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The hemodynamic influence of vessel shape such as bifurcation angle is not fully understood with clinical and quantitative observations being equivocal. The aim of this study is to use computational modeling to study the hemodynamic effect of shape characteristics, in particular bifurcation angle (BA), for non-stented and stented coronary arteries. Nine bifurcations with angles of 40°, 60° and 80°, representative of ±1 SD of 101 asymptomatic computed tomography angiogram cases (average age 54±8 years; 57 females), were generated for (1) a non-stented idealized, (2) stented idealized, and (3) non-stented patient-specific geometry. Only the bifurcation angle was changed while the geometries were constant to eliminate flow effects induced by other vessel shape characteristics. The commercially available Biomatrix stent was used as a template and virtually inserted into each branch, simulating the T-stenting technique. Three patient-specific geometries with additional shape variation and ±2 SD BA variation (33°, 42° and 117°) were also computed. Computational fluid dynamics (CFD) analysis was performed for all 12 geometries to simulate physiological conditions, enabling the quantification of the hemodynamic stress distributions, including a threshold analysis of adversely low and high wall shear stress (WSS), low time-averaged WSS (TAWSS), high spatial WSS gradient (WSSG) and high Oscillatory Shear Index (OSI) area. The bifurcation angle had a minor impact on the areas of adverse hemodynamics in the idealized non-stented geometries, which fully disappeared once stented and was not apparent for patient geometries. High WSS regions were located close to the carina around peak-flow, and WSSG increased significantly after stenting for the idealized bifurcations. Additional shape variations affected the hemodynamic profiles, suggesting that BA alone has little effect on a patient׳s hemodynamic profile. Incoming flow angle, diameter and tortuosity appear to have stronger effects. This suggests that other bifurcation shape characteristics and stent placement/strategy may be more important than bifurcation angle in atherosclerotic disease development, progression, and stent outcome., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Stent induced hemodynamic changes in the coronary arteries are associated with higher risk of adverse clinical outcome. The purpose of this study was to evaluate the impact of stent design on wall shear stress (WSS), time average WSS, and WSS gradient (WSSG), in idealized stent geometries using computational fluid dynamics. Strut spacing, thickness, luminal protrusion, and malapposition were systematically investigated and a comparison made between two commercially available stents (Omega and Biomatrix). Narrower strut spacing led to larger areas of adverse low WSS and high WSSG but these effects were mitigated when strut size was reduced, particularly for WSSG. Local hemodynamics worsened with luminal protrusion of the stent and with stent malapposition, adverse high WSS and WSSG were identified around peak flow and throughout the cardiac cycle respectively. For the Biomatrix stent, the adverse effect of thicker struts was mitigated by greater strut spacing, radial cell offset and flow-aligned struts. In conclusion, adverse hemodynamic effects of specific design features (such as strut size and narrow spacing) can be mitigated when combined with other hemodynamically beneficial design features but increased luminal protrusion can worsen the stent's hemodynamic profile significantly.

Objectives: This study sought to compare rates of stent thrombosis and major adverse cardiac and cerebrovascular events (MACCE) (composite of death, myocardial infarction, or stroke) after coronary stenting with drug-eluting stents (DES) versus bare-metal stents (BMS) in patients who participated in the DAPT (Dual Antiplatelet Therapy) study, an international multicenter randomized trial comparing 30 versus 12 months of dual antiplatelet therapy in subjects undergoing coronary stenting with either DES or BMS., Background: Despite antirestenotic efficacy of coronary DES compared with BMS, the relative risk of stent thrombosis and adverse cardiovascular events is unclear. Many clinicians perceive BMS to be associated with fewer adverse ischemic events and to require shorter-duration dual antiplatelet therapy than DES., Methods: Prospective propensity-matched analysis of subjects enrolled into a randomized trial of dual antiplatelet therapy duration was performed. DES- and BMS-treated subjects were propensity-score matched in a many-to-one fashion. The study design was observational for all subjects 0 to 12 months following stenting. A subset of eligible subjects without major ischemic or bleeding events were randomized at 12 months to continued thienopyridine versus placebo; all subjects were followed through 33 months., Results: Among 10,026 propensity-matched subjects, DES-treated subjects (n = 8,308) had a lower rate of stent thrombosis through 33 months compared with BMS-treated subjects (n = 1,718, 1.7% vs. 2.6%; weighted risk difference -1.1%, p = 0.01) and a noninferior rate of MACCE (11.4% vs. 13.2%, respectively, weighted risk difference -1.8%, p = 0.053, noninferiority p < 0.001)., Conclusions: DES-treated subjects have long-term rates of stent thrombosis that are lower than BMS-treated subjects. (The Dual Antiplatelet Therapy Study [DAPT study]; NCT00977938)., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: The aim of this IVUS substudy was to assess the efficacy of the Y-shaped Medtronic bifurcation-dedicated stent (BDS) for the treatment of de novo coronary bifurcated lesions., Methods and Results: In the BRANCH trial, post-procedure IVUS was performed in 45 patients. IVUS was available in both branches in 19 lesions and only the main branch (MB) in 26 lesions. IVUS analysis included four distinct locations: proximal MB, bifurcation site, distal MB, and side branch (SB). Lumen symmetry was calculated as minimum/maximum lumen diameters. The quantity of isolated stent struts across the SB ostium was used to assess inadequate strut apposition to the carina resulting in partial jailing of the SB orifice. A minimum stent area (MSA) <4 mm2 was found in 0% of proximal and distal MB, and in 15.4% of SB. In SB, MSA was located mainly at mid or distal segments (84.6%), rather than at the SB ostium. Eccentric stent expansion and edge dissection were seen primarily at proximal MB. Isolated struts were seen in only 20.9% of SB ostia with a minimum length of 0.7±0.4 mm., Conclusions: Implantation of BDS resulted in adequate stent dimensions and strut apposition at the carina and SB ostium. ClinicalTrials.gov Identifier: NCT00607321.

Importance: Despite antirestenotic efficacy of coronary drug-eluting stents (DES) compared with bare metal stents (BMS), the relative risk of stent thrombosis and adverse cardiovascular events is unclear. Although dual antiplatelet therapy (DAPT) beyond 1 year provides ischemic event protection after DES, ischemic event risk is perceived to be less after BMS, and the appropriate duration of DAPT after BMS is unknown., Objective: To compare (1) rates of stent thrombosis and major adverse cardiac and cerebrovascular events (MACCE; composite of death, myocardial infarction, or stroke) after 30 vs 12 months of thienopyridine in patients treated with BMS taking aspirin and (2) treatment duration effect within the combined cohorts of randomized patients treated with DES or BMS as prespecified secondary analyses., Design, Setting, and Participants: International, multicenter, randomized, double-blinded, placebo-controlled trial comparing extended (30-months) thienopyridine vs placebo in patients taking aspirin who completed 12 months of DAPT without bleeding or ischemic events after receiving stents. The study was initiated in August 2009 with the last follow-up visit in May 2014., Interventions: Continued thienopyridine or placebo at months 12 through 30 after stent placement, in 11,648 randomized patients treated with aspirin, of whom 1687 received BMS and 9961 DES., Main Outcomes and Measures: Stent thrombosis, MACCE, and moderate or severe bleeding., Results: Among 1687 patients treated with BMS who were randomized to continued thienopyridine vs placebo, rates of stent thrombosis were 0.5% vs 1.11% (n = 4 vs 9; hazard ratio [HR], 0.49; 95% CI, 0.15-1.64; P = .24), rates of MACCE were 4.04% vs 4.69% (n = 33 vs 38; HR, 0.92; 95% CI, 0.57-1.47; P = .72), and rates of moderate/severe bleeding were 2.03% vs 0.90% (n = 16 vs 7; P = .07), respectively. Among all 11,648 randomized patients (both BMS and DES), stent thrombosis rates were 0.41% vs 1.32% (n = 23 vs 74; HR, 0.31; 95% CI, 0.19-0.50; P < .001), rates of MACCE were 4.29% vs 5.74% (n = 244 vs 323; HR, 0.73; 95% CI, 0.62-0.87; P < .001), and rates of moderate/severe bleeding were 2.45% vs 1.47% (n = 135 vs 80; P < .001)., Conclusions and Relevance: Among patients undergoing coronary stent placement with BMS and who tolerated 12 months of thienopyridine, continuing thienopyridine for an additional 18 months compared with placebo did not result in statistically significant differences in rates of stent thrombosis, MACCE, or moderate or severe bleeding. However, the BMS subset may have been underpowered to identify such differences, and further trials are suggested., Trial Registration: clinicaltrials.gov Identifier: NCT00977938.

Bioresorbable scaffolds (BRS) provide a new tool for percutaneous treatment of coronary stenosis. Initially, relatively simple coronary artery lesions were treated with this novel technology; nowadays, we have gained more experience with a wide variety of lesions, including bifurcation lesions. Data are limited in terms of the use of BRS in coronary bifurcation lesions, although it has been demonstrated that over time the bioresorbable struts are replaced by a tissue bridge resembling a "neo-carina". Furthermore, data are emerging about the endothelial shear stress (ESS) alterations and blood flow patterns after scaffold implantation. It is likely that ESS and blood flow determinations will guide correct future bifurcation techniques. In the future, BRS with thinner struts and more resistant to fracture are likely to improve bifurcation treatment with BRS.

Aims: The BRANCH study was a prospective, multicentre, non-randomised, single arm trial to investigate the feasibility, safety, efficacy, and performance of the bare metal Medtronic Bifurcation Stent System for the treatment of de novo bifurcation lesions., Methods and Results: Sixty patients were enrolled in the study. After a learning curve of one case at seven centres, 53 patients from six centres were prospectively treated. The primary endpoint was target vessel failure (TVF) at 30 days. Secondary endpoints included acute device, lesion, and procedure success and TVF at 12 months. Medina complex bifurcation lesions (1,1,1; 1,1,0; 1,0,1; 0,1,1) were treated in 71.7%. The stent was successfully implanted in 86.8% of cases. Acute device, lesion, and procedure success rates were 83.0%, 92.5%, and 88.7%, respectively. TVF occurred in 2/52 patients (3.8%) at 30 days. No other major adverse cardiac adverse events (MACE) occurred through 30 days follow-up. At 12 months, TVF occurred in 6/47 (12.8%) patients, and MACE occurred in 5/47 (10.6%) patients., Conclusions: Results from the BRANCH study demonstrate that the Medtronic Bifurcation Stent System is safe and can be successfully and effectively deployed in a variety of bifurcation lesions with good clinical outcomes.

Objectives: We sought to determine the 2-year impact of early and late-acquired incomplete stent apposition (ISA) on clinical events., Background: The late clinical impact of early or late-acquired ISA in bare-metal stents (BMS) and TAXUS stents (Boston Scientific, Natick, Massachusetts) is debatable., Methods: We evaluated 1,580 patients enrolled in the intravascular ultrasound (IVUS) substudies of TAXUS IV, V, VI and TAXUS-ATLAS WH, LL, and DS trials., Results: There were 96 cases of early ISA in 26 (7.2%) BMS patients, 35 (9.7%) TAXUS Express patients (p = 0.28 vs. BMS), and 35 (7.3%) TAXUS Liberté patients (p = 0.21 vs. TAXUS Express, and p = 1.00 vs. BMS). Major adverse cardiovascular events were similar at 9 months in patients with early ISA versus control subjects with no ISA for BMS (3.8% vs. 15.2%, p = 0.13) and for TAXUS (11.6% vs. 8.8%, p = 0.45). There was no impact of early ISA on stent thrombosis. At 9-month follow-up, there were 36 cases of late-acquired ISA in 7 (2.7%) BMS patients, 17 (3.1%) patients with TAXUS slow-release (TAXUS Express or TAXUS Liberté), and 12 (15.4%) patients receiving TAXUS moderate-release. Over 2 ensuing years, major adverse cardiovascular events were similar in patients with late-acquired ISA versus control subjects with no ISA for BMS (14.3% vs. 7.9%, p = 0.54), TAXUS (overall, 8.3% vs. 8.1% p = 0.87), or TAXUS slow-release formulation (0% vs. 7.9%, p = 0.28). There was no impact of late-acquired ISA on stent thrombosis., Conclusions: Neither routinely detected acute ISA nor routinely detected late-acquired ISA in BMS or TAXUS patients was associated with adverse clinical events over long-term follow-up., (Copyright 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: The 12-month results of RESOLUTE were favourable for the new Resolute stent. Two-year safety and efficacy results from RESOLUTE have been evaluated and are now reported., Methods and Results: RESOLUTE was a prospective, multicentre, non-randomised, single-arm, controlled trial of the Resolute stent in 139 participants with symptomatic ischaemic heart disease due to single de novo lesions in a native coronary artery. The 2-year rates of MACE (all-cause death, myocardial infarction, emergent cardiac bypass surgery, and target lesion revascularisation [TLR]), death, late stent thrombosis, target vessel revascularisation (TVR), and target vessel failure (TVF) were assessed. Clinical events included two MACE (one TLR; one non-cardiac death) occurring between year one and two resulting in cumulative 2-year TLR, TVR, and TVF rates of 1.4%, 1.4%, and 7.9%, respectively. One possible stent thrombosis event occurred in the first year after stent implantation however no late or very late ARC-defined definite and probable stent thromboses occurred through two years., Conclusions: The 2-year data from RESOLUTE demonstrated no safety concerns including no late stent thrombosis or loss of effectiveness with the Resolute stent. The finding that few events occurred in year two is encouraging, yet requires verification in a larger population.

The aim of this first-in-human study was to evaluate the feasibility and safety of the novel AST petal side-access bifurcation stent. Outcomes following percutaneous coronary intervention for bifurcations remain inferior to those of nonbifurcated lesions. Even with drug-eluting stents, restenosis occurs especially at the side-branch (SB) ostium. The petal stent uniquely deploys strut elements into the SB, supporting the ostium and carina. The primary endpoint of this 13-patient prospective registry was in-hospital major adverse cardiac events (MACE). Secondary end points included acute minimum lumen diameter (MLD) at the SB ostium, lesion success, device success, procedural success, 30-day MACE, and 4-month SB ostial MLD. The study lesion was successfully treated in 13 patients with the study stent being successfully implanted in 12. Target lesions were left anterior descending coronary artery in nine subjects, left circumflex in three, and right coronary artery in one. In-hospital MACE were limited to two non-Q-wave myocardial infarctions. In-stent main branch MLD increased from a mean of 0.63 +/- 0.45 mm to 2.61 +/- 0.47 mm at the index procedure and for this initial bare metal version of the stent, 4-month mean MLD measured 1.02 +/- 0.42 mm and there was target vessel revascularization on two patients. The feasibility of safely deploying this first-generation petal stent was demonstrated in selected patients with challenging coronary bifurcation lesions. It is a promising platform for drug delivery, with unique scaffolding of the side-branch ostium., ((c) 2007 Wiley-Liss, Inc.)

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

Background: The use of the Endeavor stent might reduce restenosis and stent thrombosis at 9 months., Methods and Results: Patients (n = 1197) treated for single coronary artery stenosis were enrolled in a prospective, randomized, double-blind study and randomly assigned to receive the Endeavor zotarolimus-eluting phosphorylcholine polymer-coated stent (n = 598) or the same bare metal stent but without the drug or the polymer coating (n = 599). The 2 groups were well matched in baseline characteristics. Diabetes was present in 20.1% of patients; the mean reference vessel diameter was 2.75 mm; and the mean lesion length was 14.2 mm. The primary end point of target vessel failure at 9 months was reduced from 15.1% with the bare metal stent to 7.9% with the Endeavor (P = 0.0001), and the rate of major adverse cardiac events was reduced from 14.4% with the bare metal stent to 7.3% with the Endeavor (P = 0.0001). Target lesion revascularization was 4.6% with Endeavor compared with 11.8% with the bare metal stent (P = 0.0001). The rate of stent thrombosis was 0.5% with the Endeavor, which was not significantly different from 1.2% with the bare metal stent. In 531 patients submitted to angiographic follow-up, late loss was reduced from 1.03 +/- 0.58 to 0.61 +/- 0.46 (P < 0.001) in stent and from 0.72 +/- 0.61 to 0.36 +/- 0.46 (P < 0.001) in segment. The rate of in-segment restenosis was reduced from 35.0% to 13.2% with Endeavor (P < 0.0001). There was no excessive edge stenosis, aneurysm formation, or late acquired malapposition by intravascular ultrasound imaging. Differences in clinical outcome were maintained at 12 and 24 months (P < 0.0001)., Conclusions: Compared with bare metal stents, the Endeavor stent is safe and reduces the rates of clinical and angiographic restenosis at 9, 12, and 24 months.

The purpose of the study was to examine the safety and efficacy of two different formulations of mycophenolic acid (MPA)-eluting Duraflex stents on coronary de novo lesions. Recent data indicate that local delivery of MPA in the porcine overstretch coronary model significantly reduces neointimal hyperplasia (NIH). Patients were divided into three consecutive groups. The first (n=50) and second (n=55) groups received moderate- and slow-release MPA-eluting Duraflex stent, respectively. The last group (n=50) received the bare metal Duraflex stent. Clinical, angiographic, and intravascular ultrasound analysis were performed at 6-month follow-up. All stents were successfully deployed and patients were discharged home without clinical events. Compared to controls, 6-month in-lesion and in-stent minimum luminal diameter as well as late lumen loss were not significantly different in the moderate- and slow-release treatment groups. At follow-up, percentage obstruction and NIH volume were also similar between the three groups. At 30 days and 6 and 12 months, there were no differences noted between the three groups with respect to major adverse cardiac events as well as the individual rates of mortality, myocardial infarction, or repeat revascularization. There were no cases of subacute or late thrombosis. In this feasibility trial, the MPA-eluting Duraflex stents in either slow- or moderate-release formulations were well tolerated, but showed no benefit for treatment of coronary lesions when compared to controls. Further testing with different drug dosing or delivery rate might improve these results., (Copyright (c) 2005 Wiley-Liss, Inc.)

Objectives: The goal of this study was to evaluate the safety and performance of the Multi-Link Frontier coronary bifurcation stent system (Guidant Corp., Santa Clara, California), a novel dedicated device designed for permanent side branch (SB) access, stent delivery by simultaneous kissing balloon inflation, and optimal main branch (MB) and SB ostium scaffolding., Background: The treatment of coronary bifurcation lesions remains challenging, and various approaches using stents have been proposed., Methods: The primary end point was the 180-day incidence of major adverse cardiac events (MACE) per intent-to-treat analysis. Secondary end points included device success, 30-day MACE, angiographic restenosis, and target lesion revascularization (TLR) rates at 180 days., Results: After a learning phase of two cases per center, 105 patients were prospectively included in 11 centers. The left anterior descending coronary artery/diagonal bifurcation was the target in 80% of cases. The Frontier stent was successfully implanted in 96 patients (91%), and procedural success was obtained in 93%. Two patients suffered in-hospital myocardial infarction (MI) secondary to SB occlusion, and one patient underwent elective coronary artery bypass grafting. At 30 days and 6 months, the MACE rates were 2.9% and 17.1% (no death, no subacute stent thrombosis, Q-wave MI 1.0% and 1.9%, non-Q-wave MI 1.0% and 1.9%, TLR 1.0% and 13.3%). The MB in-stent restenosis was 25.3%, in-segment 29.9%. The SB restenosis was 29.1%. The overall restenosis rate for any branch was 44.8%., Conclusions: The results of this Frontier registry demonstrate the safety and performance of this dedicated stent system for the treatment of bifurcation lesions. The device can be successfully implanted in more than 90% of all cases, with a high procedural success rate and low 30-day and 6-month MACE rates.

Objective: To evaluate the association between baseline homocysteine concentrations and restenosis rates in patients electively undergoing their first percutaneous coronary intervention (PCI) without stenting., Design: Prospective, single centre, observational study., Setting and Patients: Patients electively undergoing their first PCI without stenting at a tertiary referral centre between 1990 and 1998., Methods: Blood samples were collected from all patients at baseline and assayed to determine the patients' homocysteine concentrations. Patients whose PCI was successful underwent repeat angiography at a median of 6.4 (interquartile range 6-6.8) months. Their baseline and follow up angiograms were compared by quantitative coronary angiography to assess the incidence of restenosis. For the analysis, the patients were divided into two groups based on whether their baseline homocysteine concentrations were above or below the median value. These two groups were compared to determine whether there was any association between their baseline homocysteine concentrations and the incidence of restenosis at six months., Results: 134 patients had a successful first PCI without stenting (involving 200 lesions). At six month angiography, restenosis was observed in 33 patients (49.3%) with baseline homocysteine concentrations above the median value and in 31 patients (46.3%) with concentrations below the median value (p = 0.74). There was no difference in the percentage of lesions developing restenosis (38 (39.6%) v 40 (38.5%), respectively, p = 0.87) or late lumen loss (0.40 mm v 0.31 mm, respectively, p = 0.24). On multivariable analysis, there was no association between homocysteine concentrations and late lumen loss (r = -0.11, p = 0.11) or the percentage diameter stenosis at follow up (r = -0.07, p = 0.32)., Conclusion: Baseline homocysteine concentrations were not associated with six month restenosis rates in patients electively undergoing their first PCI without stenting.

Background: Polymer-controlled paclitaxel-eluting stents have shown a pronounced reduction in neointimal hyperplasia compared with bare metal stents (BMS). The aim of this substudy was to evaluate local arterial responses through the use of serial quantitative intravascular ultrasound (IVUS) analyses in the TAXUS II trial., Methods and Results: TAXUS II was a randomized, double-blind study with 536 patients in 2 consecutive cohorts comparing slow-release (SR; 131 patients) and moderate-release (MR; 135 patients) paclitaxel-eluting stents with BMS (270 patients). This IVUS substudy included patients treated with one study stent who underwent serial IVUS examination after the procedure and at 6-month follow-up (BMS, 152 patients; SR, 81; MR, 81). The analyzed stented segment (15 mm) was divided into 5 subsegments in which mean vessel area (VA), stent area (SA), lumen area (LA), intrastent neointimal hyperplasia area (NIHA), and peristent area (VA-SA) were measured. NIHA was significantly reduced in SR (0.7+/-0.9 mm2, P<0.001) and MR (0.6+/-0.8 mm2, P<0.001) compared with BMS (1.9+/-1.5 mm2), with no differences between the two paclitaxel-eluting release formulations. Longitudinal distribution of neointimal hyperplasia throughout the paclitaxel-eluting stent was uniform. Neointimal growth was independent of peristent area at postprocedure examination in all groups. There were progressive increases in peristent area from BMS to SR to MR (0.5+/-1.7, 1.0+/-1.8, and 1.4+/-2.0 mm2, respectively; P<0.001). The increase in peristent area was directly correlated with increases in VA., Conclusions: Both SR and MR paclitaxel-eluting stents prevent neointimal formation to the same degree compared with BMS. However, the difference in peristent remodeling suggests a release-dependent effect between SR and MR.

Percutaneous coronary intervention using smaller-diameter guide catheters may have a favorable impact on groin complications, mobilization time, hospital stay, and contrast use. This prospective registry study assessed the feasibility of routine stent delivery through 5 Fr guide catheters. Of the 100 consecutive patients, 5 Fr guided intervention was attempted in 84 and was successful in all but 2 patients who had chronic complete occlusions. Reasons for not selecting a 5 Fr guide were planned kissing balloons (eight), directional coronary atherectomy (one), and no suitable 5 Fr guide in stock (seven). There was no stent dislodgment, need to change to a larger-caliber guide, or inadequate contrast opacification. When necessary, guide support was achieved by deep-vessel intubation, which was not associated with vascular damage. The only adverse sequelae were non-Q-wave myocardial infarctions in two patients. Coronary artery stenting using 5 Fr guide catheters is feasible and applicable to most patients.

This randomized trial compared a strategy of direct stenting without predilatation (n = 39) with conventional stenting with predilatation (n = 42) in patients with suitable lesions in native vessels > or = 2. 5-mm diameter to be covered by either a 9- or 16-mm-length NIR Primo stent. Equipment cost [mean (median) +/- SD] was less in those with direct stenting [$1,199 (979) +/- 526] than in those with predilatation [$1,455 (1,285) +/- 401, P < 0.001]. There was no significant difference in contrast use or fluoroscopy time. Procedural time was shorter in the direct stenting group. The clinical outcome at 1 month was satisfactory in both groups. In selected patients, a strategy of direct stenting is feasible, costs less, and is quicker to perform than the conventional strategy of stenting following predilatation.

Longitudinal flexibility is an important property of coronary stents, facilitating delivery and allowing the expanded stent to conform to vessel contour. Subjective descriptions of flexibility abound, but there are few independent quantitative data to aid stent selection. A three-point bend test was employed to measure stiffness, the reciprocal of flexibility, for 13 stent designs in the unexpanded (bare) state, then after expansion with a 3.5-mm balloon. For eight of the designs, stiffness of the proprietary stent/balloon delivery system was also measured. In the unexpanded state, there was a wide spread of stiffness, which ranged from 0.5+/-0.2 to 91.5+/-10.0 g force/mm, depending on design. Stiffness was least for the coil (Wiktor and Crossflex) and hybrid (AVE GFX and Bard XT) designs. The MultiLink was the most flexible and the Crown the stiffest of the slotted tube designs. All stents became stiffer upon expansion. For most manufacturer-mounted stents, the delivery balloon was the main determinant of stent/balloon delivery system stiffness. Manufacturer-mounted stent profile ranged from 1.15+/-0.11 mm for the Jostent to 1.53 +/- 0.05 mm for the MultiLink system. Independent quantitative assessment of characteristics such as flexibility and profile should aid rational comparison of stent designs.

Objectives: This study was performed to assess whether angiography six months after coronary balloon angioplasty or stent implantation has an influence on clinical management and one-year outcome., Background: The Benestent II study randomized 827 patients to balloon angioplasty or stent implantation. A subrandomization was undertaken allocating patients to six-month clinical follow-up (CF) or clinical and angiographic follow-up (AF)., Methods: Seven hundred and six patients (349 CF and 357 AF) had no intercurrent angiography, so that restenosis and disease progression elsewhere remained unknown until the time of six-month follow-up. These two groups, which were well matched at enrolment, were compared with respect to symptoms, medication and major cardiac events defined as death, myocardial infarction and need for revascularization at six and 12 months., Results: At six-month follow-up, 53 (15%) of the CF and 76 (21%) of the AF patients had stable angina (p = 0.041), while 5 (1%) and 4 (1%) had symptoms of unstable angina. At 12-month follow-up, 44 (13%) patients in both groups had stable angina, and only 1 patient in the CF group had unstable angina. Seventy-seven patients (27 CF and 50 AF; p < 0.01) had major cardiac events between 6 and 12 months. Of the 349 patients in the CF group, 21 underwent repeat percutaneous transluminal coronary angioplasty or coronary artery bypass graft surgery between 6 and 12 months, compared with 44 of the 357 patients in the AF group (relative risk 2.05 [1.24 to 3.37], p = 0.003)., Conclusions: Patients who had AF six months after balloon angioplasty or stent implantation experienced more repeat revascularization procedures than those who had CF. They also had significantly more angina at six-month follow-up but this may be due to bias.

Procedural and 1-month outcome data following implantation of the V-Flex Plus stent in our first 54 consecutive patients (35 male; mean age, 62 years) are described. Sixty-four stents were implanted for 60 mainly complex lesions; 48% were left anterior descending; 20%, circumflex; 27%, right coronary artery; and 5%, saphenous vein graft. The Indication for stenting was elective in half of the patients and for a suboptimal result or as a bailout procedure in the other half. The stents were deployed at a mean of 12 atm (range, 6-18) and postdilatated to a mean of 15 atm (range, 8-20). Pre- and postdilatation balloon sizes were 2.96 +/- 0.57 mm and 3.16 +/- 0.34 mm, respectively. The procedural success rate was 98%. There were no deaths or Q-wave myocardial infarctions. One patient suffered a non-Q-wave myocardial infarction and another developed a femoral false aneurysm. At 1-month follow-up, there were no additional events, in particular no revascularization procedures. Eighty-nine percent of patients were free of angina. Implantation of the V-Flex Plus stent is safe and effective with an excellent early success rate comparable to that of published randomized trials and registries of carefully selected patients.

We aimed to determine the effects of simulated stent side-branch dilatation and subsequent redilatation of the central lumen. Following coronary stent implantation it may be necessary to dilate through the side of a stent to maintain branch patency. Branch dilatation through the side of 3.5-mm-diameter stents (AVE GFX, beStent, Crown, MultiLink, and NIR) was simulated in a plexiglass phantom using 2.5-, 3.0-, 3.5-, and 4.0-mm balloons. In further experiments, the main lumen was redilated with a 3.5-mm balloon after 3.0-mm side-branch dilatation. Thereafter, a 3.5-mm central and a 3.0-mm side-branch balloon were simultaneously inflated ("kissing balloons"). The larger the balloon size used for side-branch dilatation, the greater the distortion of the stent immediately distal to the side-branch, which for a 4.0-mm balloon ranged from 36% +/- 2% (Crown) to 65% +/- 6% (NIR). Central lumen redilatation or kissing balloons abolished this stenosis with little reduction of the side-lumen diameter. The main stent lumen compromise caused by side-branch dilatation can be abolished by main-lumen redilatation or by kissing balloons.

Background: The multicentre, randomised Benestent-II study investigated a strategy of implantation of a heparin-coated Palmar-Schatz stent plus antiplatelet drugs compared with the use of balloon angioplasty in selected patients with stable or stabilised unstable angina, with one or more de-novo lesions, less than 18 mm long, in vessels of diameter 3 mm or more., Methods: 827 patients were randomly assigned stent implantation (414 patients) or standard balloon angioplasty (413 patients). The primary clinical endpoint was event-free survival at 6 months, including death, myocardial infarction, and the need for revascularisation. The secondary endpoints were the restenosis rate at 6 months and the cost-effectiveness at 12 months. There was also one-to-one subrandomisation to either clinical and angiographic follow-up or clinical follow-up alone. Analyses were by intention to treat., Findings: Four patients (one stent group, three angioplasty group) were excluded from analysis since no lesion was found. At 6 months, a primary clinical endpoint had occurred in 53 (12.8%) of 413 patients in the stent group and 79 (19.3%) of 410 in the angioplasty group (p=0.013). This significant difference in clinical outcome was maintained at 12 months. In the subgroup assigned angiographic follow-up, the mean minimum lumen diameter was greater in the stent group than in the balloon-angioplasty group, (1.89 [SD 0.65] vs 1.66 [0.57] mm, p=0.0002), which corresponds to restenosis rates (diameter stenosis > or =50%) of 16% and 31% (p=0.0008). In the group assigned clinical follow-up alone, event-free survival rate at 12 months was higher in the stent group than the balloon-angioplasty group (0.89 vs 0.79, p=0.004) at a cost of an additional 2085 Dutch guilders (US$1020) per patient., Interpretation: Over 12-month follow-up, a strategy of elective stenting with heparin-coated stents is more effective but also more costly than balloon angioplasty.

To assess the early outcome of implantation of the Multilink stent in everyday angioplasty practice, we prospectively collected procedural and 1-mo follow-up data on the first 126 patients (93 male, mean age 61+/-9 yr) in 3 centers. One hundred and seventy-four stents were implanted for 134 lesions: left anterior descending artery in 46%, circumflex in 20%, right coronary artery in 31%, and protected left main in 3%. The indication was elective in 56%, a suboptimal result in 43%, and bailout in 1%. Stents were deployed at 10.8+/-1.9 atmospheres and postdilated to 15.7+/-2.4 atmospheres. There were 115 patients who received ticlopidine and aspirin, 10 received aspirin alone, and 1 received warfarin and aspirin following the procedure. The reference diameter increased from 3.02+/-0.44 mm pre- to 3.13+/-0.43 mm postprocedure, with the minimal luminal diameter increasing from 0.82+/-0.47 to 2.86+/-0.45 mm (diameter stenosis 73% pre- and 9% postprocedure). The procedural success rate was 93.7%. There were no deaths, 1 (0.8%) Q- and 5 (4.0%) non-Q-wave myocardial infarctions, 3 (2.4%) emergency bypass operations, and 1 (0.8%) repeat angioplasty during the hospital admission (median stay, 1 day). There were 2 (1.6%) cases of subacute stent thrombosis. At 1-mo follow-up there were no additional events, with 88% of patients remaining free of angina. Implantation of the Multilink stent is safe and effective in everyday angioplasty practice, with a complication rate comparable to those of published trials of carefully selected patients.