STenting for Ostial Vertebral Artery Stenosis (STOVAST Trial): Results from a prospective randomized study comparing bare-metal with drug-eluting stents. P. Paluszek, P. Pieniazek, P. Musialek, T. Przewlocki, L. Tekieli, A. Kablak-Ziembicka, K. Dzierwa, M. Hlawaty, M. Trystula, P. Podolec Institute of Cardiology, Jagiellonian University John Paul II Hosp., Krakow, Poland
Speaker s name: Piotr Paluszek I have the following potential conflicts of interest to report: Research contracts Consulting Employment in industry Stockholder of a healthcare company Owner of a healthcare company Other(s) I do not have any potential conflict of interest
Strokes in the posterior circulation account for 25% to 35% of all ischemic cerebrovascular events¹. Symptomatic vertebral artery stenosis (VAS) is a well-known risk factor for vertebrobasilar (VB) stroke and carries a 10% to 15% incidence of stroke or death at 1 year ². The mortality associated with a VB stroke may be as high as 30%³!!! After a VB stroke or TIA, the risk of stroke within next 5 years without treatment is 25-35%³! ¹Stayman AN et al. A systematic review of stenting and angioplasty of symptomatic extracranial vertebral artery stenosis. Stroke. 2011 Aug;42(8):2212-6. ²Amin-Hanjani S et al., Vertebrobasilar Flow Evaluation and Risk of Transient Ischaemic Attack and Stroke study (VERiTAS): rationale and design. Int J Stroke. 2010 Dec;5(6):499-505. ³Antoniou GA et al., Percutaneous transluminal angioplasty and stenting in patients with proximal vertebral artery stenosis. J Vasc Surg. 2012 Apr;55(4):1167-77
The best treatment of patients with VAS is not clear: First line treatment: risk factors modification pharmacotherapy: statin + antiplatelet drugs Second line treatment: surgical treatment (low rates of stroke/death but high technical complexity is limiting!) endovascular therapy safe and valuable alternative
BUT!!! Baloon angioplasty is associated with a tremendously high restenosis rate (up to 100% - Cloud et al.) The use of bare-metal stents (BMS) is associated with high restenosis rate (up to 48% - Taylor et al.), limiting wider applicability of this treatment modality. It is not known whether drug-eluting stents (DES) in the ostial vertebral location can improve long-term results.
Author, year No. of patients No. of DES implanted Restenosis rate No. of BMS implanted Restenosis rate Song, 2012 206 112 3.6 % (3-year) 94 20.2% (3-year) Hatano, 2011 117 117 9.6% (6-months) Chen, 2011 47 47 5.3% (16-months) Zhou, 2011 61 63 31% (12-months) Ogilvy, 2010 50 15 17% (21 months) 35 38% (21 months) Jenkins, 2010 105 3 114 7.4% (12-months) Werner, 2010 28 28 21.4% (16-months) Paluszek, Pieniazek, 2009 52 26 8.5% (12-months) 26 23% (12-months) Taylor, 2008 44 48 48% (8-months) Gupta, 2006 59 36 (extracranial) Lugmayr, 2004 7 8 62.5% (6-months) SSYLVIA Trial, 2004 7% 61 18 (VA) 43% (6-months)
Purpose: To prospectively evaluate angiographic and clinical outcome of stent-assisted vertebral artery angioplasty with a randomized allocation to DES vs BMS.
Material & Methods: 100 consecutive patients (65% men) with neurologist-confirmed diagnosis of symptomatic VAS External randomization to BMS vs. DES use. Duplex Doppler imaging and quantitative angiography (QA) prior to and immediately after stenting, and at one-year. QA evaluation performed by an independent Core Lab*, blinded to the BMS vs DES use. Technical success defined as <20% residual stenosis. Restenosis defined as an in-stent stenosis (ISR) > 50% diameter stenosis. *Krakow Cardiovascular Research Institute (KCRI)
VERTEBRAL ARTERY STENOSIS EVALUATION Fig. 1 Critical VA stenosis on Duplex Doppler Fig. 2 Critical VA stenosis on CT-angio
Angiography gold standard
100 patients: 49 DES (Ø 2.5-4.0, postdilated to 4.5mm as required angiographically): 19 zotarolimus-, 19 everolimus-, 6 paclitaxel-, 5 sirolimus-eluting 50 BMS (Ø 2.5-4.5mm): 35 stainless steel stents 15 cobalt-chromium stents
Clinical characteristics were not different between groups. Age History of VB Stroke History of VB TIA Drop attacks Severe vertigo/ dizziness Hyperten -sion Hyperlipidemia Type 2 diabetes Coronary artery disease Carotid artery disease DES (n=50) 64.9 6 (12%) 7 (14%) 4 (8%) 45 (90%) 46 (92%) 43 (86%) 14 (28%) 42 (84%) 31 (62%) p 0.67 0.75 0.77 1 0.24 0.67 0.16 0.65 0.44 0.4 BMS (n=50) 66.3 5 (10%) 6 (12%) 4 (8%) 48 (96%) 48 (96%) 48 (96%) 12 (24%) 39 (78%) 35 (70%)
Immediate Results: Procedural success rate - 99% (in 1 patient RSA cannulation and RVA wireing were unsuccesful due to excessive access tortuosities) Technical success rate 100% Periprocedural VA stenosis severity was reduced from 74 ± 10.5% to 10 ± 5.5% (p<0.001) 1 transient global amnesia (TGA) occurred periprocedurally in the BMS-arm.
Results: 99 patients (100%) completed 1-month follow-up; 93% patients were asymptomatic (the only remaining symptoms were vertigo/dizziness). 93 patients (93.9%) completed one-year follow-up. 3 cardiac- and 1 cancer-death occurred in the DES-arm and 2 cardiac deaths in the BMS-arm. 1 new VB stroke occurred in the BMS-arm, 1 episode of VB TIA in the DESarm. Both ischaemic events were related to a significant progression of contralateral VAS! 63% patients remained asymptomatic at one-year.
Results (clinical): 1-month follow - up 1-year follow-up VB Stroke / TIA / Deaths Symptoms free Deaths VB TIA VB Stroke Symptoms free Consent for f/u angio withdrawn DES 0 46 4 1 0 30/45 2/45 (n=49) (0%) (93.9%) (8%) (2.2%) (0%) (66.7%) (4.4%) p 1 0.49 0.65 0.97 0.97 0.53 0.31 BMS 0 46 2 0 1 29/48 6/48 (n=50) (0%) (92%) (4%) (0%) (2.1%) (60.4%) (12.5%) 8 patients withdrew follow-up angiography consent, 85 patients were thus available for one-year angiographic follow-up.
Results (angiographic): RVA / LVA Lesion Stent length Stent Direct length diameter stenting DES (n=49) 26 / 23 7.7 ± 3.4 mm 11.5 ± 3.6 mm 3.49 ± 0.5 mm 36 p 0.36 0.81 0.64 0.11 0.12 BMS (n=50) 22 / 28 7.9 ± 2.2 mm 11.3 ± 2.3 mm 3.67 ± 0.5 mm 43
Results (angiographic - QA): Index stenosis severity In-stent lumen reduction directly after stenting In-stent lumen reduction after 12 mo (including restenosis) In-stent lumen reduction after 12 mo (excluding restenosis) Stent occlusion Restenosis rate (>50% ISR) DES (n=49) 74.8 ± 10.8% 9.3 ± 4.6 % 31.9 ± 23.8% 22.7 ± 11.1% 3 (7%) 9 / 43 20.9% p 0.48 0.18 0.23 0.33 0.62 0.75 BMS (n=50) 73.3 ± 10.4% 10.7 ± 6.2 % 38.6 ± 25.8 % 25.3 ± 9.6% 1 (2.4%) 10 / 42 23.8% In 1-year follow-up 2 cases of stent fracture were observed
Results (angiographic): DES BMS Stent type Stainless steel Paclitaxeleluting Sirolimuseluting Everolimuseluting Zotarolimuseluting Cobaltchromium No. of stents implanted Restenosis Restenosis rate 6 2/4 50% 5 1/5 20% 19 4/19 21% 19 2/15 13.3% 35 9/30 30% 15 1/12 8.3%
Results restenosis group: Stent length Stent diameter Index stenosis severity In-stent lumen reduction directly after stenting <12mm 12mm <3.5mm 3.5 mm <75% 75% <10% 10% DES 1 8 4 5 7 2 6 3 (n=9) (11.1%) (88.9%) (44.4%) (55.5%) (77.8%) (22.2%) (66.7%) (33.3%) BMS 6 4 1 9 8 2 2 8 (n=10) (60%) (40%) (10%) (90%) (80%) (20%) (20%) (80%) All 7 12 5 14 15 4 8 11 (n=19) (36.8%) (63.1%) (26.3%) (73.7%) (78.9%) (21%) (42%) (57.9%)
RVA stenosis at the ostium A prior to stenting B - after DES implantation C - 12 mo outcome
In-stent restenosis in BMS A prior to stenting B after BMS implantation C ISR in BMS D after DES in BMS implantation
Conclusions: Vertebral artery stenting for symptomatic vertebral artery stenosis is safe. Results from this randomized trial show no evidence for instent restenosis reduction with DES vs BMS use at the ostial vertebral location. Cobalt-chromium stents may have the lowest restenosis rate, however this needs to be confirmed in further large-volume multicenter randomized trials.