Vascular response to sirolimus-eluting stents delivered with a nonaggressive implantation technique: comparison of intravascular ultrasound results from the multicenter, randomized E-SIRIUS, and SIRIUS trials.

BACKGROUND: The effectiveness of SES to reduce the risk of restenosis was initially demonstrated in short lesions using stent implantation with routine pre-dilatation and post-dilatation. This intravascular ultrasound (IVUS) substudy of the E-SIRIUS trial sought to evaluate local arterial responses to sirolimus-eluting stents (SES) delivered with a stent implantation technique allowing direct stenting and only selectively applying high-pressure post-dilatation. METHODS AND RESULTS: IVUS was performed immediately after intervention and at 8-month follow-up in 51 patients randomised to either bare-metal stents (BMS; Bx-Velocitytrade mark; N=20) or SES (Cyphertrade mark N=31). Direct stenting was allowed (24%) and post-dilation was performed only selectively (32%). Lumen dimensions, intimal hyperplasia and vessel remodeling were compared between SES and BMS. Subsequently, results of SES in the E-SIRIUS IVUS substudy (N=31) were compared to those of SES in the IVUS substudy of the SIRIUS trial (N=137). SES in SIRIUS IVUS substudy were delivered with 100% pre-dilatation and 77% post-dilatation. Baseline stent and reference segment measurements were similar between BMS and SES in E-SIRIUS IVUS patients. Using SES there was a 96% reduction in intimal hyperplasia volume within the stented segment (1.8+/-4.9 vs 50.6+/-39.7 mm3, P<0.001) and a significantly larger minimal lumen cross sectional area at 8-month follow-up (4.5+/-1.1 vs 2.3+/-0.9 mm2, P<0.001). No vessel remodeling was observed with the use of SES. The applied stent implantation technique resulted in a minimal stent/reference vessel area ratio of 0.75+/-0.17 in E-SIRIUS SES as compared to 0.84+/-0.23 in SIRIUS SES (P=0.046). Mean intimal hyperplasia cross-sectional area at follow-up was 0.1+/-0.2 mm2 in the SES group of E-SIRIUS and 0.5+/-0.8 mm2 in the SES group of SIRIUS (P=0.003). CONCLUSIONS: An implantation technique of SES which includes direct stenting and minimizes the use of high-pressure post-dilatation results in less optimal stent expansion. However, follow-up results compare very favourable to those of BMS and are characterised by even less intimal hyperplasia than after a more forceful implantation of SES.     

Randomized comparison of sirolimus and paclitaxel drug-eluting stents for long lesions in the left anterior descending artery: an intravascular ultrasound study.

OBJECTIVES: The goal of this work was to verify whether the superiority of the sirolimus-eluting stent (SES) in inhibiting neointimal hyperplasia could be demonstrated in complex coronary lesions. BACKGROUND: Both the SES (Cypher, Cordis, Miami Lakes, Florida) and the paclitaxel-eluting stent (PES) (Taxus, Boston Scientific, Natick, Massachusetts) have shown a marked reduction in neointimal hyperplasia compared with bare-metal stents. Intravascular ultrasound (IVUS) is the best method to assess arterial response to stent deployment, but few IVUS data are available comparing complex lesions treated with SES or PES. METHODS: We prospectively randomized patients with complex lesions to SES or PES implantation. Intravascular ultrasound and quantitative angiography were performed post-procedure and at 9 months. Mean neointimal hyperplasia area (NIHA), percent of NIHA (NIHA%), mean peristent plaque area (PSPA), and percent of PSPA (PSPA%) were calculated. The primary end point was NIHA% at follow-up. Secondary end points included change in PSPA% and angiographic late luminal loss at follow-up. RESULTS: Of the 100 patients enrolled, 42 receiving the SES and 43 receiving the PES had adequate IVUS assessment. Vessel, plaque, and lumen areas were comparable at follow-up, but NIHA% was significantly lower with SES than PES (7.4 +/- 4.2% vs. 15.4 +/- 8.1%; p < 0.001). A significant reduction in PSPA% was observed with SES (-4 +/- 10% vs. 0 +/- 8%; p = 0.01). Late loss was significantly lower with SES (0.16 +/- 0.19 mm vs. 0.32 +/- 0.33 mm; p = 0.003). CONCLUSIONS: The SES shows a significantly higher inhibition of neointimal hyperplasia compared with PES in complex lesions. However, both stents have excellent IVUS and angiographic results at 9 months. A significant reduction in peri-stent plaque is observed only with SES.     

The wound healing response after implantation of a drug-eluting stent is impaired persistently in the long term

A 70-year-old man underwent stent implantation for right coronary artery (RCA) lesions with a bare metal stent (BMS) and two sirolimus-eluting stents (SES). However, as both the BMS and SES stented sites developed restenosis after 13 months, he underwent target lesion revascularization using directional coronary atherectomy (DCA). On histopathology, the restenosis lesion at the SES-deployed site showed greater inflammation and less re-endothelialization than that at the BMS-deployed site. Three months later, the SES-deployed site developed a second restenosis, in which paclitaxel-eluting stents (PES) were implanted (PES-in-SES), while the BMS-deployed site was restenosis free. Five years later, restenosis was absent in these RCA lesions. However, by optical coherence tomography and/or coronary angioscopy, the PES-in-SES site in the RCA showed poor neointimal coverage over the stent struts and yellowish neointima, suggesting lipid-rich neoatheroma formation, whereas at the BMS site appropriate white neointima formation was observed. Drug-eluting stents still have problems of persistent inflammation, inappropriate neointima formation, and neoatherosclerosis. Although we are now in the era of second generation DESs in which better stent performance would be promising, we should remember that we are obliged to continue to follow-up all patients in whom first generation DESs such as SES or PES have been placed.     

Distribution pattern of neointimal hyperplasia following sirolimus-eluting stent implantation assessed by 3-dimensional intravascular ultrasound

Sirolimus-eluting stents (SES) have been shown to reduce intimal hyperplasia (IH) within the stent. Although angiographic studies have suggested focal distribution of IH, these data are limited by its spatial resolution and the minimal amount of IH. Therefore, the exact distribution pattern of SES IH remains unclear. Ninety-six SIRIUS trial patients who underwent SES (51) or bare metal stent (45) implantation and three-dimensional IVUS at 8 months follow-up were enrolled. Neointimal area (stent-lumen area) was obtained at every 0.5-mm interval throughout the stented segment. The length of each stent with IVUS-detectable neointima was determined and divided by the stented length in each case to normalize the data. Even with IVUS, IH was detectable in very limited SES stented segments (median 8% of total stented length) compared to the diffuse nature of IH within BMS with only 5 stented lesions having segments free from IH. In 25% (13 of 51) of patients, no IH was detectable within whole SES stented segments. In conclusion, SES has reduced not only the total amount of IH, but also limited the distribution. These data suggest that local conditions (heterogeneity of biological responses of particular plaques, pharmacokinetics, or their combination) may play a role in IH following SES implantation.     

Vascular effects of sirolimus-eluting versus bare-metal stents in diabetic patients: three-dimensional ultrasound results of the Diabetes and Sirolimus-Eluting Stent (DIABETES) Trial.

OBJECTIVES: A predefined intravascular ultrasound (IVUS) substudy was performed to evaluate the vascular effects of sirolimus-eluting stent (SES) versus bare-metal stent (BMS). BACKGROUND: The Diabetes and Sirolimus-Eluting Stent (DIABETES) trial is a prospective, multicenter, randomized, controlled trial aimed at demonstrating the efficacy of the SES compared with BMS in diabetic patients. METHODS: Serial intravascular ultrasound analyses were performed in 140 lesions (SES = 75; BMS = 65) immediately after stent implantation and at nine-month follow-up. Vessel, luminal, and stent mean areas and volumes were evaluated at both edges and within the stented segment. Qualitative assessment of residual dissections and stent apposition were also performed. RESULTS: Baseline clinical and angiographic characteristics were similar between groups. At 9 months, in-stent neointimal hyperplasia (NIH) mean area and volume were significantly reduced in the SES group (median NIH area 0.01 mm2 [0.0 to 0.1] vs. 2.0 mm2 [1.0 to 2.9] and median NIH volume 0.11 mm3 [0 to 2.1] vs. 35.3 mm3 [16.6 to 62.6]; both p < 0.0001). In the SES group, stent edges evidenced significant increase in lumen dimensions mainly due to significant increase in vessel volume, whereas those of the BMS group presented vessel shrinkage leading to significant lumen reduction. Late acquired incomplete stent apposition was observed in 11 lesions (14.7%) in the SES group and 0 in the BMS group (p = 0.001). At one year, no stent thromboses occurred in malapposed stents. CONCLUSIONS: The SES implantation effectively inhibits NIH in diabetic patients. The antirestenotic effect of SES is also appreciated at the stent edges. Late acquired stent malapposition is a frequent phenomenon in diabetic patients treated with SES.     

Late incomplete stent apposition after sirolimus-eluting stent implantation: a serial intravascular ultrasound analysis.

OBJECTIVES: We sought to identify the frequency of incomplete stent apposition (ISA) in sirolimus-eluting stents (SES) and clarify its findings and clinical sequelae. BACKGROUND: Late-acquired ISA has been reported in bare-metal stents (BMS) and brachytherapy and recently in drug-eluting stents. However, the characteristics of late ISA in SES have not been clarified. METHODS: From the SIRIUS trial, a randomized, multicenter study comparing SES and BMS, serial qualitative intravascular ultrasound (IVUS; at stent implantation and eight-month follow-up) was available in 141 patients (BMS: n = 61; SES: n = 80). The IVUS images were reviewed for the presence of ISA. RESULTS: Incomplete stent apposition at follow-up was observed in 19 patients (BMS: n = 6 [9.8%]; SES: n = 13 [16.3%]; p = NS). Among these, 12 had ISA after intervention and at follow-up (persistent ISA). Late-acquired ISA was seen in the remaining seven cases, all from the SES group (BMS: n = 0; SES: n = 7 [8.7%]; p < 0.05). In late-acquired ISA, there was an increase in external elastic membrane area (after intervention: 16.2 +/- 2.7 m2; follow-up: 18.9 +/- 3.6 mm2; p < 0.05). The location of stent-vessel wall separation was primarily at the stent edges in persistent ISA cases, whereas late-acquired ISA in SES occurred mostly in the mid portion of the stent. There were no negative clinical events reported for any ISA cases at 12-month clinical follow-up. CONCLUSIONS: Late ISA was observed in 8.7% of patients after SES implantation. There were no negative clinical events associated with this IVUS finding at 12-month clinical follow-up; however, careful long-term follow-up will be necessary.     

A randomized comparison of paclitaxel-eluting stents versus bare-metal stents for treatment of unprotected left main coronary artery stenosis.

OBJECTIVES: To optimize percutaneous coronary intervention (PCI) strategy for unprotected left main (LM) disease, we performed a randomized study: intravascular ultrasound (IVUS)-guided bare-metal stent (BMS) or paclitaxel-eluting stent (PES) implantation after lesion pre-treatment with cutting balloon (CB) for unprotected LM lesions. BACKGROUND: Recent studies have shown promising results in terms of safety and feasibility for patients with LM disease who underwent PCI with stent implantation. However, comparison of BMS and PES for LM lesions has not yet been evaluated. METHODS: One hundred three patients were randomly assigned to receive BMS (n = 50) or PES (n = 53) implantation. All interventions were IVUS guided, and CB pre-treatment before stenting was performed in all patients. All patients were scheduled for 6-month follow-up. RESULTS: Baseline clinical characteristics were comparable in both cohorts. Stent implantation was successful in all lesions. Follow-up analysis showed binary restenosis in 11 (22%) BMS and in 3 (6%) PES patients (p = 0.021). By IVUS, percentage of neointimal volume obstruction at 6 months was reduced from 25.20 +/- 22.02% with BMS to 16.60 +/- 17.25% with PES (p = 0.02). At 6 months, the major adverse cardiac event-free survival rate was 70% in BMS and 87% in PES patients (p = 0.036). CONCLUSIONS: This study demonstrates that PCI of LM with IVUS guidance and CB pre-treatment is safe and effective. No serious procedure-related complications were observed, and clinical outcomes appeared to be good. Finally, the findings demonstrate that implantation of PES may be superior to BMS in the large-diameter LM vessel at 6 months, warranting the performance of a large-scale randomized trial.     

Effectiveness of sirolimus-eluting stent implantation for the treatment of ostial left anterior descending artery stenosis with intravascular ultrasound guidance

OBJECTIVES: This study was designed to evaluate the clinical and angiographic outcomes of sirolimus-eluting stent (SES) implantation for ostial left anterior descending (LAD) lesions compared with bare-metal stent (BMS) implantation. BACKGROUND: The effectiveness of SES implantation for ostial LAD lesions is currently unknown. METHODS: Sirolimus-eluting stents were implanted in 68 consecutive patients with ostial LAD stenoses. The control group was composed of 77 patients treated with BMS during the preceding two years. In the SES group, for complete lesion coverage, stent positioning was intentionally extended into the distal left main coronary artery (LMCA) in 23 patients (34%) with intermediate LMCA narrowing. RESULTS: Compared with the BMS group, the SES group had more multivessel involvement, received fewer debulking atherectomies, underwent more direct stenting, had a greater number of stents, and had more segments stented. The procedural success rate was 100% in both groups. The six-month angiographic restenosis rate was significantly lower in the SES group than in the BMS group (5.1% vs. 32.3%, p < 0.001). During the one-year follow-up period, neither death nor myocardial infarction occurred in either group, but target lesion revascularization was less frequent in the SES group than in the BMS group (0% vs. 17%, p < 0.001). In the SES group, there were no restenoses in cases with LMCA coverage, compared with three restenoses (7.9%) in cases with precise stent positioning (p = NS). CONCLUSIONS: Sirolimus-eluting stent implantation in ostial LAD lesions achieved excellent results regarding restenosis and clinical outcomes compared with BMS implantation. This finding may be associated with reduced neointimal hyperplasia and complete lesion coverage.     

Angiographic and clinical outcomes of a pharmacokinetic study of sirolimus-eluting stents: lesson from restenosis cases.

BACKGROUND: A pharmacokinetic (PK) study was conducted to evaluate sirolimus-eluting stents (SES) in Japanese people, representing the first clinical trial of the use of drug-eluting stents in Japan. METHODS AND RESULTS: The PK study was conducted in 20 patients with 30 lesions treated with sirolimus-coated BX Velocity stents. All lesions were treated with a single SES (3 x 18 mm). Angiographic follow-up was performed at 8 months after SES implantation, and the clinical outcomes were evaluated at 1 year in all cases. All procedures were successful, and all patients were discharged without any adverse cardiac events. The total restenosis rate was 10% (3 lesions) and target vessel revascularization was performed in those 3 cases (15%). Restenoses occurred at the proximal and distal stent margins. Intravascular ultrasound examination of restenosis cases revealed abundant plaque burden at the stent edges even though the luminal area was preserved. CONCLUSIONS: The sirolimus-eluting BX Velocity stent is safe and useful for Japanese patients with coronary artery disease. However, restenosis at proximal stent edge seems to be a problem.     

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.     

Sirolimus- and paclitaxel-eluting stents in comparison with balloon angioplasty for treatment of in-stent restenosis.

This study evaluated the acute and follow-up effectiveness of sirolimus-eluting stents (SESs) and nonpolymer-based paclitaxel-eluting stents (PESs) in comparison will balloon angioplasty for treatment of complex in-stent restenosis (ISR) lesions. Drug-eluting stents have been demonstrated to be highly effective for treatment of de novo lesions. The use of drug-eluting stents for treatment of complex ISR is less well defined. Eighty one lesions with in-stent restenosis (lesion length < 30 mm in a native coronary artery) were treated with either PTCA alone (n = 26 lesions in 25 patients), PES (n = 27 lesions in 24 patients; Achieve, Cook; 3,1 mug paclitaxel/mm(2) nonpolymer-based coating), SES (n = 28 lesions in 28 patients; Cypher, Cordis; 140 mug sirolimus/cm(2) metal surface area). Nine-month MACE rates were 32%, 8%, and 14% (all due to repeated revascularization procedures, except one death in the SES group) in the PTCA, PES, and SES group, respectively. Postintervention minimal lumen diameter in stent was significantly greater in the SES and the PES group in comparison with the PTCA group (2.37 +/- 0.26, 2.54 +/- 0.42, 1.78 +/- 0.23 mm; P < 0.001). At 6-month angiographic follow-up, late loss in stent was 0.77 +/- 0.45, 0.43 +/- 0.53, and 0.29 +/- 0.52 mm for the PTCA, PES, and SES group, respectively (P = 0.005). In-lesion restenosis rate was 61% for the PTCA group, 20% for the PES group, and 13% for the SES group (P = 0.042). The implantation of SES as well as nonpolymer PES proved to be effective for treatment of ISR. The combination of improved acute gain and reduced late loss results in a significantly improved angiographic follow-up result in comparison with PTCA.     

Stent thrombosis after sirolimus- and paclitaxel-eluting stent implantation in daily clinical practice: analysis of a single center registry.

OBJECTIVES: To evaluate stent thrombosis (ST) rate after sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES) implantation in daily clinical practice. BACKGROUND: The safety profile of drug-eluting stents (DES) was predominantly determined in randomized clinical trials with narrow inclusion criteria. Concerns about ST have been raised in unselected patients treated with DES. METHODS: We prospectively evaluated 867 patients undergoing DES implantation, 618 patients with SES, and 249 with PES, in a single academic center. RESULTS: Multivessel disease was present in 72% of patients, multivessel stenting was performed in 17%, long (>18 mm) lesions were treated in 30%, and multiple stents per lesion were needed in 31%. On average, 1.7 +/- 0.8 stents per patient were implanted (stented segment length: 32 +/- 25 mm/vessel). IIb/IIIa inhibitors were used in 7.5%. Intravascular ultrasound (IVUS) guidance was employed in 65% of SES and 50% of PES implantations, and the procedural success rate was 100% in SES and 99% in PES cases. Six-month follow-up was performed in all patients, whereas one-year follow-up was completed in 87% patients of the SES group and in 95% of the PES group. We considered that ST occurred when angiographic evidence of thrombus was available, or when patients experienced sudden cardiac death or either ST-elevation or non-ST-elevation myocardial infarction (MI) through the 12-month follow-up period. The overall incidence of ST was 0.9% (0.4% in SES and 2% in PES, P = 0.03). Of the eight ST, two (25%) were acute, four (50%) subacute, one (12.5%) was a late event, and one (12.5%) a very late event. Seven ST were confirmed by angiography. No IVUS guidance was used in 4/8 (50%) ST patients, while antiplatelet therapy was prematurely discontinued in 3/8 (37.5%). Among ST patients, mortality and nonfatal MI rates were 25% and 37.5%, respectively. No ST was diagnosed between 6 and 12 months, while one very late thrombosis occurred at 15 months. CONCLUSIONS: The incidence of ST after DES use in daily clinical practice is low and similar to that observed in randomized clinical trials.     

Comparison of three-year clinical outcome of sirolimus- and paclitaxel-eluting stents versus bare metal stents in patients with ST-segment elevation myocardial infarction (from the RESEARCH and T-SEARCH Registries)

Sirolimus-eluting stents (SESs) recently proved to be superior to bare metal stents (BMSs) in decreasing the need for repeat revascularization in patients with ST-segment elevation myocardial infarction (STEMI) at 1 year. Whether this also holds for paclitaxel-eluting stents (PESs) is currently unclear and the long-term relatively efficacy of the 2 drug-eluting stents is currently unknown. We investigated the 3-year efficacy of SESs and PESs versus BMSs in patients with STEMI. Primary angioplasty was performed in a consecutive group of 505 patients (BMSs in 183, SESs in 186, PESs in 136). At 3 years, the cumulative mortality rate was comparable in the 3 groups: 13.3% in the BMS group, 11.5% in the SES group, and 12.4% in the PES group (nonsignificant for all). The rate of target vessel revascularization (TVR) was 12.0% in the BMS group compared with 8.0% and 7.7% in the SES and PES groups, respectively (p = 0.12 for BMS vs SES, 0.30 for BMS vs PES, 0.62 for SES vs PES). The cumulative incidence of death, MI, or TVR was 25.5% in the BMS group compared with 17.9% and 20.6% in the SES and PES groups, respectively (p = 0.06 for BMS vs SES, 0.32 for BMS vs PES, 0.45 for SES vs PES). Angiographic stent thrombosis occurred in 2.4% of all patients (BMS 1.6%, SES 2.7%, PES 2.9%). In conclusion, in this relatively small consecutive patient cohort, the use of SESs and PESs was no longer associated with significantly lower rates of TVR and major adverse cardiace events in patients with STEMI after 3 years of follow-up. A high frequency of stent thrombosis was observed in the 2 drug-eluting stent groups.     

Relocation of minimal luminal diameter after bare metal and drug-eluting stent implantation: incidence and impact on angiographic late loss.

Late loss (LL) has been a fundamental angiographic end-point in drug-eluting stents (DES) clinical trials. However, calculation of LL may be affected by a mismatch between post-procedure (PO) and follow-up (FU) sites of the minimal lumen diameter (MLD). Our aims were to investigate the incidence and methodological implications of the relocation of MLD after bare metal (BMS), sirolimus-eluting (SES), and paclitaxel-eluting (PES) stent implantation. Data from DIABETES I and II trials, which involved diabetic patients treated with BMS, SES, and PES, were analyzed. Angiographic data with matched projections between PO and 9-month angiographic FU were included. In-stent, in-lesion, and in-segment analyses included conventional and customized sub-segmental (5-mm/subsegment) methodology. MLD relocation was considered when the sites of MLD shifted a distance > the intrinsic variability of the method. Conventional LL, site matched LL, maximal LL (MaxLL), and average LL (AvgLL) were calculated. Relationships between various LL and 1-year target lesion revascularization (TLR) were investigated. Post MLD was located distally, outside the stent, in > or =65% of the analyses. At FU, MLD relocation occurred in 70.5% (BMS), 40% (SES), and 35% (PES). MLD shifted > or =11 mm on average, mainly towards the stented segment. MLD relocation still occurred in 42.8% (BMS), 33.7% (SES), and 36.4% (PES), when analysis was restricted to in-stent segment. Among LL measurements, MaxLL showed the best association with TLR rates. Relocation of the MLD is a frequent phenomenon after both BMS and DES, and should be taken into account when calculating LL. Comprehensive LL analyses, including MaxLL and AvgLL, provides a better appraisal of the biological and clinical effectiveness of DES.     

Drug-eluting stent implantation could be associated with long-term coronary endothelial dysfunction

Drug-eluting stent (DES) implantation may be associated with endothelial dysfunction. However, changes in long-term endothelial function based on the type of DES remain largely unknown. We assessed coronary endothelial function after DES implantation compared to bare-metal stents (BMS) and determined the differences according to DES type. Patients who had single BMS or DES implantation in the left anterior descending artery and showed no restenosis in follow-up angiography at 6 to 9 months were assigned to the BMS group (5 patients) or DES group (9 sirolimus-eluting stents, SES, and 8 paclitaxel-eluting stents, PES). Endothelium-dependent vasomotion, after intracoronary infusion of acetylcholine, was determined by quantitative coronary angiography. Also, endothelium-independent vasomotion was assessed after nitrate infusion. In the distal and far distal segments, the SES (SES versus BMS, distal: -27.6 +/- 16.3% versus -0.6 +/- 1.6%; P = 0.01, far distal: -24.8 +/- 13.2% versus -0.9 +/- 1.3%; P = 0.02) and PES groups (PES versus BMS, distal: -25.4 +/- 17.1% versus -0.6 +/- 1.6%; P = 0.01, far distal: -26.6 +/- 15.9% versus -0.9 +/- 1.3%; P = 0.01) had similar patterns showing significant vasoconstriction compared with the BMS group. In addition, the DES group showed a significant reduction of diameter in distal (SES: P = 0.001, PES: P = 0.04) and far distal segments (SES: P = 0.002, PES: P = 0.001) compared with proximal and near proximal segments. However, the BMS group did not demonstrate significantly different vasomotion between proximal and distal segments. Vasodilatation by nitrate infusion was preserved in all subjects. SES or PES implantation could be associated with the similar pattern of endothelial dysfunction identified predominantly in the long distal portion of the treated vessel.     

Comparison of paclitaxel-eluting stent and sirolimus-eluting stent expansion at incremental delivery pressures

OBJECTIVES: We sought to compare the adequacy of paclitaxel-eluting stent (PES) and sirolimus-eluting stent (SES) expansion based on intravascular ultrasound (IVUS) imaging criteria at conventional delivery pressures. METHODS: Forty-six patients underwent SES implantation and 42 patients underwent PES implantation for de novo native coronary lesions<33 mm in length with reference lumen diameters of 2.5-3.5 mm. Stents were serially expanded with gradual balloon inflations at 14 and 20 atm. IVUS imaging was performed prior to intervention and after each balloon inflation. Stent expansion (minimal stent cross-sectional area/reference lumen cross-sectional area) was measured. Inadequate stent expansion was defined using the MUSIC criteria (all struts apposed, no tissue protrusion, and final lumen cross-sectional area>80% of the reference or >90% if minimal lumen cross-sectional area was <9 mm2). RESULTS: The baseline characteristics of the two groups were similar except for shorter lesion length, larger mean lumen cross-sectional area, larger lumen diameter, and lower plaque burden in the PES group. Stent expansion was inadequate in 80% of patients with SES versus 63% of patients with PES at 14 atm, although this was not statistically significant. After 20 atm, 48% of patients with SES remained underexpanded as compared with 35% of patients with PES. CONCLUSION: Drug-eluting stents showed significant underexpansion by MUSIC criteria at conventionally used inflation pressures. Higher balloon inflations are required especially during deployment of a SES. IVUS guidance is recommended to ensure optimal results and outcomes with both stents.     

Thirty-day incidence and six-month clinical outcome of thrombotic stent occlusion after bare-metal, sirolimus, or paclitaxel stent implantation

OBJECTIVES: We sought to determine the real-world incidence of angiographically confirmed and possible stent thrombosis (ST) in an unrestricted population during the first 30 days after bare-metal stent (BMS), sirolimus-eluting stent (SES), and paclitaxel-eluting stent (PES) implantation. BACKGROUND: Current data on ST in drug-eluting stents (DES) have come from randomized trials with strict entry criteria, which limits their generalizability to daily practice. METHODS: The study population comprised three sequential cohorts of 506 consecutive patients with BMS, 1,017 consecutive patients with SES, and 989 consecutive patients treated with PES. RESULTS: In the first 30 days after stent implantation, 6 BMS (1.2%, 95% confidence interval [CI] 0.5% to 2.6%; p = 0.9), 10 SES (1.0%, 95% CI 0.5% to 1.8%), and 10 PES (1.0%, 95% CI 0.6% to 1.9%) patients developed angiographically proven ST. Multiple potential risk factors were identified in most patients with ST. Bifurcation stenting in the setting of acute myocardial infarction was an independent risk factor for angiographic ST in the entire population (odds ratio [OR] 12.9, 95% CI 4.7 to 35.8, p < 0.001). In patients with DES who had angiographic ST, 30-day mortality was 15%, whereas another 60% suffered a nonfatal myocardial infarction; no further deaths occurred during six months of follow-up. Including possible cases, 7 BMS (1.4%, 95% CI 0.7% to 2.8%), 15 SES (1.5%, 95% CI 0.9% to 2.4%), and 16 PES (1.6%, 95% CI 1.0% to 2.6%) patients had ST. CONCLUSIONS: The unrestricted use of SES or PES is associated with ST rates in the range expected for BMS. Stent thrombosis was associated with a high morbidity and mortality. Bifurcation stenting, when performed in patients with acute myocardial infarction, was associated with an increased risk of ST.     

Comparison of sirolimus‐eluting stent,paclitaxel‐eluting stent,and bare metal stent in the treatment of long coronary lesions

Objective: This study compared the efficacy of the sirolimus‐eluting stent (SES), the paclitaxel‐eluting stent (PES), and the bare metal stent (BMS) for long coronary lesions. Background: The outcome of drug‐eluting stent (DES) implantation in long coronary lesions remains unclear. Methods: The study involved 527 patients with de novo long coronary lesions (≥24 mm), which were treated with long (≥28 mm) SESs (223 lesions), PESs (194 lesions), or BMSs (201 lesions). Results: Lesions in the SES (36.0 ± 14.9 mm, P < 0.001) and PES (36.3 ± 14.5 mm, P < 0.001) groups were longer than those in the BMS group (32.0 ± 12.3 mm), meaning the two DES groups had longer stented segments than did the BMS group. Six‐month angiographic follow‐up showed the SES (9.3%, P < 0.001) and PES (21.3%, P < 0.001) groups had lower in‐segment restenosis rates than that of the BMS group (42.5%). The rate of major adverse cardiac events (MACE) including death, myocardial infarction, and target lesion revascularization at 9 months was higher in the BMS group (26.6%) than that in the SES (13.0%, P < 0.001) and PES (15.7%, P < 0.001) groups. Posthoc analysis of the two DES groups showed that the in‐segment restenosis rate was lower for the SES than that for the PES group (P = 0.002), while the MACE rate was similar. Conclusions: The use of DESs for long coronary lesions appears to be safe and more effective than the use of BMSs in terms of restenosis and adverse clinical events. SES use was associated with lower late luminal loss and a lower angiographic restenosis rate compared with PES use. © 2006 Wiley‐Liss, Inc.     

Four‐year clinical outcome of sirolimus‐ and paclitaxel‐eluting stents compared to bare‐metal stents for the percutaneous treatment of stable coronary artery disease

Background : There are limited data on the long‐term safety and efficacy profile of coronary stent implantation in patients with stable coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI). Objective : We aimed to assess the 4‐year clinical outcome in patients who received a bare‐metal stent (BMS), sirolimus‐eluting stent (SES), or a paclitaxel‐eluting stent (PES) for the percutaneous treatment of stable angina in our center during 2000–2005. Methods : In the study period, a total of 2,449 consecutive patients (BMS = 1,005; SES = 373; and PES = 1071) underwent a PCI as part of three historical PCI‐cohorts for stable angina and were routinely followed for the occurrence of major adverse cardiac events (MACE). Results : At 4 years follow‐up, 264 BMS patients (26.8%) had a MACE, compared to 75 SES patients (20.9%) and 199 PES patients (23.9%). Multivariate analysis showed that SES and PES were superior to BMS with respect to MACE [hazard ratio (HR) = 0.62, 95% confidence interval (CI): 0.47–0.81; HR = 0.67, 95% CI: 0.55–0.82, respectively]. The occurrence of MACE was significantly lower in the SES and PES population, primarily due to less target‐vessel revascularization (TVR) procedures (HR = 0.53, 95% CI: 0.37–0.75; HR = 0.71, 95% CI: 0.62–0.81, respectively). The occurrence of early, late, and very late stent thrombosis was equally rare with each stent type. There were no significant differences between SES and PES on death, myocardial infarction, TVR, and MACE. Conclusion : These findings suggest that SES and PES result in decreased TVR procedures and MACE compared to BMS at 4 years follow‐up. SES or PES implantation should be the preferred choice over BMS for patients with stable CAD undergoing PCI. © 2010 Wiley‐Liss, Inc.     

Late incomplete apposition after drug-eluting stent implantation: incidence and potential for adverse clinical outcomes.

AIM: Late-acquired incomplete stent apposition (ISA) has been documented after drug-eluting stent (DES) implantation; however, its clinical role remains controversial. We sought to investigate the incidence and long-term clinical consequences of late ISA after implantation of sirolimus- (SES) or paclitaxel-eluting stent (PES) in a non-selected population. METHODS AND RESULTS: From our database, we analysed 195 consecutive patients who underwent DES placement (175 with SES and 20 with PES) into native artery lesions and had serial intravascular ultrasound studies (IVUS) performed at index procedure and after 6-8 months. They were clinically followed for 29 +/- 15 months (median of 24.3 months, interquartile range 18.1-31.6 months). Late ISA was defined as separation of at least one stent strut from the vessel wall in a segment without a side-branch and where the immediate post-implantation IVUS revealed complete apposition of stent struts. We identified 10 patients (5.1%) with late ISA, three patients after PES, and seven patients after SES implantation. ISA was localized almost exclusively at body of the stents (nine out of 10 cases). Mean ISA volume and length were 44.5 +/- 41.9 mm(3) and 7.4 +/- 11 mm, respectively. There was a marked increase in vessel volume from 416.0 +/- 163.9 mm(3) at baseline to 514.4 +/- 247.9 mm(3) at follow-up (P = 0.001) with no significant change in plaque volume (232.4 +/- 52.7 at baseline and 226.4 +/- 22.3 mm(3) at follow-up, P = 0.3) in patients who presented with late-acquired ISA. During the follow-up period, one patient with SES and one patient with PES who presented late-acquired ISA had late stent thrombosis and acute myocardial infarction. CONCLUSION: Late-acquired ISA was observed in 5.1% of patients after DES implantation and is related to regional vessel positive remodelling. The relationship between late-acquired ISA and long-term adverse outcomes (e.g. stent thrombosis) requires further analysis.