Stent Volume Research Articles

Abstract 2770: Neointimal Hyperplasia Patterns Among 3 Drug-Eluting Stents: A Comparative Intravascular Ultrasound Analysis of Everolimus-, Sirolimus-, and Paclitaxel-Eluting Stents

Background The amount of neointimal hyperplasia as well as the percentage of neointimal stent surface coverage may be different among various types of drug-eluting stents (DES). Methods From the Stanford University Intravascular Ultrasound (IVUS) Core Laboratory database, this study consisted of the patients enrolled in prospective, multicenter clinical trials with DES deployment for de novo coronary lesions and 3-D IVUS at 8- to 9-month follow-up as part of their study protocol. In these cases, 155 single DES: (1) an 18-mm everolimus-eluting (EES, 52 stents in 50 patients); (2) an 18-mm sirolimus-eluting (SES, 51 stents); or (3) a 16-mm paclitaxel-eluting (PES, 52 stents) stent in 153 patients were investigated. Using Simpson’s rule, %neointimal volume was defined as neointimal volume / stent volume × 100. Circumferential stent length covered with neointima (L N ) and stent perimeter (L S ) were also measured at every 1-mm cross section throughout the stent. Then, %neointimal coverage was defined as total L N / total L S × 100. Results EES had comparable %neointimal volume to SES, but less %neointimal volume than PES (5.2±5.3 vs 2.6±4.0 vs 9.2±8.7%, P< 0.0001), whereas EES had greater %neointimal coverage than SES, but comparable %neointimal coverage to PES (25.7±19.9 vs 9.1±14.6 vs 29.3±23.5%, P< 0.0001). Conclusions Compared to SES, EES had comparable neointimal hyperplasia, but greater neointimal stent coverage by IVUS. Compared to PES, EES had less neointimal hyperplasia, but comparable neointimal stent coverage by IVUS. This unique pattern of neointimal hyperplasia with these platforms may be important to the balance of the short-term efficacy and the long-term safety.

Comparison Between Pancreaticojejunostomy and Pancreaticogastrostomy After Pancreaticoduodenectomy

Pancreatic leakage is a leading cause of morbidity and mortality after pancreaticoduodenectomy (PD). Pancreaticogastrostomy (PG) has been reported to be associated with a lower pancreatic leakage rate and morbidity rate than pancreaticojejunostomy (PJ). This study compared the preoperative characteristics, surgical risk factors, intraoperative parameters, and postoperative outcome between PJ and PG. From March 1992 to March 2005, a comparative study between PJ and PG for patients with periampullary lesions undergoing PD was conducted. A total of 377 consecutive patients underwent PD. Among them, 188 patients underwent PJ and 189 underwent PG. The overall mortality, morbidity and pancreatic leakage following PD were 5%, 45.1% and 10.6%, respectively. The mortality, morbidity and pancreatic leakage were 8.9%, 56.4% and 17.6% in the PJ group, and 2.1%, 33.9% and 3.7% in the PG group (p < 0.001). Mean operative time was 9.3 hours versus 6.7 hours (p < 0.001), mean blood loss was 1032 mL versus 891 mL (p = 0.064) and mean hospital stay was 34.8 days versus 26.1 days (p < 0.001) in the PJ and PG groups, respectively. PJ, soft pancreas, pancreatic duct stenting, low surgical volume (< 20) and age (> 65 years) were identified as risk factors for pancreatic leakage, while PJ, soft pancreas, pancreatic duct stenting and low surgical volume (< 20) were four significant risk factors for surgical morbidity. Further, PJ, pancreatic leakage, low surgical volume (< 20) and age (> 65 years) were identified to be surgical risk factors for mortality. PG is a safer method than PJ following PD as a significantly lower rate of pancreatic leakage, surgical morbidity and mortality, shorter operation time, and shorter postoperative hospital stay are reported.

Single‐Center Randomized Evaluation of Paclitaxel‐Eluting Versus Conventional Stent in Acute Myocardial Infarction (SELECTION)

To evaluate the superiority of the paclitaxel-eluting stent (PES) in reducing neointimal hyperplasia (NIH) over its corresponding bare metal stent (BMS) during primary percutaneous coronary intervention (PCI). Primary PCI with stent implantation is the repercussion strategy of choice for ST-elevation myocardial infarction (STEMI); nonetheless restenosis rate is still high. Drug-eluting stents have been proven to reduce restenosis rate in many settings, but their use during primary PCI is still controversial. Consecutive patients with STEMI <12 hours were randomized to receive PES or BMS. The primary end-point was the percentage of the stent volume obstructed by neointimal proliferation (NIH) measured by intravascular ultrasound (IVUS) at a 7-month angiographic follow-up. Secondary end-points were binary restenosis rate and major adverse cardiac events (MACE, i.e., death, nonfatal myocardial infarction, and target lesion revascularization). Eighty patients with STEMI were randomized into the PES or BMS group. Patients were well matched for baseline characteristics and the index procedure was always successful. In-hospital and 1-month MACE were 2.5% per group. NIH at 7 months was 4.6% versus 20% (P< 0.01), late lumen loss 0.1 versus 1.01 mm (P = 0.01). MACE were 7.5% versus 42.5% (P = 0.001) with no difference in death and recurrent myocardial infarction rates. Late-acquired incomplete stent apposition (ISA) rate was 5.1% versus 2.7% (P = 0.65). One subacute stent thrombosis was reported in each group. PES was superior to its corresponding BMS in reducing NIH in the STEMI setting without any increase in early and long-term clinical adverse events.

Carotid artery stenting with emboli protection surveillance study: Thirty‐day results of the CASES‐PMS study

This study examined whether physicians with varying carotid stent experience would obtain safety and efficacy outcomes as good as those from the pivotal SAPPHIRE trial following participation in a comprehensive carotid stent training program. This study was performed as a condition of approval study for the PRECISE(R) Nitinol Stent and the ANGIOGUARD XP Emboli Capture Guidewire. Patients at high surgical risk who were either symptomatic with >or=50% stenosis or asymptomatic with >or=80% stenosis of the common or internal carotid artery received carotid artery stenting with distal emboli protection using the PRECISE Nitinol Stent and the ANGIOGUARD XP Emboli Capture Guidewire. Physicians were qualified based on either prior experience in carotid stenting with the ANGIOGUARD XP Emboli Capture Guidewire or following participation in a formal training program. The primary endpoint of major adverse events (MAE) at 30 days (death, myocardial infarction (MI), or stroke) was tested for non-inferiority compared with an objective performance criterion (OPC) of 6.3% established from the stent cohort of the SAPPHIRE trial. The 30-day MAE rate was 5.0%, meeting the criteria for non-inferiority to the prespecified OPC (95% CI [3.9%, 6.2%] P<0.001). Asymptomatic patients (N=1,158, 78.2%) had similar outcomes to the overall results (MAE 4.7%). Outcomes were similar across levels of physician experience, carotid stent volume, geographic location, presence/absence of training program. Utilizing a comprehensive training program, carotid artery stenting by operators with differing experience in a variety of practice settings yielded safety and efficacy outcomes similar to those reported in the SAPPHIRE trial.

Intravascular ultrasound findings in patients with restenosis of sirolimus- and paclitaxel-eluting stents

Objective We used intravascular ultrasound (IVUS) to compare restenotic sirolimus-eluting (SES) vs paclitaxel-eluting (PES) stents. Background Little is known about the IVUS pattern and mechanisms of restenosis, in the two widely available drug-eluting stent (DES) platforms. Methods Volumetric IVUS analysis was performed in patients with clinical restenosis in DES ( n = 29 SES and 11 PES respectively). Results Despite similar vessel volumes (347.5 ± 155.6 vs 356.5 ± 164.1 mm 3, p = 0.84) and stent volumes (175.6 ± 74.57 vs 179.7 ± 84.24 mm 3, p = 1.0), IVUS analysis showed that neointimal hyperplasia volume was significantly greater in PES restenoses than in SES restenoses (40.0 ± 44.2 vs 19.3 ± 11.4 mm 3, p = 0.02) without any significant difference in distribution over the stent length. This leads to a higher percent of volume obstruction (intimal hyperplasia volume divided by stent volume: 18.5 ± 13.7% vs 11.8 ± 7.7%, p = 0.045). Minimal stent area was smaller in SES than in PES (4.3 ± 1.2 vs 5.6 ± 1.2 mm 2, p = 0.06) and stent underexpansion was more frequently observed in SES stents: minimal stent area < 4.5 mm 2 (65% in SES vs 27% in PES, p = 0.04). Stent edge restenosis occured in 1/29 SES (3%) vs 3/11 PES (27%) stents, p = 0.056. Conclusion The magnitude of neointimal hyperplasia was greater in PES than in SES while stent underexpansion appeared to be more common in SES.

Volume do stent à ultra-sonografia intracoronária como preditor de reestenose angiográfica: estudo em pacientes com alto risco de reestenose

INTRODUÇÃO: Em populações não selecionadas, obstruções em vasos de fino calibre são mais susceptíveis à reestenose após intervenção coronária percutânea (ICP). Por isso, entre as características angiográficas preditoras do fenômeno, o diâmetro luminal de referência (D.L.R.) é particularmente relevante. Tais resultados são corroborados por ultra-sonografia intracoronária (USIC), evidenciando a influência das dimensões vasculares sobre a resposta clínica no processo da reestenose, independente da presença de outros preditores, nessas populações não selecionadas. O objetivo deste trabalho foi avaliar os preditores angiográficos e ultra-sonográficos intracoronários de reestenose, em pacientes em que o alto risco de reestenose foi especialmente caracterizado por busca ativa de diabete melito (DM) e de disglicidemia. MÉTODO: Setenta pacientes portadores de 77 lesões obstrutivas ateroscleróticas coronarianas foram submetidos a ICP com stent, com sucesso. Realizou-se controle angiográfico e com USIC do resultado do implante, imediatamente após o término do procedimento e 6 meses após. Procedeu-se à busca ativa de alterações do metabolismo da glicose mediante a realização de GTTo, em todos os casos sem diagnóstico prévio de DM. RESULTADOS: Foram identificados 23 (32,86%) indivíduos com DM e 16 (22,85%) com intolerância à glicose. Pela análise bivariada, os parâmetros considerados preditores de reestenose angiográfica pelo critério binário foram: D.L.R. > 2,82 mensurado na condição controle 6 meses após ICP - RR=0,60 (0,15-0,81) IC 95% (p=0,014), volume de stent < 119,8 mm³ ao USIC - RR=0,74 (0,38- 0,89) IC 95% (p=0,0005) e área de stent < 8,91 mm² ao USIC - RR=0,66 (0,24-0,85) IC 95% (p=0,006). A análise multivariada evidenciou que o único parâmetro preditor de reestenose foi volume de stent < 119,8 mm³ (p=0,01). CONCLUSÃO: Com base nestes resultados, conclui-se que, em população de pacientes com alto risco para desenvolvimento de reestenose, o calibre do vaso esteve relacionado de forma inversa à taxa de reestenose, sendo o volume de stent pelo USIC < 119,8 mm³ considerado preditor independente de reestenose.

Comparison of the Efficacy of Direct Coronary Stenting With Sirolimus-Eluting Stents Versus Stenting With Predilation by Intravascular Ultrasound Imaging (from the DIRECT Trial)

A direct coronary stenting technique using drug-eluting stents may decrease drug-eluting stent efficacy due to possible damage to the surface coating of the stent. The DIRECT is a multicenter, prospective, nonrandomized trial designed to evaluate the direct stenting strategy for the sirolimus-eluting Bx-Velocity stent compared with the historical control (SIRIUS trial, stenting with predilation). Volumetric and cross-sectional intravascular ultrasound analyses at 8-month follow-up were performed in 115 patients (DIRECT n= 64, control n = 51). Patient and lesion characteristics were comparable between groups. The DIRECT group achieved an equivalent uniform expansion index, defined as minimum stent area/maximum stent area x 100, compared with the control group (65.9 +/- 11.7 vs 63.1 +/- 12.7, p = NS). At 8-month follow-up, vessel, stent, lumen, and neointimal volume index (volume in cubic millimeters/length in millimeters) and percent neointimal volume were similar between the DIRECT and control groups (vessel volume index 13.9 +/- 4.40 vs 15.0 +/- 3.83; stent volume index 6.83 +/- 2.02 vs 6.94 +/- 2.04; lumen volume index 6.71 +/- 2.04 vs 6.81 +/- 2.07; neointimal volume index 0.14 +/- 0.24 vs 0.16 +/- 0.23; percent neointimal volume 3.73 +/- 6.97 vs 3.14 +/- 5.32, p = NS for all). In addition, in-stent neointimal hyperplasia distribution was significantly smaller near the distal stent edge (0.22 vs 0.098 mm(3)/mm, p = 0.01 for an average neointimal volume index within 3 mm from the distal stent edge). In conclusion, direct coronary stenting with the sirolimus-eluting Bx-Velocity stent is equally effective in terms of uniform stent expansion and long-term quantitative intravascular ultrasound results compared with conventional stenting using predilation. This strategy appears to be associated with less neointimal hyperplasia near the distal stent edge.

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

A predefined intravascular ultrasound (IVUS) substudy was performed to evaluate the vascular effects of sirolimus-eluting stent (SES) versus bare-metal stent (BMS). 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. 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. 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. 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.

Revisiting late loss and neointimal volumetric measurements in a drug‐eluting stent trial: Analysis from the SPIRIT FIRST trial

This study was conducted to reevaluate the significance of angiographic late loss and to assess the agreement between new proposed neointimal volumetric measurements derived from quantitative coronary angiography (QCA) and standard intravascular ultrasound (IVUS)-based parameters. Neointimal volumetric measurements may better estimate the magnitude of neointimal growth after stenting than late loss. In 56 in-stent segments (27, everolimus; 29, bare metal) in the SPIRIT FIRST study, we compared QCA measures with the corresponding IVUS parameters. Two IVUS-late loss models were derived from minimal luminal diameter (MLD) using either a circular model or a so-called projected MLD. QCA-neointimal volume was calculated as follows: stent volume (mean area of the stented segment x stent length) at post procedure - lumen volume (mean area of the stented segment x stent length) at follow-up (the stent length either from nominal stent length or the length measured by QCA). Videodensitometric neointimal volume was also evaluated. Each of the three neointimal volume and percentage volume obstruction by QCA showed significant correlation with the corresponding IVUS parameters (r = 0.557-0.594, P < 0.0001), albeit with a broad range of limits of agreement. Late loss and volumetric measurements by QCA had a broader range of standard deviation than those by IVUS. QCA-volumetric measurements successfully confirmed the efficacy of everolimus-eluting stents over bare metal stents (P < 0.05). Our proposed QCA volumetric measurements may be a practical surrogate for IVUS measurements and a discriminant methodological approach for assessment of treatment effects of drug-eluting stents.

&lt;b&gt;Poststenting Axial Redistribution of Atherosclerotic Plaque Into the Reference Segments and Lumen Reduction at the Stent Edge&lt;/b&gt;

Lumen enlargement during coronary stenting results from vessel expansion and axial redistribution of atheromatous plaque along the stented segment and proximal and distal reference segments. Plaque burden predicts stenosis at the stent edge. The aim of this study was to investigate the fate of shifted plaque with special reference to whether or not plaque shift (PSh) correlates with late lumen reduction. This is a prospective study conducted on 54 consecutive patients who underwent bare metal stenting. In all stent edges (108 edges), PSh volume was measured as postintervention plaque-media volume (PMV) minus preintervention PMV. Changes in lumen volume (DeltaLV), vessel volume (DeltaVV), and PMV (DeltaPMV) were measured by serial intravascular ultrasound (IVUS) examination. After stenting, PSh was detected in 81.5% of proximal edges versus 72.2% of distal edges (P = 0.36). It correlated significantly with DeltaVV (r = 0.34, P = 0.002), and inversely with DeltaLV (r = 0.32, P = 0.003). However, at 6-month follow-up, it did not correlate with DeltaLV (r = -0.03, P = 0.8), DeltaVV (r = 0.1, P = 0.6), or DeltaPMV (r = 0.1, P = 0.4). Furthermore, DeltaLV correlated more strongly with DeltaVV (r = 0.62, P < 0.00001) than with DeltaPMV (r = -0.39, P = 0.001). By multivariate analysis, PSh area was an independent predictor of the postintervention change in lumen area (partial eta squared 0.21, P = 0.01), but not the follow-up change. Two patients (3.7%) developed proximal edge stenosis with no evident PSh after stenting. Thus, axial redistribution of atheromatous plaque into the reference segments was frequently encountered after stenting. Although PSh correlated with the immediate reduction in stent edge lumen volume, it did not correlate with the late lumen reduction.

Predictors of Sub-Acute Stent Thrombosis in Acute Myocardial Infarction Patients Following Primary Coronary Stenting With Bare Metal Stent

The aim of the present study was to identify the relationship between sub-acute stent thrombosis (SAT) and acute-phase inflammatory reactants, such as high-sensitivity C-reactive protein (hs-CRP) and serum amyloid-A protein (SAA), in patients with acute myocardial infarction (AMI) successfully treated with primary coronary stenting. The 381 consecutive AMI subjects were reperfused by primary coronary stenting within 24 h of onset. SAT was confirmed angiographically in 10 patients (2.6%). There were no significant differences between the patients with or without SAT in terms of patient characteristics, Killip classification on admission, or stent diameter, nor were there significant differences between the 2 groups in terms of left ventricular function soon after stenting (left ventricular ejection fraction) or end-diastolic volume index. The plasma levels of both hs-CRP and SAA were significantly higher in the SAT patients than in the others (hs-CRP: 6.7+/-6.7 mg/dl vs 3.3+/-3.8 mg/dl, p=0.007; SAA: 699+/-812 mug/dl vs 208+/-273 mug/dl, p<0.0001). Multivariate analysis identified SAA as an independent predictor of SAT (risk ratio: 4.9, 95% confidence interval: 1.7-14.9, p<0.05). In patients with AMI who are treated with primary coronary stenting, inflammation may be closely related to SAT, for which SAA is a useful predictor.

Heterogeneity of Neointimal Distribution of In-Stent Restenosis in Patients With Diabetes Mellitus

Diabetes mellitus is an independent predictor of restenosis after percutaneous coronary intervention. The pattern of restenosis after bare metal stent implantation in diabetic patients was examined with 3-dimensional intravascular ultrasound analysis. Lumen and stent were manually traced at every 0.5-mm interval in stented segments. Using Simpson's method, stent, luminal, and neointimal (stent minus lumen) volumes were calculated and average area was calculated as volume data divided by length. To measure the cross-sectional and longitudinal severities of luminal encroachment by the neointima, percent neointimal area (neointimal area divided by stent area) and neointimal hyperplasia 50 (IH50) (defined as percent stent length with percent neointimal area >50%) were calculated. In 278 patients (68 with diabetes and 210 without diabetes), there was a significantly higher percentage of maximal percent neointimal area with significantly longer percent stent length that was severely encroached by the neointima in diabetic patients. Diabetic patients showed a more heterogenous pattern of the neointima after bare metal stenting, resulting in longer high-grade obstruction segments. This may have important implications for stent design and pharmacokinetic properties of next-generation drug-eluting technology for this complex patient subset.

Comparison Between Sirolimus-Eluting Stents and Intracoronary Catheter-Based Beta Radiation for the Treatment of In-Stent Restenosis

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.

In vivo volumetric analysis of coronary stent using optical coherence tomography with a novel balloon occlusion-flushing catheter: A comparison with intravascular ultrasound

Optical coherence tomography (OCT) is limited as an intravascular imaging tool because of interference with blood. This study tested a new balloon occlusion-flushing catheter for OCT scanning of stented coronary arteries and compared stent measurements between OCT and intravascular ultrasound (IVUS). Motorized pullback with OCT and IVUS was examined in coronary stents deployed in swine. Quantitative measurements were obtained and compared between both groups. In addition, stent strut thickness was compared among OCT, IVUS and actual measurement. The occlusion catheter successfully provided motorized pullback OCT images in the stented coronary arteries without any complications. There were no differences in calculated lumen volume. However, stent volumes were significantly smaller with OCT than with IVUS ( p < 0.05). OCT significantly underestimated the stent strut thickness compared with the actual measurement. Although OCT underestimates the stent strut thickness, motorized pullback OCT imaging with the occlusion catheter can provide appropriate in-stent images in the porcine coronary arteries. (E-mail: ykawase@partners.org)

Filter no reflow during percutaneous coronary interventions using the Filterwire distal protection device

Background Distal protection devices are increasingly used to prevent embolization during percutaneous coronary interventions (PCI) in saphenous vein grafts (SVG) and native coronary arteries (NV). During interventions with the Filterwire device we have observed reduced flow that is reversible following removal of the filter (filter no reflow, FNR), which might be erroneously interpreted as true no reflow and might be associated with reduced capture efficiency of the basket. Methods We analyzed the incidence of FNR in 58 patients (60 lesions) at high risk of embolization undergoing PCI of either a SVG or a NV using the Filterwire (Boston Scientific, Natick, MA). Qualitative and quantitative angiographic analysis was performed, and the volume of collected debris was estimated using a photographic technique. Results In our population, about 1 / 3 of the cases showed FNR, which was associated with angiographically visible filling defects within the basket, indicating macroembolism. However some patients (especially those undergoing vein graft interventions) showed filling defects without FNR, and some others FNR without filling defects. Thus we tried to understand the predictors of FNR: FNR was associated with higher amount of collected debris (36.97 ± 42.98 mm 3 vs. 11.31 ± 18.47 mm 3, p = 0.005), was neither prevented by abciximab, nor predicted by high thrombotic burden, increasing stent volume or need for predilatation. When patient with and without angiographically evident macroembolisation were separately analyzed, a linear correlation of FNR with the quantity of debris was only apparent in the macroembolization group. Conclusions Interventionalists should be aware of the “Filter No Reflow”, a common but reversible angiographic complication when the Filterwire device is used. Reduced flow seen during these procedures should be treated conservatively. Mechanical obstruction of the filter, but also other mechanisms (pharmacologically active debris? platelet aggregates?) play a role in this phenomenon.

Endothelial Progenitor Cell Capture by Stents Coated With Antibody Against CD34: The HEALING-FIM (Healthy Endothelial Accelerated Lining Inhibits Neointimal Growth-First In Man) Registry

This study was designed to evaluate whether rapid endothelialization of stainless steel stents with a functional endothelium prevents stent thrombosis and reduces the restenotic process. A "pro-healing" approach for prevention of post-stenting restenosis is theoretically favored over the use of cytotoxic or cytostatic local pharmacologic therapies. It is believed that the central role of the vascular endothelium is to maintain quiescence of the underlying media and adventitia. Sixteen patients with de novo coronary artery disease were successfully treated with implantation of endothelial progenitor cell (EPC) capture stents. Complete procedural and angiographic success was achieved in all 16 patients. The nine-month composite major adverse cardiac and cerebrovascular events (MACCE) rate was 6.3% as a result of a symptom-driven target vessel revascularization in a single patient. There were no other MACCE despite only one month of clopidogrel treatment. At six-month follow-up, mean angiographic late luminal loss was 0.63 +/- 0.52 mm, and percent stent volume obstruction by intravascular ultrasound analysis was 27.2 +/- 20.9%. This first human clinical investigation of this technology demonstrates that the EPC capture coronary stent is safe and feasible for the treatment of de novo coronary artery disease. Further developments in this technology are warranted to evaluate the efficacy of this device for the treatment of coronary artery disease.

Circulating Monocytes and In-Stent Neointima After Coronary Stent Implantation

The authors investigated the relationship between circulating white blood cells, especially monocytes, and restenosis after stent implantation. Coronary stents were placed in 107 patients. The white blood cell fraction count was analyzed from peripheral blood obtained from patients immediately before the procedures and repeated after the procedure for 7 days. Patients received angiographic and volumetric intravascular ultrasound analysis at 6-month follow-up. The counts of circulating monocytes increased and peaked 2 days after stent implantation. A multiregression analysis showed a significant positive correlation with in-stent neointimal volume with stent volume immediately after implantation and maximum monocyte count. Twenty-two patients with angiographic restenosis showed a significantly larger maximum monocyte count than the patients without restenosis. The authors concluded that circulating monocytes contribute to the process of in-stent neointimal hyperplasia.

The angiotensin II receptor blocker candesartan cilexetil reduces neointima proliferation after coronary stent implantation: A prospective randomized study under intravascular ultrasound guidance

The purpose of this study was to evaluate whether an angiotensin II receptor blocker, candesartan cilexetil, reduced neointima formation after coronary stent implantation by way of serial intravascular ultrasound analysis. Previous experimental studies have suggested that angiotensin II receptor blocker reduced neointima formation after vascular injury. However, it is unclear whether candesartan cilexetil has a similar effect on human coronary artery. We recruited 50 consecutive patients with stable angina pectoris and 60 stenotic lesions. Patients were prospectively randomized into 2 groups: (1) 25 patients with 31 lesions received candesartan cilexetil (4-12 mg/d), and (2) 25 patients with 29 lesions did not receive the drug. Follow-up intravascular ultrasound was performed 6 m after the stent implantation. Cross-sectional images were obtained at 1-mm intervals within the stent, and the stent volume (SV), lumen volume (LV), and neointima volume (NV = SV - LV) were calculated using Simpson's rule. The percentage neointima volume obstruction (%NV) was calculated as NV/SV x 100. Clinical and angiographic backgrounds were comparable between the 2 groups. At follow-up, the candesartan group had smaller SV and larger LV (SV, 156.3 +/- 53.7 vs 165.4 +/- 61.8 mm3 , ns; LV, 122.2 +/- 49.0 vs 113.1 +/- 45.5 mm3 , ns), and significantly smaller NV and significantly smaller %NV than the control group (NV, 34.2 +/- 16.6 vs 52.3 +/- 32.6 mm3 , P < .01; %NV, 22.7 +/- 10.9% vs 31.3 +/- 13.4%, P < .01). Candesartan treatment decreases neointima formation and hence may reduce in-stent restenosis.

Comparison of quantitative angiographic parameters with the magnitude of neointimal hyperplasia measured by volumetric intravascular ultrasound in patients treated with bare metal and nonpolymeric paclitaxel-coated stents

We used data from the ASian Paclitaxel-Eluting Stent Clinical Trial (a 3-center, randomized, placebo-controlled trial of nonpolymeric paclitaxel-coated stents with a single-center intravascular ultrasound substudy) to compare angiographic indexes of drug-eluting stent efficacy with the magnitude of intimal hyperplasia (IH) assessed by intravascular ultrasound. Overall, percent IH (IH volume divided by stent volume) was larger in restenotic lesions than in nonrestenotic lesions (46 +/- 19% vs 15 +/- 13%, p <0.0001); angiographic late loss and follow-up diameter stenoses correlated strongly with percent IH.

Angiographic and three-dimensional intravascular ultrasound analysis of combined intracoronary beta radiation and self-expanding stent implantation in human coronary arteries

This study tested the combination of vascular brachytherapy (VBT) and self-expanding Wallstent implantation in coronary lesions of patients at high risk for restenosis as assessed angiographically by quantitative coronary analysis and by 3-dimensional intravascular ultrasound analysis. Twenty-nine "de novo" lesions were managed with a self-expanding stent alone (n = 19) or with a self-expanding stent after beta-VBT (n = 10) in 27 patients who had been identified by high levels of plasma angiotensin-converting enzyme as being prone to myointimal growth after stent implantation. At 6 months, the increase in stent strut diameter was similar in the 2 groups by quantitative coronary analysis and 3-dimensional intravascular ultrasound (Delta mean stent strut diameter -0.33 +/- 0.3 vs -0.40 +/- 0.3 mm, p = 0.5; Delta stent area -11.8 +/- 6.1 vs -12.0 +/- 6.1 mm(2), p = 0.9; Delta stent volume -96.9 +/- 112 vs -83.5 +/- 73 mm(3), p = 0.7; for groups treated with VBT and self-expanding stents and only self-expanding stents, respectively). In-stent neointimal proliferation was decreased in the group treated with VBT and self-expanding stents (minimal luminal diameter 2.5 +/- 0.8 vs 1.88 +/- 0.8 mm, p = 0.04) by quantitative coronary analysis (minimal luminal area 6.7 +/- 2.5 vs 4.1 +/- 1.9 mm(2), p = 0.01), by intravascular ultrasound, and proliferation volume (84.6 +/- 66.4 vs 159.2 +/- 103.5 mm(3), p = 0.05) by 3-dimensional intravascular ultrasound. Positive vessel and luminal remodelings were observed in 50% of the group treated with VBT and self-expanding stents and in 11% of the group treated only with self-expanding stents (p = 0.02). The combined use of VBT and self-expanding stents is a novel approach that enlarges vascular lumen by preventing vessel constriction and neointimal proliferation. The feasibility and good results of this experimental approach suggest that the simultaneous use of these 2 technologies may be an interesting alternative for difficult vascular districts with high restenosis rates, such as peripheral circulation in the lower limbs.