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New stent designs
TUESDAY 9/24/02 9:00 –10:00
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New Stent Designs Tuesday, September 24, 2002 9:00 –10:00 AM 3:00 – 4:00 PM
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Background: We conducted this study to determine the restenosis rate after silicon carbide– coated stent implantation compared with uncoated stent. Methods: This was a single-center, randomized trial in patients with stable or unstable angina (Braunwald IB/C or IIB/C). All patients were nondiabetic, had single-vessel disease, and were scheduled to undergo to coronary angioplasty of lesions 2 to 4 mm in diameter and 10 to 25 mm in length. The primary end point was angiographic restenosis rate at 6 months’ follow-up. Results: Results are presented in the Figure.
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TCT-182 Acute and Intermediate-Term Clinical Outcomes After HeparinCoated BX Coronary Stent Implantation in Patients with Thrombus-Containing Lesions. J. Madduri, A. Assali, I. Teplizky, N. Shor, R. Kornowski. Cardiac Catheterization Laboratories, Cardiology Department, Rabin Medical Center, Petach Tikva, Israel. Background: Coronary stenting (CS) in acute coronary syndromes (especially if thrombus is angiographically visible) is associated with increased procedural risk and stent thrombosis. Heparin-coated stent (HCS) may improve CS outcomes in these high-risk lesions. The purpose of this analysis is to determine safety and efficacy of HCS (Johnson & Johnson BX Velocity type) in patients receiving coronary stents in thrombus-containing lesions. Methods: Between January 2001 and January 2002, 49 patients (42 men) with thrombus-containing lesions (32 acute myocardial infarction [MI]) at “high risk” for CS received HCS at our center. Inhospital and 6-month outcomes and quantitative angiographic analysis data were obtained from all patients. Results: The mean age of patients was 58 ⫾ 14 years; 45% had multivessel disease and 24% had diabetes. Fifteen patients (31%) received a second HCS for suboptimal result or threatened closure. Procedural success (%diameter stenosis ⬍20% and Thrombolysis in Myocardial Infarction (TIMI) 3 flow) was achieved in 94%. The mean TIMI flow increased from 1.3 ⫾ 1.3 to 2.9 ⫾ 0.3. The mean stent diameter and length was 3.2 ⫾ 0.2 mm and 18.2 ⫾ 7.4 mm. The mean diameter stenosis before and after intervention was 84% ⫾ 21% and 12% ⫾ 14%, respectively. The mean minimal lumen diameter increased from 0.4 ⫾ 0.5 mm before to 2.6 ⫾ 0.7 mm after CS. Inhospital and 1-month follow-up were without the occurrence of death, MI, stent thrombosis, emergency coronary artery bypass graft, or repeat percutaneous transluminal coronary angioplasty. At 6 months’ follow-up, survival free of mortality or recurrent MI was 100%, target vessel revascularization (TVR) was 6.1%, and 90% of pts were free of angina. Conclusion: In this preliminary series of high-risk patients with acute ischemic syndromes associated with angiographic evidence of thrombus, the use of the heparin-coated BX stent resulted in favorable procedural and 6-month outcomes, no incidence of subacute stent thrombosis or recurrent MI, and a relatively low rate of TVR.
TCT-183 Silicon Carbide–Coated Stent: Restenosis Study (SICARS). N.T. Duda1,2, R.T. Tumelero3, A.P. Tognon2. Departments of 1 Internal Medicine and 2Interventional Cardiology, 3School of Medicine, Universidade de Passo Fundo.
The American Journal of Cardiology姞
Conclusion: Silicon carbide– coated 316L stainless steel stents showed better outcomes at 6 months’ follow-up than did uncoated stainless steel stents.
TCT-184 Primary Stenting in Angiographic Small Coronary Arteries Using a Carbon-Coated Stent. B. Mut-Vitcu, D. Maximov, C. Dina, M. Slovenski, D. Gaita, A. Ionac, S.I. Dragulescu. Timisoara Institute of Cardiovascular Medicine, Timisoara, Romania. Background: Elective stenting of de novo lesions in coronary arteries ⬍3 mm diameter is still controversial because of high risk of acute/ subacute thrombosis and restenosis rate. The Sorin carbostent, Sorin Biomedica S.p.A. Saluggia, Italy has an optimized cellular design and improved thromboresistance and biocompatibility. We prospectively analyzed the safety, efficacy, and long-term angiographic patency after elective Carbostent placement for 26 consecutive de novo lesions (21 patients) in angiographic small coronary arteries (⬍3 mm). Methods: Ancor Siemens quantitative coronary angiography was used to measure reference vessel diameter, minimal lumen diameter (MLD), and percent diameter stenosis before and after stenting and at angiographic follow-up study. Results: Clinical indications for percutaneous coronary intervention were unstable angina (10 patients), stable angina (7 patients), and recent myocardial infarction (4 patients). Seven patients (33%) had diabetes mellitus. Fifteen lesions (71%) were type B2 and C. Reference vessel diameter was 2.57 ⫾ 0.27 mm, MLD was 0.70 ⫾ 0.28 mm, diameter stenosis was 73.3% ⫾ 10.5%, and the lesion length was 14.2 ⫾ 6.4 mm. Successful carbostent placement was achieved for 25 lesions (96%). One stent embolization occurred. Balloon size for stent delivery was 2.5 mm in 24 lesions and 3.0 mm in 2 lesions. Mean inflation pressure was 12.4 ⫾ 2.2 atm. MLD increased to 2.48 ⫾ 0.37 mm and percent diameter stenosis decreased to 10.9% ⫾ 7.1%. Antithrombotic regimen included aspirin for all patients and clopidogrel or
SEPTEMBER 24, 2002
TCT ABSTRACTS/Poster
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TUESDAY 9/24/02 9:00 –10:00 ticlopidine for 11 patients (52%). No acute or subacute stent thrombosis occurred. Angiographic follow-up was done in 20 patients, including 25 target lesions (96%), and restenosis (⬎50% diameter stenosis) was found in 6 lesions (24%). At 155 ⫾ 31 days mean MLD was 1.87 ⫾ 0.47 mm, percent diameter stenosis 32% ⫾ 21%, and late lumen loss 0.75 ⫾ 0.63 mm. Conclusion: Carbostent seems feasible and safe, with good longterm patency for small coronary arteries. Studies in a larger number of patients are needed to assess the restenosis.
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cross-sectional area changes with incremental water chamber pressure increases for 3 examples of each stent design. Stents tested were Multilink, Duet, Tetra, Penta (Guidant), Bx velocity, Crossflex (Cordis J&J), S7 (Medronic), JoStent (Jomed), Express (Boston) and Duraflex (Avantec). Results: See Figure.
TCT-185 Comparative Biocompatibility Testing of Stent Materials. J.C. Palmaz, E.A. Sprague, S.R. Bailey. The University of Texas Health Science Center, San Antonio, Texas, USA.
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Background: To compare metallic, polymeric, and ceramic materials, commonly used in the manufacture of coronary stents, in regard to thrombogenic, inflammatory, and endothelial cell– binding potential. Methods: Iodine 125-radiolabeled fibrinogen attachment to surfaces was tested for quantitative analysis on 2 alloys (316L stainless steel and Nitinol) and 8 pure elements (iron, chromium, nickel, tantalum, titanium, gold, molybdenum, and manganese) commonly used in the manufacture of coronary stents. The same method was applied to 4 polymers (polyhydroxyethylmethacrilate [pHEMA], polyethylenetherephthalate [PET], polytetrafluoethylene [PTFE], and polydimethylsiloxane [PDMS]) and 4 ceramics (chromium oxicarbide, diamondlike carbon, silicon carbide, and turbostratic carbon). All test surfaces were compared with 316L stainless steel as a reference material. Indium 111 platelet and monocyte attachment and human aortic endothelial cell migration distance were evaluated on all surfaces. The data were evaluated by comparative and correlation statistics. Results: Except for Nitinol, significantly greater amounts of fibrinogen were bound to all metallic surfaces (p ⬍0.05 for Ni,Ta and p ⬍0.01 for Au, Fe,Cr, Ti, Mo, Mn). Except for polyHEMA, all polymers attached more fibrinogen compared with steel (p ⬍0.05 for PDMS, p ⬍0.01 for PET, p ⫽ NS for PTFE). Also, all ceramic surfaces bound greater amounts of fibrinogen than did stainless steel (p ⬍0.01). Fibrinogen attachment was positively correlated with monocyte (p ⫽ 0.0002) and platelet (p ⫽ 0.008) attachment and negatively with human aortic endothelial cell migration distance (p ⫽ 0.05). Conclusion: We found that 316L stainless steel has the lowest fibrinogen-, platelet-, and monocyte-binding potential among metals, most polymers, and ceramics used in the manufacture of coronary stents. Also, it has the highest affinity for migrating endothelial cells. The use of coating materials to improve the biocompatibility of stainless steel does not seem justified.
TCT-186
Conclusion: With contemporary design, stents can have high radial strength without loss of flexibility and vice versa. Older designs (Multilink and Crossflex) had high flexibility but low radial strength. Stent choice can be tailored for lesion characteristics, eg, a stent of high radial strength may be chosen for an ostial lesion, or a high-flexibility stent may be chosen for an acute bend.
TCT-187 Stent/Delivery System Characteristics That Influence Delivery: Benchtop Measurements of Profile and Flexibility. J.A. Ormiston, M.W.I. Webster, P.N. Ruygrok, J.T. Stewart, E. Currie, M.J. Panther. Green Lane and Mercy Hospitals, Auckland, New Zealand. Background: The ease with which a stent can be delivered to a lesion is dependent on characteristics such as stent/delivery system (SDS) flexibility and profile (diameter). In addition SDS profile is important in direct stenting and use of smaller-caliber guides. These characteristics remain important in the drug-eluting stent era. Independent quantitative assessment can assist the interventionalist in rational stent selection. Methods: Flexibility of 3 examples of each SDS was measured 3 times using our previously published standardized 3-point bend test method. SDS profile was measured with a calibrated microscope 3 times at 3 sites on 3 examples of each SDS. Stents tested were Duraflex
Expanded Stent Radial Strength and Flexibility: Benchtop Testing of 10 stents. J.A. Ormiston, J. Blake, C. Peebles, M.W.I. Webster, J.T. Stewart, P.N. Ruygrok, B. O’Shaughnessy. Green Lane and Mercy Hospitals, Auckland, New Zealand. Background: The radial strength of the expanded stent determines resistance to the compressive forces of calcified, fibrotic, and ostial lesions. The flexibility of the expanded stent is important to allow conformation to vessel contours and to minimize distortion at the stent-vessel junction when stents are deployed on bends. The aim of this study is to compare the relation between expanded stent flexibility and radial strength for 10 stent designs. Methods: Flexibility was measured 3 times for each of 3 examples of each expanded stent using our previously described standardized 3-point bend test. Radial strength was assessed by recording continuously with a luminal intravascular ultrasound transducer the stent
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The American Journal of Cardiology姞
SEPTEMBER 24, 2002
TCT ABSTRACTS/Poster
TUESDAY 9/24/02 9:00 –10:00
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(Avantec), NIR, Express (Boston), BxVelocity, Crossflex (Cordis J&J), Multilink, Duet, Tetra, Penta (Guidant), S7, AVE, Bestent (Medtronic). Results: See figure. Conclusion: Newer stents have reduced profile by up to 0.4 mm compared with second-generation stents. Overall there has been little change in SDS stiffness but with considerable range from 20 to 60 gm force/mm. Some designs combine low profile with low stiffness, which are 2 important determinants for deliverability.
TCT-188 A Polymer-Based Copper Coating Generates Nitric Oxide from S-Nitrosoglutathione But Does Not Induce Significant Neointimal Formation When Used as a Stent Coating. G. Richardson1,2, J. Gunn4, A.C. Morton4, S.E. Greenwald3, N. Benjamin2, M.T. Rothman1. 1Department of Cardiology, London Chest Hospital, London, United Kingdom; Departments of 2Clinical Pharmacology and 3Morbid Anatomy, St. Bartholomew’s Medical College, London, United Kingdom; 4Cardiovascular Research Group, University of Sheffield, Sheffield, United Kingdom. Background: Current research is directed toward finding an agent that can be coated onto a stent to inhibit in-stent restenosis, a process that involves platelet, inflammatory cell, and vascular smooth muscle cell responses. Nitric oxide (NO) is a potential candidate for this role, as it can theoretically inhibit all aspects of the vascular response to stent deployment, while also enhancing endothelial cell regrowth. S-nitrosothiols (RSNOs) are endogenous circulating NO donors. We have previously shown that NO can be generated from RSNOs by copper, in a dose-dependent manner, to inhibit platelet aggregation in vitro. However, copper-coated stents have been shown by others to induce severe inflammatory responses in the vessel wall. To coat stainless steel with small quantities of copper we have developed a novel polymer-based method. The coating, containing 5% or 20% copper (wt/wt), can be used to generate NO from RSNOs to inhibit platelet aggregation in vitro in a dose-response manner. Methods: Stainless steel discs were implanted into subcutaneous tissues in mice, and inflammatory responses were assessed by measuring histologic tissue changes and macrophage acid phosphatase activity on the surface of the disc 7 days after implantation. The effect of the coating on the development of neointima was then tested in the porcine coronary artery model. Stents coated with the polymer-copper coating (1% and 5% copper [wt/wt]; n ⫽ 6 per group) were deployed at a balloon artery ratio of 1.25:1. The vessels were harvested at 28 days, and the resulting neointimal areas were compared with that seen after implantation of stents coated with polymer alone. Results: The 20% copper coating induced significantly more inflammation in the mouse than both the 5% copper and the polymer coating alone. There were no differences between the effects of 5% copper and the polymer itself. In the porcine coronary artery, neointimal areas (arbitrary units), corrected for vessel size and injury score, were the same in the 3 groups, 0.019 ⫾ 0.001, 0.032 ⫾ 0.009, and 0.021 ⫾ 0.001 for 1% copper, 5% copper and polymer alone, respectively (mean ⫾ SEM; p ⫽ 0.152; 1-way analysis of variance). Conclusion: NO can theoretically inhibit the process of in-stent restenosis. Copper can generate NO from RSNOs, but it has proinflammatory properties. Stents coated with a polymer-copper mixture, at concentrations of copper that will inhibit platelet aggregation in vitro, do not induce significantly more neointimal formation in porcine coronary arteries than those coated with polymer alone. These preliminary data warrant further investigation.
TCT-189 Titanium Nitric Oxide–Coated Stent: First Implantations in Humans and Preliminary 6 Months’ Angiographic Follow-Up.
The American Journal of Cardiology姞
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C. Caussin1, M. Hamon2, D. Carrie´3, P. Commeau4, G. Grollier2, J. Puel3, B. Lancelin1. 1CC Marie Lannelongue, LePlessis Robinson; 2 CHU Caen, Caen, France; 3CHU Rangueil, Toulouse, France; 4 Polyclinique les Fleurs, Ollioules, France. Background: Titanium nitric oxide (Ti-NO) is biologically inert and has excellent biocompatibility, as exemplified by the lack of a redox and hydrolysis reaction, as well as an absent complex metal ion-organic molecule binding formation. Ti-NO– coated stents have significantly reduced neointimal proliferation compared with stainless steel stent in pigs. The aim of our study was to prospectively evaluate the feasibility, safety, and 6-month angiographic restenosis rate of a Ti-NO stainless steel coated stent (Helistent; Hexacath, France) in humans. Ref Diam (mm)
MLD Pre (mm)
% Area Stenosis (Pre)
MLD Post (mm)
% Area Stenosis (Post)
3.21 ⫾ 0.36
1.14 ⫾ 0.32
86.7 ⫾ 5.7
2.99 ⫾ 0.35
13.2 ⫾ 8.9
MLD ⫽ minimal lumen diameter; Ref Diam ⫽ reference diameter. Methods: Twenty centers prospectively included patients. Inclusion criteria were a single lesion ⬍15 mm in length in a native coronary artery with a reference diameter between 3.0 and 4.0 mm eligible for percutaneous coronary intervention. Exclusion criteria were high-grade calcification, ostial or bifurcation lesion, and ⬍72 hours acute myocardial infarction. Clinical follow-up was performed at 1 month, and angiographic follow-up was systematically performed at 6 months. Quantitative coronary angiography analysis was centralized. Results: A total of 133 patients were included in the study. Mean age was 60.9 ⫾ 11.1 yrs. Prior history of diabetes was 21%; coronary artery bypass graft,1%; percutaneous transluminal coronary angioplasty, 6%; myocardial infarction, 13%. Clinical presentation was unstable angina, 46%; stable angina, 30%; post MI, 15%; silent ischemia, 9%. ACC/AHA classification lesion was A, 29%; B, 71%; and C, 0%. The implantation success rate was 100%. Inhospital events were 1 death due to periprocedure aortic dissection, 1 regressive stroke, and 2 groin haematomas. At 1 month, no subacute thrombosis, no target lesion revascularization, and no myocardial infarction were observed. Conclusion: Immediate and 1-month follow-up results are very promising. The 6-month angiographic follow-up is ongoing. Results of the first 60 patients will be communicated during the presentation.
TCT-190 Can Stent Coating with Turbostratic Carbon Reduce the Rate of Clinical Events and Coronary Restenosis Compared with Stainless Steel Stents? J. Haase, C.E. Schwarz, H. Stoerger, M. Hofmann, H. Braun, F. Schwarz. Red Cross Hospital Cardiology Center, Frankfurt, Germany. Background: Stent coating with turbostratic carbon was supposed to reduce the local inflammatory response after stent implantation and thereby also reduce clinical events and restenosis rates. This study represents the first prospective randomized trial comparing the incidence of major adverse cardiac events (MACE), target lesion revascularization rate (TLR), and binary angiographic restenosis rate after implantation of coronary stents coated with turbostratic carbon versus uncoated stainless steel stents. Methods: From October 1999 to October 2001, a total of 292 patients with symptomatic coronary artery disease eligible for singlelesion percutaneous transluminal coronary angioplasty were randomized for implantation of either a CarboStent: Sorin Biomedica Cardio S.p.A., 13040 Saluggia (VC), Via Crescentino, Italy, Stainless steel stent (Tristar, Tetra, Penta): Guidant Europe NV/SA, Park Lane, Culliganlaan 2B, 1831 Diegem, Belgium (C; n ⫽ 152) or a stainless steel
SEPTEMBER 24, 2002
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stent (S; n ⫽140). S were Tristar stents in 69.3%, Tetra stents in 21.7%, and Penta stents in 10%. There was no between-groups difference with regard to patient age (C: 63.9 ⫾ 10.4 years; S: 62.7 ⫾ 10.0 years); sex (C: 73% men; S: 76% men); incidence of diabetes (C: 20%; S: 17%); or complexity of the lesion (C: type A/B1 56.1%, type B2/C 43.9%; S: type A/B1 64.8%, type B2/C 35.2%). Angiographic follow-up (FU) was obtained after 6 months in 202 patients (69%) and clinical FU in 206 patients (71%). Results: There were no significant differences between C and S with regard to lesion length (C: 10.46 ⫾ 4.56 mm; S: 10.48 ⫾ 4.93 mm), Reference diameter (RD) (C: 2.94 ⫾ 0.59 mm; S: 2.90 ⫾ 0.55 mm), minimal lumen diameter (MLD) pre (C: 0.78 ⫾ 0.36 mm; S: 0.82 ⫾ 0.36 mm), MLD post (C: 2.58 ⫾ 0.43 mm; S: 2.74 ⫾ 0.47 mm), MLD at FU (C: 1.71 ⫾ 0.67 mm; S: 1.66 ⫾ 0.54 mm), late loss (C: 0.88 ⫾ 0.65 mm; S: 1.11 ⫾ 0.58 mm), and angiographic restenosis rate (C: 18.0%; S: 21.6%). There were also no significant differences regarding MACE rates: death (C: 0%; S: 1%), myocardial infarction (C: 0%; S: 1%), coronary artery bypass graft (C: 1%; S: 2.5%), or TLR (C: 17.3%; S: 23.5%). Conclusion: Coronary stents coated with turbostratic carbon gave a nonsignificant trend toward reduction of MACE, TLR, and restenosis rate when compared with uncoated stainless steel stents.
TCT-192 TCT-191
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Stent Mesh Access and Deformation in the Treatment of Coronary Bifurcation Lesions: An In Vitro-In Vivo Study. P. Brunel, B. Leurent, Y. Banus, J.P. Cebron, D. Gras. Unite´ de Soins et de Cardiologie Interventionelle, NCN Clinique St.-Henri, Nantes, France.
Efficacy of Polytetrafluoroethylene-Covered Stent Implantation in Emergency Treatment of Coronary Ruptures During Percutaneous Coronary Interventions. I. Sheiban, K. Prathap, C. Moretti, C. Paone, T. Montaldo, A. Gangnor, I. Paglia, S. Colangelo, S. Frea, G.P. Trevi. Interventional Cardiology, Division of Cardiology, University of Torino, Turin, Italy.
Background: Good technical tips were developed for coronary bifurcation lesion (CBL) stenting. Treatment of CBL remains a compromise between technical access to the side branch and good conformation and coverage of the lesion for better long-term results. We wanted to analyze the behavior of different stent designs when used for the treatment of CBL with crossing the mesh with guidewire, balloon, and stents. Methods: In vivo side-branch access through the strut (with 0.014-in guidewire, balloon, and premounted stent) was analyzed in 50 procedures with different stent designs. In vitro evaluation of mesh deformation of different 3-mm stent designs (BxVelocity, Biodyvisio, Express, AVES7, Helistent, Penta, Sirius, Jostent, and DLCstent) before and after a 3-mm balloon inflation through the mesh and then after final kissing balloon (performed without any constraint) was done. We measured axial deformation, metal-induced stenosis, and percentage of element stretch adjacent to the crossed strut. Results: Mesh design is depicted in the Figure. Easy insertion of 0.014-in wire occurred in 40 cases (80%). Insertion was difficult in 8 cases (16%) and impossible in 2 cases (4%). Failure to cross the mesh and side branch with a balloon occurred in 1 case (2%). A stent was successfully inserted in all 3 attempted cases. Success was 100% in the main branches and 92% in the side branches. The angle between the proximal and distal part of the deformed stent was 17° to 79°; induced stenosis was 3% to 29% and 0% to 10 % after kissing balloon. Strut stretch was 4% to 63%. Data on deformations induced in a bench bifurcation model to include the action-reaction process due to the arterial wall will be presented. Conclusion: Access of side branches through a stent mesh remains difficult or impossible in 20% of the cases. Stent-induced stenosis and axial deformation by side branch balloon are well corrected after kissing balloon. Axial deformation and strut stretch demonstrate a large range of values. Global design preservation of adjacent crossed meshes seems to be associated with the type of link between basic constituent elements.
Background: Coronary perforation or rupture is a rare but life-threatening complication of percutaneous coronary intervention (PCI). When prolonged balloon inflation and reversal of anticoagulation are unsuccessful, surgery becomes mandatory. However, in recent years, the implantation of a covered stent at the site of the perforation has emerged as an additional strategy when the traditional conservative approach fails. In particular, thanks to the ready-to-use attribute, the polytetrafluoroethylene (PTFE)-covered coronary stent has emerged as a new tool for the nonsurgical treatment of this complication. In the present study we report our experience in the treatment of coronary perforation during PCI procedures Methods: In the last 2 years, PCI was complicated with coronary rupture or perforation in 9 patients (9 of 1,772; 0.5%) and was treated with 11 PTFE-covered stents. Two covered stents were needed in 2 patients to seal the culprit lesion. Coronary perforation or rupture occurred after stent implantation in calcified and angled lesions that were predilated with Cutting Balloon in 4 patients, after directional coronary atherectomy in 2 patients, after rotational atherectomy with Rotablator in 2 patients, and following balloon dilatation in 1 patient (during angioplasty for chronic total occlusion). Results: All vessel perforations or ruptures treated with PTFEcovered stent were successfully sealed. The time necessary to deploy the stent was 8 ⫾ 3 minutes (range, 4 to 12 minutes). All patients were discharged from the hospital and had optimal early clinical outcome. Percardiocentesis was needed in 4 patients. One patient, with sustained slow-flow in the target vessel, had experienced non–Q-wave myocardial infarction during hospitalization. Clinical follow-up was available in all patients. At 9 ⫾ 3 months, all patients were free from any major adverse coronary event. In only 1 patient was repeat percutaneous transluminal coronary angioplasty needed because of recurrence of angina. Conclusion: Coronary rupture during PCIs still represents a rare but life-threatening complication. The data reported in this study support the utility and efficacy of the PTFE-covered stent for the nonsur-
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SEPTEMBER 24, 2002
The American Journal of Cardiology姞
TCT ABSTRACTS/Poster
TUESDAY 9/24/02 9:00 –10:00
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gical treatment and safe management of vessel perforations or ruptures complicating PCI.
TCT-193 Initial US Experience with Covered Stents in the Treatment of Saphenous Vein Graft Lesions: 30-Day Follow-Up. B. Roukoz1, H. Arjomand1, S. Surabhi1, D. McCormick1, Z. Turi1, G. Stone2, D. Baim3, S. Goldberg1. 1MCP Hahnemann University, Philadelphia, Pennsylvania, USA; 2Lenox Hill Hospital, New York, New York, USA; 3Brigham and Women’s Hospital, Boston, Massachusetts, USA. Background: Percutaneous interventions in lesions of degenerated aortocoronary vein grafts are associated with a high risk of short- and long-term adverse coronary events. The 30-day clinical safety and effectiveness of the polytetrafluoreoethylene (PTFE)-covered stents in the treatment of these high-risk lesions were studied in the roll-in phase of this prospective randomized trial. Methods: A group of 88 patients were included in the roll-in phase of a larger randomized trial, with 104 de novo lesions in saphenous vein grafts (SVGs). Patients were randomized to receive ⱖ1 stent. The 30-day complication rate and the incidence of major adverse coronary events (MACE; consisting of death, Q-wave or non–Q-wave myocardial infarction [MI], and target vessel revascularization [TVR]) were available on 79 patients Results: In all, 79 patients with a mean age of 66 years (range, 45 to 87 years; 73% men) received 102 PTFE-covered stents for 97 stenoses in vein grafts 10.2 ⫾ 5.8 years after bypass surgery. Clinical characteristics included diabetes (34%), hyperlipidemia (91%), hypertension (75%), and smoking (64%). Glycoprotein IIb/IIIa inhibitors were used in 65% of cases. Complications and MACE rates are shown in the Table. 30-Day Complications and MACE (n ⴝ 79)
Death Cardiac Noncardiac (bleeding) Q-wave MI Non–Q-wave MI TVR (2 abrupt closures) Any event Major vascular events
n
%
1 1 2 6 3 11 2
1.3 1.3 2.5 7.6 3.8 13.9 2.5
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Conclusion: These preliminary results suggest that the use of covered stents appears to be safe and effective in treating high-risk lesions in SVGs, with a relatively low rate of MACE at 30-day follow-up, especially in-stent thrombosis. A larger randomized study is currently underway comparing this device to bare stents.
TCT-194 Nanomanufactured Stent Grafts: In Vivo Evaluation of Angiographic and Histologic Data. S.R. Bailey1, E. Sprague1, C. Banas2, C. Boyle2, R. Naidu1, J. Palmaz1. 1University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, USA; 2 Advanced Bioprosthetic Surfaces, San Antionio, Texas, USA. Background: Stents are currently manufactured using commercially produced metals that are then cut and polished into tubes for implantation into vessels. Current techniques incorporate impurities into the stent material and its surfaces. The manufacturing process, by etching or laser cutting, increases the impurities. Novel manufacturing techniques using ultralow-pressure magnetrons were developed to allow the manufacture of ultrapure metals specifically for medical implant applications. Methods: Self-expanding stent grafts covered with a nanomanufactured Nitinol mircroporous membrane were implanted into the 12 common carotid arteries in 6 farm swine (sous scrofula) and evaluated angiographically at 10 and 28 days for patency, thrombosis, and neointimal proliferation. Histopathologic data will also be presented. All animals were treated with aspirin and Plavix (clopidogrel; BristolMyers Squibb, Princeton, NJ) for the duration of the study. Results: Angiographic evaluation demonstrated patency in all vessels at 10 and 28 days. All stent grafts were successfully deployed. No acute or subacute thrombosis occurred. All animals survived to the assigned time point. The reference vessel diameter at the time of killing was 4.8 ⫾ 0.15 mm proximally and 4.7 ⫾ 0.67 mm distally. The stent graft diameter was 5.2 ⫾ 0.17 mm proximally and 4.8 ⫾ 0.42 mm distally. The proximal stent was significantly larger (p ⫽ 0.008) than proximal reference vessel without any difference at the distal segments. Only 1 stent exhibited any in-stent stenosis, and this was ⬍20% compared with the reference vessel lumen. Conclusion: Nanomanufacture of new pure thin metals that can be used for micorporous stent grafts can be accomplished. Self-expanding stents covered with an ultrathin membrane can be safely delivered and expanded in carotid vessels. These stent grafts have excellent biocompatibility, without acute or subacute thrombosis and with minimal neointimal proliferation.
P O S T E R A B S T R A C T S
The American Journal of Cardiology姞
SEPTEMBER 24, 2002
TCT ABSTRACTS/Poster
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New Stent Designs Tuesday, September 24, 2002 9:00 –10:00 AM 3:00 – 4:00 PM
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Background: We conducted this study to determine the restenosis rate after silicon carbide– coated stent implantation compared with uncoated stent. Methods: This was a single-center, randomized trial in patients with stable or unstable angina (Braunwald IB/C or IIB/C). All patients were nondiabetic, had single-vessel disease, and were scheduled to undergo to coronary angioplasty of lesions 2 to 4 mm in diameter and 10 to 25 mm in length. The primary end point was angiographic restenosis rate at 6 months’ follow-up. Results: Results are presented in the Figure.
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TCT-182 Acute and Intermediate-Term Clinical Outcomes After HeparinCoated BX Coronary Stent Implantation in Patients with Thrombus-Containing Lesions. J. Madduri, A. Assali, I. Teplizky, N. Shor, R. Kornowski. Cardiac Catheterization Laboratories, Cardiology Department, Rabin Medical Center, Petach Tikva, Israel. Background: Coronary stenting (CS) in acute coronary syndromes (especially if thrombus is angiographically visible) is associated with increased procedural risk and stent thrombosis. Heparin-coated stent (HCS) may improve CS outcomes in these high-risk lesions. The purpose of this analysis is to determine safety and efficacy of HCS (Johnson & Johnson BX Velocity type) in patients receiving coronary stents in thrombus-containing lesions. Methods: Between January 2001 and January 2002, 49 patients (42 men) with thrombus-containing lesions (32 acute myocardial infarction [MI]) at “high risk” for CS received HCS at our center. Inhospital and 6-month outcomes and quantitative angiographic analysis data were obtained from all patients. Results: The mean age of patients was 58 ⫾ 14 years; 45% had multivessel disease and 24% had diabetes. Fifteen patients (31%) received a second HCS for suboptimal result or threatened closure. Procedural success (%diameter stenosis ⬍20% and Thrombolysis in Myocardial Infarction (TIMI) 3 flow) was achieved in 94%. The mean TIMI flow increased from 1.3 ⫾ 1.3 to 2.9 ⫾ 0.3. The mean stent diameter and length was 3.2 ⫾ 0.2 mm and 18.2 ⫾ 7.4 mm. The mean diameter stenosis before and after intervention was 84% ⫾ 21% and 12% ⫾ 14%, respectively. The mean minimal lumen diameter increased from 0.4 ⫾ 0.5 mm before to 2.6 ⫾ 0.7 mm after CS. Inhospital and 1-month follow-up were without the occurrence of death, MI, stent thrombosis, emergency coronary artery bypass graft, or repeat percutaneous transluminal coronary angioplasty. At 6 months’ follow-up, survival free of mortality or recurrent MI was 100%, target vessel revascularization (TVR) was 6.1%, and 90% of pts were free of angina. Conclusion: In this preliminary series of high-risk patients with acute ischemic syndromes associated with angiographic evidence of thrombus, the use of the heparin-coated BX stent resulted in favorable procedural and 6-month outcomes, no incidence of subacute stent thrombosis or recurrent MI, and a relatively low rate of TVR.
TCT-183 Silicon Carbide–Coated Stent: Restenosis Study (SICARS). N.T. Duda1,2, R.T. Tumelero3, A.P. Tognon2. Departments of 1 Internal Medicine and 2Interventional Cardiology, 3School of Medicine, Universidade de Passo Fundo.
The American Journal of Cardiology姞
Conclusion: Silicon carbide– coated 316L stainless steel stents showed better outcomes at 6 months’ follow-up than did uncoated stainless steel stents.
TCT-184 Primary Stenting in Angiographic Small Coronary Arteries Using a Carbon-Coated Stent. B. Mut-Vitcu, D. Maximov, C. Dina, M. Slovenski, D. Gaita, A. Ionac, S.I. Dragulescu. Timisoara Institute of Cardiovascular Medicine, Timisoara, Romania. Background: Elective stenting of de novo lesions in coronary arteries ⬍3 mm diameter is still controversial because of high risk of acute/ subacute thrombosis and restenosis rate. The Sorin carbostent, Sorin Biomedica S.p.A. Saluggia, Italy has an optimized cellular design and improved thromboresistance and biocompatibility. We prospectively analyzed the safety, efficacy, and long-term angiographic patency after elective Carbostent placement for 26 consecutive de novo lesions (21 patients) in angiographic small coronary arteries (⬍3 mm). Methods: Ancor Siemens quantitative coronary angiography was used to measure reference vessel diameter, minimal lumen diameter (MLD), and percent diameter stenosis before and after stenting and at angiographic follow-up study. Results: Clinical indications for percutaneous coronary intervention were unstable angina (10 patients), stable angina (7 patients), and recent myocardial infarction (4 patients). Seven patients (33%) had diabetes mellitus. Fifteen lesions (71%) were type B2 and C. Reference vessel diameter was 2.57 ⫾ 0.27 mm, MLD was 0.70 ⫾ 0.28 mm, diameter stenosis was 73.3% ⫾ 10.5%, and the lesion length was 14.2 ⫾ 6.4 mm. Successful carbostent placement was achieved for 25 lesions (96%). One stent embolization occurred. Balloon size for stent delivery was 2.5 mm in 24 lesions and 3.0 mm in 2 lesions. Mean inflation pressure was 12.4 ⫾ 2.2 atm. MLD increased to 2.48 ⫾ 0.37 mm and percent diameter stenosis decreased to 10.9% ⫾ 7.1%. Antithrombotic regimen included aspirin for all patients and clopidogrel or
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TUESDAY 9/24/02 9:00 –10:00 ticlopidine for 11 patients (52%). No acute or subacute stent thrombosis occurred. Angiographic follow-up was done in 20 patients, including 25 target lesions (96%), and restenosis (⬎50% diameter stenosis) was found in 6 lesions (24%). At 155 ⫾ 31 days mean MLD was 1.87 ⫾ 0.47 mm, percent diameter stenosis 32% ⫾ 21%, and late lumen loss 0.75 ⫾ 0.63 mm. Conclusion: Carbostent seems feasible and safe, with good longterm patency for small coronary arteries. Studies in a larger number of patients are needed to assess the restenosis.
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cross-sectional area changes with incremental water chamber pressure increases for 3 examples of each stent design. Stents tested were Multilink, Duet, Tetra, Penta (Guidant), Bx velocity, Crossflex (Cordis J&J), S7 (Medronic), JoStent (Jomed), Express (Boston) and Duraflex (Avantec). Results: See Figure.
TCT-185 Comparative Biocompatibility Testing of Stent Materials. J.C. Palmaz, E.A. Sprague, S.R. Bailey. The University of Texas Health Science Center, San Antonio, Texas, USA.
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Background: To compare metallic, polymeric, and ceramic materials, commonly used in the manufacture of coronary stents, in regard to thrombogenic, inflammatory, and endothelial cell– binding potential. Methods: Iodine 125-radiolabeled fibrinogen attachment to surfaces was tested for quantitative analysis on 2 alloys (316L stainless steel and Nitinol) and 8 pure elements (iron, chromium, nickel, tantalum, titanium, gold, molybdenum, and manganese) commonly used in the manufacture of coronary stents. The same method was applied to 4 polymers (polyhydroxyethylmethacrilate [pHEMA], polyethylenetherephthalate [PET], polytetrafluoethylene [PTFE], and polydimethylsiloxane [PDMS]) and 4 ceramics (chromium oxicarbide, diamondlike carbon, silicon carbide, and turbostratic carbon). All test surfaces were compared with 316L stainless steel as a reference material. Indium 111 platelet and monocyte attachment and human aortic endothelial cell migration distance were evaluated on all surfaces. The data were evaluated by comparative and correlation statistics. Results: Except for Nitinol, significantly greater amounts of fibrinogen were bound to all metallic surfaces (p ⬍0.05 for Ni,Ta and p ⬍0.01 for Au, Fe,Cr, Ti, Mo, Mn). Except for polyHEMA, all polymers attached more fibrinogen compared with steel (p ⬍0.05 for PDMS, p ⬍0.01 for PET, p ⫽ NS for PTFE). Also, all ceramic surfaces bound greater amounts of fibrinogen than did stainless steel (p ⬍0.01). Fibrinogen attachment was positively correlated with monocyte (p ⫽ 0.0002) and platelet (p ⫽ 0.008) attachment and negatively with human aortic endothelial cell migration distance (p ⫽ 0.05). Conclusion: We found that 316L stainless steel has the lowest fibrinogen-, platelet-, and monocyte-binding potential among metals, most polymers, and ceramics used in the manufacture of coronary stents. Also, it has the highest affinity for migrating endothelial cells. The use of coating materials to improve the biocompatibility of stainless steel does not seem justified.
TCT-186
Conclusion: With contemporary design, stents can have high radial strength without loss of flexibility and vice versa. Older designs (Multilink and Crossflex) had high flexibility but low radial strength. Stent choice can be tailored for lesion characteristics, eg, a stent of high radial strength may be chosen for an ostial lesion, or a high-flexibility stent may be chosen for an acute bend.
TCT-187 Stent/Delivery System Characteristics That Influence Delivery: Benchtop Measurements of Profile and Flexibility. J.A. Ormiston, M.W.I. Webster, P.N. Ruygrok, J.T. Stewart, E. Currie, M.J. Panther. Green Lane and Mercy Hospitals, Auckland, New Zealand. Background: The ease with which a stent can be delivered to a lesion is dependent on characteristics such as stent/delivery system (SDS) flexibility and profile (diameter). In addition SDS profile is important in direct stenting and use of smaller-caliber guides. These characteristics remain important in the drug-eluting stent era. Independent quantitative assessment can assist the interventionalist in rational stent selection. Methods: Flexibility of 3 examples of each SDS was measured 3 times using our previously published standardized 3-point bend test method. SDS profile was measured with a calibrated microscope 3 times at 3 sites on 3 examples of each SDS. Stents tested were Duraflex
Expanded Stent Radial Strength and Flexibility: Benchtop Testing of 10 stents. J.A. Ormiston, J. Blake, C. Peebles, M.W.I. Webster, J.T. Stewart, P.N. Ruygrok, B. O’Shaughnessy. Green Lane and Mercy Hospitals, Auckland, New Zealand. Background: The radial strength of the expanded stent determines resistance to the compressive forces of calcified, fibrotic, and ostial lesions. The flexibility of the expanded stent is important to allow conformation to vessel contours and to minimize distortion at the stent-vessel junction when stents are deployed on bends. The aim of this study is to compare the relation between expanded stent flexibility and radial strength for 10 stent designs. Methods: Flexibility was measured 3 times for each of 3 examples of each expanded stent using our previously described standardized 3-point bend test. Radial strength was assessed by recording continuously with a luminal intravascular ultrasound transducer the stent
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(Avantec), NIR, Express (Boston), BxVelocity, Crossflex (Cordis J&J), Multilink, Duet, Tetra, Penta (Guidant), S7, AVE, Bestent (Medtronic). Results: See figure. Conclusion: Newer stents have reduced profile by up to 0.4 mm compared with second-generation stents. Overall there has been little change in SDS stiffness but with considerable range from 20 to 60 gm force/mm. Some designs combine low profile with low stiffness, which are 2 important determinants for deliverability.
TCT-188 A Polymer-Based Copper Coating Generates Nitric Oxide from S-Nitrosoglutathione But Does Not Induce Significant Neointimal Formation When Used as a Stent Coating. G. Richardson1,2, J. Gunn4, A.C. Morton4, S.E. Greenwald3, N. Benjamin2, M.T. Rothman1. 1Department of Cardiology, London Chest Hospital, London, United Kingdom; Departments of 2Clinical Pharmacology and 3Morbid Anatomy, St. Bartholomew’s Medical College, London, United Kingdom; 4Cardiovascular Research Group, University of Sheffield, Sheffield, United Kingdom. Background: Current research is directed toward finding an agent that can be coated onto a stent to inhibit in-stent restenosis, a process that involves platelet, inflammatory cell, and vascular smooth muscle cell responses. Nitric oxide (NO) is a potential candidate for this role, as it can theoretically inhibit all aspects of the vascular response to stent deployment, while also enhancing endothelial cell regrowth. S-nitrosothiols (RSNOs) are endogenous circulating NO donors. We have previously shown that NO can be generated from RSNOs by copper, in a dose-dependent manner, to inhibit platelet aggregation in vitro. However, copper-coated stents have been shown by others to induce severe inflammatory responses in the vessel wall. To coat stainless steel with small quantities of copper we have developed a novel polymer-based method. The coating, containing 5% or 20% copper (wt/wt), can be used to generate NO from RSNOs to inhibit platelet aggregation in vitro in a dose-response manner. Methods: Stainless steel discs were implanted into subcutaneous tissues in mice, and inflammatory responses were assessed by measuring histologic tissue changes and macrophage acid phosphatase activity on the surface of the disc 7 days after implantation. The effect of the coating on the development of neointima was then tested in the porcine coronary artery model. Stents coated with the polymer-copper coating (1% and 5% copper [wt/wt]; n ⫽ 6 per group) were deployed at a balloon artery ratio of 1.25:1. The vessels were harvested at 28 days, and the resulting neointimal areas were compared with that seen after implantation of stents coated with polymer alone. Results: The 20% copper coating induced significantly more inflammation in the mouse than both the 5% copper and the polymer coating alone. There were no differences between the effects of 5% copper and the polymer itself. In the porcine coronary artery, neointimal areas (arbitrary units), corrected for vessel size and injury score, were the same in the 3 groups, 0.019 ⫾ 0.001, 0.032 ⫾ 0.009, and 0.021 ⫾ 0.001 for 1% copper, 5% copper and polymer alone, respectively (mean ⫾ SEM; p ⫽ 0.152; 1-way analysis of variance). Conclusion: NO can theoretically inhibit the process of in-stent restenosis. Copper can generate NO from RSNOs, but it has proinflammatory properties. Stents coated with a polymer-copper mixture, at concentrations of copper that will inhibit platelet aggregation in vitro, do not induce significantly more neointimal formation in porcine coronary arteries than those coated with polymer alone. These preliminary data warrant further investigation.
TCT-189 Titanium Nitric Oxide–Coated Stent: First Implantations in Humans and Preliminary 6 Months’ Angiographic Follow-Up.
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C. Caussin1, M. Hamon2, D. Carrie´3, P. Commeau4, G. Grollier2, J. Puel3, B. Lancelin1. 1CC Marie Lannelongue, LePlessis Robinson; 2 CHU Caen, Caen, France; 3CHU Rangueil, Toulouse, France; 4 Polyclinique les Fleurs, Ollioules, France. Background: Titanium nitric oxide (Ti-NO) is biologically inert and has excellent biocompatibility, as exemplified by the lack of a redox and hydrolysis reaction, as well as an absent complex metal ion-organic molecule binding formation. Ti-NO– coated stents have significantly reduced neointimal proliferation compared with stainless steel stent in pigs. The aim of our study was to prospectively evaluate the feasibility, safety, and 6-month angiographic restenosis rate of a Ti-NO stainless steel coated stent (Helistent; Hexacath, France) in humans. Ref Diam (mm)
MLD Pre (mm)
% Area Stenosis (Pre)
MLD Post (mm)
% Area Stenosis (Post)
3.21 ⫾ 0.36
1.14 ⫾ 0.32
86.7 ⫾ 5.7
2.99 ⫾ 0.35
13.2 ⫾ 8.9
MLD ⫽ minimal lumen diameter; Ref Diam ⫽ reference diameter. Methods: Twenty centers prospectively included patients. Inclusion criteria were a single lesion ⬍15 mm in length in a native coronary artery with a reference diameter between 3.0 and 4.0 mm eligible for percutaneous coronary intervention. Exclusion criteria were high-grade calcification, ostial or bifurcation lesion, and ⬍72 hours acute myocardial infarction. Clinical follow-up was performed at 1 month, and angiographic follow-up was systematically performed at 6 months. Quantitative coronary angiography analysis was centralized. Results: A total of 133 patients were included in the study. Mean age was 60.9 ⫾ 11.1 yrs. Prior history of diabetes was 21%; coronary artery bypass graft,1%; percutaneous transluminal coronary angioplasty, 6%; myocardial infarction, 13%. Clinical presentation was unstable angina, 46%; stable angina, 30%; post MI, 15%; silent ischemia, 9%. ACC/AHA classification lesion was A, 29%; B, 71%; and C, 0%. The implantation success rate was 100%. Inhospital events were 1 death due to periprocedure aortic dissection, 1 regressive stroke, and 2 groin haematomas. At 1 month, no subacute thrombosis, no target lesion revascularization, and no myocardial infarction were observed. Conclusion: Immediate and 1-month follow-up results are very promising. The 6-month angiographic follow-up is ongoing. Results of the first 60 patients will be communicated during the presentation.
TCT-190 Can Stent Coating with Turbostratic Carbon Reduce the Rate of Clinical Events and Coronary Restenosis Compared with Stainless Steel Stents? J. Haase, C.E. Schwarz, H. Stoerger, M. Hofmann, H. Braun, F. Schwarz. Red Cross Hospital Cardiology Center, Frankfurt, Germany. Background: Stent coating with turbostratic carbon was supposed to reduce the local inflammatory response after stent implantation and thereby also reduce clinical events and restenosis rates. This study represents the first prospective randomized trial comparing the incidence of major adverse cardiac events (MACE), target lesion revascularization rate (TLR), and binary angiographic restenosis rate after implantation of coronary stents coated with turbostratic carbon versus uncoated stainless steel stents. Methods: From October 1999 to October 2001, a total of 292 patients with symptomatic coronary artery disease eligible for singlelesion percutaneous transluminal coronary angioplasty were randomized for implantation of either a CarboStent: Sorin Biomedica Cardio S.p.A., 13040 Saluggia (VC), Via Crescentino, Italy, Stainless steel stent (Tristar, Tetra, Penta): Guidant Europe NV/SA, Park Lane, Culliganlaan 2B, 1831 Diegem, Belgium (C; n ⫽ 152) or a stainless steel
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stent (S; n ⫽140). S were Tristar stents in 69.3%, Tetra stents in 21.7%, and Penta stents in 10%. There was no between-groups difference with regard to patient age (C: 63.9 ⫾ 10.4 years; S: 62.7 ⫾ 10.0 years); sex (C: 73% men; S: 76% men); incidence of diabetes (C: 20%; S: 17%); or complexity of the lesion (C: type A/B1 56.1%, type B2/C 43.9%; S: type A/B1 64.8%, type B2/C 35.2%). Angiographic follow-up (FU) was obtained after 6 months in 202 patients (69%) and clinical FU in 206 patients (71%). Results: There were no significant differences between C and S with regard to lesion length (C: 10.46 ⫾ 4.56 mm; S: 10.48 ⫾ 4.93 mm), Reference diameter (RD) (C: 2.94 ⫾ 0.59 mm; S: 2.90 ⫾ 0.55 mm), minimal lumen diameter (MLD) pre (C: 0.78 ⫾ 0.36 mm; S: 0.82 ⫾ 0.36 mm), MLD post (C: 2.58 ⫾ 0.43 mm; S: 2.74 ⫾ 0.47 mm), MLD at FU (C: 1.71 ⫾ 0.67 mm; S: 1.66 ⫾ 0.54 mm), late loss (C: 0.88 ⫾ 0.65 mm; S: 1.11 ⫾ 0.58 mm), and angiographic restenosis rate (C: 18.0%; S: 21.6%). There were also no significant differences regarding MACE rates: death (C: 0%; S: 1%), myocardial infarction (C: 0%; S: 1%), coronary artery bypass graft (C: 1%; S: 2.5%), or TLR (C: 17.3%; S: 23.5%). Conclusion: Coronary stents coated with turbostratic carbon gave a nonsignificant trend toward reduction of MACE, TLR, and restenosis rate when compared with uncoated stainless steel stents.
TCT-192 TCT-191
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Stent Mesh Access and Deformation in the Treatment of Coronary Bifurcation Lesions: An In Vitro-In Vivo Study. P. Brunel, B. Leurent, Y. Banus, J.P. Cebron, D. Gras. Unite´ de Soins et de Cardiologie Interventionelle, NCN Clinique St.-Henri, Nantes, France.
Efficacy of Polytetrafluoroethylene-Covered Stent Implantation in Emergency Treatment of Coronary Ruptures During Percutaneous Coronary Interventions. I. Sheiban, K. Prathap, C. Moretti, C. Paone, T. Montaldo, A. Gangnor, I. Paglia, S. Colangelo, S. Frea, G.P. Trevi. Interventional Cardiology, Division of Cardiology, University of Torino, Turin, Italy.
Background: Good technical tips were developed for coronary bifurcation lesion (CBL) stenting. Treatment of CBL remains a compromise between technical access to the side branch and good conformation and coverage of the lesion for better long-term results. We wanted to analyze the behavior of different stent designs when used for the treatment of CBL with crossing the mesh with guidewire, balloon, and stents. Methods: In vivo side-branch access through the strut (with 0.014-in guidewire, balloon, and premounted stent) was analyzed in 50 procedures with different stent designs. In vitro evaluation of mesh deformation of different 3-mm stent designs (BxVelocity, Biodyvisio, Express, AVES7, Helistent, Penta, Sirius, Jostent, and DLCstent) before and after a 3-mm balloon inflation through the mesh and then after final kissing balloon (performed without any constraint) was done. We measured axial deformation, metal-induced stenosis, and percentage of element stretch adjacent to the crossed strut. Results: Mesh design is depicted in the Figure. Easy insertion of 0.014-in wire occurred in 40 cases (80%). Insertion was difficult in 8 cases (16%) and impossible in 2 cases (4%). Failure to cross the mesh and side branch with a balloon occurred in 1 case (2%). A stent was successfully inserted in all 3 attempted cases. Success was 100% in the main branches and 92% in the side branches. The angle between the proximal and distal part of the deformed stent was 17° to 79°; induced stenosis was 3% to 29% and 0% to 10 % after kissing balloon. Strut stretch was 4% to 63%. Data on deformations induced in a bench bifurcation model to include the action-reaction process due to the arterial wall will be presented. Conclusion: Access of side branches through a stent mesh remains difficult or impossible in 20% of the cases. Stent-induced stenosis and axial deformation by side branch balloon are well corrected after kissing balloon. Axial deformation and strut stretch demonstrate a large range of values. Global design preservation of adjacent crossed meshes seems to be associated with the type of link between basic constituent elements.
Background: Coronary perforation or rupture is a rare but life-threatening complication of percutaneous coronary intervention (PCI). When prolonged balloon inflation and reversal of anticoagulation are unsuccessful, surgery becomes mandatory. However, in recent years, the implantation of a covered stent at the site of the perforation has emerged as an additional strategy when the traditional conservative approach fails. In particular, thanks to the ready-to-use attribute, the polytetrafluoroethylene (PTFE)-covered coronary stent has emerged as a new tool for the nonsurgical treatment of this complication. In the present study we report our experience in the treatment of coronary perforation during PCI procedures Methods: In the last 2 years, PCI was complicated with coronary rupture or perforation in 9 patients (9 of 1,772; 0.5%) and was treated with 11 PTFE-covered stents. Two covered stents were needed in 2 patients to seal the culprit lesion. Coronary perforation or rupture occurred after stent implantation in calcified and angled lesions that were predilated with Cutting Balloon in 4 patients, after directional coronary atherectomy in 2 patients, after rotational atherectomy with Rotablator in 2 patients, and following balloon dilatation in 1 patient (during angioplasty for chronic total occlusion). Results: All vessel perforations or ruptures treated with PTFEcovered stent were successfully sealed. The time necessary to deploy the stent was 8 ⫾ 3 minutes (range, 4 to 12 minutes). All patients were discharged from the hospital and had optimal early clinical outcome. Percardiocentesis was needed in 4 patients. One patient, with sustained slow-flow in the target vessel, had experienced non–Q-wave myocardial infarction during hospitalization. Clinical follow-up was available in all patients. At 9 ⫾ 3 months, all patients were free from any major adverse coronary event. In only 1 patient was repeat percutaneous transluminal coronary angioplasty needed because of recurrence of angina. Conclusion: Coronary rupture during PCIs still represents a rare but life-threatening complication. The data reported in this study support the utility and efficacy of the PTFE-covered stent for the nonsur-
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gical treatment and safe management of vessel perforations or ruptures complicating PCI.
TCT-193 Initial US Experience with Covered Stents in the Treatment of Saphenous Vein Graft Lesions: 30-Day Follow-Up. B. Roukoz1, H. Arjomand1, S. Surabhi1, D. McCormick1, Z. Turi1, G. Stone2, D. Baim3, S. Goldberg1. 1MCP Hahnemann University, Philadelphia, Pennsylvania, USA; 2Lenox Hill Hospital, New York, New York, USA; 3Brigham and Women’s Hospital, Boston, Massachusetts, USA. Background: Percutaneous interventions in lesions of degenerated aortocoronary vein grafts are associated with a high risk of short- and long-term adverse coronary events. The 30-day clinical safety and effectiveness of the polytetrafluoreoethylene (PTFE)-covered stents in the treatment of these high-risk lesions were studied in the roll-in phase of this prospective randomized trial. Methods: A group of 88 patients were included in the roll-in phase of a larger randomized trial, with 104 de novo lesions in saphenous vein grafts (SVGs). Patients were randomized to receive ⱖ1 stent. The 30-day complication rate and the incidence of major adverse coronary events (MACE; consisting of death, Q-wave or non–Q-wave myocardial infarction [MI], and target vessel revascularization [TVR]) were available on 79 patients Results: In all, 79 patients with a mean age of 66 years (range, 45 to 87 years; 73% men) received 102 PTFE-covered stents for 97 stenoses in vein grafts 10.2 ⫾ 5.8 years after bypass surgery. Clinical characteristics included diabetes (34%), hyperlipidemia (91%), hypertension (75%), and smoking (64%). Glycoprotein IIb/IIIa inhibitors were used in 65% of cases. Complications and MACE rates are shown in the Table. 30-Day Complications and MACE (n ⴝ 79)
Death Cardiac Noncardiac (bleeding) Q-wave MI Non–Q-wave MI TVR (2 abrupt closures) Any event Major vascular events
n
%
1 1 2 6 3 11 2
1.3 1.3 2.5 7.6 3.8 13.9 2.5
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Conclusion: These preliminary results suggest that the use of covered stents appears to be safe and effective in treating high-risk lesions in SVGs, with a relatively low rate of MACE at 30-day follow-up, especially in-stent thrombosis. A larger randomized study is currently underway comparing this device to bare stents.
TCT-194 Nanomanufactured Stent Grafts: In Vivo Evaluation of Angiographic and Histologic Data. S.R. Bailey1, E. Sprague1, C. Banas2, C. Boyle2, R. Naidu1, J. Palmaz1. 1University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, USA; 2 Advanced Bioprosthetic Surfaces, San Antionio, Texas, USA. Background: Stents are currently manufactured using commercially produced metals that are then cut and polished into tubes for implantation into vessels. Current techniques incorporate impurities into the stent material and its surfaces. The manufacturing process, by etching or laser cutting, increases the impurities. Novel manufacturing techniques using ultralow-pressure magnetrons were developed to allow the manufacture of ultrapure metals specifically for medical implant applications. Methods: Self-expanding stent grafts covered with a nanomanufactured Nitinol mircroporous membrane were implanted into the 12 common carotid arteries in 6 farm swine (sous scrofula) and evaluated angiographically at 10 and 28 days for patency, thrombosis, and neointimal proliferation. Histopathologic data will also be presented. All animals were treated with aspirin and Plavix (clopidogrel; BristolMyers Squibb, Princeton, NJ) for the duration of the study. Results: Angiographic evaluation demonstrated patency in all vessels at 10 and 28 days. All stent grafts were successfully deployed. No acute or subacute thrombosis occurred. All animals survived to the assigned time point. The reference vessel diameter at the time of killing was 4.8 ⫾ 0.15 mm proximally and 4.7 ⫾ 0.67 mm distally. The stent graft diameter was 5.2 ⫾ 0.17 mm proximally and 4.8 ⫾ 0.42 mm distally. The proximal stent was significantly larger (p ⫽ 0.008) than proximal reference vessel without any difference at the distal segments. Only 1 stent exhibited any in-stent stenosis, and this was ⬍20% compared with the reference vessel lumen. Conclusion: Nanomanufacture of new pure thin metals that can be used for micorporous stent grafts can be accomplished. Self-expanding stents covered with an ultrathin membrane can be safely delivered and expanded in carotid vessels. These stent grafts have excellent biocompatibility, without acute or subacute thrombosis and with minimal neointimal proliferation.
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