAS as an acceptable alternative stroke prevention therapy to CEA in high-surgical-risk patients [1–26] The ASTI study did not have a prespecified performance criterion, but the 30-day and 1-year MAE rates are within the ranges reported by other studies of CAS with embolic protection Reported 30-day composite stroke, MI, and death rates from these studies range from 2.7 to 8.3 % [4, 6–8, 13, 14, 16–20, 27], and 1-year MAE rates range from 11.6 to 12.5 % [14, 17] The durability of revascularization procedures is an important consideration A secondary analysis of CREST provided the most comprehensive investigation of 123 restenosis after carotid revascularization in symptomatic and asymptomatic patients In this analysis, there was a low overall composite rate of restenosis (defined as C70 % diameter-reducing stenosis, or target-artery occlusion) of 6.3 % through years, with similar rates of restenosis occurring in patients who underwent CAS and CEA [29] Reported one-year revascularization rates following CAS with embolic protection range from 0.6 to 2.2 % (including both target lesion and target vessel rates, as reported in the respective studies) [4, 14, 17, 27] Encouragingly, in the present ASTI trial, the durability of revascularization through year was excellent; no patient experienced an instent restenosis (diameter stenosis C50 %) and none underwent an additional revascularization M Bosiers et al.: ASTI One-Year Results Fig Major adverse events in symptomatic and asymptomatic patients at 1-year postprocedure Fig Stroke subcategories at 30-days and 1-year postprocedure In addition to restoring the original diameter of the artery, carotid artery stents might prevent post-procedural embolization by sequestering plaque against the artery wall Closed-cell stents, like the Adapt Carotid Stent, are designed to provide a higher degree of scaffolding than open-cell designs Stent scaffolding effectiveness is influenced by the strut design and free cell area In a retrospective study of more than 3,000 patients who had CAS, stents with closed-cell designs were associated with lower 30-day composite rates of death, stroke, and transient ischemic attack [30] Likewise, secondary analysis from a trial of more than 500 patients randomized to CAS showed a lower 30-day rate of ipsilateral stroke or ipsilateral stroke-related death for patients who received closed-cell versus open-cell stents [31] In the ASTI study, both of the two major strokes observed through 30 days were hemorrhagic, which may indicate that periprocedural ischemic stroke (embolic in nature) may be less likely when closedcell stent designs are used However, more studies are necessary to confirm this hypothesis In addition to stent design features, patient-specific factors contribute to CAS success Evidence suggests that symptomatic patients are more likely to have poorer outcomes with CAS compared with asymptomatic patients In a recent analysis of a European registry of high-volume centers, the 30-day stroke and death rate was 2.0 % for symptomatic and 1.1 % for asymptomatic patients [22], and in another large registry the in-hospital rate of stroke, death, or MI in symptomatic patients who underwent CAS was 5.8 %, whereas the rate among asymptomatic patients was 1.1 % [32] Interestingly, in the current ASTI trial, the 30-day MAE rate (driven completely by the stroke rate) in symptomatic patients following CAS with the Adapt Carotid Stent System and the FilterWireEZ was half the rate of asymptomatic patients (3.2 vs 6.5 %) Although these Fig Stroke subcategories in symptomatic and asymptomatic patients at 1-year postprocedure results conflict with most of the published literature, we have to acknowledge the study limitations (outlined below), which may have contributed to these results By 1-year postprocedure, the overall MAE rates in symptomatic and asymptomatic subjects had nearly balanced Limitations of the ASTI study include those inherent in single-arm studies, including its limited sample size Criteria for patient selection aligned with the device labeling and previous studies of CAS in high-surgical-risk populations, but certain procedural steps and patient management decisions were performed according to local practice and physician discretion, rather than protocol requirements This study design allowed assessment of a study population and outcomes representative of typical practice Conclusions Results of the ASTI study demonstrate that CAS with the Adapt Carotid Stent System and FilterWire EZ under conditions representative of real-world practice yielded a low composite MAE rate through year in symptomatic and asymptomatic high-surgical-risk patients Acknowledgments Study investigators and clinical investigation sites were Marc Bosiers, MD, AZ Sint-Blasius, Dendemonde, 123 M Bosiers et al.: ASTI One-Year Results Belgium; Dierk Scheinert, MD, Park-Krankenhaus Leipzig, Leipzig, Germany; Klaus Mathius, MD, Klinikum Dortmund GmbH, Dortmund, Germany; Ralf Langhoff, MD, Ev Krankenhaus Koănigin Elisabeth, Berlin, Germany; Harald Mudra, MD, Klinikum Neuperlach, Munich Germany; Patrick Peeters, Imelda Ziekenhuis, Bonheiden, Belgium; Ulrike Enemann, MD, Universitaetsklinikum Tuăbingen, Tuăbingen, Germany; Erwin Blessing, MD, Universitaăt Heidelberg, Heidelberg, Germany; Christophe Martinez, MD, Centre Hopital Universitaire Sart Tilman, Lie`ge, Belgium; Manuel Doblas, MD, Hospital Virgen De La Salud, Toledo, Spain; and Angel Martinez, MD, Hospital Juan Canalejo La Corun˜a, La Corun˜a, Spain The authors thank Paginae Incorporated (North Hampton, NH) and Elizabeth J Davis, PhD (Boston Scientific Corporation) for assistance in manuscript preparation and Lan Pan, MS and Joe Bero, MS (Boston Scientific Corporation) for statistical analysis Conflict of Interest This study was funded by Boston Scientific Corporation, Natick, Massachusetts USA Marc Bosiers, Klaus Mathias, and Harald Mudra declare that they have no conflicts of interest Dierk Scheinert serves as a 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