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First generation drug-eluting stents (DES) are associated with reduced in-stent restenosis but significant increased risk of very late stent thrombosis (VLST). The absence of polymer in DES systems may reduce the occurrence of VLST. Optic coherence tomography (OCT) has been used for stent analysis as a surrogate safety endpoint. This study aimed to assess the long-term follow up of strut apposition and tissue coverage of BioMatrix DES by OCT. 20 patients undergoing BioMatrix DES (n = 15) or S-Stent BMS (n = 5) implantation were followed for at least 5 years and evaluated by quantitative coronary angiography, intravascular ultrasound, and OCT. The difference between the stent types was evaluated by nonparametric Mann-Whitney U test while categorical variables were evaluated by Fisher exact test. Rates of in-stent late loss were similar between groups [0.40 (0.21;0.77) vs. 0.68 (0.66; 0.82) mm, p = 0.205, for BioMatrix and S-Stent, respectively]. The vessel, stent and lumen volumes did not differ between groups. Patients treated with BioMatrix had significantly less stent obstruction [5.6 (4.4;9.7) vs. 28.6 (24.7;29.0) %, p = 0.001]. OCT analysis of 12 stents (Biomatrix = 9 and S-Stent = 3) demonstrated 126 (8.7 %) uncovered struts in the BioMatrix group compared to 23 (4.0 %) in the S-Stent group (p = 0.297), being the majority of them well apposed (117/126 and 21/23, respectively, p = 0.292). Only 9 (0.6 %) struts in the DES and 2 (0.4 %) struts in the BMS groups were simultaneously uncovered and malapposed (p = 0.924). BioMatrix DES was associated with lower rates of in-stent obstruction, and similar percentage of neointimal coverage on struts and of complete strut apposition.

Background: Current recommendations for antithrombotic therapy after drug-eluting stent (DES) implantation include prolonged dual antiplatelet therapy (DAPT) with aspirin and clopidogrel ≥12 months. However, the impact of such a regimen for all patients receiving any DES system remains unclear based on scientific evidence available to date. Also, several other shortcomings have been identified with prolonged DAPT, including bleeding complications, compliance, and cost. The second-generation Endeavor zotarolimus-eluting stent (E-ZES) has demonstrated efficacy and safety, despite short duration DAPT (3 months) in the majority of studies. Still, the safety and clinical impact of short-term DAPT with E-ZES in the real world is yet to be determined., Methods: The OPTIMIZE trial is a large, prospective, multicenter, randomized (1:1) non-inferiority clinical evaluation of short-term (3 months) vs long-term (12-months) DAPT in patients undergoing E-ZES implantation in daily clinical practice. Overall, 3,120 patients were enrolled at 33 clinical sites in Brazil. The primary composite endpoint is death (any cause), myocardial infarction, cerebral vascular accident, and major bleeding at 12-month clinical follow-up post-index procedure., Conclusions: The OPTIMIZE clinical trial will determine the clinical implications of DAPT duration with the second generation E-ZES in real-world patients undergoing percutaneous coronary intervention., (Copyright © 2012 Mosby, Inc. All rights reserved.)

Objectives: This study sought to assess the temporal course of neointimal hyperplasia (NIH) formation following implantation of 2 different generations of drug-eluting stents (DES)., Background: The amount of NIH following DES implantation correlates with the potency of the antiproliferative drug, its kinetic release, as well as some individual characteristics, as the presence of diabetes mellitus (DM). Recently, some publications have suggested a continuous growth of NIH following DES, which in some cases, might result in late "catch-up.", Methods: Twenty-five patients with single, de novo lesions were treated with sirolimus-eluting stents (SES) (n = 12) and biolimus-eluting stents (BES) (n = 13) and underwent intravascular ultrasound evaluation immediately after the procedure and at 9-month and 5-year follow-ups. The primary endpoint was the comparison of the percentage of NIH obstruction between mid- and long-term follow-up., Results: Mean age was 59 years and 28% of patients had DM. Overall, the percentage of NIH obstruction significantly increased from 9 months to 5 years (1.3% at first follow-up vs. 4.8% at second follow-up, p = 0.002). There was no significant difference in the variation of vessel volume (Δ = -0.70 mm(3)/mm BES vs. Δ = 0.18 mm(3)/mm SES, p = 0.56), lumen volume (Δ = 0.40 mm(3)/mm BES vs. Δ = -0.05 mm(3)/mm SES, p = 0.71), and percentage of NIH obstruction (Δ = 3.0% BES vs. Δ = 3.8% SES, p = 0.55) among DES. However, diabetic patients had a marked NIH increase along the years (NIH volume at second follow-up: 10.15 mm(3) DM vs. 5.11 mm(3) non-DM, p = 0.028)., Conclusions: The present serial intravascular ultrasound assessment supports the occurrence of continuous NIH growth following different generations of DES. These findings seem to be particularly more pronounced among patients with DM., (Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Despite the expressive reduction in the intimal hyperplasia (IH) formation after DES implantation at the mid-term, late restenosis has been recently noticed. Our objective was to determine, by means of serial angiography (QCA) and intravascular ultrasound (IVUS) at two different time points, whether the occurrence of the "late catch-up" phenomenon occurs after sirolimus-eluting stent (SES) implantation. Thirty-eight non-complex patients treated with a single 18-mm SES who had systematic serial QCA and IVUS analyses at mean 8 and 20 months were enrolled. Primary endpoint is to evaluate the temporal course of IH formation after SES implantation, by comparing QCA in-stent late loss and IVUS percent IH obstruction between the invasive follow-ups. Mean cohort age was 59.3 years and 31.6% were diabetics. Baseline reference vessel diameter was 2.8 ± 0.4 mm and lesion length was 11.5 ± 3.5 mm. Left anterior descending artery was the most frequent target vessel (55.3%). Between 8 and 20 months, a non-significant increase in in-stent late loss from 0.10 ± 0.18 to 0.15 ± 0.30 mm (P = 0.38) was observed. By IVUS, a slight increase in the percent IH obstruction (1.03 ± 2.13 to 1.76 ± 1.87%, P = 0.12) was detected between the two evaluations. Interestingly, all the neoformed tissue accrued from 8 to 20 months accumulated in the distal portion of the stent. In the non-complex scenario, SES implantation was associated with a minimal, non-significant increase in the IH volume between 8 and 20 months.

Background: Differences between geographic regions in patient characteristics and outcomes, particularly for acute coronary syndromes, have been demonstrated in clinical trials. Clinical outcomes after percutaneous coronary interventions with the Zotarolimus-eluting stent in a real-world population were assessed over time., Objectives: The influence of geographic location on clinical outcomes with the Zotarolimus-eluting stent was assessed in 3 regions: Asia Pacific, Europe, and Latin America., Methods: A total of 8,314 patients (6,572 Europe, 1,522 Asia Pacific, and 220 Latin America) were followed for 1 year; 2,116 of these (1,613, 316, and 187, respectively) were followed for 2 years. Patient and lesion characteristics, dual antiplatelet therapy, and clinical outcomes were compared between Latin America and the other regions., Results: Patients in Latin America had the highest proportions of risk factors and prior myocardial infarction. Dual antiplatelet therapy usage rapidly declined in Latin America, from 44.9% at 6 months to 22.5% at 1 year and 7.8% at 2 years (Europe: 87.4%, 61.5%, 19.7%; Asia Pacific: 82.4%, 67.0%, 45.7%). There were no significant differences between Latin America and Europe or Asia Pacific for any outcome at either time point. The incidence of Academic Research Consortium definite and probable stent thrombosis was low (<1.2%) among all patients at 1 year and 2 years., Conclusion: Clinical outcomes were comparable between patients in Latin America and Europe, and Latin America and Asia Pacific, despite less favorable clinical subsets in Latin America, a higher risk profile, and markedly lower use of dual antiplatelet therapy over time.

At present, percutaneous coronary intervention with drug-eluting stent (DES) implantation represents the default strategy to treat coronary artery disease in many institutions around the world. However, concerns regarding long-term safety of first-generation DES have prompted the development of novel DES systems such as the NEVO (Cordis Corporation, Johnson & Johnson, Warren, NJ) sirolimus-eluting stent with biodegradable polymer and reservoir technology. In the current report, we present, for the first time, a complete midterm invasive assessment of a patient treated with this novel device in the Res-Elution I study., (Copyright © 2010 Wiley-Liss, Inc.)

Objective: To retrospectively evaluate the 12-month effectiveness of the Endeavor zotarolimus-eluting stent (ZES) in diabetic versus non-diabetic patients enrolled in the E-Five Registry., Design and Setting: The E-Five Registry is a prospective, multicentre registry of 8314 patients presenting with symptomatic coronary artery disease treated with the Endeavor (ZES). Patients were treated at 188 centres located in 37 countries across Europe, Latin America and Asia Pacific., Patients: There were 2721 (32.7%) patients with diabetes (DM) and among these patients 682 were insulin-treated (ITDM) and 2039 were non-insulin-treated diabetic patients (NITDM). Interventions All enrolled patients received an Endeavor ZES and were followed for 12 months., Main Outcome Measurements: The primary outcome measure was major adverse cardiac event (MACE) at 12 months. Secondary endpoints included target lesion revascularisation (TLR), target vessel revascularisation (TVR), target vessel failure (TVF) and stent thrombosis., Results: Compared with non-DM patients, DM patients had higher rates of MACE (9.7% vs 6.4%, p<0.001), TLR (5.3% vs 4.0%, p=0.028) and Academic Research Consortium (ARC) definite and probable stent thrombosis (1.5% vs 0.9%, p=0.041). Compared with non-DM patients, ITDM patients had higher rates of MACE (12.6% vs 6.4%, p<0.001). ITDM patients had higher rates of death (6.7% vs 1.7%, p<0.001), cardiac death (4.5% vs 1.2%, p<0.001) and TLR (6.5% vs 4.0%, p=0.011) than non-DM patients., Conclusions: The Endeavor ZES performed well in DM patients; however, DM patients experienced higher rates of adverse clinical events compared with non-DM patients. TRIAL REG NO:, Clinical Trial Registration Information: http://www.clinicaltrials.gov; Unique identifier: NTC00623441.

Aims: The aim of this study was to investigate the angiographic and intravascular ultrasound (IVUS) findings of the Endeavor zotarolimus-eluting stent (ZES) in patients from a "real-world" clinical practice., Methods and Results: From January to March 2006, 100 patients undergoing routine or emergency percutaneous intervention were prospectively enrolled at one institution. Overall, 39% of the patients were diabetics and 80.8% of lesions were type B2/C. A total of 140 lesions were successfully treated with 174 ZES, and procedural success was 98%. Mean vessel diameter was 2.69 mm and mean lesion length was 16.0 mm; at 6-month angiographic follow-up (completed in 96%), in-stent late lumen loss was 0.66 mm, and in-segment restenosis was 8.2%. Angiographic restenosis was increased among diabetics (15.5 vs. 2.6%, p=0.009), and diabetes was the only significant predictor of angiographic restenosis (OR=15.27 [95%CI 2.45-95.04], p=0.003). By IVUS (performed in 88% at 6-month), % volume obstruction was 14.4+/-13.4%, and there was no late acquired incomplete stent apposition (ISA). At 1-year, overall MACE rate was 6%, including 5 TLRs (4% of patients), with no occurrence of stent thrombosis., Conclusions: In this prospective "real-world" experience, the ZES demonstrated favourable angiographic and IVUS results in complex patients, with overall in-stent late lumen loss of 0.66 mm, and absence of late acquired ISA. At 1-year, there were no safety concerns including absence of death and stent thrombosis.

Objectives: We sought to assess the safety and efficacy of the novel VESTAsync-eluting stent (MIV Therapeutics, Atlanta, Georgia) combining a stainless steel platform with a nanothin-microporous hydroxyapatite surface coating impregnated with a polymer-free low-dose of sirolimus (55 microg)., Background: Durable polymers in first-generation drug-eluting stents (DES) have been linked to local inflammatory reaction leading to a positive vessel remodeling, late incomplete stent apposition, and in some cases, stent thrombosis. The removal of the polymer from the DES system could increase the safety profile of this novel technology., Methods: A total of 15 patients with single de novo lesions in native coronary arteries with 3.0- to 3.5-mm diameter and

Objectives: We sought to investigate the performance and efficacy of the third-generation polymer-free Vestasync-eluting stent (VES)., Background: Recent concerns regarding the long-term safety of drug-eluting stents have been raised. Synthetic polymers have been associated with intensive inflammatory response and late stent thrombosis. Newly developed, the VES combines a stainless steel platform with a nanothin-microporous hydroxyapatite surface coating impregnated with a polymer-free sirolimus formulation (55 mum)., Methods: In May 2007, 15 patients with single de novo lesion located in native coronary arteries 3.0 to 3.5 mm in diameter and < or =14 mm in length were consecutively enrolled. Primary end points included in-stent late lumen loss and in-stent percent of obstruction at 4 months. Serial angiography and intravascular ultrasound were obtained at the index procedure and repeated at 4-month follow-up., Results: Mean population age was 63.8 years; 33% of patients were diabetic. The left anterior descending artery was the prevalent target vessel (47%). Reference vessel diameter and lesion length were 2.67 +/- 0.32 mm and 9.98 +/- 1.98 mm, respectively. The VES was successfully implanted in all cases, and there were no procedure and in-hospital complications. Life-long aspirin and 6-month clopidogrel therapy were prescribed for all patients. At 4 months, in-stent late lumen loss was 0.30 +/- 0.25 mm and percent of stent obstruction was 2.8 +/- 2.2%. After up to 6 months of clinical follow-up, no major adverse cardiac event was registered., Conclusions: The third-generation VES demonstrated excellent acute results in the treatment of de novo coronary lesions. Longer follow-up with a more complex subset of patients and lesions is required to confirm these preliminary results.

Aims: First generation DES have markedly reduced restenosis. However, there is a major interest in developing new DES with greater flexibility, radiopacity and safety profile. The Elixir Medical drug eluting stent is a novel DES that combines a chromium-cobalt platform with novolimus (an antiproliferative sirolimus-analogue drug) and a polymer from the methacrylate family. As potential advantages, it provides a lower drug dose as compared to Cypher (85 microg of novolimus vs. 140 microg of sirolimus) and therefore has a lower polymer load. We sought to evaluate the safety and efficacy of this novel device in reducing neointimal hyperplasia as assessed by QCA and IVUS., Methods and Results: In April 2007 a consecutive cohort of patients with de novo lesions < or = 14 mm in length, located in native coronaries of diameter from 3.0 to 3.5 mm were consecutively enrolled in this First-in-Man study (FIM). By protocol, angiography and IVUS would be done at baseline and repeated at four and eight months. Dual anti-platelet therapy was maintained for a minimum of 12 months. The primary endpoint was QCA lumen loss at 4-month follow-up. Secondary endpoints included MACE, in-stent neointimal obstruction by IVUS and device success. A total of 15 patients were included with 67% female patients and diabetes was detected in 47% of the cohort. Angiographic and procedural success was achieved in all patients. At 4-month angiographic follow-up there was in-stent late lumen loss (0.15 +/- 0.29 mm) by QCA and % volume obstruction (2.6 +/- 2.6) by IVUS. The angiographic in-stent late lumen loss results at eight months were 0.31 +/- 0.25 mm and % volume obstruction by IVUS was 6.0 +/- 4.4%. Late incomplete stent apposition (ISA) were not observed among these patients and no MACE was evidenced through nine month clinical follow-up., Conclusions: In this FIM study, implantation of the novolimus-eluting stent was proven to be feasible, safe and elicited minimum neointimal proliferation. Additional large clinical trials should be considered to confirm these promising results.

Introduction: Vascular response at edges of drug-eluting stents is still not well established, particularly in diabetic patients who are prone to aggressive atherosclerosis progression. Recently, Biolimus and Zotarolimus have demonstrated potent antiproliferative effects., Objective: To compare the vascular responses at edges of sirolimus analogous-eluting stents in patients with and without diabetes, using intravascular ultrasound (IVUS)., Methods: 306 edges were analyzed in 153 patients treated with drug-eluting stents and divided in: diabetics (122 edges) and nondiabetics (166 edges). IVUS was performed postintervention and at 6-month follow-up and included 5 mm distal and proximal to the stented segment. Vessel, lumen, and plaque volumes were calculated. Volume variation (follow-up minus basal) was also calculated. Edge restenosis was defined as obstruction >50%., Results: Baseline characteristics were similar between groups. In both groups the entire lesion length was covered (stent length/lesion length ratio was 1.5 for both groups). There were no differences in edge volumes and restenosis rate between the groups. Among diabetics, there was no significant volume variation. However, in nondiabetic patients there was significant increase in vessel volume in proximal (from 67.1 +/- 22 mm(3) to 72.2 +/- 25 mm(3): P = 0.02) and distal (from 54.4 +/- 22 mm(3) to 59.8 +/- 22 mm(3): P = 0.001) edges., Conclusion: Nondiabetic patients showed a significant positive vascular remodeling in proximal and distal edges of sirolimus analogous-eluting stent. This vascular mechanism was not observed in diabetic patients. Although different vascular responses were observed, restenosis rates were equivalent between the 2 groups at 6-month follow-up., ((c) 2007 Wiley-Liss, Inc.)

Introduction and Objectives: C-reactive protein (CRP) is an inflammatory marker that predicts cardiac events in patients with coronary syndromes. However, data on the relationship between the CRP level and in-stent restenosis are contradictory. The objective of this study was to investigate the relationship between the basal CRP level and the neointimal hyperplasia volume measured by intracoronary ultrasound 4 months after implantation of a zotarolimus-eluting stent., Methods: The study included 40 consecutive patients who underwent zotarolimus-eluting stent implantation. Patients were divided into quartiles according to their preprocedural CRP level. Intracoronary ultrasound was performed after stent implantation and at 4 months, and the neointimal hyperplasia volume was determined using Simpson's rule. Correlation and linear regression analyses were used to evaluate the relationships between variables. Multivariate analysis was used to identify variables that were independently related to neointimal hyperplasia volume., Results: The patients' mean age was 58 (8) years, 55% were male, and 40% had diabetes mellitus. There was no difference in baseline characteristics between the quartiles. The hyperplasia volumes were 4.8 (4.2) microl and 15.8 (10.0) microl in the first and fourth quartiles, respectively (P< .001). There was a significant positive correlation between the CRP level and neointimal hyperplasia volume (r = 0.64, P=.0001). The CRP level, the postimplantation lumen volume, and the final deployment pressure were all independent predictors of neointimal hyperplasia., Conclusions: In this study, an independent correlation was observed between the CRP level before zotarolimus-eluting stent implantation and the neointimal hyperplasia volume at 4-month follow-up.

Background: Despite the effectiveness of sirolimus- and paclitaxel-eluting stents in reducing intimal hyperplasia (IH) and the need for repeat revascularization, concerns about their long-term safety have motivated the search for new drug-eluting stents (DES). Recently developed, the ZoMaxx stent combines a sirolimus-analogous agent (zotarolimus), featuring a phosphorycoline polymer and stainless steel and tantalum platform. We sought to assess the efficacy of this new DES in reducing IH., Methods: A total of 40 patients were treated with the ZoMaxx stent and compared to 50 patients treated with its non-drug-eluting equivalent, the TriMaxx stent. Only single de novo lesions in native coronary vessels greater than or equal to 3.0 mm were enrolled. Serial quantitative coronary angiography and intravascular ultrasound (IVUS) images were obtained at baseline and 6- month follow up. All patients were clinically followed for 1 year. This analysis aimed to compare the percent of IH between the 2 stents. Secondarily, we assessed in-segment late loss, binary restenosis and major adverse cardiac events., Results: Baseline patient and lesion characteristics were comparable between the 2 groups. At follow up, zotarolimus efficiently suppressed neointimal hyperplasia formation with a marked reduction in the percentage of stent obstruction by IVUS (4.6 +/- 3.6% vs. 31.2 +/- 16%; p < 0.0001). Almost 90% of the segments stented with ZoMaxx did not exhibit more than 10% of obstruction. After 1 year, 12 patients treated with the TriMaxx and 2 patients treated with the ZoMaxx presented in-segment binary restenosis (p = 0.03)., Conclusions: In this initial experience, ZoMaxx proved to be clinically safe and superior to its non-drug-coated equivalent in reducing in-stent IH formation and restenosis.

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.

The ZoMaxx Coronary Stent System elutes the antiproliferative agent zotarolimus via a biocompatible phosphorylcholine polymer loaded onto a novel, thin, stainless steel stent platform containing an 0.0007-inch inner layer of tantalum that enhances fluoroscopic radiopacity. The objective of this single-arm prospective clinical trial was to assess the safety and performance of the ZoMaxx stent for the treatment of coronary artery stenosis. Forty consecutive patients with ischemic coronary occlusive disease due to single de novo obstructive lesions of native coronary arteries were treated with 3 x 18 mm ZoMaxx stents at the Dante Pazzanese de Cardiologie in Saõ Paulo, Brazil, between April and July 2005. Independent core laboratories analyzed quantitative coronary angiography and intravascular ultrasound results immediately after stent implantation, and after 4 months. The lesion, procedure, and device-deployment success rates were all 100% (40 of 40). There were no major adverse cardiac events during the study. Follow-up quantitative coronary angiography at 4 months revealed in-stent and in-segment late lumen losses of 0.20 +/- 0.35 and 0.17 +/- 0.35 mm, respectively. Follow-up intravascular ultrasound at 4 months revealed 6.5 +/- 6.2% neointimal volume obstruction. There were no instances of late acquired stent incomplete apposition or stent thrombosis. In conclusion, the ZoMaxx Coronary Stent can be safely implanted for the treatment of de novo coronary artery stenosis. The inhibition of neointima formation as measured by follow-up angiography and IVUS after 4 months suggests therapeutic potential for the reduction of restenosis.

Objective: To assess the performance of multidetector computed tomography in determining late clinical outcomes of patients undergoing sirolimus-eluting stent implantation., Methods: Thirty patients, successfully submitted to sirolimus-eluting stent implantation for more than six months, were selected to participate in the study. All underwent invasive angiography and intravascular ultrasound following CT angiography using iodinated contrast medium at a dose of 1.5 ml/kg., Results: Mean proximal reference diameter was 3.01 +/- 0.31 mm by tomography and 3.14 +/- 0.31 mm by angiography (p = 0.04). When the left circumflex artery was excluded from the analysis, the difference between both examinations was no longer significant (tomography = 3.01 +/- 0.32 mm; angiography = 3.10 +/- 0.30 mm, p = 0.65). Mean distal reference diameter was 2.86 +/- 0.30 mm by tomography and 2.92 +/- 0.32 by angiography (p = 0.25). Mean in-stent minimal lumen diameter was 2.85 +/- 0.25 mm by tomography and 2.85 +/- 0.29 mm by angiography (p = 0.27). Mean minimal in-stent cross-sectional area was 7.19 +/- 1.47 mm(2) by tomography and 6.90 +/- 1.52 mm(2) by intravascular ultrasound (p = 0.36), but there was only a weak correlation between these measurements (r = 0.33)., Conclusion: Computed tomography allows the qualitative assessment of sirolimus-eluting stents, accurate estimate of proximal and distal reference diameters of the target vessel, and in-stent minimal lumen diameter. Its correlation with measurements performed using intravascular ultrasound, however, is less strong.

Stent thrombosis is a rare but potentially fatal complication of percutaneous treatment of coronary disease. Its occurrence after drug eluting stent (DES) placement has raised concerns, especially when it occurs late after the stent implantation. The mechanisms of late thrombosis after DES have yet to be completely understood. By means of serial angiography and intravascular (IVUS) images we described a relatively new and unusual vessel response to drug-eluting stents (e.g. huge positive remodeling in all vessel extension), leading to impressive late-acquired incomplete stent apposition and finally causing stent thrombosis and acute myocardial infarction. After describing the two cases, one after Cypher stent implantation and one after Taxus stent implantation, we briefly reviewed the literature available on stent thrombosis with special emphasis on its late occurrence., (Copyright 2006 Wiley-Liss, Inc.)

Objective: This study aimed at evaluating reduction in intimal hyperplasia volume following angioplasty using sirolimus-eluting stents (Cypher) compared with thin-strut bare-metal stents (Pixel) in patients with small vessels., Methods: Eighty patients with coronary artery disease were prospectively included in two consecutive series, the first using sirolimus-eluting stents (50) and the second using bare-metal stents (30)., Results: The use of sirolimus-eluting stents reduced: in-stent net volume obstruction [5.0% (SE = 0.77) x 39.0% (SE = 4.72), p < 0.001], in-stent late loss [0.25 mm (SE = 0.03) x 1,11 mm (SE = 0.13), p < 0.001], in-segment late loss [0.30 mm (SE = 0.04) x 0.83 mm (SE = 0.11), p < 0.001], in-stent restenosis (0% x 33.3%, p < 0.001) and in-segment restenosis (4% x 36.7%, p < 0.001). The event-free survival rate was 96% in the sirolimus-eluting stent group versus 86.7% in the bare-metal stent group (BMS) (p = 0.190)., Conclusion: Sirolimus-eluting stents are superior to thin-strut bare-metal stents in reducing intimal hyperplasia (less in-stent obstruction and less late lumen loss) in patients with small vessels. The use of these stents significantly reduced angiographic restenosis at eight months.

Background: Sirolimus-eluting stents (SES) have already demonstrated their long-term effectiveness in suppressing neointimal hyperplasia in non-high risk patients. The long-term follow up of diabetic patients treated with SES has not been yet evaluated., Methods and Results: Quantitative coronary angiography and intravascular ultrasound analysis were performed in 35 diabetic patients treated with a SES at short- (6.0 +/- 1.0 months) and long-term (18.5 +/- 4.9 months) follow up. There were no significant changes in the in-stent minimum lumen diameter (MLD) between short- and long-term follow up (2.69 +/- 0.46 vs. 2.61 +/- 0.44 mm; p = 0.5), as well as in the in-lesion MLD (2.38 +/- 0.54 vs. 2.30 +/- 0.62 mm; p = 0.6). None of the patients reached binary restenosis (diameter stenosis > 50%) at either follow-up periods. Stent obstruction volume by 3-D IVUS was very small at short-term follow up and has remained virtually the same at long-term follow up (3.4% vs. 3.5%; p = 0.8). There were no aneurysm formations, late stent strut malappositions or late stent thromboses., Conclusion: The present study demonstrates the 18-month efficacy and safety of SES for the treatment of diabetic patients without the so-called late catch-up phenomenon.

We report the outcomes of patients who had in-stent restenosis (IRS) that was treated with intravascular brachytherapy (IVBT) or sirolimus-eluting stent (SES) implantation. The benefit of IVBT for treating ISR is well documented. SES implantation decreases first-time ISR and, in preliminary reports, has been used to treat ISR. Fifty consecutive patients who had ISR were treated; the first 25 patients underwent SES implantation and the next 25 patients were treated with IVBT using a beta-Cath System (a 40-mm strontium-90/yttrium-90 source). Quantitative angiographic and intravascular ultrasound follow-up were performed at 5.2 +/- 1.1 and 12.1 +/- 1.2 months; clinical follow-up was performed at 15 months. SES deployment and IVBT were successful in all patients. At 12-month follow-up, 8 patients who underwent IVBT had angiographic recurrence (4 in the stent and 4 at the stent edge); only 1 patient who underwent SES implantation developed recurrent ISR. At 12 months, in-stent late luminal loss was similar between the SES and IVBT groups (0.35 +/- 0.45 vs 0.34 +/- 0.46 mm, p = 0.9); however, in-stent net luminal gain was higher in the SES group than in the IVBT group (1.32 +/- 0.13 vs 0.57 +/- 0.19 mm, p <0.0001), and in-lesion late luminal loss was higher in the IVBT group (0.48 +/- 0.32 vs 0.16 +/- 0.42 mm, p = 0.004). At 12 months, intravascular ultrasound stent volume obstruction was higher after IVBT versus than after SES implantation (38.7% vs 6.7%, p <0.0001). At 15-month clinical follow-up, 64% and 96% (p <0.01) of patients who underwent IVBT and SES implantation, respectively, were free of major adverse cardiac events. In conclusion SES implantation for the treatment of ISR was effective and superior to catheter-based IVBT in preventing recurrent neointimal proliferation and angiographic restenosis at 1-year follow-up.

This pilot study evaluated the safety and efficacy of an intensified oral sirolimus regimen (15-mg loading dose 24 hr before PCI, followed by a daily dose of 5 mg for 4 weeks) in 15 patients subjected to elective bare metal coronary stent implantation for de novo lesions. Mean patient age was 59+/-9; 73% were male, and 13% were diabetic patients. The reference diameter was 3.04+/-0.38 mm, and the lesion length was 14+/-2 mm. Angiographic and volumetric intravascular ultrasound (IVUS) analyses were performed in all patients at 6.0+/-0.2 months. Two patients (13%) met the definition of in-segment binary restenosis; in-stent and in-segment angiographic late loss was 0.61+/-0.31 mm and 0.67+/-0.45 mm, respectively, and the percent neointimal volume was 28.5+/-15.8%. At adjacent reference segments, there was neither significant plaque increase nor constrictive vascular remodeling. At 24-month follow-up no deaths, myocardial infarctions, or target lesion revascularizations were detected. Mean sirolimus blood level was 13+/-7 ng/ml. No correlations were found between drug levels and late loss (r=0.15, P=0.59) or IVUS percent neointimal volume (r=0.23, P=0.47). Side effects were frequent (80%), leading to dose reductions in four and drug discontinuation in one patient. The results of this pilot study suggest that an intensified 5-mg oral sirolimus regimen resulted in no relevant improvements in the angiographic and IVUS parameters of restenosis after stent implantation in de novo lesions when compared with historic controls. Considering the efficacy/safety balance, our results do not encourage further trials evaluating the current protocol for the prevention of in-stent restenosis., (Copyright (c) 2005 Wiley-Liss, Inc.)

Background: Despite the proven superiority of sirolimus-eluting stents (SESs) compared with bare stents in the first year after implantation, long-term outcomes of patients treated with these novel devices remain unknown. Our goal was to evaluate the clinical, angiographic, and intravascular ultrasound (IVUS) outcomes of patients treated with SESs 4 years after implantation., Methods and Results: The study included 30 patients treated with sirolimus-eluting Bx Velocity stenting (slow release [SR; n=15] and fast release [FR; n=15]). Twenty-six patients underwent 4-year angiographic and IVUS follow-up and had matched assessments at all time points (index and 4-, 12-, 24-, and 48-month follow-up). One death occurred during the study period in a patient with a patent SES. There were no target-vessel revascularizations or thromboses between 2- and 4-year follow-up examinations. There was no stent thrombosis, target-lesion revascularization, death, or myocardial infarction in the SR group up to 4 years. Cumulative event-free survival rate was 87% for the total population (80% in the FR group and 93% in the SR group). In-stent late loss was slightly greater in the FR group (0.41+/-0.49 mm) than the SR group (0.09+/-0.23) after 4 years. One patient in the FR group had a 52% in-stent restenosis lesion. Percent neointimal hyperplasia volume, as detected by IVUS, remained minimal after 4 years (FR=9.1% and SR=5.7%)., Conclusions: This study confirms the longevity of the optimal outcomes observed in patients treated with sirolimus-eluting Bx Velocity stents 4 years after implantation. In-stent lumen dimensions remained essentially unchanged at 4-year follow-up, particularly in the population treated with the currently available SES (SR formulation).

Conventional sirolimus-eluting stent (SES) implantation typically follows balloon predilation. The impact of direct SES implantation on in-stent neointimal hyperplasia and the adjacent reference segments has not been evaluated. The aim of this study was to analyze direct and conventional SES implantation techniques by angiography and serial intravascular ultrasound. Fifty-three patients with single de novo coronary lesions underwent successful conventional (n = 26) and direct (n = 27) SES implantation. At 6-month follow-up, similar in-stent late luminal loss and decreased neointimal hyperplasia volume were seen in the 2 groups, preserving the luminal dimensions at the edges of the stents.

Drug-eluting stents have been investigated as a treatment option for in-stent restenosis after bare metal stenting. However, it remains unclear whether overlapping drug-eluting stents have a toxic effect on the vessel wall. The aim of this study was to analyze the 1-year intravascular ultrasound findings after 2 overlapping sirolimus-eluting stent implantations in patients with in-stent restenosis lesions. Eight patients required 2 sirolimus-eluting stents, 18 mm in length, for full lesion coverage; these stents were implanted with >1-mm overlap. At 1-year follow-up, there were no significant quantitative changes in intravascular ultrasound measurements within the overlapped segment.

FIM STUDY: We investigated the 2-year safety and efficacy of sirolimus-eluting stents. Thirty patients had a single 18-mm sirolimus-eluting coronary stent implanted. Twenty-eight patients underwent angiographic and intravascular ultrasound follow-up at 2 years. No death occurred during the study period. No patient developed in-stent restenosis. One patient had a 52% in-lesion stenosis that required repeated revascularization and another patient underwent target vessel revascularization. Neointimal hyperplasia volume was minimal at 2 years in both groups. This study demonstrates the 2-year safety and efficacy of sirolimus-eluting stenting. The slow release formulation showed slight superiority over the fast-release formulation in preventing late lumen loss, which was minimal in both groups., Ravel Trial: This-study was a randomized, double-blind study that included 238 patients at 19 medical centers (15 in Europe, 3 in Brazil, and 1 in Mexico). Patients were eligible for the study if they were between 18 and 85 years of age, and had been given a diagnosis of stable or unstable angina or silent ischemia. Additional eligibility criteria were presence of a single primary target lesion in a native coronary artery that was 2.5 to 3.5 mm in diameter and that could be covered by an 18-mm stent stenosis of 51% to 99% of the luminal diameter and a flow rate of grade 1 or higher according to the Thrombolysis in Myocardial Infarction., Results: One hundred twenty patients were randomly assigned to receive the sirolimus-eluting stent, and 118 were assigned to receive the standard stent. At 6 months, the degree of neointimal proliferation, manifested as the mean (+/-SD) late luminal loss, was significantly lower in the sirolimus-stent group (-0.01 +/- 0.33 mm) than in the standard-stent group (0.80 +/- 0.53 mm, P <.001). None of the patients in the sirolimus-stent group, as compared with 26.6% of those in the standard-stent group, had restenosis of >/=50% of the luminal diameter (P <.001). There were no episodes of stent thrombosis. During a follow-up period of up to 1 year, the overall rate of major cardiac events was 5.8% in the sirolimus-stent group and 28.8% in the standard-stent group (P <.001). The difference was due entirely to the higher rate of revascularization of the target vessel in the standard-stent group., Conclusion: Patients with angina who received sirolimus-eluting stents for the treatment of single, primary lesions in native coronary arteries had no angiographic evidence of late luminal loss or in-stent restenosis at 6 months, no episodes of thrombosis, and a very low rate of cardiac events at 1 year.

Background: The safety and efficacy of sirolimus-eluting stenting have been demonstrated, but the outcome of patients treated with this novel technology beyond the first year remains unknown. We sought to evaluate the angiographic, intravascular ultrasound (IVUS), and clinical outcomes of patients treated with sirolimus-eluting stents 2 years after implantation., Methods and Results: This study included 30 patients treated with sirolimus-eluting Bx Velocity stenting (slow release [SR], n=15, and fast release [FR], n=15) in São Paulo, Brazil. Twenty-eight patients underwent 2-year angiographic and IVUS follow-up. No deaths occurred during the study period. In-stent late loss was slightly greater in the FR group (0.28+/-0.4 mm) than in the SR group (-0.09+/-0.23 mm, P=0.007). No patient had in-stent restenosis. At 2-year follow-up, only 1 patient (FR group) had a 52% diameter stenosis within the lesion segment, which required repeat revascularization. The target-vessel revascularization rate for the entire cohort was 10% (3/30) at 2 years. All other patients had < or =35% diameter stenosis. Angiographic lumen loss at the stent edges was also minimal (in-lesion late loss was 0.33+/-0.42 mm [FR] and 0.13+/-0.29 mm [SR]). In-stent neointimal hyperplasia volume, as detected by IVUS, remained minimal after 2 years (FR= 9.90+/-9 mm3 and SR=10.35+/-9.3 mm3)., Conclusions: This study demonstrates the safety and efficacy of sirolimus-eluting Bx Velocity stents 2 years after implantation in humans. In-stent lumen dimensions remained essentially unchanged at 2-year follow-up in the 2 groups, although angiographic lumen loss was slightly higher in the FR group. Restenosis "catch-up" was not found in our patient population.

Background: We have previously reported the safety and effectiveness of sirolimus-eluting stents for the treatment of de novo coronary lesions. The present investigation explored the potential of this technology to treat in-stent restenosis., Methods and Results: Twenty-five patients with in-stent restenosis were successfully treated with the implantation of 1 or 2 sirolimus-eluting Bx VELOCITY stents in São Paulo, Brazil. Nine patients received 2 stents (1.4 stents per lesion). Angiographic and volumetric intravascular ultrasound (IVUS) images were obtained after the procedure and at 4 and 12 months. All vessels were patent at the time of 12-month angiography. Angiographic late loss averaged 0.07+/-0.2 mm in-stent and -0.05+/-0.3 mm in-lesion at 4 months, and 0.36+/-0.46 mm in-stent and 0.16+/-0.42 mm in-lesion after 12 months. No patient had in-stent or stent margin restenosis at 4 months, and only one patient developed in-stent restenosis at 1-year follow-up. Intimal hyperplasia by 3-dimensional IVUS was 0.92+/-1.9 mm(3) at 4 months and 2.55+/-4.9 mm(3) after 1 year. Percent volume obstruction was 0.81+/-1.7% and 1.76+/-3.4% at the 4- and 12-month follow-up, respectively. There was no evidence of stent malapposition either acutely or in the follow-up IVUS images, and there were no deaths, stent thromboses, or repeat revascularizations., Conclusion: This study demonstrates the safety and the potential utility of sirolimus-eluting Bx VELOCITY stents for the treatment of in-stent restenosis.

Background: Restenosis remains an important limitation of interventional cardiology. Therefore, we aimed to determine the safety and efficacy of sirolimus (a cell-cycle inhibitor)-coated BX Velocity stents., Methods and Results: Thirty patients with angina pectoris were electively treated with 2 different formulations of sirolimus-coated stents (slow release [SR], n=15, and fast release [FR], n=15). All stents were successfully delivered, and patients were discharged without clinical complications. Independent core laboratories analyzed angiographic and 3D volumetric intravascular ultrasound data (immediately after procedure and at 4-month follow-up). Eight-month clinical follow-up was obtained for all patients. There was minimal neointimal hyperplasia in both groups (11.0+/-3.0% in the SR group and 10.4+/-3.0% in the FR group, P:=NS) by ultrasound and quantitative coronary angiography (in-stent late loss, 0.09+/-0.3 mm [SR] and -0.02+/-0.3 mm [FR]; in-lesion late loss, 0.16+/-0.3 mm [SR] and -0.1+/-0.3 mm [FR]). No in-stent or edge restenosis (diameter stenosis >or=50%) was observed. No major clinical events (stent thrombosis, repeat revascularization, myocardial infarction, or death) had occurred by 8 months., Conclusions: The implantation of sirolimus-coated BX Velocity stents is feasible and safe and elicits minimal neointimal proliferation. Additional placebo-controlled trials are required to confirm these promising results.