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Since late vessel failure has been speculated as a significant limitation of vascular brachytherapy (VBT), we conducted a prospective clinical evaluation at 6, 12, 24, 36 and 60 months follow-up after irradiation with (90)Sr/(90)Y for in-stent restenosis (ISR) regardless of the patient's symptomatic status. Complete five-year follow-up is reported for 104 consecutive patients. The cumulative rate of death was 13.5% (6 months: 0.96%; 12 months: 2.88%; 24 months: 4.81%; 36 months: 7.69%), of acute myocardial infarction 4.81% (2.88%; 4.81%; 4.81%; 4.81%), of late thrombotic occlusion 4.81% (3.85%; 4.81%; 4.81%; 4.81%), of target lesion revascularization (TLR) 27.9% (8.65%; 12.5%; 17.3%; 21.2%), of target vessel revascularization (TVR) 43.3% (12.5%; 19.2%; 22.1%; 29.8%), and of all major adverse cardiovascular events (MACE) 61.5% (16.3%; 26.9%; 31.7%; 42.3%), respectively. Considered that the annual incidence of TVR after the first year following drug-eluting stenting for in-stent restenosis has been reported as approximately 3% per year, an incidence of 5.8% per year following VBT of our study population clearly indicates a more pronounced, delayed and, even in the fifth year after the index procedure, ongoing restenotic process following beta-irradiation of in-stent restenotic lesions associated with clinically relevant adverse cardiovascular events.

Aims: The aim of this study is to compare the anti-inflammatory effect of the dexamethasone preloaded stent (Dexamet, Abbott, Galway, Ireland) with the bare metal stent (BMS; BiodivYsio, Biocompatibles Cardiovascular LTD, Galway, Ireland) in patients with acute coronary syndrome (ACS) assessed by angiographic (QCA) and intracoronary ultrasound (ICUS)., Methods and Results: One hundred twenty patients with ACS were randomly assigned to revascularization using the Dexamet stent (n = 60) or BMS (n = 60). Serial QCA analysis and ICUS analysis were performed during long-term follow-up (2.9 F; 20 MHz transducer; Volcano Corp, Brussels, Belgium). Power calculations were performed for QCA-derived differences of lumen loss. In addition, statistical analysis was performed (SPSS for Windows 12.0.1). The target lesion revascularization rate was lower in the Dexamet group (10 [16.67%] vs 20 [33.33%] patients; P = .031). The QCA revealed improved lumen restoration in the Dexamet stent group (lumen loss, 0.55 +/- 0.65 vs 1.07 +/- 0.92 mm [P = .001]; loss index, 0.20 +/- 0.23 vs 0.46 +/- 0.42 [P < .001]). The ICUS revealed greater neointimal proliferation in the BMS versus the Dexamet stent group (3.36 +/- 1.03 vs 3.05 +/- 1.38 mm2; P < .001). Death (n = 1) and the number of total occlusions of the stent segment (n = 1) were identical in both groups., Conclusion: Dexamet stents, in comparison with the BMS stents, reduced the target lesion revascularization rate in patients with ACS and lead to better lumen restoration during long-term follow-up.

Because late vessel failure has been speculated as a possible limitation of vascular brachytherapy, we conducted a prospective clinical evaluation at 6, 12, 24, and 36 months of follow-up after irradiation with strontium-90/yttrium-90 for in-stent restenosis, regardless of the patient's symptomatic status. We report complete 3-year follow-up data for 106 consecutive patients. The cumulative rate of death at 6, 12, 24, and 36 months was 0.9%, 0.9%, 0.9%, and 1.9% respectively. The corresponding rates for acute ST-elevation myocardial infarction were 2.8%, 4.7%, 4.7%, and 4.7%, respectively. The cumulative rate of late thrombotic occlusion at 6, 12, 24, and 36 months was 3.8%, 4.7%, 4.7%, and 4.7%, respectively. The corresponding rates of target lesion revascularization and target vessel revascularization were 8.5% and 12.3% (p = 0.046), 14.2% (p = 0.157) and 18.0% (p = 0.046), 12.3% and 18.9% (p = 0.008), and 21.7% (p = 0.083) and 29.2% (p = 0.005), respectively. The cumulative rate of all major adverse cardiovascular events at 6, 12, 24, and 36 months was 16.1%, 24.5% (p = 0.003), 27.4% (p = 0.083), and 35.8% (p = 0.003), respectively. In conclusion, these results indicate a delayed and, even in the third year after the index procedure, continued restenotic process after beta irradiation of in-stent restenotic lesions.

Background: Intravascular ultrasound (IVUS) is the reference method for in vivo assessment of vessel dimensions and coronary plaque composition, which can influence device selection as well as stent sizing., Objectives: The objective of this prospective multicenter-study was to test the application, safety, and feasibility of a new combined IVUS and stent delivery system., Methods: A total of 32 patients with planned direct stent implantation under IVUS guidance were included in the study. Procedural as well as angiographical and IVUS characteristics of the stent implantation with the combined IVUS and stent delivery system were assessed and compared to a historical control cohort where IVUS-guided stenting was performed with a separate IVUS catheter., Results: Direct stent placement was successfully performed in all patients and no malfunctions of the system were noted. A post-interventional IVUS assessment was possible in 27 (87%) of the 31 patients. The IVUS information led to a change in therapeutic strategy in 16 (50%) of the 32 patients. In the study group, both the procedural time and the amount of contrast dye were significantly lower than in the historical IVUS-guided stenting control group. A clinical 12-month follow-up revealed a 89% event-free survival and a target vessel revascularization rate of 7%., Conclusion: The use of a combined IVUS and stent delivery device is safe, easy to handle, and can provide helpful additional information to guide a percutaneous coronary interventions procedure. Beyond angiography, these informations had significant impact on the interventional strategy in these patients, which resulted in a low rate of major adverse cardiac events. The concept of combining IVUS information and a stent delivery system may be increasingly attractive with evolving imaging modalities like virtual histology or a combination with drug-eluting stents., ((J Interven Cardiol 2005;18:367-374).)

Background: The aim of the study was to compare the angioplasty mechanisms of drug (sirolimus)-eluting stent (DES) implantation and vascular brachytherapy (VBT) for the treatment of in-stent restenosis (ISR) as assessed by intravascular ultrasound (IVUS)., Methods: We performed IVUS in 53 patients (28 DES, 25 VBT) before and after angioplasty of ISR and at 6-month follow-up. Cross-sectional areas of the external elastic membrane, the stent, and the lumen were measured. Plaque + media, peristent plaque, and intimal hyperplasia areas were calculated, respectively., Results: Clinical and IVUS baseline characteristics did not differ between groups at baseline. After the index procedure, the lumen at the stent site was smaller in the DES group (DES 6.7 +/- 2.0 mm2 vs VBT 7.5 +/- 2.2 mm2, P = .042). Because of less intimal hyperplasia (DES 0.2 +/- 0.5 mm2 vs VBT 0.7 +/- 0.7 mm2, P = .043), the lumen dimensions revealed no difference between groups at follow-up (DES 6.5 +/- 2.3 mm2 vs VBT 6.8 +/- 2.2 mm2, P = .374). At the reference site, the index procedure led to a similar increase of plaque + media (DES 0.9 +/- 0.9 mm2 vs VBT 0.6 +/- 1.2 mm2, P = .150). At follow-up, the plaque + media was significantly smaller in the DES group (DES 8.0 +/- 6.6 mm2 vs VBT 9.9 +/- 7.8 mm2, P = .013)., Conclusions: Drug-eluting stent for the treatment of ISR more effectively inhibits neointima formation when compared with VBT. Yet insufficient stent expansion might be a reason for device failure and should be avoided. At the reference site, lumen loss by an increased plaque burden, as has been well recognized following VBT, is not present with DES.

Pathogenic events leading to in-stent restenosis (ISR) are still incompletely understood. Among others, inflammation, immune reactions, deregulated cell death and growth have been suggested. Therefore, atherectomy probes from 21 patients with symptomatic ISR were analyzed by immunohistochemistry for pathogen burden and compared to primary target lesions from 20 stable angina patients. While cytomegalovirus, herpes simplex virus, Epstein-Barr virus and Helicobacter pylori were not found in ISR, acute and/or persistent chlamydial infection were present in 6/21 of these lesions (29%). Expression of human heat shock protein 60 was found in 8/21 of probes (38%). Indicated by distinct signals of CD68, CD40 and CRP, inflammation was present in 5/21 (24%), 3/21 (14%) and 2/21 (10%) of ISR cases. Cell density of ISR was significantly higher than that of primary lesions (977 +/- 315 vs. 431 +/- 148 cells/mm(2); p < 0.001). There was no replicating cell as shown by Ki67 or PCNA. TUNEL(+) cells indicating apoptosis were seen in 6/21 of ISR specimens (29%). Quantitative analysis revealed lower expression levels for each intimal determinant in ISR compared to primary atheroma (all p < 0.05). In summary, human ISR at the time of clinical presentation is characterized by low frequency of pathogen burden and inflammation, but pronounced hypercellularity, low apoptosis and absence of proliferation., (Copyright 2004 S. Karger AG, Basel.)

In-stent restenosis (ISR), especially after vascular brachytherapy, is a therapeutic challenge. Sirolimus-eluting stent implantation is a promising new option for the treatment of patients with ISR. The efficacy of sirolimus-eluting stent implantation for the treatment of patients with their first episodes of ISR and with recurrent ISR due to the failure of vascular brachytherapy was compared using intravascular ultrasound imaging.

The self-expanding Wallstent (WS) and balloon-expandable Palmaz-Schatz stents (PS) display different mechanical and dynamical stent properties. We analyzed the impact of the respective stent design on coronary wall geometry using quantitative coronary angiography (QCA) and intracoronary ultrasound (ICUS) measurements. Serial measurements were performed within the stent and within reference segments of 50 patients (25 WS, 25 PS). Relative changes for each parameter in both stent designs were calculated (Mann-Whitney U-test; 95% CI). The luminal net gain in WS was not significantly higher in WS compared with PS (1.63 +/- 1.11 vs. 1.44 +/- 0.63 mm; P = 0.2554). The respective loss indexes were also similar (0.38 +/- 0.42 vs. 0.36 +/- 0.23; P = 0.8578). The WS segments showed significant postinterventional stent expansion with positive vessel remodeling. The neointima formation was significantly higher in WS segments (4.23 +/- 2.07 vs. 2.22 +/- 2.22 mm(2)). The coronary wall morphology and stent geometry after 6.5 +/- 1.2 months are related to the stent design. In WS segments, the neointima formation was balanced by postinterventional stent expansion, resulting in a comparable relative lumen loss in both stent types. The respective stent design had no impact on the vessel reference segments., (Copyright 2002 Wiley-Liss, Inc.)

Fractional flow reserve (FFR) as a new technique for physiological assessment of coronary stenoses could identify patients with CAD in whom the deferral of an intended PCI was more beneficial than performing the planned procedure. It is up to now unknown whether a FFR-based therapy stratification is also safe in patients with multivessel disease and complex coronary lesions. This study demonstrates in 71 symptomatic patients with predominantly multivessel disease and angiographically intermediate coronary lesions that patients do not benefit from PCI procedures in terms of overall survival, target vessel patency or clinical symptoms during 12 month follow-up if FFR is above 0.75.

In-stent restenosis (ISR) represents the major limitation of stent implantation. Treatment, although of relative technical ease, is unsatisfactory due to the high incidence of recurrent restenosis. Long ISR lesions are especially prone to restenosis. Vascular brachytherapy (VBT) has emerged as a powerful adjunct therapeutic modality to treat ISR. However, VBT may be less effective in very long, diffuse ISR lesions. The present study investigated serial changes of the extent and distribution of neointima formation after beta-radiation as assessed by intravascular ultrasound (IVUS). Following interventional procedures of long ISR in 30 patients, a 40 mm or 60 mm non-centered 90Sr/90Y seed train was used for VBT. Serial (post radiation (PR) and follow-up (FU)) quantitative coronary angiography (QCA) measurements of minimal lumen diameter (MLD) and late lumen loss (LLL) and intravascular ultrasound measurements (IVUS) of cross-sectional areas of the lumen (L-CSA), stent (S-CSA) and intimal hyperplasia (IH-CSA) were performed and compared with historic controls. LLL (0.34 +/- 0.27 mm; p = 0.196), mean decrease of L-CSA (-1.0 +/- 0.8 mm2; p = 0.024) and mean increase of IH-CSA (0.5 +/- 1.3 mm2; p = 0.038) in long ISR were comparable with previously reported results of short ISR. In conclusion the average changes of lumen and intimal hyperplasia after beta-radiation of long ISR are similar to those of short ISR.

Objectives: Determination of fractional flow reserve (FFR) allows the functional assessment of coronary stenoses before and after an intervention. Preliminary data suggest that a FFR > or = 0.94 is associated with an excellent clinical outcome after stent implantation. However, these results were limited both by the number of patients included and the use of non-contemporary stent designs. We sought to determine the prognostic value of FFR measurements in a large patient cohort undergoing coronary stent implantation., Methods: Eighty-nine consecutive patients were enrolled in whom a stent implantation was performed and a pressure wire was used as a guide wire. Patients were followed for at least 6 months. Death, myocardial infarction (MI) and target vessel revascularization (TVR) were considered cardiac events. A FFR > or = 0.94 was regarded as an optimal functional result., Results: A complete follow-up was available in all patents. Pre-interventional FFR increased from 0.66 +/- 0.16 to 0.95 +/- 0.05 (p < 0.0001) after stent implantation. Sixteen (18%) events occurred during follow-up including 10 (11.2%) TVR. Final FFR was significantly higher in patients without compared to patients with an event (0.92 +/- 0.06 vs. 0.96 +/- 0.05, p < 0.003). By univariate analysis, the presence of diabetes mellitus, left ventricular function, residual diameter stenosis and final FFR were associated with a worse clinical outcome. In the multivariate analysis, only the final FFR and left ventricular function remained as significant predictors for cardiac events (relative risk, 3.50; 95% CI: 1.29-9.52, P < 0.014, and 0.97; 95% CI: 0.93-1.00, p = 0.047)., Conclusion: These results demonstrate in a nonselected patient cohort a strong correlation between FFR values after coronary stenting and subsequent cardiac events. Further studies have to investigate whether outcome after stenting might be improved by guiding the procedure with a pressure guide wire.

Background: The extent of myocardial salvage after primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI) is variable and can not be predicted on the basis of vessel patency. The aim of this study was to evaluate the tissue salvage and the microvascular integrity after successful intervention in AMI by coronary blood flow velocity and sestamibi perfusion imaging., Methods: Twenty-two patients (17 m, 5f; mean age 57 +/- 14 yrs.) undergoing primary PTCA and stent implantation for AMI were studied. 99mTc Sestamibi was injected intravenously before intervention and single photon emission computed tomography (SPECT) was performed immediately after successful reperfusion to determine the area at risk before PTCA due to the minimal 99mTc Sestamibi redistribution. Sestamibi SPECT was repeated 3 days and 6 months after AMI. Area at risk (%) was determined automatically by myocardial perfusion tomography (PERFIT) with the use of a multistage, 3D iterative inter-subject registration of patient images to normal templates (2SD) and myocardial salvage was calculated. Coronary flow velocity was measured using a Doppler-tipped guidewire in the infarct-related artery after successful completion of primary PTCA and in an angiographically normal reference vessel. Absolute coronary flow reserve (CFR) and relative CFR (rCFR) were calculated using hyperemic to basal average peak velocity., Results: Despite successful reperfusion of the target vessel (TIMI grade III flow) CFR and rCFR remained impaired (1.8 +/- 0.9 and 0.77 +/- 0.21). Area at risk decreased significantly from 21 +/- 9% to 9 +/- 10% (p < 0.05) corresponding to 11 +/- 8% myocardial salvage. Acute CFR and rCFR showed no correlation with the area at risk before and after primary PTCA. The increase of CFR within 6 months correlated with the myocardial salvage (p < 0.05)., Conclusions: Despite successful primary PTCA in AMI, CFR and rCFR often remain impaired because of a significant loss of microvascular integrity. The long-term success of primary PTCA can be assessed by myocardial salvage and the change of CFR which might be a useful parameter for additional reperfusion strategies such as glycoprotein IIb/IIIA receptor inhibition.

A variety of different stent types is available for the treatment of coronary stenosis. However, in-stent restenosis remains the major limitation for the use of these devices. Intracoronary ultrasound (ICUS) in addition to coronary angiography provides precise measurements of coronary wall dimensions during stent implantation and of intimal hyperplasia during follow-up. The extent of coronary injury during stent implantation was shown to play an important role in neointima formation. It is characterized by endothelial exposure, intima laceration, and media permeation. Stent-induced coronary injury has been considered to depend on stent design and stent strut size with consecutive deep wall laceration. ICUS analysis showed a correlation between the stent design and the amount of neointimal tissue proliferation. The role of adventitial remodeling in the process of restenosis is discussed controversially. Post-procedural stent expansion may provoke adventitial remodeling. The stent design and stenting strategy determines the extent of peri- and post-procedural coronary injury. Post-procedural coronary morphologic changes and changes of the stent geometry depend upon the stent design. Beside further modifications as the use of drug-eluting stents the decrease of stent-related vessel injury should be an important criterion for the development of future stent design.