Impact of Technique and Device Selection on Clinical Outcomes in Carotid Artery Stenting
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Introduction
Each year about 780,000 people experience a new or recurrent stroke, accounting for 17% of cardiovascular deaths.1 Approximately 80% of strokes are caused by focal cerebral ischemia and the remaining 20% are caused by hemorrhage.2 Almost 20% of ischemic strokes result from carotid artery stenosis.3,4 Various options for the management of carotid artery stenosis include medical therapy, carotid artery endarterectomy (CEA) and carotid artery stenting (CAS). CEA has been established as a gold-standard treatment for carotid artery stenosis by randomized, controlled clinical trials.5–8 CAS has emerged as an appropriate alternative therapy to surgery for carotid artery stenosis.
Background
The earliest reports on CEA were published in the 1950s,9,10 and its superiority to medical management was established in the 1990s by four randomized trials which include NASCET5 (North American Symptomatic Carotid Endarterectomy Trial), ECST6 (European Carotid Surgery Trial), ACAS7 (Asymptomatic Carotid Atherosclerosis Study) and ACST8 (Asymptomatic Carotid Surgery Trial). The NASCET and ECST trials established CEA superiority to medical management in symptomatic patients. ACAS and ACST established in asymptomatic patients that CEA was superior to medical therapy for prevention of stroke. This led to the recognition of CEA as a gold-standard treatment for symptomatic and asymptomatic patients with severe carotid artery stenosis. However, a substantial limitation to the trial experience is the general population differs from the carefully selected patients in the above-mentioned trials. NASCET excluded patients with age >80 years or patients with multiple comorbid conditions.5
CAS has emerged as an alternative revascularization option after the initial experience from prospective single-center studies.11,12 Multiple trials including CAVATAS13 (Carotid and Vertebral Artery Transluminal Angioplasty Study), Wallstent Trial14 and CaRESS15 (Carotid Revascularization Using Endarterectomy or Stenting Systems) provided developmental experience and guidance for successful CAS. The SAPPHIRE16 (Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy), a multicenter randomized trial established the noninferiority of CAS with embolic protection compared to CEA in high-risk patients. Subsequent to the promising results in high-risk patients, SPACE17 (Stent-supported Percutaneous Angioplasty of the Carotid artery versus Endarterectomy) trial was designed to address the optimal revascularization in low risk patients. This trial failed to enroll the required number of patients and remained inconclusive.
The EVA-3518 (Endarterectomy Versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis), demonstrated a 30-day rate of any stroke or death to be significantly higher in the CAS group (9.6%) than the CEA group (3.9%) (p = 0.01). However, the use of embolic protection devices (EPD) was not mandatory early in the trial. Patients treated without EPD experienced a 25% 30-day rate of stroke or death. This lead to protocol changes by the EVA-3S safety committee and the use of EPD was made mandatory. In addition, the physicians participating in EVA-3S had unequal experience. Surgeons performing CEA had to have performed at least 25 endarterectomies in the past year before trial entry, while endovascular physicians were allowed to perform stenting after completing 5–12 CAS procedures. Multiple CAS pilot trials and registries (Figure 1)15,16,18–32 for patients with high risk for CEA have demonstrated low rates of stroke and death. Therefore, it is difficult to accept higher complication rates in EVA-3S as outcomes in general CAS practice. The results of EVA- 3S with high CVA rates emphasized the importance of EPD in CAS as well as rigorous training for CAS physicians.
The role of CAS in the management of carotid artery stenosis is evolving and improving. CAS outcomes are directly affected by patient characteristics, vascular anatomy, operator’s skill, device selection and the technique. In this review, we will discuss them briefly.
Carotid Artery Stenting Techniques and Device Selection
Patient selection. A careful selection of appropriate patients for CAS is of utmost importance. It involves a comprehensive approach, which includes a thorough history and physical examination, along with diagnostic data including duplex ultrasonography combined with either computed tomography angiography (CTA) or magnetic resonance angiography (MRA).
Several factors in patient selection have been documented to affect the outcomes of CAS including clinical status (symptomatic vs. asymptomatic), age and lesion characteristics. The symptomatic clinical status carries a high risk of recurrent stroke in medically treated patients5 and the same holds true for periprocedural outcomes in CAS. Gray et al32 showed that the incidence of stroke, myocardial infarction (MI) and death at 30 days is higher in symptomatic (5.3%) versus asymptomatic (2.9%) patients aged <80 years. Similarly, age is an independent risk factor for increased periprocedural complications in CAS.24,33 There are other comorbidities known to affect on the outcomes of CAS (Table 1).34
Anatomical features. The aortic arch morphology and carotid artery lesion characteristics are associated with complications of CAS. Madhwal et al35 described that a difficult arch (based on the takeoff from the innominate artery) significantly increases the fluoroscopy time of the procedure (Figures 2A and 2B). Similarly, aortic arch anomalies lead to higher periprocedural complication rates compared to patients with normal arch anatomy.36 Roubin GS et al34 (Table 1) have reported various lesion-related features that need to be taken into account when selecting the patients for CAS.
1. Heart Disease and Stroke Statistics — 2008 Update, pp. 7,14. (http://www.americanheart.org/presenter.jhtml?identifier=3037327)
2. Feigin VL, Lawes CM, Bennett DA, Anderson CS. Stroke epidemiology: A review of population-based studies of incidence, prevalence, and case-fatality in the late 20th century. Lancet Neurol 2003;2:43–53.
3. Veith, FJ, Amor M, Ohki T, et al. Current status of carotid bifurcation angioplasty and stenting based on a consensus of opinion leaders. J Vasc Surg 2001;33(2 Suppl):S111–S116.
4. Chaturvedi S, Bruno A, Feasby T, et al. Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Carotid endarterectomy — An evidence-based review: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology.Neurology. 2005;65:794–801.
5. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators. N Engl J Med 1991;325:445–453.
6. Randomized trial of endarterectomy for recently symptomatic carotid stenosis: Final results of the MRC European Carotid Surgery Trial (ECST). Lancet 1998;351:1379–1387.
7. Endarterectomy for asymptomatic carotid artery stenosis. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. JAMA 1995;2731421–1428.
8. Halliday A, Mansfield A, Marro J, et al. MRC Asymptomatic Carotid Surgery Trial (ACST) Collaborative Group. Prevention of disabling and fatal strokes by successful carotid endarterectomy in patients without recent neurological symptoms: Randomized controlled trial. Lancet 2004;363:1491–1502.
9. Eastcott HH, Pickering GW, ROB CG. Reconstruction of internal carotid artery in a patient with intermittent attacks of hemiplegia. Lancet 1954;267:994–996.
10. De Bakey ME, Crawford ES, Cooley DA, Morris GC Jr. Surgical considerations of occlusive disease of innominate, carotid, subclavian, and vertebral arteries. Ann Surg 195;149:690–710.
11. Roubin GS, Yadav S, Iyer SS, Vitek J. Carotid stent-supported angioplasty: A neurovascular intervention to prevent stroke. Am J Cardiol 1996;78(3A):8–12.
12. Diethrich EB, Ndiaye M, Reid DB. Stenting in the carotid artery: Initial experience in 110 patients. J Endovasc Surg 1996;3:42–62.
13. CAVATAS Investigators. Endovascular versus surgical treatment in patients with carotid stenosis in the CArotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS): A randomized trial. Lancet 2001;357:1729–1737.
14. Alberts MJ, Publications Committee of WALLSTENT. Results of a multicenter prospective randomized trial of carotid artery stenting vs. carotid endarterectomy (abstract 53). Stroke 2001;32:325.
15. CARESS Steering Committee. CaRESS Steering Committee. Carotid revascularization using endarterectomy or stenting systems (CARESS): Phase I clinical trial. J Endovasc Ther 2003;10:1021–1030.
16. Yadav JS, Wholey MH, Kuntz RE, et al. Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med 2004;351:1493–1501.
17. Ringleb PA, Allenberg J, Bruckmann H, et al. 30-day results from the SPACE trial of stent-protected angioplasty versus carotid endarterectomy in symptomatic patients: a randomized non-inferiority trial. Lancet 2006;368:1239–1247.
18. Mas JL, Chatellier G, Beyssen B, et al. Endarterectomy versus stenting in patients with symptomatic severe carotid stenosis. N Engl J Med 2006;355:1660–1671.
19. Gray WA, Hopkins LN, Yadav S, et al; ARCHeR Trial Collaborators. Protected carotid stenting in high-surgical-risk patients: The ARCHeR results. J Vasc Surg 2006;44:258–268.
20. White CJ, Iyer SS, Hopkins LN, et al; BEACH Trial Investigators. Carotid stenting with distal protection in high surgical risk patients: The BEACH trial 30-day results. Catheter Cardiovasc Interv 2006;67:503–512.
21. Hopkins LN, Myla S, Grube E, et al. Carotid artery revascularization in high surgical risk patients with the NexStent and the Filterwire EX/EZ: 1-year results in the CABERNET trial. Catheter Cardiovasc Interv 2008;71:950–960.
22. Gray WA, Yadav JS, Verta Pet al; CAPTURE Trial Collaborators. The CAPTURE registry: Predictors of outcomes in carotid artery stenting with embolic protection for high surgical risk patients in the early post-approval setting. Catheter Cardiovasc Interv 2007;70:1025–1033.
23. Safian RD, Bresnahan JF, Jaff MR, et al; CREATE Pivotal Trial Investigators. Protected carotid stenting in high-risk patients with severe carotid artery stenosis. J Am Coll Cardiol 2006;47:2384–2389.
24. Hobson RW, Howard VJ, Roubin GS, et al; CREST Investigators. Carotid artery stenting is associated with increased complications in octogenarians: 30-day stroke and death rates in the CREST lead-in phase. J Vasc Surg 2004;40:1106–1111.
25. Ramee S, Higashida R. Evaluation of the Medtronic self-expanding carotid stent system with distal protection in the treatment of carotid artery stenosis: The MAVErIC Trial Phase II 30-day update (abstr). Am J Cardiol 2004;94:61E.
26. Reimers B, Sievert H, Schuler GC, et al. Proximal endovascular flow blockage for cerebral protection during carotid artery stenting: Results from a prospective multicenter registry. Endovasc Ther 2005;12:156–165.
27. Coppi G, Moratto R, Silingardi R, et al. PRIAMUS — Proximal flow blockage cerebral protectIon during carotid stenting: Results from a multicenter Italian registry. J Cardiovasc Surg (Torino) 2005;46:219–227.
28. Whitlow P. SECuRITY Investigators. SECuRITY: Multicenter evaluation of carotid stenting with a distal protection filter. Available at: http://www.tctmd.com/csportal/ appmanager/tctmd/main?nfpb=true&pageLabel=TCTMDContent&hdCon=862459.
29. Massop D, Dave R, Metzger C, et al; SAPPHIRE Worldwide Investigators. Stenting and angioplasty with protection in patients at high-risk for endarterectomy: SAPPHIRE Worldwide Registry first 2,001 patients. Catheter Cardiovasc Interv 2009;73:129–136.
30. EMPiRE: A Multi-Center Registry Evaluating Neuroprotection During Carotid Stenting with a Novel Flow Reversal System. Presented at the 20th annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium. October 2008.
31. A multicenter registry evaluating neuroprotection during carotid stenting with a novel distal protection device first in human report: Initial experience with a stentless and retrievable percutaneous aortic valve prosthesis. Presented at the 20th annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium. October 2008.
32. Gray WA, Chaturvedi S, and Verta P. 30-day outcomes for carotid artery stenting in 6,320 patients from two prospective, multicenter, high surgical risk registries. Circ Cardiovasc Intervent 2009; Epub ahead of print. Published online, March 2009.
33. Gray WA, Yadav JS, Verta P, et al. The CAPTURE registry: Results of carotid stenting with embolic protection in the post approval setting. Catheter Cardiovasc Interv 2007;69:341–348.
34. Roubin GS, Iyer S, Halkin A, et al. Realizing the potential of carotid artery stenting: Proposed paradigms for patient selection and procedural technique. Circulation 2006;113:2021–2030.
35. Madhwal S, Rajagopal V, Bhatt DL, et al. Predictors of difficult carotid stenting as determined by aortic arch angiography. J Invasive Cardiol 2008;20:200–204.
36. Faggioli GL, Ferri M, Freyrie A, et al. Aortic arch anomalies are associated with increased risk of neurological events in carotid stent procedures. Eur J Vasc Endovasc Surg 2007;33:436–441.
37. Al-Mubarak N, Roubin GS, Vitek JJ, et al. Effect of the distal-balloon protection system on microembolization during carotid stenting. Circulation 2001;104:1999–2002.
38. Bates ER, Babb JD, Casey DE Jr, et al. ACCF/SCAI/SVMB/SIR/ASITN 2007 clinical expert consensus document on carotid stenting: A report of the American College of Cardiology Foundation Task Force. J Am Coll Cardiol 2007;49:126–170.
39. Parodi JC, La Mura R, Ferreira LM, et al. Initial evaluation of carotid angioplasty and stenting with three different cerebral protection devices. J Vasc Surg 2000;32:1127–1136.
40. Atkins MD, Bush RL. Embolic protection devices for carotid artery stenting: Have they made a significant difference in outcomes? Semin Vasc Surg 2007;20:244–251.
41. Iyer V, de Donato G, Deloose K, et al. The type of embolic protection does not influence the outcome in carotid artery stenting. J Vasc Surg 2007;46:251–256.
42. Powell RJ, Alessi C, Nolan B, et al. Comparison of embolization protection device-specific technical difficulties during carotid artery stenting. J Vasc Surg 2006;44:56–61.
43. Bosiers M, Peeters P, Deloose K, et al. Does carotid artery stenting work on the long run: 5-year results in high-volume centers (ELOCAS Registry). J Cardiovasc Surg 2005;46:241–247.
44. Yadav JS, Roubin GS, Iyer S, et al. Elective stenting of the extracranial carotid arteries. Circulation 1997;95:376–381.
45 Roubin GS, New G, Iyer SS, et al. Immediate and late clinical outcomes of carotid artery stenting in patients with symptomatic and asymptomatic carotid artery stenosis: A 5-year prospective analysis. Circulation 2001;103:532–537.
46. Schillinger M, Gschwendtner M, Reimers B, et al. Does carotid stent cell design matter? Stroke 2008;39:905–909.
47. Roffi M, Chan A, Yadav J. Can ultrasound accurately predict restenosis after carotid artery stenting? Circulation 2001;104(Suppl II):II–583.
48. Leclerc X, Gauvrit JY, Pruvo JP. Usefulness of CT angiography with volume rendering after carotid angioplasty and stenting. Am J Roentgenol 2000;174:820–822.
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