Mark H. Wholey

Global experience in cervical carotid artery stent placement

The purpose of this article is to review and update the current status of carotid artery stent placement in the world. Surveys to major interventional centers in Europe, North and South America, and Asia were initially completed in June 1997. Subsequent information from these 24 centers in addition to 12 new centers has been obtained to update the information. The survey asked the various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 5,210 procedures involving 4,757 patients. There was a technical success of 98.4% with 5,129 carotid arteries treated. Complications that occurred during the carotid stent placement or within a 30‐day period following placement were recorded. Overall, there were 134 transient ischemic attacks (TIAs) for a rate of 2.82%. Based on the total patient population, there were 129 minor strokes with a rate of occurrence of 2.72%. The total number of major strokes was 71 for a rate of 1.49%. There were 41 deaths within a 30‐day postprocedure period resulting in a mortality rate of 0.86%. The combined minor and major strokes and procedure‐related death rate was 5.07%. Restenosis rates of carotid stenting have been 1.99% and 3.46% at 6 and 12 months, respectively. The rate of neurologic events after stent placement has been 1.42% at 6–12‐month follow‐up. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative for vascular surgery, especially for patients that are high risk for standard carotid endarterectomy. The periprocedure risks for major and minor strokes and death are generally acceptable at this early stage of development and have not changed significantly since the first survey results. Cathet. Cardiovasc. Intervent. 50:160–167, 2000. ©2000 Wiley–Liss,Inc.

Updated review of the global carotid artery stent registry

The purpose of this article was to review and update the current status of carotid artery stent placement in the world. Surveys of major interventional centers in Europe, North and South America, and Asia were initially completed in June 1997. Subsequent updates from these 24 centers in addition to 29 new centers have been obtained to bring up to date the information. The survey asked the various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 12,392 procedures involving 11,243 patients. There was a technical success of 98.9% with 12,254 carotid arteries treated. Complications that occurred during the carotid stent placement or within a 30‐day period following placement were recorded. Overall, there was transient ischemic attack rate of 3.07%, minor strokes of 2.14%, major strokes of 1.20%, and procedure‐related deaths of 0.64%. The combined minor and major strokes and procedure‐related death rate was 3.98% based on procedure number. With nonprocedure‐related death rate of 0.77%, the total stroke and death rate was 4.75%. Subsets of questions were directed at the new use of distal embolic protection devices; there were 6,753 cases done without protection and which incurred a 5.29% rate of strokes and procedure‐related deaths. In the 4,221 cases with cerebral protection, there was a 2.23% rate of strokes and procedure‐related deaths. Restenosis rates of carotid stenting have been 2.7%, 2.6%, and 2.4% at 1, 2, and 3 years, respectively. The rate of neurologic events after stent placement has been 1.2%, 1.3%, and 1.7% at 1, 2, and 3 years, respectively. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative for vascular surgery, especially for patients who are high risk for standard carotid endarterectomy. The periprocedure risks for major and minor strokes and death are generally acceptable at this early stage of development and have shown an improvement with technological developments, including distal embolic protection. Catheter Cardiovasc Interv 2003;60:259‐266

Current global status of carotid artery stent placement.

Our purpose was to review the current status of carotid artery stent placement throughout the world. Surveys were sent to major interventional centers in Europe, North and South America, and Asia. Information from peer-reviewed journals was also included and supplemented the survey. The survey asked various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. Of the centers which were sent surveys, 24 responded. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 2,048 cases, with a technical success of 98.6%. Complications that occurred during carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 63 minor strokes, with a rate of occurrence of 3.08%. The total number of major strokes was 27, for a rate of 1.32%. There were 28 deaths within a 30-day postprocedure period, resulting in a mortality rate of 1.37%. Restenosis rates of carotid stenting have been 4.80% at 6 mo. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative to vascular surgery, especially for patients that are at high risk for standard carotid endarterectomy. The periprocedural risks for major and minor strokes and death are generally acceptable at this early stage of development.

The CAPTURE registry: Results of carotid stenting with embolic protection in the post approval setting

Background: Pivotal study data examining carotid stenting with embolic protection as a less invasive alternative to endarterectomy for high surgical risk patients have been acquired under controlled conditions with highly selected physicians and hospitals. This report examines outcomes of carotid stenting post‐approval after diffusion of this technology to a broader cross‐section of physicians and hospitals. Methods: The Carotid Acculink/Accunet Post‐Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) is a prospective, multi‐center registry to assess two important aspects of the post‐IDE experience: the safety of carotid stenting by physicians with varying levels of experience as a measure of the adequacy of physician training, and the identification of rare/unexpected device‐related complications. The primary endpoint was a composite of death, any stroke, or myocardial infarction within 30 days post‐procedure. Results: 3,500 patients were enrolled by 353 physicians at 144 sites. The 30‐day primary endpoint event rate was 6.3% (95% CI: 5.5–7.1%) and did not differ among the three operator experience levels (5.3%, 6.0%, and 7.4%; P = 0.31) from most to least experienced, respectively. There were no differences in outcomes among physician specialties when adjusted for case mix. There were no unanticipated device related adverse events. Conclusions: The results of the CAPTURE study compare favorably to those achieved in the predicate pivotal investigations, and suggest that the post‐approval transfer of this new therapy to the community practice setting via carotid stent training programs is effective in preparing physicians with varying experience levels and specialty training backgrounds.

The CAPTURE registry: Predictors of outcomes in carotid artery stenting with embolic protection for high surgical risk patients in the early post-approval setting

The use of carotid artery stenting with embolic protection has been practiced for over a decade in the United States, and increasingly so since carotid stenting received FDA approval in 2004. While there have been attempts at establishing predictors of outcomes in carotid artery stenting, they have generally been limited to single center experiences and/or multicenter retrospective surveys. This report examines predictors of outcomes in carotid stenting in the earliest and largest prospective multicenter neurologist‐adjudicated experience in the United States post device approval.

Multicenter Trial of the Wallstent in the Iliac and Femoral Arteries

PURPOSE To report the results of the FDA phase II, multicenter trial of the Wallstent in the iliac and femoral arteries. PATIENTS AND METHODS Two hundred twenty-five patients entered the trial. Stents were placed in the iliac system in 140 patients and in the femoral system in 90 (five patients required both iliac and femoral stents). Clinical patency was measured over 2 years by means of life-table analysis with use of clinical and hemodynamic data and the Rutherford scale. Angiographic patency was measured at 6 months. RESULTS In the iliac system the primary clinical patency was 81% at 1 year and was 71% at 2 years. The secondary clinical patency was 91% and 86%, respectively. The 6-month angiographic patency was 93%. In the femoral system the primary clinical patency was 61% at 1 year and 49% at 2 years. The secondary patency was 84% and 72%, respectively. The 6-month angiographic patency was 80%. CONCLUSIONS The results are similar to those with the Palmaz stent in the iliac system and with angioplasty alone in the iliac and femoral systems.

Endovascular Stents for Carotid Artery Occlusive Disease

Purpose: To study the feasibility and safety of endovascular stenting of cervical carotid artery stenosis. Methods: Between April 1994 and May 1997, 108 consecutive patients (58 men; mean age 70.1 years) with ≥ 70% carotid stenosis were treated with percutaneous stent implantation under a protocol that featured independent neurological review. Forty-four percent were asymptomatic. Over half the lesions (59%) were in the internal carotid artery; the mean stenosis was 86%. Palmaz stents were implanted without cerebral protection following preliminary balloon dilation; two Wallstents were used in long lesions. Results: Carotid stents were successfully placed in 108 of 114 (95%) lesions. Of the 6 technical failures, 5 were access related and 1 was due to seizures during balloon dilation. Two major (1.8%) and 2 minor (1.8%) strokes occurred (3.7% stroke rate for 108 patients; 3.5% in 114 procedures), all in symptomatic patients, one of whom died. There were 5 (4.4%) transient ischemic attacks and 2 (1.8%) brief seizure episodes during dilation. One patient died of a cardiac event on day 20. The all stroke or death rate was 5.3% based on 114 arteries at risk (5.6% in 108 patients). In the mean 6-month follow-up (range 1 to 36) of 97 eligible patients, 3 (3.1%) died from unrelated causes. There was 1 restenosis (1.0%) from a stent compression, which was successfully redilated. There were no neurological sequelae, cranial palsies, or cases of stent or vessel thrombosis in follow-up. Conclusions: The use of stents in the treatment of cervical carotid occlusive disease appears feasible, effective in the short term, and without excessive risk of periprocedural stroke.

Safety, efficacy, and durability of carotid artery stenting for restenosis following carotid endarterectomy: a multicenter study.

Purpose: To present the results of a multicenter registry established to collect data on carotid stent procedures in patients with restenosis following carotid endarterectomy. Methods: The procedural details, outcomes, and late follow-up results were collected from 14 centers in the United States. Thirty-day and late stroke and death rates were analyzed. Results: Three hundred and thirty-eight patients (201 men; 71 ± 8 years) underwent carotid stenting in 358 arteries. The average duration from carotid endarterectomy was 5.5 ± 7.3 years. Sixty-one percent of the patients were asymptomatic. The overall 30-day stroke and death rate was 3.7%. The minor stroke rate was 1.7% (6/358), and the major nonfatal stroke rate was 0.8% (3/358). The fatal stroke rate was 0.3% (1/358), and the nonstroke-related death rate was 0.9% (3/338). There was 1 (0.3%) fatal and 1 (0.3%) nonfatal stroke during the follow-up period. The overall 3-year rate of freedom from all fatal and nonfatal strokes was 96% ± 1% (±SE). Conclusions: Carotid artery stenting can be performed in patients with restenosis following carotid endarterectomy with 30-day complication rates comparable to those of most published studies on repeat carotid endarterectomy. Results of late follow-up suggest that this technique is durable and efficacious.

Carotid artery revascularization in high-surgical-risk patients using the Carotid WALLSTENT and FilterWire EX/EZ: 1-year outcomes in the BEACH Pivotal Group.

OBJECTIVES The multicenter, single-arm BEACH (Boston Scientific EPI: A Carotid Stenting Trial for High-Risk Surgical Patients) evaluated outcomes in high-surgical-risk patients with carotid artery stenosis treated with the Carotid WALLSTENT plus FilterWire EX/EZ Emboli Protection System (Boston Scientific, Natick, Massachusetts). BACKGROUND Carotid artery stent (CAS) placement offers a less invasive alternative for high-risk surgical carotid endarterectomy (CEA) patients. METHODS The trial enrolled 480 pivotal patients who were candidates for carotid revascularization but considered high surgical risk due to pre-specified anatomic criteria and/or medical comorbidities. The primary end point (all stroke, death, or Q-wave myocardial infarction [MI] through 30 days; non-Q-wave MI through 24 h; and ipsilateral stroke or neurologic death through 1 year) was compared with a proportionally weighted objective performance criterion (OPC) of 12.6% for published surgical endarterectomy results in similar patients, plus a pre-specified noninferiority margin of 4%. RESULTS Among pivotal patients, 41.2% were at high surgical risk due to comorbid risk factors, and 58.8% due to anatomic risk factors; 76.7% were asymptomatic with flow-limiting carotid stenosis >80%. At 1 year, the composite primary end point occurred in 8.9% (40 of 447), with a repeat revascularization rate of 4.7%. With an upper 95% confidence limit of 11.5% for the primary composite end point, the BEACH trial results met the pre-specified criteria for noninferiority relative to the calculated OPC plus noninferiority margin (16.6%) for historical surgical CEA outcomes in similar patients (p < 0.0001 for noninferiority). CONCLUSIONS The BEACH trial results demonstrate that CAS with the WALLSTENT plus FilterWire embolic protection is non-inferior (equivalent or better than) to CEA at 1-year in high-surgical-risk patients.

The CAPTURE registry - Analysis of strokes resulting from carotid artery stenting in the post approval setting: Timing, location, severity, and type

Background:Although previous reports of carotid stenting with embolic protection (CAS) have focused on clinical outcomes of death, stroke and myocardial infarction, there are few data available characterizing the strokes that occur during CAS, thus limiting understanding of potential mechanisms. This report examines the timing, location, severity, and type of strokes occurring with CAS in the Carotid ACCULINK/ACCUNET Post Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) study. Methods:CAPTURE is a prospective, multicenter registry conducted to assess outcomes of CAS in the postapproval setting after device approval. A neurologist examined the patients before the procedure, at 24 hours and 30 days post-procedure. The primary end point was a composite of death, any stroke, or myocardial infarction within 30 days post-procedure. Strokes and all neurologic events suspected to be strokes were adjudicated by an independent Clinical Events Adjudication Committee using prespecified definitions. Source documents of all patients with strokes in this cohort were reviewed. Results:The 30-day results were available for 3500 patients. The 30-day primary end point event rate of death, stroke, and myocardial infarction was 6.3% (95% confidence interval: 5.5%–7.1%), and the rate of major stroke and death was 2.9% (95% confidence interval: 2.4 to 3.5). 4.8% of patients experienced a stroke (3.9% ipsilateral and 0.9% nonipsilateral, 2% major). A majority of stroke symptoms (57.7%) were noted post-procedure and pre-discharge, whereas 22.3% were noted during the procedure and 20% postdischarge. A similar timing distribution regardless of preprocedural symptomatic status was found. Overall, 41% (69 of 170) of all strokes were major. The incidence of major strokes was statistically significantly greater among symptomatic compared with asymptomatic patients, 4.6% (22 of 482) and 1.6% (47 of 3018), respectively. There were more minor than major strokes in asymptomatic patients (63% vs. 37%; P = 0.10), whereas stroke severity was equally distributed in symptomatic patients. Among the ipsilateral strokes, almost half (44%) were major, whereas only one-quarter (26%) of the nonipsilateral strokes were major. Overall, 23% of the major strokes were hemorrhagic and 94% of these strokes were noted on the ipsilateral side. There was a tendency toward more major hemorrhagic strokes in symptomatic than in asymptomatic patients (36% vs. 17%; P = 0.07). Fifty-four percent of the strokes post-procedure and pre-discharge were major, whereas 27% of the strokes postdischarge were major. Furthermore, 65% of hemorrhagic strokes were noted post-procedure and pre-discharge, 30% postdischarge. Conclusions:Strokes related to CAS seem to become clinically apparent after the procedure but before discharge in the majority of events. Nevertheless, a significant minority of stroke symptoms follows discharge from the hospital, typically after 24 hours. Timing of stroke after CAS seems to be similar to timing of stroke after carotid endarterectomy. Moreover, nearly 1 in 5 strokes occur in a nonipsilateral distribution, with the exception of intraprocedural events, which were all ipsilateral to the stent being implanted. Hemorrhagic stroke seemed to be more prevalent in the strokes occurring in the post-procedure period. These descriptors of stroke severity, location, and timing may provide insight in to the mechanistic causes of adverse neurologic outcomes in CAS.