Patterns of activation and deposition of platelets exposed to the polymeric surface of the paclitaxel eluting stent

The interaction of platelets with the polymeric surface of drug eluting stents has not been fully described in the literature. Our aim was to analyze the patterns of activation and deposition of platelets exposed to two different stent platforms; (a) the polymeric surface of the paclitaxel eluting stent (Taxus^® stent, PES,) and (b) the metallic surface of a stent with identical structural design (Express^® stent, BMS). Platelet activation was tested by deploying stents in an in vitro flow chamber model. Anticoagulated blood of 25 healthy volunteers was circulated (flow rate 10 ml/min for 60 min) into the flow chamber system. P-selectin expression, glycoprotein IIb/IIIa activation (PAC-1 binding) and platelet-monocyte complexes (PMC) formation were evaluated at 0, 10, 30 and 60 min. Surface platelet deposition was assessed by surface electron microscopy in stents implanted in the in vitro system for 60 min and in stents implanted in normal porcine coronary arteries for 24 h. Platelet activation evaluation showed a higher P-Selectin expression (92.9% of baseline in PES versus 68.3 % in BMS, P = 0.01) and higher PMC formation (125.7 % of baseline in PES versus 75.6% in BMS, P < 0.01) in the PES compared to the BMS control group. PAC-1 binding levels did not differ among groups. In the in vitro study, SEM analysis of the stent surface showed no statistical differences on platelet deposition between the groups. In addition, presence of proteinaceous material was more frequently seen on the BMS group (moderate to complete coverage = 80% in BMS versus 26% in PES, P < 0.01). In the in vivo study, complete platelet coverage was similar between groups (PES = 7% versus BMS = 8%, P = NS). However, there was an overall trend towards less platelet deposition on the BMS surface (mild and moderate coverage = 83%, 9% in BMS versus 49%, 44% in PES, P < 0.001 for both) but thrombus formation was not observed in either group. The polymeric surface of the PES appears to induce a higher degree of platelet activation and deposition compared to the BMS surface. The biological implications of these findings on the patterns of vascular healing need to be further studied in vivo. Condensed Abstract The interaction of human platelets with the surface of drug eluting stents has not been fully characterized. Patterns of platelet activation and adhesion were evaluated in vitro and in vivo after exposing platelets to the surface of the paclitaxel-eluting stent and identical bare metal stent. The degree of PMC formation and P-selectin expression was increased in PES compared to BMS. In the in vivo study, complete platelet coverage was similar between groups. There was an overall trend towards less platelet deposition on the BMS surface, however, thrombus formation was not observed on either surface. The polymeric surface of the PES appears to induce a higher degree of platelet activation and deposition compared to the BMS surface.     

Comparison of long-term clinical and angiographic outcomes following implantation of bare metal stents and drug-eluting stents in aorto-ostial lesions

Percutaneous coronary intervention (PCI) to aorto-ostial (AO) lesions is technically demanding and associated with high revascularization rates. The aim of this study was to assess outcomes after bare metal stent (BMS) compared to drug-eluting stent (DES) implantation after PCI to AO lesions. A retrospective cohort analysis was conducted of all consecutive patients who underwent PCI to AO lesions at 2 centers. Angiographic and clinical outcomes in 230 patients with DES from September 2000 to December 2009 were compared to a historical control group of 116 patients with BMS. Comparison of the baseline demographics showed more diabetics (32% vs 16%, p = 0.001), lower ejection fractions (52.3 ± 9.7% vs 55.0 ± 11.5%, p = 0.022), longer stents (17.55 ± 7.76 vs 14.37 ± 5.60 mm, p <0.001), and smaller final stent minimum luminal diameters (3.43 ± 0.53 vs 3.66 ± 0.63 mm, p = 0.001) in the DES versus BMS group. Angiographic follow-up (DES 68%, BMS 66%) showed lower restenosis rates with DES (20% vs 47%, p <0.001). At clinical follow-up, target lesion revascularization rates were lowest with DES (12% vs 27%, p = 0.001). Cox regression analysis with propensity score adjustment for baseline differences suggested that DES were associated with a reduction in target lesion revascularization (hazard ratios 0.28, 95% confidence interval 0.15 to 0.52, p <0.001) and major adverse cardiac events (hazard ratio 0.50, 95% confidence interval 0.32 to 0.79, p = 0.003). There was a nonsignificantly higher incidence of Academic Research Consortium definite and probable stent thrombosis with DES (n = 9 [4%] vs n = 1 [1%], p = 0.131). In conclusion, despite differences in baseline characteristics favoring the BMS group, PCI with DES in AO lesions was associated with improved outcomes, with lower restenosis, revascularization, and major adverse cardiac event rates.     

Comparison of neointimal coverage by optical coherence tomography of a sirolimus-eluting stent versus a bare-metal stent three months after implantation

No detailed data regarding neointimal coverage of bare-metal stents (BMSs) at 3 months after implantation was reported to date. This investigation was designed to evaluate the neointimal coverage of BMSs compared with sirolimus-eluting stents (SESs) using optical coherence tomography. A prospective optical coherence tomographic follow-up examination was performed 3 months after stent implantation for patients who underwent BMS (n = 16) or SES implantation (n = 24). Neointimal hyperplasia (NIH) thickness on each stent strut and percentage of NIH area in each cross section were measured. Malapposition of stent struts to the vessel wall and the existence of in-stent thrombi were also evaluated. There were 5,076 struts of SESs and 2,875 struts of BMSs identified. NIH thickness and percentage of NIH area in the BMS group were higher than in the SES group (351 +/- 248 vs 31 +/- 39 mum; p <0.0001; 45.0 +/- 14% vs 10.0 +/- 4%; p <0.0001, respectively). The frequency of uncovered struts was higher in the SES group than the BMS group (15% vs 0.1%; p <0.0001). Malapposed struts were observed more frequently in the SES group than the BMS group (15% vs 1.1%; p <0.0001). In conclusion, there was no difference in incidence of in-stent thrombus between the 2 groups (14% vs 0%; p = 0.23). The present study showed almost all BMS struts to be well covered at a 3-month follow-up, suggesting that patients receiving BMS stents may not require dual-antiplatelet therapy >3 months after implantation.     

Paradoxical effects of aurintricarboxylic acid and RG-13577: acute thrombosis and in-stent stenosis in a passive-coated stent.

PURPOSE: To investigate if a platelet inhibitor (aurintricarboxylic acid [ATA]) and a heparin-mimicking antagonist (RG-13577) of basic fibroblast growth factor 2 (bFGF2) could be combined as a stable compound and attached to conventional bare metal stents to hinder thrombus formation and inflammatory reactions of stenting. METHODS: Fifteen domestic pigs were stented with RG-13577/ATA-coated (n=6), ATA-coated (n=12), and bare metal stents (n=12) in the left anterior descending (LAD) and left circumflex (LCX) coronary arteries. All surviving pigs were evaluated with contrast angiography and intravascular ultrasonography (IVUS) after 4 weeks. Histological analysis of the stented arteries was performed after hematoxylin-eosin staining. Tissue factor (TF) staining and scanning electron microscopy (SEM) were performed in animals with acute stent thrombosis. RESULTS: Five of the 6 animals receiving an RG-13577/ATA-coated stent experienced acute stent thrombosis, while no adverse events occurred in the animals of the other 2 groups. Follow-up angiography did not show significant in-stent stenosis in either bare or ATA-coated stents. However, histomorphometry revealed larger neointimal area (3.54+/-0.69 mm2 versus 1.82+/-0.27 mm2, p<0.05) and outward plaque area (1.56+/-0.34 mm2 versus 0.61+/-0.12 mm2, p<0.05) in ATA-coated stents. Three-dimensional IVUS analysis showed analogous results, with significantly larger neointimal volume and outward plaque volume in ATA-coated stents. There was a slight increase in TF staining around the stent struts, while SEM showed increased platelet adhesion and activity in RG-13577/ATA-coated stents versus the ATA-coated and bare metal stents. CONCLUSION: RG-13577/ATA-coated stents lead to acute stent thrombosis. The ATA coating alone did not lead to acute events, but resulted in higher neointimal hyperplasia and expansive remodeling. These results underline the importance of preclinical studies before using new coated stents in human arteries.     

Everolimus-eluting versus paclitaxel-eluting stents for treatment of bare metal stent restenosis

First-generation drug-eluting stents have been proved to be very effective for the treatment of bare metal stent in-stent restenosis (BMS ISR). The efficacy of second-generation drug-eluting stents in this setting remains less well defined. The present study compared the long-term clinical outcome after treatment of BMS ISR using the second-generation everolimus-eluting stent (EES) to that after treatment using the paclitaxel-eluting stent (PES). A total of 174 patients with BMS ISR underwent percutaneous coronary intervention using a PES (95 patients) or an EES (79 patients) from 2003 to 2010. The patients in the PES and EES groups were followed up for 42.2 ± 22.2 and 18.3 ± 8.2 months, respectively. The primary end point of the study was survival free of major adverse cardiac events at 1 year. The secondary end points were survival free of the need for revascularization of the target lesion and definite stent thrombosis. The baseline clinical and angiographic parameters were comparable between the 2 groups. The freedom from major adverse cardiac event rate at 1 year of follow-up was 4.5% and 13.6% (p = 0.0663) for the EES and PES groups, respectively. The target lesion revascularization (TLR) rates were greater in the PES group at 1 year of follow-up compared to the EES group (1% vs 11.5%, p = 0.0193). The rate of myocardial infarction, death, and definite stent thrombosis for the EES and PES groups at 1 year of follow-up was 0% versus 4.2% (p = 0.0984), 3% versus 2.1% (p = 0.6855), and 0% versus 2.1% (p = 0.2382), respectively. The use of a PES for treatment of ISR was the only independent predictor of recurrent TLR at 1 year of follow-up (odds ratios 1.11, 95% confidence interval 1.05 to 1.18; p = 0.0193). During the complete follow-up period, the rates of TLR, myocardial infarction, death, major adverse cardiac events, and definite stent thrombosis were not different between the 2 treatment groups. In conclusion, EES resulted in reduced rates of TLR at 1 year of follow-up compared to PES when used for treatment of BMS ISR. However, at long-term follow-up, the event rates between EES and PES were comparable after treatment of BMS ISR.     

Prevention of lesion recurrence in chronic total coronary occlusions by paclitaxel-eluting stents

OBJECTIVES: The aim of this research was to assess the efficacy of paclitaxel-eluting stents in chronic total coronary occlusions (CTO). BACKGROUND: Percutaneous coronary interventions for CTOs are characterized by a high target vessel failure rate. METHODS: In 48 consecutive patients, paclitaxel-eluting stents (Taxus, Boston Scientific Corp., Natick, Massachusetts) were implanted after successful recanalization of a CTO (duration >2 weeks). Patients underwent an angiography after 6 months and were followed clinically for 12 months. They were compared with 48 lesion- and risk-matched patients with CTOs treated with bare metal stents (BMS). Primary clinical end point was the one-year incidence of major adverse cardiac events (MACE) (death, myocardial infarction, repeat revascularization); secondary end points were the rate of restenosis and re-occlusion. RESULTS: In-hospital MACE was 4.2% with Taxus, and 2.1% with BMS (p = NS). The one-year MACE rate was 12.5% in the Taxus group, and 47.9% in the BMS group (p < 0.001), which was due to a reduced need for repeat revascularization. The angiographic restenosis rate was 8.3% with Taxus versus 51.1% with BMS (p < 0.001). There was only one late re-occlusion with Taxus (2.1%) as compared with 23.4% with BMS (p < 0.005). The late loss was reduced in the Taxus group by 84% as compared with BMS. All nonocclusive restenoses in the Taxus group were focal and successfully treated by implanting an additional Taxus stent. CONCLUSIONS: The treatment of CTOs with a paclitaxel-eluting stent drastically reduces MACE and restenosis, and almost eliminates re-occlusion, which is typically frequent with BMS in CTOs. Chronic total coronary occlusion should be a preferred indication for drug-eluting stents.     

光学相干断层成像在冠心病介入治疗中的应用价值

目的应用光学相干断层成像（OCT）技术评价冠状动脉内粥样硬化斑块、血管对置入支架后即刻和中远期的反应。方法20例冠心病患者,有22支血管在完成冠状动脉造影或介入治疗后进行OCT成像。同时获取23个支架OCT成像,在23个支架中有15个为支架术后4～35个月随访,其中7个为雷帕霉素药物洗脱支架,8个为金属裸支架,另外8个为支架置放后即刻成像。结果入选的20例患者均成功进行OCT检查,并获取22支血管和23个支架满意的图像。通过OCT成像清晰地显示8处纤维斑块、3处钙化斑块、9处富含脂质斑块、2处血栓形成、斑块破裂3处及血管壁上夹层、粥样硬化斑块微小裂口和夹层等。7个置入雷帕霉素药物洗脱支架后OCT随访,均未发现有明显再狭窄,支架表面有少量内膜覆盖,部分支架表面没有内膜覆盖,其中1个支架血管出现瘤样扩张、支架与血管壁分离、支架表面没有内膜覆盖,有1个支架没有充分扩张。8个金属裸支架后用OCT随访发现,所有置入金属裸支架后支架表面内膜增殖明显,其中有3个支架因为内膜过度增殖而出现再狭窄,并再次接受介入治疗。8个支架术后即刻OCT检查显示,与血管贴壁均良好、支架扩张充分有3个支架,4个支架充分扩张,但可见到斑块裂片通过支架网眼突入管腔,1个支架支撑杆分布不均,可见支架与血管壁分离,在8个支架中有2个为支架内套叠支架。结论OCT成像技术可清晰显示各种冠状动脉粥样斑块情况,并可用于评价冠状动脉介入治疗的效果。     

Late acute thrombosis after implantation of sirolimus‐eluting stent to treat in‐stent restenosis

Drug‐eluting stents (DES) have significantly reduced the incidence of in‐stent restenosis (ISR) compared to bare metal stents (BMS). However, recent randomized trials comparing DES with BMS reported few cases of late DES thrombosis. We report the case of late sirolimus‐eluting stent thrombosis occurring 22 months after its elective implantation in a restenotic BMS and soon after the interruption of combined anti‐platelet therapy with aspirin and Clopidogrel.     

Tissue characterization of in-stent neointima using intravascular ultrasound radiofrequency data analysis

Using virtual histology and intravascular ultrasound (VH-IVUS), tissue characterization of restenotic in-stent neointima after drug-eluting stent (DES) and bare metal stent (BMS) implantation was assessed. VH-IVUS was performed in 117 lesions (70 treated with DESs and 47 treated with BMSs) with angiographic in-stent restenosis and intimal hyperplasia (IH) > 50% of the stent area. The region of interest was placed between the luminal border and the inner border of the struts and tissue composition was reported as percentages of IH area (percent fibrous, percent fibrofatty, percent necrotic core, percent dense calcium) at the 2 sites of maximal percent IH and maximal percent necrotic core. Mean follow-up times between stent implantation and VH-IVUS study were 43.5 ± 33.8 months for BMS-treated lesions and 11.1 ± 7.8 months for DES-treated lesions (p < 0.001). The 2 groups had greater percent necrotic core and percent dense calcium at maximal percent IH and maximal percent necrotic core sites, especially in stents that had been implanted for longer periods. In conclusion, this VH-IVUS analysis showed that BMS- and DES-treated lesions develop in-stent necrotic core and dense calcium, suggesting the development of in-stent neoatherosclerosis.     

Promising efficacy of the sirolimus-eluting stent in patients with acute myocardial infarction

OBJECTIVES: This study investigated the safety and efficacy of sirolimus-eluting stents (SESs) on early and late outcomes in patients with acute myocardial infarction. METHODS: A series of 100 consecutive patients (September 2004 to November 2005)with acute myocardial infarction undergoing primary stenting using SES ptember 24 hr) was compared with 100 consecutive patients (September 2003 to August 2004) treated with bare metal stent (BMS). The frequency of major adverse cardiac events (MACE) and stent thrombosis, and status of ticlopidine administration were assessed at 270 days. RESULTS: The rates of premature discontinuation of ticlopidine (SES group <3 months: 11%, BMS group <1 month: 11%, p = NS) and stent thrombosis (SES group: 1%, BMS group: 0%, p = NS) were similar in the two groups. At follow-up, restenosis rate and target vessel revascularization rate were lower in the SES group(4% vs 19%, p < 0.001 and 4% vs 10%, p = 0.149, respectively). Furthermore, the occurrence of MACE at 270 days was significantly less frequent in the SES group compared with the BMS group (6% vs. 17%, p = 0.038). Multivariate analysis showed SES use tended to predict 270-day MACE (hazard ratio 0.37, 95% confidence interval 0.14-1.02, p = 0.055). Culprit lesion located in the left main trunk was identified as an independent predictor of 270-day MACE (hazard ratio 5.43, 95% confidence interval 1.07-27.59, p = 0.041). CONCLUSIONS: The use of a SES was not associated with increased risk of stent thrombosis compared with a BMS. With lower rates of restenosis and subsequent target vessel revascularization, SES placement could provide superior outcomes in patients with acute myocardial infarction.     

Difference in neointimal coverage at chronic stage between bare metal stent and sirolimus-eluting stent evaluated at stent-strut level by optical coherence tomography

Compared with the bare metal stent (BMS), suppression of neointimal growth in the sirolimus-eluting stent (SES) reduced restenosis at the cost of more exposed struts that could impose the risk of stent thrombosis. The present study was conducted to analyze neointimal coverage patterns of stents at a strut-level after implantation of BMS or SES with the use of optical coherence tomography (OCT). We enrolled 35 patients and analyzed neointimal coverage of every strut from 41 stents (BMS: n = 8, SES: n = 33) by using OCT at follow-up of the stent implantation. All of the 371 struts from eight BMSs were covered with ≥100 μm of neointima, while 19.8 and 3.5 % of 3,478 struts from 33 SESs were uncovered (neointimal thickness of <10 μm) and malapposed, respectively. The histogram of neointimal thickness showed basically normal distribution in BMS but skewed in SES. No regional difference in neointimal thickness was observed in BMS (proximal, 535.7 ± 25.2 μm; body, 532.4 ± 17.0 μm; distal, 485.8 ± 27.0 μm). In SES, however, the body segment showed thinner neointima [median 40 μm (interquartile range (IQR) 10–90 μm)] than proximal [60 μm (IQR 10–140 μm), p < 0.001] or distal [50 μm (IQR 10–110 μm), p < 0.001] segment, while uncovered and malapposed struts were more frequent in the proximal and body segments. In conclusion, SES, compared with BMS, showed more suppressed neointimal growth with regional variation: neointimal thickness was the least in the body part while the ratio of exposed and malapposed struts was minimal in the distal segment. OCT was useful for a strut-level analysis of neointimal coverage over the whole stent.     

Comparison of Endothelial Barrier Functional Recovery After Implantation of a Novel Biodegradable-Polymer Sirolimus-Eluting Stent in Comparison to Durable- and Biodegradable-Polymer Everolimus-Eluting Stents

AimsThe advantage of biodegradable-polymer drug-eluting stents (BP-DES) versus durable-polymer (DP) DES remains uncertain. We compared neointimal formation and endothelial barrier function of new BP sirolimus-eluting stents (BP-SES, BuMA Supreme®) to other contemporary BP-DES, DP-DES, and bare metal stents (BMS).Methods and resultsLight microscopic assessment in swine coronary arteries showed comparable neointimal formation between BP-SES and DP everolimus-eluting stent (DP-EES). The performance of BP-SES was compared with DP-EES (Xience Xpedition®), BP-EES (Synergy®), and BMS (Multi-Link Vision®) at 45- and 90-days in rabbit ilio-femoral arteries using Evans blue dye (EBD) followed by immunostaining for endothelial barrier proteins (p120/vascular endothelial-cadherin [VE-cad]) to evaluate endothelial barrier function and scanning electron microscopy (SEM) to determine strut tissue coverage. BMS followed by BP-SES and BP-EES exhibited smaller EBD positive areas versus that of DP-EES at 45- and 90-days. p120/VE-cad immunostaining and SEM-determined strut coverage was greater at 45- and 90-days for BMS followed by all DESs. Regardless of stent type, the lack of p120/VE-cad co-localization showed greater leukocyte and platelet aggregation.ConclusionThree types of DES showed different endothelial healing pattern regardless their equivalent suppression of neointimal formation.     

Incomplete neointimal coverage of sirolimus-eluting stents: angioscopic findings.

OBJECTIVES: The goal of this study was to use angioscopy to investigate the amount of neointimal coverage after sirolimus-eluting stent (SES) implantation. BACKGROUND: Sirolimus-eluting stents reduce intimal hyperplasia. METHODS: We used angioscopy to evaluate 37 consecutive stented coronary artery lesions (15 SES and 22 bare-metal stents [BMS]) in 25 patients (18 men, 7 women) at 3 to 6 months after stent implantation. Angioscopic evaluation focused on: 1) neointimal coverage of stent struts, and 2) the existence of thrombi. The degree of neointimal coverage was classified as grade 0 when there was no neointimal coverage (similar to immediately after the implantation); grade 1 when stent struts bulged into the lumen, but were covered and still translucently visible; grade 2 when stent struts were visible but not clearly seen (not translucent); and grade 3 when stent struts were not visible because they were embedded in the neointima. RESULTS: Thrombi were identified in eight stented segments, tended to be more common with SES (p = 0.14), but were not seen on angiography. Three of the 15 SES (20%) had grade 0 neointimal coverage, and only 2 SES (13.3%) had complete coverage (grades 2/3). In contrast, all 22 BMS showed complete intimal coverage (grades 2/3). Thrombi were more common in stents with incomplete neointimal coverage (p = 0.09). CONCLUSIONS: The SES had incomplete neointimal coverage three to six months after implantation, and this was associated with subclinical thrombus formation.     

Impact of final stent dimensions on long-term results following sirolimus-eluting stent implantation: serial intravascular ultrasound analysis from the sirius trial

OBJECTIVES: We assessed the predictive value of minimum stent area (MSA) for long-term patency of sirolimus-eluting stents (SES) implantation compared to bare metal stents (BMS). BACKGROUND: Although MSA is a consistent predictor of in-stent restenosis, its predictive value in BMS is still limited because of biologic variability in the restenosis process. METHODS: From the SIRolImUS (SIRIUS) trial, 122 cases (SES: 72; BMS: 50) with complete serial intravascular ultrasound (IVUS) (baseline and 8-month follow-up) were analyzed. Postprocedure MSA and follow-up minimum lumen area (MLA) were obtained. Based on previous physiologic studies, adequate stent patency at follow-up was defined as MLA >4 mm(2). RESULTS: In both groups, a significant positive correlation was observed between baseline MSA and follow-up MLA (SES: p < 0.0001, BMS: p < 0.0001). However, SES showed higher correlation than BMS (0.8 vs. 0.65) with a higher regression coefficient (0.92 vs. 0.59). The sensitivity and specificity curves identified different optimal thresholds of MSA to predict adequate follow-up MLA: 5 mm(2) for SES and 6.5 mm(2) for BMS. The positive predictive values with these cutoff points were 90% and 56%, respectively. CONCLUSIONS: In this SIRIUS IVUS substudy, SES reduced both biologic variability and restenosis, resulting in increased predictability of long-term stent patency with postprocedure MSA. In addition, SES had a considerably lower optimal MSA threshold compared to BMS.     

Initial and mid-term effects of > or = 30 mm long sirolimus-eluting stents in patients with diffuse long coronary lesions: comparison with bare metal stents

OBJECTIVES AND METHODS: Sirolimus-eluting stents (SES) can reduce restenosis and reintervention compared with bare metal stents (BMS). However, the safety and efficacy of SES for diffuse long lesions remain unknown. This study compared the efficacy of SES and BMS using the initial and mid-term outcomes of 124 patients with 130 long coronary lesions (SES lengths > or = 30 mm) compared to 141 patients with 146 lesions treated with BMS. RESULTS: Quantitative coronary arteriography parameters and initial success rate were not significantly different between the two groups. Occurrence of stent thrombosis was not different between the groups (1 case, 0.7% in group SES vs 0 case, 0% in group BMS). Restenosis and major adverse cardiac event rates at 6 months were lower in the SES group than in the BMS group (3.1% vs 34.2%, p < 0.0001, 3.8% vs 31.5%, p < 0.0001). CONCLUSIONS: Initial effects of sirolimus-eluting stents for diffuse long lesions are as useful and as safe as BMS. The mid-term outcomes for SES are superior due to the lower rates of both restenosis and major adverse cardiac event.     

C-Reactive protein, clinical outcome, and restenosis rates after implantation of different drug-eluting stents

Sirolimus-eluting stents (SESs), paclitaxel-eluting stents (PESs), and dexamethasone-eluting stents (DEXs) have anti-inflammatory properties; thus, the decreased in-segment restenosis rate observed with the use of these stents might be related to a weaker postprocedural inflammatory response. One hundred sixty consecutive patients with stable coronary artery disease who underwent successful single-vessel/lesion coronary artery stenting were prospectively studied. Thin-strut bare metal stents were deployed in 39 patients, SESs in 30, PESs in 61, and DEXs in 30. The 4 groups were similar with respect to demographic and angiographic variables and prevalence of risk factors. C-reactive protein (CRP) was measured at baseline and 24 and 48 hours after the procedure. Maximal increase in CRP was calculated as the increase in CRP at 48 hours/CRP compared with baseline. Angiographic follow-up was performed after 12.9 +/- 1.3 months or sooner, if needed, on the basis of clinical evidence. All patients presented a postprocedural increase in CRP that peaked at 48 hours (median 10.0 mg/L). Maximal CRP increase was similar across the 4 groups (medians 3.5 mg/L in the bare metal stent group, 3.6 mg/L in the SES group, 4.0 mg/L in the PES group, 3.5 mg/L in the DEX group, p = 0.45). Incidences of angiographic binary restenosis (>50% lumen diameter decrease) were 20.5% in the bare metal stent group, 3.3% in the SES group, 4.9% in the PES group, and 36.6% in the DEX group (p = 0.0004 for SES and PES groups vs bare metal stent and DEX groups). Postprocedural increase in CRP was significantly correlated with clinical and angiographic outcomes. In conclusion, the acute postprocedural systemic inflammatory response induced by drug-eluting stent implantation appears to be similar to that induced by bare metal stents. However, the restenosis rate is lower for SESs and PESs than for DEXs and bare metal stents. Thus, the decreased incidence of stent restenosis that was observed after SES and PES deployment is unlikely to be related to a decreased acute systemic inflammatory response, but rather to an increased local resistance to inflammatory mediators.     

Comparison of effects of drug-eluting stents versus bare metal stents on plasma C-reactive protein levels

After coronary stenting, inflammatory mechanisms play a crucial role in the pathogenesis of neointimal proliferation and in-stent restenosis. Drug-eluting stents (DESs) have been shown to decrease in-stent restenosis in different studies. We compared plasma C-reactive protein (CRP) levels after DES implantation with levels after bare metal stent (BMS) implantation. We performed percutaneous coronary intervention with a single stent in 67 patients (54 men; 59 +/- 9 years of age; n = 21 in the BMS group, n = 46 in the DES group) who had stable angina. Plasma CRP levels were determined before intervention and at 48 hours, 72 hours, and 2 weeks after coronary stenting. There was no difference in clinical and angiographic baseline characteristics except that the DES group had more patients with diabetes (34.8% vs 9.5%, p = 0.04), smaller reference vessels (2.95 +/- 0.53 vs 3.29 +/- 0.53 mm, p = 0.02), and smaller stent diameters (3.0 +/- 0.4 mm vs 3.4 +/- 0.5 mm, p <0.01). Plasma CRP levels at 48 hours (13.4 +/- 14.7 vs 5.9 +/- 4.9 mg/L, p <0.01) and 72 hours (16.7 +/- 19.8 vs 5.4 +/- 3.9 mg/L, p <0.01) after stent implantation were significantly higher in the BMS than in the DES group. In conclusion, DESs showed significantly lower plasma CRP levels after coronary stenting compared with BMSs. This may reflect the potent effects of DESs on acute inflammatory reactions induced by coronary intervention.     

Comparison of drug-eluting versus bare metal stents in cardiac allograft vasculopathy

Although not a definitive treatment, percutaneous coronary intervention offers a palliative benefit to patients with cardiac allograft vasculopathy. Given the superior outcomes with drug-eluting stents (DESs) over bare metal stents (BMSs) in native coronary artery disease, similar improvements might be expected in transplant patients; however, the results have been mixed. Consecutive cardiac transplantation recipients at a single center receiving a stent for de novo cardiac allograft vasculopathy from 1997 to 2009 were retrospectively analyzed according to receipt of a DES versus a BMS. The angiographic and clinical outcomes were subsequently evaluated at 1 year. The baseline clinical and procedural characteristics were similar among those receiving DESs (n = 18) and BMSs (n = 16). Quantitative coronary angiography revealed no difference in the reference diameter, lesion length, or pre-/postprocedural minimal luminal diameter. At the 12-month angiographic follow-up visit, the mean lumen loss was significantly lower in the DES group than in the BMS group (0.19 ± 0.73 mm vs 0.76 ± 0.97 mm, p = 0.02). The DES group also had a lower rate of in-stent restenosis (12.5% vs 33%, p = 0.18), as well as a significantly lower rate of target lesion revascularization (0% vs 19%, p = 0.03). At 1 year, DESs were associated with a lower composite rate of cardiac death and nonfatal myocardial infarction (12% vs 38%, p = 0.04). In conclusion, DESs are safe and effective in the suppression of neointimal hyperplasia after percutaneous coronary intervention for cardiac allograft vasculopathy, resulting in significantly lower rates of late lumen loss and target lesion revascularization, as well as a reduced combined rate of cardiac death and nonfatal myocardial infarction.     

Patency of paclitaxel-eluting versus bare metal stents long term after implantation in acute ST-segment elevation myocardial infarction

Drug-eluting stents effectively inhibit neointimal hyperplasia within the first year, thereby reducing the need for repeat revascularization. However, a delayed pattern of restenosis might be more prominent in drug-eluting stents compared to bare metal stents (BMSs). The extent of restenosis of paclitaxel-eluting stents (PESs) long term after implantation in acute ST-segment elevation myocardial infarction is currently unknown. The present study was designed to evaluate very late luminal loss (VLLL) of PESs used in ST-segment elevation myocardial infarction compared to BMSs. A total of 116 patients (61 with PESs and 55 with BMSs) initially included in the Paclitaxel Eluting Stent Versus Conventional Stent in ST-segment Elevation Myocardial Infarction (PASSION) trial and who were free from previous lesion failure underwent angiographic follow-up. Off-line quantitative coronary analysis of the angiogram immediately after stent implantation and at follow-up was performed. The primary end point was VLLL within the stent. The presence of binary restenosis was defined as diameter stenosis >50% as a secondary end point. The mean interval between stent implantation and follow-up was 4.1 ± 0.5 years in both stent groups. In-stent VLLL was 0.12 mm (interquartile range -0.03 to 0.42) in the PES group versus 0.30 mm (interquartile range 0.08 to 0.69) in the BMS group (p = 0.011). In-segment binary restenosis was found in 4 patients (6.6%) with a PES and 6 patients (10.9%) with a BMS (p = 0.40). In conclusion, angiographic follow-up 4 years after implantation in ST-segment elevation myocardial infarction showed that in patients prospectively randomized to PESs or BMSs, VLLL was low in both stent groups. PESs were associated with lower VLLL than BMSs, and the observed rate of binary restenosis was not significantly different between the 2 stent groups.     

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.