Comparison of thrombosis and restenosis risk from stent length of sirolimus-eluting stents versus bare metal stents

Selection of coronary stent length varies from covering only the zone of maximum obstruction to stenting from normal- to normal-appearing vessels. With bare metal stenting, for any given lesion there is a high restenotic risk associated with longer stent length. With drug-eluting stents, the relation between stent length and restenosis has not been evaluated. In the angiographic follow-up cohort of the SIRIUS trial that compared the sirolimus-eluting Bx Velocity stent with the standard Bx Velocity stent (n = 699), we constructed a multiple regression model to predict 8-month percent diameter stenosis using the main effects of lesion length and excess stent length beyond the lesion length and adjusting for known predictors of restenosis. Stent length exceeded lesion length in 94% of lesions overall. Mean difference in length was 8.3 +/- 8.3 mm (mean lesion length 14.6 +/- 5.9 mm, mean stent length 22.9 +/- 9.6 mm). Stented lesion length and excess stent length were associated with absolute increases in percent diameter stenosis per 10 mm of 9.1% (p <0.0001) and 3.6% (p = 0.053) in the bare metal arm and 3.5% (p = 0.047) and 2.1% (p = 0.040) in the sirolimus-eluting stent arm. Although the effects of lesion length and excess stent length on restenosis were markedly decreased with sirolimus-eluting stents (vs bare metal stents), a small restenotic penalty is still paid for excessive stent length. Longer stent-to-lesion length strategies should be used only when a shorter stent is likely to result in incomplete lesion coverage and edge dissection, a strong determinant of stent thrombosis.     

Six-month angiographic and 12-month clinical follow-up of MultiLink long (25 to 35 mm) stents for long coronary narrowings in patients with angina pectoris

There are limited prospective angiographic data on stent deployment for long coronary lesions. This multicenter prospective study enrolled 120 patients with a single de novo stenosis >20 mm in length, in a native vessel > or =3 mm diameter, suitable for a MultiLink stent 25 to 35 mm in length with additional stent deployment if required. Quantitative angiography before and immediately after stenting and at 6-month follow-up assessed restenosis for the complete lesion and for 5-mm segments of the stented and adjacent nonstented vessel. By 1 year, myocardial infarction had occurred in 3% and target vessel repeat revascularization in 12% of patients. The mean stented length (35.8 +/- 14.6 mm) closely matched mean lesion length (30.1 +/- 13.5 mm). Restenosis to > or =50% diameter loss occurred in 32% of patients, but to > or =70% in only 8%. Of the 147 segments (5 mm in length) with baseline stenosis <25%, only 3 patients (2%) developed restenosis of > or =50%, and only in 1 of these was it > or =70%. Stenting of long narrowings is associated with good clinical outcome and a low rate of severe restenosis. Mildly diseased segments of long lesions covered by a stent rarely became severely narrowed and had negligible influence on the overall restenosis rate. These data support a strategy of full lesion coverage by stent deployment.     

Two-year follow-up intravascular ultrasound analysis after bare metal stent implantation in 120 lesions.

The objective of this study was to examine long-term changes after bare metal stent implantation in a relatively large number of patients. There are few reports of intravascular ultrasound (IVUS) studies performed on stented and nonstented (reference) segments beyond 6 months after bare metal stenting. Using IVUS, we evaluated serial changes in stented and reference segments between 6 and 24 months after stent implantation in 110 patients with 120 lesions. Serial IVUS images were acquired at five equidistant intrastent sites and at two different reference segment sites. Measurements were made of the external elastic membrane (EEM), stent, lumen, and intimal hyperplasia (IH = stent - lumen) area. For the whole patient group, between 6 and 24 months, the mean IH area in stented segments decreased from 2.6 +/- 1.0 to 2.3 36+/- 0.9 mm2 (P < 0.001), and the mean lumen area increased from 6.2 +/- 2.0 to 6.5 +/- 1.9 mm2 (P < 0.001). The mean IH area decreased in 91 lesions (76%) and increased in 29 lesions (24%) between 6 and 24 months. There were no significant changes in EEM or lumen area in the reference segments. Late angiographic restenosis (diameter stenosis > or = 50%) occurred in three lesions between 6 and 24 months. A late target lesion revascularization was performed for one lesion. In the period of time between 6 and 24 months after stenting, IH regression occurred in most (76%) stent lesions, resulting in late lumen increase. However, IH progression was observed in 24% of in-stent lesions. No significant changes of EEM or lumen area occurred in the reference segments.     

Angiographic pattern of restenosis following implantation of overlapping sirolimus-eluting (Cypher) stents

Sirolimus-eluting stents (Cypher) have been shown to reduce the frequency of neointimal hyperplasia and restenosis compared with bare metal stents. However, the clinical implication of overlapping stents with regard to the pattern of restenosis is unclear. All patients who underwent angiography at our institution from May 2003 to March 2005 who had previously received 2 overlapping Cypher stents in native coronary lesions and had binary restenosis were included in our study. Quantitative coronary analysis was performed to determine the degree and location of the restenotic lesion with respect to the overlapping stented segment. The primary end point was to determine how often restenotic lesions occurred at the overlapped segment versus the nonoverlapped stented segments. During the study, 11 patients fit the inclusion criteria for our study; 91% were men and 55% had diabetes mellitus. The mean total stent length was 33.7 +/- 8.2 mm. The mean length of the overlapped segment was 5.9 +/- 3.8 mm, equating to 19 +/- 16% of the total stented area. The average time to follow-up angiography was 277 +/- 126 days. All 11 lesions exhibited type 1 (focal) restenosis. Of these 11 lesions, 10 had focal restenosis at the overlapped segment (p = 0.01, binomial test). The single case involving in-stent restenosis in the nonoverlapped segment occurred at the proximal stent edge. In conclusion, the pattern of restenosis observed in our study suggests a higher relative incidence of binary restenosis in the overlapped stented segment in patients who receive 2 overlapping Cypher stents.     

Clinical and angiographic outcomes after placement of multiple overlapping drug-eluting stents in diffuse coronary lesions

Multiple overlapping drug-eluting stents have increasingly been used to treat diffuse coronary disease, but the safety and efficacy of this approach remains unclear. We assayed the clinical and angiographic outcomes after placement of "full metal jacket" stents (stented length >or=60 mm) in 347 consecutive patients (352 lesions) with very long de novo coronary lesions. Mean age was 61.0 +/- 10.1 years, and the mean stented length was 71.9 +/- 13.7 mm. The procedural success rate was 97.7%. Major in-hospital complications (1 death, 2 cases of acute stent thrombosis) occurred in 3 patients (0.7%). Angiographic follow-up data, obtained for 230 (234 lesions) of the 328 eligible patients (70.1%), showed that the restenosis rate was 13.7%. Multivariate analysis found that the reference artery diameter (odds ratio 0.05, 95% confidence interval [CI] 0.01 to 0.33, p = 0.002) and the use of Taxus stents (odds ratio 2.88, 95% CI 1.03 to 8.04, p = 0.043) were significant predictors of restenosis. During follow-up (16.6 +/- 6.9 months), 9 deaths (6 cardiac and 3 noncardiac), 1 nonfatal myocardial infarction, and 13 target lesion revascularizations occurred. The cumulative probability of survival without major adverse cardiac events (cardiac death, Q-wave myocardial infarction, and target lesion revascularization) was 95.4 +/- 1.1% and 91.4 +/- 2.1% at 1 and 2 years, respectively. Left ventricular dysfunction (ejection fraction <45%) was the only predictor of stent thrombosis (hazard ratio 18.24, 95% CI 1.65 to 201.19, p = 0.018) and cardiac death/Q-wave myocardial infarction (hazard ratio 5.37, 95% CI 1.28 to 22.49, p = 0.021). In conclusion, full metal jacket drug-eluting stents may be a safe and effective method to treat diffuse coronary disease and may be a useful treatment option for complex long lesions.     

Stented segment length as an independent predictor of restenosis.

OBJECTIVES: We sought to evaluate the relation between stented segment length and restenosis. BACKGROUND: Multiple or long coronary stents are now being implanted in long lesions or in tandem lesions. A longer stented segment might result in a higher probability of restenosis. However, there is little information available on the relation between stented segment length and restenosis. METHODS: Between April 1995 and December 1996, 725 patients with 1,090 lesions underwent stenting. Lesions were divided into three groups according to the length of the stented segment: 1) group I (n = 565): stented segment length < or =20 mm; 2) group II (n = 278): stented segment length >20 but < or =35 mm; and 3) group III (n = 247): stented segment length >35 mm. RESULTS: There was no significant difference in the incidence of subacute stent thrombosis among the three groups (0.4% in group I, 0.4% in group II, 1.2% in group III; p = NS). The minimal lumen diameter (MLD) after stenting was greater in group I than in group III (3.04 +/- 0.60 mm in group I, 3.01 +/- 0.54 mm in group II, 2.91 +/- 0.58 mm in group III; p < 0.05). At follow up, a smaller MLD was observed in group III as compared with group I and group II (2.04 +/- 0.93 mm in group I, 1.92 +/- 1.00 mm in group II, 1.47 +/- 0.97 mm in group III; p < 0.01). The restenosis rates were 23.9% in group I, 34.6% in group II and 47.2% in group III (p < 0.01). Using multivariate analysis, the longer stented segment, the angiographic reference vessel diameter and the percent diameter stenosis after stenting were independent predictors of restenosis. CONCLUSIONS: The present study shows that a longer stented segment is an independent predictor of restenosis without an influence on the risk of subacute thrombosis.     

Randomized, double-blind, multicenter study of the Endeavor zotarolimus-eluting phosphorylcholine-encapsulated stent for treatment of native coronary artery lesions. Clinical and angiographic results of the ENDEAVOR II Trial

AIM: The use of the Endeavor stent might reduce restenosis and stent thrombosis at 9 months. METHODS: Patients (n =1,197) treated for single coronary artery stenosis were enrolled in a prospective, randomized, double-blind study and randomly assigned to receive the Endeavor zotarolimus-eluting phosphorylcholine polymer-coated stent (n= 598) or the same bare metal stent but without the drug or the polymer coating (n=599). RESULTS: The 2 groups were well matched in baseline characteristics. Diabetes was present in 20.1% of patients; the mean reference vessel diameter was 2.75 mm; and the mean lesion length was 14.2 mm. The primary end point of target vessel failure at 9 months was reduced from 15.1% with the bare metal stent to 7.9% with the Endeavor (P=0.0001), and the rate of major adverse cardiac events was reduced from 14.4% with the bare metal stent to 7.3% with the Endeavor (P=0.0001). Target lesion revascularization was 4.6% with Endeavor compared with 11.8% with the bare metal stent (P=0.0001). The rate of stent thrombosis was 0.5% with the Endeavor, which was not significantly different from 1.2% with the bare metal stent. In 531 patients submitted to angiographic follow-up, late loss was reduced from 1.03+/-0.58 to 0.61+/-0.46 (P<0.001) in stent and from 0.72+/-0.61 to 0.36+/-0.46 (P<0.001) in segment. The rate of in-segment restenosis was reduced from 35% to 13.2% with Endeavor (P<0.0001). There was no excessive edge stenosis, aneurysm formation, or late acquired malposition by intravascular ultrasound imaging. Differences in clinical outcome were maintained at 12 and 24 months (P<0.0001). CONCLUSIONS: Compared with bare metal stents, the Endeavor stent is safe and reduces the rates of clinical and angiographic restenosis at 9, 12, and 24 months.     

Influence of stent length to lesion length ratio on angiographic and clinical outcomes after implantation of bare metal and drug-eluting stents (the TAXUS-IV Study)

Longer bare metal stent lengths have been associated with greater restenosis. However, the effect of the ratio of stent length to lesion length on clinical and angiographic restenosis after implantation of bare metal and drug-eluting stents has not been clearly defined. Patients in the TAXUS-IV study who underwent single-study stent placement were categorized into tertiles based on ratios of stent length to lesion length. Clinical results at 1 year and angiographic outcomes at 9 months were compared across the 3 groups. The median ratios of stent length to lesion length were 1.20, 1.58, and 2.27 in the 3 tertiles. Analysis segment restenosis rates at 9 months were similar across the 3 tertiles with bare metal stents (24.7% vs 26.7% vs 23.8%, respectively, p = 0.90 for trend) and paclitaxel-eluting stents (11.7% vs 6.5% vs 5.4%, respectively, p = 0.24). Similarly, there were no differences in 1-year rates of target lesion revascularization across the 3 tertiles for bare metal stents (14.6% vs 14.8% vs 13.7%, respectively, p = 0.91) or paclitaxel-eluting stents (6.1% vs 3.6% vs 4.0%, respectively, p = 0.38). By multivariate analysis, the ratio of stent length to lesion length was an independent predictor of neither 9-month angiographic restenosis nor 1-year target lesion revascularization in the bare metal stent arm (odds ratio 1.21, p = 0.36, and hazard ratio 0.80, p = 0.31, respectively) or in the paclitaxel-eluting stent arm (odds ratio 0.86, p = 0.76, and hazard ratio 0.58, p = 0.21, respectively). These data do not support the arbitrary use of larger ratios of stent length to lesion length in patients who undergo implantation of drug-eluting stents.     

Funneling: enhancing results of small-vessel stenting

Until October 2008, coronary drug-eluting stents with a diameter of ≤2.5 mm were not approved by the FDA. Target vessels of ≤2 mm in diameter pose a major challenge in view of high restenosis rates when stented bare metal stents (BMS) are used and distal edge dissection when oversized stents are deployed. Described is a method (“funneling”) to optimize stenting of small vessels. This strategy combines stenting the distal part of the lesion with short (8–12 mm length) 2-mm bare metal stent while stenting with a larger-diameter (≥2.5 mm) drug-eluting stent (DES) with considerable DES–BMS overlap (leaving only the distal 4–6 mm of the BMS not overlapped by a DES). The two stents create a funnel that is for the most part drug eluting. With funneling, both drug elution and larger diameter are attained, minimizing both edge dissection and restenosis.     

Impact of carbon coating on the restenosis rate after stenting of atherosclerotic renal artery stenosis.

PURPOSE: To investigate the impact of carbofilm coating and low-profile rapid exchange stent devices on the restenosis rate after stent-angioplasty of atherosclerotic renal artery stenosis (RAS). METHODS: During a 2-year period (7/2002-7/2004), 143 consecutive patients with 179 primary ostial atherosclerotic RAS>or=70% diameter stenosis were treated with stents selected at the discretion of the operator. Eighteen patients (32 lesions) treated with 9 different types of stents were excluded from the analysis, leaving 125 patients (69 men; mean age 67 years, range 42 to 90) with 147 lesions who received either a Radix carbofilm-coated stent in 78 (53%) lesions (68 [54%] patients) or a Palmaz Genesis bare stainless steel stent in 69 (47%) lesions (57 [46%] patients). The target vessel diameter ranged from 5 to 7 mm. RESULTS: Baseline characteristics were similar in both groups except the mean stent diameter, which was larger in the bare stent cohort (6.4+/-0.7 versus 5.9+/-0.5 mm, p<0.001). Primary success was 100% in both groups; the initial mean diameter stenosis was reduced from 79%+/-14% and 80%+/-14% in the coated versus bare stent groups to 3+/-5% and 2+/-6%, respectively. After a mean follow-up of 22+/-5 months, the restenosis rate was 6.4% for the coated stent and 5.8% for the bare stent (p=0.87). For the entire cohort, restenosis rates varied significantly (p<0.05) according to stent diameter: 19% (5/26) for 5 mm, 4% (3/81) for 6 mm, and 2.5% (1/40) for 7 mm. In a binary logistic regression analysis including carbofilm coating, stent diameter, gender, diabetes, smoking status, and body mass index, stent diameter was the only independent predictor of restenosis (odds ratio 0.12, 95% CI 0.03 to 0.48 [p=0.003] for a 1-mm increase in vessel diameter). CONCLUSIONS: Using modern low-profile stent devices, carbofilm coating does not significantly reduce the restenosis rate compared to a bare metal stent. With contemporary stent devices, the restenosis rate has been decreasing compared to earlier reports in the literature.     

Assessment of coronary artery stent restenosis by 64-slice multi-detector computed tomography.

AIMS: We investigated the feasibility of assessing coronary artery stent restenosis using a new generation 64-slice multi-detector computed tomography-scanner (MDCT) in comparison to conventional quantitative angiography. METHODS AND RESULTS: MDCT was performed in 64 consecutive patients (mean age 58+/-10 years) with previously implanted coronary artery stents (102 stented lesions: mean stent diameter 3.17+/-0.38 mm). Each stent was classified as 'evaluable' or 'unevaluable', and in evaluable stents, the presence of in-stent restenosis (diameter reduction >50%) was determined visually. Results were verified against invasive, quantitative coronary angiography. Fifty-nine stented lesions (58%) were classified as evaluable in MDCT. The mean diameter of evaluable stents was 3.28+/-0.40 mm, whereas the mean diameter of non-evaluable stents was 3.03+/-0.31 mm (P=0.0002). Overall, six of 12 in-stent restenoses were correctly detected by MDCT [50% sensitivity (confidence interval 22-77%)] and in 51 of 90 lesions, in-stent restenosis was correctly ruled out [57% specificity (46-67%)]. In evaluable stents, six of seven in-stent restenoses were correctly detected, and the absence of in-stent stenosis was correctly identified in 51 of 52 cases [sensitivity 86% (42-99%) and specificity 98% (88-100%)]. CONCLUSION: Stent type and diameter influence evaluability concerning in-stent restenosis by MDCT. The rate of assessable stents is low, but in evaluable stents, accuracy for detection of in-stent restenosis can be high.     

Persistent High Restenosis After Local Intrawall Delivery of Long-Acting Steroids Before Coronary Stent Implantation

OBJECTIVE: This pilot study was performed to evaluate the feasibility and safety of intrawall delivery of long acting steroids before stent implantation, testing the efficacy of this treatment in reducing intimal hyperplasia in lesions at high risk for restenosis. METHODS: In 24 patients (40 lesions) local intrawall drug delivery of methylprednisolone acetate, using a new catheter device, was attempted before elective stent implantation. Treated lesions were compared to a matched control group. RESULTS: Lesions were classified AHA/ACC type C in 47% of cases, had a mean lesion length of 13.6 +/- 9.1 mm, and a mean vessel diameter of 2.85 +/- 0.44 mm. In 9 cases (25%) chronic total occlusions were treated. Methylprednisolone acetate (mean 60 +/- 23 mg) was delivered in 36 lesions (21 patients; delivery success 90%) in the remaining 4 lesions (10%) the delivery device did not cross the lesion. After drug delivery 46 stents were implanted (1.2 stent/lesion; stented segment length 30.1 +/- 18.8 mm) using high pressure for stent expansion (mean 16.4 +/- 3.1 atm). Intracoronary ultrasound guidance was used in 64% of cases. Procedural and in-hospital complications were: Two non Q wave myocardial infarctions (8%) and one (3%) subacute stent thrombosis. Angiographic follow-up was obtained in all 36 treated lesions (100%) and the angiographic restenosis rate (3 50% diameter stenosis) was 39%. A reduction of the incidence of restenosis compared to the matched control group was not observed. CONCLUSIONS: Long acting steroids could be delivered locally with high success and low complication rates. The restenosis rate remained high in a subset of unfavorable lesions with high risk for restenosis.     

Sirolimus-eluting stent in chronic total occlusion: the SICTO study

Coronary stenting can significantly reduce the restenosis and reocclusion rates after successful balloon angioplasty for chronic total occlusions (CTO). Nevertheless, recanalization of CTO remains among the worst predictors for in-stent restenosis and reocclusion. This multicenter, nonrandomized study assessed the safety and effectiveness of the CYPHER sirolimus-eluting stent in reducing angiographic in-stent late loss in totally occluded native coronary arteries. A total of 25 eligible patients were treated with the CYPHER sirolimus-eluting stent. Baseline clinical and angiographic data were collected and 6-month follow-up angiography and intravascular ultrasound (IVUS) were performed. Clinical follow-up was required at 30 days, 6, 12, 18, and 24 months. Study stent implantation was successful in all patients, with a mean stent length of 28.4 +/- 11 mm. Six-month angiographic outcomes showed that mean lumen diameter stenosis did not change (2.22 +/- 0.56 mm postprocedure; 2.26 +/- 0.60 mm at 6 months follow-up; P = NS). Similarly, mean percent diameter stenosis did not change significantly (15.7 +/- 8.6% postprocedure, 19.3 +/- 11% at follow-up; P = NS). The absolute late lumen loss was -0.03 +/- 0.28 mm with a 6-month in-stent restenosis rate of 0%. IVUS follow-up revealed in-stent obstruction volume of only 4.9 +/- 6.8%. Long-term clinical follow-up showed target lesion revascularization at 12 months was only 4%, with target vessel revascularization of only 12%. The CYPHER sirolimus-eluting stent was safe and effective in the treatment of CTO compared to historical data with bare metal stents.     

Clinical and angiographic predictors of recurrent restenosis after percutaneous transluminal rotational atherectomy for treatment of diffuse in-stent restenosis

Due to the widespread use of stents in complex coronary lesions, stent restenosis represents an increasing problem, for which optimal treatment is under debate. "Debulking" of in-stent neointimal tissue using percutaneous transluminal rotational atherectomy (PTRA) offers an alternative approach to tissue compression and extrusion achieved by balloon angioplasty. One hundred patients (70 men, aged 58 +/- 11 years) with a first in-stent restenosis underwent PTRA using an incremental burr size approach followed by adjunctive angioplasty. The average lesion length by quantitative angiography was 21 +/- 8 mm (range 5 to 68) including 22 patients with a length > or = 40 mm. Twenty-nine patients had complete stent occlusions with a lesion length of 44 +/- 23 mm. Baseline diameter stenosis measured 78 +/- 17%, was reduced to 32 +/- 9% after PTRA, and further reduced to 21 +/- 10% after adjunctive angioplasty. Primary PTRA was successful in 97 of 100 patients. Clinical success was 97%, whereas 2 patients developed non-Q-wave infarctions without clinical sequelae. Clinical follow-up was available for all patients at 5 +/- 4 months without any cardiac event. Angiography in 72 patients revealed restenosis in 49%, with necessary target lesion reintervention in 35%. The incidence of rerestenosis correlated with the length of the primarily stented segment and the length of a first in-stent restenosis. Thus, PTRA offers an alternative approach to treat diffuse in-stent restenosis. Neointimal debulking of stenosed stents can be achieved effectively and safely. PTRA resulted in an acceptable recurrent restenosis rate in short and modestly diffuse lesion, whereas the restenosis rate in very long lesions remains high despite debulking.     

Preventive effects of the heparin-coated stent on restenosis in the porcine model.

The coronary stent reduces acute coronary arterial occlusion and late restenosis during and after coronary intervention. However, stent thrombosis and restenosis are still major limitations in the widespread use of the coronary stent. Local drug delivery using the heparin-coated stent may be a new approach, which reduces the incidence of stent thrombosis and restenosis. In order to evaluate the effects of the heparin-coated stent on stent restenosis, heparin-coated stents were compared with control stents in a porcine coronary stent restenosis model. Stent overdilation injury (stent:artery = 1.3:1.0) was performed with bare Wiktor stents (group I, n = 10) and heparin-coated Wiktor stents (group II, n = 20; HEPAMED, Medtronics) in porcine coronary arteries. Follow-up quantitative coronary angiography (QCA) was performed at 4 weeks after stenting, and histo-pathologic assessments of stented porcine coronary arteries were compared in both groups. On QCA, percent diameter stenosis was significantly higher in group I than in group II (16.3% +/- 6.62% vs. 9.6% +/- 5.06%, P < 0.05). The injury score of stented porcine coronary arteries was the same in both groups (1. 26 +/- 0.23 vs. 1.20 +/- 0.22). The area of pathologic stenosis of the stented arteries was higher in group I than in group II (41.6% +/- 12.5% vs. 27.1% +/- 9.9%, P < 0.005). The neointimal area was higher in group I than in group II (4.58 +/- 1.41 mm(2) vs. 2.57 +/- 1.07 mm(2), P < 0.05). By immunohistochemistry, the proliferating cell nuclear antigen (PCNA) index was higher in group I compared with group II (11.2% +/- 6.75% vs. 6.3% +/- 4.14%, P < 0.05). The heparin-coated stent is effective in the prevention of late coronary stent restenosis in a porcine coronary stent restenosis model. This may be related to the inhibition of neointimal cell proliferation.     

Long-term evaluation of paclitaxel-coated stents for treatment of native coronary lesions. First results of both the clinical and angiographic 18 month follow-up of TAXUS I

The development of restenoses due to tissue proliferation within the stented segment is a major limitation of conventional stent implantations. Recently published studies have shown that drug-eluting stents effectively decrease the incidence of stent restenosis at 6 month follow-up as compared to bare metal stents. However, a persistent efficacy of this stent design beyond the 6 month period still needs to be proven. Therefore, in this study, we are demonstrating the first 18 month follow-up results of a Paclitaxel-coated coronary stent, based on the patient population of the TAXUS I study, a multicenter randomized study to evaluate both safety and efficacy of the Paclitaxel-coated NIRx stent as compared to an uncoated, bare metal stent. In this study we evaluated the long-term outcome of NIRx patients of our center, in which 20 out of 31 patients of the TAXUS I study with NIRx stent implantation have been enrolled. A clinical follow-up was available in 20 out of 20 patients (100%) 535 +/- 82 days post stent implantation (17.8 months). An angiographic follow-up was available in 14 out of 20 patients (70%) 580 +/- 77 days post stent implantation (19.1 months). The MACE rate at 18 month follow-up was 0.0%. There was no stent restenosis in the study group up to 18 month post drug-eluting stent implantation. There was one non-clinically driven target vessel revascularization due to a stent edge lumen renarrowing, which was subsequently calculated as a 43% diameter stenosis. Accordingly, this event was not regarded as MACE. The IVUS analysis of the study population has shown a decrease of the mean minimum lumen area from 8.45 mm(2) postinterventional to 6.87 mm(2) at 6 month follow-up with a relative mean maximum plaque area of 16%. At 18 month follow-up, there were no additional significant changes with a mean minimum lumen area of 7.16 mm(2) and a relative mean maximum plaque area of 13.4%. The reported results of the 18 month follow-up of TAXUS I are the first experiences demonstrating a persistent benefit of the Paclitaxel-coated NIRx stent. Therefore, this stent design seems to be safe and effective, even in long-term follow-up.     

西罗莫司和紫杉醇洗脱支架治疗支架内再狭窄的临床近期及10个月疗效

目的比较西罗莫司洗脱支架（Cypher或Cypher select）和紫杉醇洗脱支架（TAXUS）治疗支架内再狭窄的临床近期及10个月疗效。方法自2002年12月至2005年3月,对253例支架内再狭窄的患者采用了药物洗脱支架（DES）治疗并完成了10个月的临床随访和冠状动脉造影复查。253例中男性218例,女性35例,年龄30～80岁,平均年龄57．2岁。结果253例（262处病变）中152例使用Cypher支架176个,101例使用TAXUS支架132个。使用的Cypher和TAXUS支架的平均直径分别为（2．96±0．27）mm和（3．05±0,35）mm,P=0．04,平均长度分别为（23.31±6．68）mm和（23．56±6．54）mm,P=0．745。支架内再狭窄表现为100％闭塞29处,≥90％狭窄143处,〈90％狭窄90处。病变类型为A、B1、B2和C型各为9处、45处、73处和135处。PCI的成功率两组均为100％,住院期间无死亡,Cypher组主要心脏不良事件（MACE）发生率为2．63％,TAXUS组为2．97％,P=0．872。10个月临床造影显示在Cypher支架和TAXUS支架组中造影再狭窄率分别为14．0％和29．4％,P=0．075,MACE发生率分别为6．7％和16．0％,P=0．031。结论应用Cypher和TAXUS支架治疗支架内再狭窄有良好的近期临床疗效,10个月疗效Cypher支架优于TAXUS支架。     

Treatment of lesions with a high risk of stenosis. Comparative study in 300 patients of rapamycin- and Paclitaxel-eluting polymer-based stents, and bare metal stents

INTRODUCTION AND OBJECTIVES: Rapamycin- and taxol-eluting stents have been shown to reduce restenosis, but there are no large-scale studies of their usefulness in lesions with a high risk of restenosis, or of the relative merits of the two devices. This prospective study compared their safety and efficacy in lesions with a high risk of restenosis. PATIENTS AND METHOD: We included consecutive patients with lesions to treat that met at least one of the following criteria: a) in-stent restenosis; b) diffuse (>20 mm) restenosis; c) small vessel (< or =2.5 mm) restenosis; or d) total occlusion. Patients received different devices along three consecutive study periods: bare metal (conventional) stents, sirolimus-eluting (rapamycin) stents and paclitaxel-eluting (taxol) stents. RESULTS: One hundred patients in each group were included, for a total of 300 patients. In the sirolimus group, after 8.5+/-2 months of follow-up, there were 2 late thromboses (2%) and only 1 patient (1%) required target lesion revascularization. In the paclitaxel group 2 patients (2%) had in-hospital stent thrombosis (1 acute, 1 subacute), and after 9+/-2.5 months of follow-up only 1 patient (1%) needed target lesion revascularization. In the conventional group, after 8+/-2 months of follow-up, there was 1 subacute thrombosis (1%) and 15 patients (15%) had clinical restenosis requiring target lesion revascularization. Event-free survival curves were significantly better with drug-eluting stents (P<.01 vs conventional stents). CONCLUSION: Rapamycin- and taxol-eluting stents were safe for lesions with a high risk of restenosis. These stents were associated with a lower rate of target lesion revascularization during follow-up compared to bare metal stents.     

Long-segment SFA stenting--the dark sides: in-stent restenosis, clinical deterioration, and stent fractures.

PURPOSE: To determine and compare the rates of in-stent restenosis, late clinical deterioration, and stent fractures in nitinol stents versus Wallstents implanted for suboptimal angioplasty in the superficial femoral artery (SFA). METHODS: Interrogation of an angioplasty database identified 286 consecutive patients (178 men; mean age 67+/-10 years, range 44-87) with severe claudication (n=254) or critical limb ischemia (n=32) who had stents implanted after suboptimal angioplasty over a 5-year period. Wallstents with a mean stented lesion length of 107+/-71 mm were implanted in 116 patients, while nitinol stents were used in 170 patients: 45 SMART stents (mean stented lesion length 139+/-88 mm) and 125 Dynalink/Absolute stents (mean stented lesion length 125+/-84 mm). Patients were followed for in-stent restenosis (>50%) by duplex ultrasound, clinical deterioration by at least 1 Fontaine stage compared to baseline, and stent fractures by biplanar radiography. RESULTS: In-stent restenosis rates at 1, 2, and 3 years were 46%, 66%, and 72% for Wallstents compared to 20%, 36%, and 53% for nitinol stents (p<0.001), respectively, without significant difference between the 2 nitinol stent groups (p=0.59). Clinical deterioration at 1, 2, and 3 years was found in 10%, 15%, and 18% with Wallstents versus 4%, 5%, and 5% with nitinol stents (p=0.014), respectively, without difference between the 2 nitinol stent groups (p=0.47). Fracture rates were 19% for Wallstents after a mean 43+/-24 months, 28% for SMART stents after mean 32+/-16 months, and 2% for Dynalink/Absolute stents after a mean 15+/-9 months. CONCLUSIONS: Intermediate-term in-stent restenosis remains a major problem even with current nitinol stent technology; however, clinical deterioration seems no matter of serious concern with SMART and Dynalink/Absolute stents. Stent fractures may be lower with Dynalink/Absolute stents, but randomized head-to-head comparisons are needed to validate these data.     

Clinical and angiographic results of balloon-expandable intracoronary stents in right coronary artery stenoses

Balloon-expandable stents were placed successfully in 35 (95%) of 37 patients whose right coronary artery lesion was believed to have a poor short- or long-term prognosis with conventional balloon angioplasty because of prior restenosis or adverse lesion morphology. Quantitative angiography showed a reduction in stenosis diameter from 83 +/- 14% to 42 +/- 14% after conventional balloon dilation, with a further reduction to -3 +/- 12% after stent placement (p less than 0.001). There were no acute stent thromboses, but one patient (with two stents and unstented distal disease) developed subacute thrombosis on day 8 after self-discontinuation of warfarin and was treated with thrombolytic therapy and redilation. Follow-up angiography was performed at 4 to 6 months in 25 patients, demonstrating restenosis (83 +/- 13%) in 4 (57%) of 7 patients with multiple stents, but only 3 (17%) of 18 patients with a single stent (p less than 0.05). Six of the seven in-stent restenotic lesions were subtotal (80 +/- 12%) and were subjected to repeat conventional balloon angioplasty (postdilation stenosis 13 +/- 21%). The 18 patients without restenosis had a maximal in-stent diameter stenosis of 29 +/- 15%, corresponding to a maximal focal neointimal thickness of 0.68 +/- 0.26 mm within the stented segment. These preliminary results suggest that the Schatz-Palmaz stent may be a useful adjunctive device in the performance of coronary angioplasty.