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Background In ST-segment-elevation myocardial infarction, angiography-based complete revascularization is superior to culprit-lesion-only percutaneous coronary intervention. Quantitative flow ratio (QFR) is a novel, noninvasive, vasodilator-free method used to assess the hemodynamic significance of coronary stenoses. We aimed to investigate the incremental value of QFR over angiography in nonculprit lesions in patients with ST-segment-elevation myocardial infarction undergoing angiography-guided complete revascularization. Methods and Results This was a retrospective post hoc QFR analysis of untreated nontarget vessels (any degree of diameter stenosis [DS]) from the randomized multicenter COMFORTABLE AMI (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Metal Stents in Acute ST-Elevation Myocardial Infarction) trial by assessors blinded for clinical outcomes. The primary end point was cardiac death, spontaneous nontarget vessel myocardial infarction, and clinically indicated nontarget vessel revascularization (ie, ≥70% DS by 2-dimensional quantitative coronary angiography or ≥50% DS and ischemia) at 5 years. Of 1161 patients with ST-segment-elevation myocardial infarction, 946 vessels in 617 patients were analyzable by QFR. At 5 years, the rate of the primary end point was significantly higher in patients with QFR ≤0.80 (n=35 patients, n=36 vessels) versus QFR >0.80 (n=582 patients, n=910 vessels) (62.9% versus 12.5%, respectively; hazard ratio [HR], 7.33 [95% CI, 4.54-11.83], P <0.001), driven by higher rates of nontarget vessel myocardial infarction (12.8% versus 3.1%, respectively; HR, 4.38 [95% CI, 1.47-13.02], P =0.008) and nontarget vessel revascularization (58.6% versus 7.7%, respectively; HR, 10.99 [95% CI, 6.39-18.91], P <0.001) with no significant differences for cardiac death. Multivariable analysis identified QFR ≤0.80 but not ≥50% DS by 3-dimensional quantitative coronary angiography as an independent predictor of the primary end point. Results were consistent, including only >30% DS by 3-dimensional quantitative coronary angiography. Conclusions Our study suggests incremental value of QFR over angiography-guided percutaneous coronary intervention for nonculprit lesions among patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention.

Objectives: The aim of this study was to assess race-based differences in patients undergoing percutaneous coronary intervention from a large pooled database of randomized controlled trials., Background: Data on race-based outcomes after percutaneous coronary intervention are limited, deriving mainly from registries and single-center studies., Methods: Baseline characteristics and outcomes at 30 days, 1 year, and 5 years were assessed across different races, from an individual patient data pooled analysis from 10 randomized trials. Endpoints of interest included death, myocardial infarction, and major adverse cardiac events (defined as cardiac death, myocardial infarction, or ischemia-driven target lesion revascularization). Multivariate Cox proportional hazards regression was performed to assess associations between race and outcomes, controlling for differences in 12 baseline covariates., Results: Among 22,638 patients, 20,585 (90.9%) were white, 918 (4.1%) were black, 404 (1.8%) were Asian, and 473 (2.1%) were Hispanic. Baseline and angiographic characteristics differed among groups. Five-year major adverse cardiac event rates were 18.8% in white patients (reference group), compared with 23.9% in black patients (p = 0.0009), 11.2% in Asian patients (p = 0.0007), and 21.5% in Hispanic patients (p = 0.07). Multivariate analysis demonstrated an independent association between black race and 5-year risk for major adverse cardiac events (hazard ratio: 1.28; 95% confidence interval: 1.05 to 1.57; p = 0.01)., Conclusions: In the present large-scale individual patient data pooled analysis, comorbidities were significantly more frequent in minority-group patients than in white patients enrolled in coronary stent randomized controlled trials. After accounting for these differences, black race was an independent predictor of worse outcomes, whereas Hispanic ethnicity and Asian race were not. Further research examining race-based outcomes after percutaneous coronary intervention is warranted to understand these differences., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The majority of stent-related major adverse cardiovascular events (MACE) after percutaneous coronary intervention (PCI) are believed to occur within the first year. Very-late (>1-year) stent-related MACE have not been well described., Objectives: The purpose of this study was to assess the frequency and predictors of very-late stent-related events or MACE by stent type., Methods: Individual patient data from 19 prospective, randomized metallic stent trials maintained at a leading academic research organization were pooled. Very-late MACE (a composite of cardiac death, myocardial infarction [MI], or ischemia-driven target lesion revascularization [ID-TLR]), and target lesion failure (cardiac death, target-vessel MI, or ID-TLR) were assessed within year 1 and between 1 and 5 years after PCI with bare-metal stents (BMS), first-generation drug-eluting stents (DES1) and second-generation drug-eluting stents (DES2). A network meta-analysis was performed to evaluate direct and indirect comparisons., Results: Among 25,032 total patients, 3,718, 7,934, and 13,380 were treated with BMS, DES1, and DES2, respectively. MACE rates within 1 year after PCI were progressively lower after treatment with BMS versus DES1 versus DES2 (17.9% vs. 8.2% vs. 5.1%, respectively, p < 0.0001). Between years 1 and 5, very-late MACE occurred in 9.4% of patients (including 2.9% cardiac death, 3.1% MI, and 5.1% ID-TLR). Very-late MACE occurred in 9.7%, 11.0%, and 8.3% of patients treated with BMS, DES1, and DES2, respectively (p < 0.0001), linearly increasing between 1 and 5 years. Similar findings were observed for target lesion failure in 19,578 patients from 12 trials. Findings were confirmed in the network meta-analysis., Conclusions: In this large-scale, individual patient data pooled study, very-late stent-related events occurred between 1 and 5 years after PCI at a rate of ∼2%/year with all stent types, with no plateau evident. New approaches are required to improve long-term outcomes after PCI., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: The long-term outcomes of biolimus-eluting stents (BESs) with biodegradable polymer as compared with bare-metal stent (BMS) in patients with ST-segment elevation myocardial infarction (STEMI) remain unknown., Methods and Results: We performed a 5-year clinical follow-up of 1157 patients (BES: N = 575 and BMS: N = 582) included in the randomized COMFORTABLE AMI trial. Serial intracoronary imaging of stented segments using both intravascular ultrasound (IVUS) and optical coherence tomography performed at baseline and 13 months follow-up were analysed in 103 patients. At 5 years, BES reduced the risk of major adverse cardiac events [MACE; hazard ratio (HR) 0.56, 95% confidence interval (CI): 0.39-0.79, P = 0.001], driven by lower risks for target vessel-related reinfarction (HR 0.44, 95% CI: 0.22-0.87, P = 0.02) and ischaemia-driven target lesion revascularization (HR 0.41, 95% CI: 0.25-0.66, P < 0.001). Definite stent thrombosis (ST) was recorded in 2.2% and 3.9% (HR 0.57, 95% CI: 0.28-1.16, P = 0.12) with no differences in rates of very late definite ST (1.3% vs. 1.6%, P = 0.77). Optical coherence tomography showed no difference in the frequency of malapposed stent struts at follow-up (BES 0.08% vs. BMS 0.02%, P = 0.10). Uncovered stent struts were rarely observed but more frequent in BES (2.1% vs. 0.15%, P < 0.001). In the IVUS analysis, there was no positive remodelling in either group (external elastic membrane area change BES: -0.63 mm2, 95% CI: -1.44 to 0.39 vs. BMS -1.11 mm2, 95% CI: -2.27 to 0.04, P = 0.07)., Conclusion: Compared with BMS, the implantation of biodegradable polymer-coated BES resulted in a lower 5-year rate of MACE in patients with STEMI undergoing primary percutaneous coronary intervention. At 13 months, vascular healing in treated culprit lesions was almost complete irrespective of stent type., Clinical Trial Registration: http://www.clinicaltrials.gov. Unique identifier: NCT00962416., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Aims: In preclinical studies, a bare metal cobalt-chromium stent with an active surface oxide layer modification (BMSmod) has been shown to inhibit neointimal hyperplasia effectively. We sought to assess both the clinical safety and feasibility of the BMSmod., Methods and Results: In this prospective, non-randomised, first-in-man multicentre study, a total of 31 patients with de novo coronary lesions, reference lumen diameters of 2.5-3.5 mm and lesion length ≤16 mm, were enrolled. Quantitative coronary angiography and optical coherence tomography (OCT) were performed at baseline and six-month follow-up. Primary angiographic and OCT endpoints included in-stent late lumen loss (LLL) and mean neointimal thickness at six months. The device-oriented composite endpoint (DoCE), defined as cardiac death, myocardial infarction not clearly attributable to a non-intervention vessel, and clinically indicated target lesion revascularisation (CI-TLR), was analysed according to the intention-to-treat principle. In 31 patients (33 lesions), the procedural success rate was 93.5%. At six months, angiographic LLL was 0.91±0.45 mm and binary angiographic restenosis occurred in 23.3% of lesions. Out of 33 lesions, OCT was performed in 27 lesions at both time points. Mean neointimal thickness amounted to 348±116 µm. At six months, the DoCE was 19.4% due to the occurrence of CI-TLR in five patients (including one late definite stent thrombosis of a non-study stent)., Conclusions: In contrast to previous preclinical pathophysiological work, the BMSmod did not prevent neointimal hyperplasia in a first-in-man clinical setting.

Background: To investigate the performance of the MI Sxscore in a multicentre randomised trial of patients undergoing primary percutaneous coronary intervention (PPCI)., Methods and Results: The MI Sxscore was prospectively determined among 1132 STEMI patients enrolled into the COMFORTABLE AMI trial, which randomised patients to treatment with bare-metal (BMS) or biolimus-eluting (BES) stents. Patient- (death, myocardial infarction, any revascularisation) and device-oriented (cardiac death, target-vessel MI, target lesion revascularisation) major adverse cardiac events (MACEs) were compared across MI Sxscore tertiles and according to stent type. The median MI SXscore was 14 (IQR: 9-21). Patients were divided into tertiles of Sxscorelow (≤10), Sxscoreintermediate (11-18) and Sxscorehigh (≥19). At 1 year, patient-oriented MACE occurred in 15% of the Sxscorehigh, 9% of the Sxscoreintermediate and 5% of the Sxscorelow tertiles (p<0.001), whereas device-oriented MACE occurred in 8% of the Sxscorehigh, 6% of the Sxscoreintermediate and 4% of the Sxscorelow tertiles (p=0.03). Addition of the MI Sxscore to the TIMI risk score improved prediction of patient- (c-statistic value increase from 0.63 to 0.69) and device-oriented MACEs (c-statistic value increase from 0.65 to 0.70). Differences in the risk for device-oriented MACE between BMS and BES were evident among Sxscorehigh (13% vs. 4% HR 0.33 (0.15-0.74), p=0.007 rather than those in Sxscorelow: 4% vs. 3% HR 0.68 (0.24-1.97), p=0.48) tertiles., Conclusions: The MI Sxscore allows risk stratification of patient- and device-oriented MACEs among patients undergoing PPCI. The addition of the MI Sxscore to the TIMI risk score is of incremental prognostic value among patients undergoing PPCI for treatment of STEMI., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Background: This study sought to determine whether the 1-year differences in major adverse cardiac event between a stent eluting biolimus from a biodegradable polymer and bare-metal stents (BMSs) in the COMFORTABLE trial (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Metal Stents in Acute ST-Elevation Myocardial Infarction) were sustained during long-term follow-up., Methods and Results: A total of 1161 patients were randomly assigned to biolimus-eluting stent (BES) and BMS at 11 centers, and follow-up rates at 2 years were 96.3%. A subgroup of 103 patients underwent angiography at 13 months. At 2 years, differences in the primary end point of cardiac death, target-vessel myocardial infarction, and target lesion revascularization continued to diverge in favor of BES-treated patients (5.8%) compared with BMS-treated patients (11.9%; hazard ratio = 0.48; 95% confidence interval, 0.31-0.72; P < 0.001) with a significant risk reduction during the second year of follow-up (hazard ratio 1-2 years = 0.45; 95% confidence interval, 0.20-1.00; P = 0.049). Differences in the primary end point were driven by a reduction in target lesion revascularization (3.1% versus 8.2%; P < 0.001) and target-vessel reinfarction (1.3% versus 3.4%; P = 0.023). The composite of death, any reinfarction and revascularization (14.5% versus 19.3%; P = 0.03), and cardiac death or target-vessel myocardial infarction (4.2% versus 7.2%; P = 0.036) were less frequent among BES-treated patients compared with BMS-treated patients. The 13-month angiographic in-stent percent diameter stenosis amounted to 12.0 ± 7.2 in BES- and 39.6 ± 25.2 in BMS-treated lesions (P < 0.001)., Conclusions: Among patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention, BES continued to improve cardiovascular events compared with BMS beyond 1 year., Clinical Trial Registration Url: http://www.clinicaltrials.gov. Unique identifier: NTC00962416., (© 2014 American Heart Association, Inc.)

Objectives: This study sought to study the efficacy and safety of newer-generation drug-eluting stents (DES) compared with bare-metal stents (BMS) in an appropriately powered population of patients with ST-segment elevation myocardial infarction (STEMI)., Background: Among patients with STEMI, early generation DES improved efficacy but not safety compared with BMS. Newer-generation DES, everolimus-eluting stents, and biolimus A9-eluting stents, have been shown to improve clinical outcomes compared with early generation DES., Methods: Individual patient data for 2,665 STEMI patients enrolled in 2 large-scale randomized clinical trials comparing newer-generation DES with BMS were pooled: 1,326 patients received a newer-generation DES (everolimus-eluting stent or biolimus A9-eluting stent), whereas the remaining 1,329 patients received a BMS. Random-effects models were used to assess differences between the 2 groups for the device-oriented composite endpoint of cardiac death, target-vessel reinfarction, and target-lesion revascularization and the patient-oriented composite endpoint of all-cause death, any infarction, and any revascularization at 1 year., Results: Newer-generation DES substantially reduce the risk of the device-oriented composite endpoint compared with BMS at 1 year (relative risk [RR]: 0.58; 95% confidence interval [CI]: 0.43 to 0.79; p = 0.0004). Similarly, the risk of the patient-oriented composite endpoint was lower with newer-generation DES than BMS (RR: 0.78; 95% CI: 0.63 to 0.96; p = 0.02). Differences in favor of newer-generation DES were driven by both a lower risk of repeat revascularization of the target lesion (RR: 0.33; 95% CI: 0.20 to 0.52; p < 0.0001) and a lower risk of target-vessel infarction (RR: 0.36; 95% CI: 0.14 to 0.92; p = 0.03). Newer-generation DES also reduced the risk of definite stent thrombosis (RR: 0.35; 95% CI: 0.16 to 0.75; p = 0.006) compared with BMS., Conclusions: Among patients with STEMI, newer-generation DES improve safety and efficacy compared with BMS throughout 1 year. It remains to be determined whether the differences in favor of newer-generation DES are sustained during long-term follow-up., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

To assess in a multicenter design the between-center reproducibility of volumetric virtual histology intravascular ultrasound (VH-IVUS) measurements with a semi-automated, computer-assisted contour detection system in coronary lesions that were consecutively stented. To evaluate the reproducibility of volumetric VH-IVUS measurements, experienced analysts of 4 European IVUS centers performed independent analyses (in total 8,052 cross-sectional analyses) to obtain volumetric data of 40 coronary segments (length 20.0 ± 0.3 mm) from target lesions prior to percutaneous intervention that were performed in the setting of stable (65%) or unstable angina pectoris (35%). Geometric and compositional VH-IVUS measurements were highly correlated for the different comparisons. Overall intraclass correlation for vessel, lumen, plaque volume and plaque burden was 0.99, 0.92, 0.96, and 0.83, respectively; for fibrous, fibro-lipidic, necrotic core and calcified volumes overall intraclass correlation was 0.96, 0.94, 0.98, and 0.99, respectively. Nevertheless, significant differences for both geometrical and compositional measurements were seen. Of the plaque components, fibrous tissue and necrotic core showed on average the highest measurement reproducibility. A central analysis for VH-IVUS multicenter studies of lesions prior to PCI should be pursued. Moreover, it may be problematical to pool VH-IVUS data of individual trials analyzed by independent centers.

Background: Cardiac marker release after percutaneous coronary interventions (PCI) reflects myocardial necrosis which is usually the result of periprocedural (micro)embolization of atherothrombotic debris and associated with impaired left ventricular function and adverse outcome., Methods: In this prospective study, we examined 55 patients treated by direct stenting of single de-novo lesions to assess the relationship between plaque composition, as determined by preinterventional intravascular ultrasound (IVUS) with radiofrequency data (IVUS-RF) analysis (so-called Virtual Histology) versus coronary microembolization, as determined by serial measurement of cardiac markers. IVUS was performed with an electronic system and 20-MHz IVUS catheters. Serum creatine kinase (CK) and cardiac troponin I (CTnI) were determined before PCI and after 6, 12, and 24 hours., Results: Plaques had a volume of 99 +/- 63 mm(3) and were composed of fibrous (61 +/- 9%) and fibro-fatty tissue (27 +/- 12%), dense calcium (4 +/- 3%), and necrotic core (NC) (8 +/- 6%). NC volume per se, volume per 10 mm of segment length, and volume % were correlated (r = 0.64, 0.66, and 0.52 respectively; all P < 0.01) with the maximum increase in cardiac markers (CK 55.4 +/- 55.7 U/l; CTnI 0.49 +/- 0.68 ng/ml). Patients in the 4th quartile of NC volume (>10.8 mm(3)) had a particularly high increase in markers (P < 0.001). In contrast, total plaque volume and plaque components other than NC had no relation with cardiac markers (ns)., Conclusions: Patients with large NC in culprit lesions may experience more myocardial injury from peri-interventional microembolization. IVUS-RF assessment before PCI has the potential to identify lesions at particular high risk which may help to tailor PCI.

Intravascular ultrasound (IVUS) is a catheter-based technique which provides high-resolution cross-sectional images of both, coronary lumen and vessel wall. Various scientific studies recently established IVUS as a valuable tool for the assessment of the natural history of coronary atherosclerosis and the effect of different pharmacological and non-pharmacological interventions on progression-regression of atherosclerosis. Novel technical approaches that use IVUS radiofrequency data may provide further interesting information on vessel wall characteristics but require further validation. In addition, numerous trials applied IVUS to assess the short- and long-term outcome of different percutaneous coronary interventions, including the implantation of drug-eluting stents. Besides the importance of IVUS in the field of scientific trials, IVUS can be clinically helpful for the evaluation of angiographically ambiguous lesions, guidance of catheter-based interventions, and management of complications. Settings in which IVUS may be particular useful are: ostial and bifurcation lesions; the presence of diffuse atherosclerotic disease; severely calcified or very tight lesions; relatively small vessels; diabetic patients; and if multiple, long or novel stents are implanted. This article gives an overview on the value of IVUS for the assessment of coronary atherosclerosis and percutaneous coronary interventions. In this context, we reviewed a selection of recently published IVUS studies which provide interesting new information in this field.

Purpose: To report the incidence and management of aortoesophageal fistula (AEF) secondary to endovascular stent-graft repair of the descending thoracic aorta., Methods: A retrospective review was conducted of patients treated at our facility between July 1999 and June 2003. During this interval, 60 patients (46 men; average age 66+/-10 years) underwent thoracic aortic stent-graft placement for a variety of pathologies., Results: AEF occurred in 3 (5%) patients. One 62-year-old man presented with recurrent back pain and fever and died suddenly due to fatal exsanguination; the AEF was revealed at necropsy. The other 2 patients (both women) presented with hematemesis after endovascular repair of thoracic aortic aneurysms. AEF was detected by esophagogastroduodenoscopy. Both patients were treated conservatively, as open surgical repair was refused because of their general condition. Both patients developed severe mediastinitis and died after 5 weeks and 10 months, respectively., Conclusions: Aortoesophageal fistula is, in our experience, a catastrophic complication of endovascular stent-graft placement. Treatment options are very limited, as these patients are usually not candidates for open surgery. Outcome under conservative management is, however, almost invariably fatal.

The mechanisms of lumen enlargement during stent implantation may be significantly affected by arterial remodeling. To assess effects of lesion remodeling, we performed 3-dimensional intravascular ultrasound (IVUS) analyses in 55 coronary lesions before and after deployment of balloon-expandable stents. Standard quantitative analysis was performed, and arterial remodeling was assessed by the remodeling index (target site divided by mean of proximal and distal reference segment vessel areas), which classified lesions into group A (remodeling index < or =1, negative or intermediate remodeling, n = 40) or group B (remodeling index >1, positive remodeling, n = 15) lesions. Characteristics of the 55 patients and the interventional procedures were similar in the 2 groups. IVUS demonstrated that stenting resulted in increased lumen and vessel dimensions and in a reduced plaque size (p < or =0.001 each) in both group A and group B lesions. The extent of lumen increase inside the stents was almost identical, but resulted from different mechanisms: (1) vessel stretch was greater in group A (p <0.002 at minimum lumen site); (2) plaque compression (or embolization) tended to be greater in group B (p = 0.05, along entire stented segment); (3) plaque redistribution within the stent was observed in both groups (p <0.005 both); and (4) significant (p <0.01) plaque extrusion into the distal reference segment was found in group B only. Thus, the remodeling pattern of coronary lesions has a significant impact on the mechanisms of lumen enlargement during stent deployment. Lesions with positive remodeling show more plaque extrusion into the distal reference and less stent-induced vessel stretch than those with negative remodeling.

Various clinical studies have shown the superiority of stent implantation as compared to conventional balloon angioplasty for the treatment of significant coronary stenosis. However, restenosis remains a major drawback of this interventional technique. Against the background of this serious problem, the concept of stent coating has been developed. In general, coatings can be classified into two types: passive coatings, which only serve as a barrier between the stainless steel, and the tissue and active coatings, which directly interfere with the process of intima proliferation. At this moment, primarily immunosuppressive and cytostatic substances are used as active coatings. Large randomised studies have shown that this novel concept can be successfully implemented into clinical practice. Beside these promising results, studies also revealed potential risks of this new approach. Not only the dosage of the drug but also an optimised kinetic of drug release seem to be essential in preventing restenosis. As with most drugs, the inhibition of neointima proliferation is not restricted to vascular smooth muscle cells but also affects the process of re-endothelialisation, thus we may face a new pitfall of late-stent thrombosis. Although this technique may harbour potential risks, the introduction of stent coating has the potential to dramatically reduce the incidence of restenosis and an exciting chapter in the field of cardiology has been opened.

Objective: To identify the incidence and clinical significance of myocardial injury following elective stent implantation., Design: Prospective clinical study with 278 consecutive patients undergoing stenting of de novo coronary or saphenous vein graft lesions. Incidence of periprocedural myocardial injury was assessed by analysis of 12 lead ECG, creatine kinase (CK; upper limit of normal (ULN) 70 IU/l for women, 80 IU/l for men), and cardiac troponin T (cTnT; point of care test; threshold 0.1 ng/ml) before and 6, 12, and 24 hours after the intervention. Major adverse cardiac events (MACE: acute myocardial infarction, bypass surgery, and cardiac death) were recorded during clinical follow up (mean (SD) 7.8 (5.3) months)., Results: Following elective stenting, the rate of a positive cTnT status was 17.3%, the rate of CK increase of 1-3x ULN 14.7%, the rate of CK increase of > 3x ULN 1.4%, and the rate of Q wave myocardial infarction 0.4%. Cardiac mortality during follow up was higher in patients with postprocedurally increased CK (7.1% v 1.3%, p = 0.01, log rank) and cTnT (9.1% v 0.9%, p < 0.001, log rank). In addition, postprocedurally increased cTnT was associated with a higher overall incidence of MACE (13.1% v 4.0%, p < 0.01, log rank) and was identified as an independent factor for MACE during follow up (hazard ratio 3.27, 95% confidence interval 1.14 to 9.41, p = 0.028)., Conclusions: Following elective stent implantation, a positive cTnT status identified patients at risk of a worse long term outcome. Treatment strategies have to be developed that lead to prognostic improvement by reducing periprocedural myocardial injury.

Embolization of coronary stents before deployment is a rare but challenging complication of coronary stenting. Different methods for nonsurgical stent retrieval have been suggested. There were 20 cases (0.90%) of intracoronary stent embolization among 2,211 patients who underwent implantation of 4,066 stents. Twelve of 1,147 manually crimped stents (1.04%) and eight of 2,919 premounted stents were lost (0.27%, P < 0.01) during retraction of the delivery system, because the target lesion could not be either reached or crossed. Percutaneous retrieval was successfully carried out in 10 of 14 patients (71%) in whom retrieval was attempted. In 10 patients, stent retrieval was tried with 1.5-mm low-profile angioplasty balloon catheters (success in 7/10) and in seven cases with myocardial biopsy forceps or a gooseneck snare (success in 3/7). Three patients (15%) underwent urgent coronary artery bypass surgery after failed percutaneous retrieval, but their outcomes were fatal. In two patients, stents were compressed against the vessel wall by another stent, without compromising coronary blood flow. In two patients, a stent was lost to the periphery without clinical side effects; treatment was conservative in these cases. Embolization of stents before deployment is a rare but serious complication of coronary stenting, with hazardous potential for the patient. Manual mounting of stents is associated with a significantly higher risk of stent embolization. Stent retrieval from the coronary circulation with low-profile angioplasty balloon catheters is a readily available and technically familiar approach that has a relatively high success rate.

In a 73 year-old male patient with generalized atherosclerosis, known infrarenal abdominal aortic aneurysm, renal artery stenosis, and coronary artery disease, an aneurysm of the proximal left subclavian artery was successfully excluded by implantation of a JOSTENT-Peripheral stent graft. Angiographic follow up after 6 and 12 months showed an excellent outcome with complete exclusion of the aneurysm. Intravascular ultrasound showed no neo-intimal hyperplasia within the stent. A computed tomography revealed complete thrombosis of the aneurysm.

Coating stents with autologous venous grafts has been suggested to prevent problems associated with conventional stenting, but the need for surgical vessel harvest hampered broad application. A novel synthetic coronary stent graft (CSG) overcomes this limitation by a synthetic membrane, fixed between two thin metallic stents. We successfully implanted 21 CSGs in 18 patients for treatment of acute coronary rupture, thrombus-containing lesions, and lesions with plaque rupture or adjacent pseudoaneurysm. Substantial residual angiographic diameter stenoses were seen in seven CSGs (25% +/- 10% vs. 8% +/- 6%; P < 0.01), which were implanted with relatively small balloon catheters (balloon-to-artery ratio 1.00 +/- 0.09 vs. 1.24 +/- 0.18; P = 0.01) and required postdilatation. Overall, the largest balloon catheter applied measured 4.0 +/- 0.7 mm (balloon-to-artery ratio 1.21 +/- 0.20) and the inflation pressure was 16 +/- 3 atm. Final intravascular ultrasound imaging demonstrated adequate and symmetrical expansion of the CSG (> or = 85% +/- 15% of the reference lumen). Elective implantation was associated with two small non-Q-wave myocardial infarctions, resulting from unavoidable occlusions of side branches. Thus, implantation of CSG is feasible and safe. Adequate expansion can be achieved by the use of relatively large low-compliant balloon catheters inflated with high pressure.

The objective of this study was to evaluate the potential benefit of stepwise intravascular ultrasound (IVUS)-guided coronary stent deployment compared to angiographic stent implantation with final IVUS assessment only. Acute procedural success and 6-month angiographic follow-up were compared in both groups. Intravascular ultrasound was performed using a 20- or 30-MHz mechanically rotated catheter in 85 patients who were prospectively randomized to group A (n=42; IVUS-guided) and group B (n=43; angiography +/- final IVUS assessment). There was no difference in the number of stents implanted (1.5+/-0.9 stents/lesion in group A and 1.3+/-0.6 stents/lesion in group B), the duration of the procedure, or the amount of contrast medium used. Defined criteria of optimal stent deployment (stent apposition, stent symmetry, complete coverage of dissections, >90% in-stent lumen area/reference lumen area) were achieved in 54.2% in group A and 56.6% in group B (NS). Angiographic follow-up was 87.1% at 6+/-2 months, and clinical follow-up was 100% at 8+/-1 months. There was no significant difference in restenosis rate (33.3% vs. 34.9%) applying a binary >50% diameter stenosis criterion for both groups. There was no significant difference in minimal in-stent lumen area at both baseline (7.91+/-2.64 mm2 vs. 7.76+/-2.21 mm2) and follow-up (5.84+/-2 mm2 vs. 5.52+/-1.87 mm2). With regard to immediate procedural lumen gain and rate of restenosis, multiple IVUS examinations during the procedure showed no advantage compared to final IVUS assessment only.

A 59 year old patient underwent percutaneous transluminal coronary angioplasty of a de novo stenosis of the proximal right coronary artery. Vessel perforation occurred after balloon angioplasty and was successfully treated by implantation of a new stent graft, which completely covered the perforation without residual leakage. Emergency coronary surgery could, thus, be avoided.

Adjunct high-pressure balloon inflations following the delivery of oversized self-expandable Wallstents may affect their implied late, postprocedural self-expansion. Consequently, we examined 15 "Magic" Wallstents, which were implanted following a strategy of stent oversizing and subsequent adjunct high-pressure balloon inflations (16 +/- 2 atm; all > or = 12 atm). The excellent radiographic visibility of this stent permitted reliable quantitative coronary angiographic measurement of both lumen and stent dimensions (before and after stenting, and at follow-up). At follow-up, extent and distribution of in-stent neointimal proliferation were evaluated with volumetric intravascular ultrasound. Between postintervention and follow-up examination, mean stent diameter increased from 3.7 +/- 0.4 to 4.2 +/- 0.4 mm (p <0.0001); there was no significant difference in late stent expansion between proximal, mid-, and distal stent subsegments. Late stent expansion showed a significant (reverse) relation to maximum balloon size (r = -0.56, p <0.04), but not with follow-up lumen size or late lumen loss. On average, 52 +/- 18% of the stent was filled with neointimal ingrowth; neointimal volume/cm stent length was 64 +/- 22 mm3. Both late stent expansion (r = 0.36, p <0.02) and maximum balloon pressure (r = 0.41, p <0.001) were related to neointimal volume/cm stent but not to follow-up lumen size. Thus, despite high-pressure implantation, Wallstents showed significant late self-expansion, which resulted in larger stent dimensions at follow-up that assisted in accommodating in-stent neointimal proliferation. Conversely, late stent expansion had a significant relation to the extent of in-stent neointimal ingrowth. Beneficial and disadvantageous effects of the late stent expansion appear to be balanced, because a relation to late lumen loss or follow-up lumen dimensions was not found to be present.

Three-dimensional (3D) intracoronary ultrasound (ICUS) systems allow dynamic 3D reconstruction of coronary segments after stent deployment, but motion artifacts are frequently present. The use of an electrocardiographic-gated ICUS image acquisition workstation and a dedicated pullback device may overcome this problem. In the present study, we evaluated the potential of dynamic 3D reconstruction of intracoronary stents in 51 patients. Two different types of stent designs were investigated: (1) the Wallstent (mesh type; n = 36) and (2) the Cordis Coronary stent (coil type; n = 15). There was a tendency for imaging of the mesh stent type to be better than imaging of coil type stents (p = 0.06). Differences in the orientation of the stent struts (mesh:longitudinal; coil:transversal) most likely explain this difference. These in vivo observations were tested and confirmed in in vitro experiments. In conclusion, dynamic 3D ICUS reconstruction of the entire stent architecture in vivo was feasible for stents of mesh type, while stents of coil type were incompletely visualized.

History and Clinical Findings: A 54-year-old man was urgently admitted because of sudden onset of progressively worsening angina pectoris, his first attack. Physical examination was unremarkable., Investigations: Electrocardiography and laboratory tests excluded acute myocardial infarction. With the exception of hypercholesterolemia (total cholesterol 247 mg/dl) laboratory tests were normal. Coronary angiography revealed a 60% eccentric narrowing in the proximal part of the interventricular branch with adjacent aneurysmatic dilatation. Intravascular ultrasound (IVUS) showed a coronary pseudoaneurysm, its cavity communicating with the empty atheroma hole of an adjacent ruptured coronary plaque., Treatment and Course: A 19 mm stent graft was implanted, via a percutaneously inserted balloon-catheter system, in the region of the stenosis and the pseudoaneurysm. Subsequent angiography demonstrated a smooth nonstenotic lumen. The membrane of the graft (made of polytetrafluoroethylene [PTFE]), fixed between two thin metal stents, had occluded the pseudoaneurysm. Occlusion of an immediately distal septal branch briefly produced an asymptomatic rise of creatine kinase to maximally 173 U/l. Oral medication included ticlopidine hydrochloride (2 x 250 mg daily for 4 weeks). The patient was symptom-free after the procedure and was discharged 5 days later., Conclusion: Implantation of a new type of stent-graft provides quick and uncomplicated treatment of a coronary aneurysm. The membrane fixed between two stents prevents wash out of any thrombi. The method may also be applicable to other potentially thrombus-containing lesions.

Objective: This study evaluates the feasibility, reliability and reproducibility of electrocardiogram (ECG)-gated intravascular ultrasound (IVUS) image acquisition during automated transducer withdrawal and automated three-dimensional (3D) boundary detection for assessing on-line the result of coronary stenting., Background: Systolic-diastolic image artifacts frequently limit the clinical applicability of such automated analysis systems., Methods: In 30 patients, after successful angiography-guided implantation of 34 stents in 30 target lesions, we carried out IVUS examinations on-line with the use of ECG-gated automated 3D analyses and conventional manual analyses of two-dimensional images from continuous pullbacks. These on-line measurements were compared with off-line 3D reanalyses. The adequacy of stent deployment was determined by using ultrasound criteria for stent apposition, symmetry and expansion., Results: Gated image acquisition was successfully performed in all patients to allow on-line 3D analysis within 8.7 +/- 0.6 min (mean +/- SD). Measurements by on-line and off-line 3D analyses correlated closely (r > or = 0.95), and the minimal stent lumen differed only minimally (8.6 +/- 2.8 mm2 vs. 8.5 +/- 2.8 mm2, p = NS). The conventional analysis significantly overestimated the minimal stent lumen (9.0 +/- 2.7 mm2, p < 0.005) in comparison with results of both 3D analyses. Fourteen stents (41%) failed to meet the criteria by both 3D analyses, all of these not reaching optimal expansion, but only 7 (21%) were detected by conventional analysis (p < 0.02). Intraobserver and interobserver comparison of stent lumen measurements by the automated approach revealed minimal differences (0.0 +/- 0.2 mm2 and 0.0 +/- 0.3 mm2) and excellent correlations (r = 0.99 and 0.98, respectively)., Conclusions: ECG-gated image acquisition after coronary stent deployment is feasible, permits on-line automated 3D reconstruction and analysis and provides reliable and reproducible measurements; these factors facilitate detection of the minimal lumen site.

The use of coronary stents decreases the morbidity associated with acute closure and restenosis after balloon angioplasty. Intracoronary ultrasound (ICUS) guidance of stent implantation has been advocated to improve stent deployment and thereby to further improve the clinical outcome after stenting, over and above balloon angioplasty. Whereas the merits of intracoronary ultrasound in this respect still remain to be proven, the present paper illustrates that ICUS itself may also entail complications. This paper reports on three cases of stent damage induced or aggravated by the ICUS procedure.

The use of 2-dimensional intravascular ultrasound (2-D IVUS) to improve the outcome of coronary stenting has gained clinical acceptance, and recently 3-D IVUS has been introduced to clinical practice. However, there have been no comprehensive studies comparing the measurements of the coronary dimensions after stenting obtained by the different approaches of IVUS and quantitative coronary angiography. We examined the minimal luminal cross-sectional area of 38 stents using 2-D IVUS, 3-D IVUS, and 2 standard methods of quantitative coronary angiography, edge detection (ED) and videodensitometry (VD). Correlations between 2-D IVUS and ED (r = 0.72; p < 0.0001), VD (r = 0.87; p < 0.0001), and 3-D IVUS (r = 0.81; p < 0.0001) were higher than the correlations seen between 3-D IVUS and ED (r = 0.58; p < 0.0005) and VD (r = 0.70; p < 0.0001). The measurements by 2-D and 3-D IVUS (8.32 +/- 2.50 mm2 and 8.05 +/- 2.66 mm2) were larger than the values obtained by the quantitative angiographic techniques ED and VD (7.55 +/- 2.22 mm2 and 7.27 +/- 2.21 mm2). Thus, concordance was seen among all of the 4 techniques, confirming the validity of using IVUS for determination of the minimal luminal cross-sectional area after coronary stenting. A particularly good correlation was found between VD and IVUS, perhaps because measurement of the luminal area is the basic quantification approach of both techniques, whereas the lower correlations of ED with IVUS and VD may be explained by the dependence of ED on the angiographic projections used, which is especially important in eccentric stent configurations.

Optimized stent expansion by high-pressure inflations of oversized balloons has initially been derived from experience obtained with the Palmaz-Schatz stent, whereas there is little experience with this strategy in the Wallstent. By using this approach with quantitative coronary angiographic guidance, 20 Wallstents and 20 Palmaz-Schatz stents were implanted in 34 patients and consecutively examined by conventional two-dimensional (2D) intracoronary ultrasound (ICUS) and three-dimensional (3D) ICUS on the basis of the application of a pattern recognition algorithm. Ultrasound criteria of adequate stent expansion were defined as a complete apposition of the stent to the vessel wall, a stent symmetry index (SSI = minimum/maximum lumen diameter) > or = O.7, and a stent-reference lumen area ratio (SRR = Minimum intrastent lumen area/Average of proximal and distal reference lumen area) > or = O.8. In all cases a smooth angiographic lumen and a negative diameter stenosis, on the basis of a distal reference, was achieved. For the Wallstents ICUS showed a higher SSI (2D, 0.95 +/- 0.04 vs 0.85 +/- 0.09; p < 0.001; 3D, 0.90 +/- 0.09 vs 0.82 +/- 0.11, p < 0.05) and a lower SRR (2D, 0.66 +/- 0.12 vs 0.81 +/- 0.13, p < 0.005; 3D, 0.63 +/- 0.14 vs 0.74 +/- 0.15, p < 0.05) than for the Palmaz-Schatz stents. Ninety percent of failure in meeting these criteria resulted from a low SRR. The incidence of incomplete stent apposition (one in both stents) or SSI <0.7 was low and generally associated with an SRR <0.8. The Wallstents met the ICUS criteria less often (2D, 2(1O%) vs 10(50%), p < 0.01; 3D, 3(15%) vs 9(45%), p < 0.05), were significantly longer (35.1 +/- 7.7 mm and 14.3 +/- 3.3 mm, p < 0.0001), and generally demonstrated a larger vessel tapering, measured as proximal minus distal ICUS reference lumen area (1.33 +/- 2.91 mm2 vs 0.44 +/- 1.97 mm(2), not significant). Wallstents meeting the ICUS criteria, however, showed less vessel tapering (0.18 +/- 1.64 mm(2)). Thus optimized stent expansion was followed by excellent angiographic results for both Palmaz-Schatz and Wallstent. Although angiographic results and visual assessment of the ICUS examination suggested a good outcome, few Wallstents met the ICUS criteria in contrast to the Palmaz-Schatz stents. The low value of the SRR in the Wallstents is likely to be caused by vessel tapering, suggesting that this criterion may be unsuitable in assessing the adequacy of the expansion of relatively long stents such as the Wallstent.

We examined 49 coronary stents in 33 patients after angiographically guided optimization of the deployment by intracoronary ultrasound, and compared the findings of a conventional 2-dimensional analysis approach with the results obtained from an automatic lumen recognition provided by a 3-dimensional reconstruction system. The automatic lumen analysis demonstrated that only 15 stents (31%) fulfilled defined ultrasound criteria of adequate stent deployment, and that 5 of these cases were missed by the conventional approach, which systematically overestimated the dimensions of the minimal stent lumen.

The additional information provided by automated on-line 3-dimensional (3-D) reconstruction of intracoronary ultrasound (ICUS) was assessed in 42 patients (62 stents) who underwent stent deployment after achieving an optimal quantitative angiographic result. In 10 of 42 patients, 3-D ICUS was also performed before stenting. ICUS images of stents and adjacent reference segments were acquired by using a motorized pullback at a constant speed (1 mm/s) and immediately processed in the catheterization laboratory. Optimal stent expansion was detected by 3-D ICUS in case of complete apposition of stent struts to the vessel wall. Furthermore, an attempt was made to maximize the intrastent lumen area to match lumen area of the reference segment and to cover with stents all the segments with residual significant lesions (plaque burden >50%). Three-dimensional automated reconstruction of ICUS was successful in 8 of 10 patients (80%) before, and in 36 of 42 patients (86%) after stent deployment. In all 8 patients who underwent successful 3-D ICUS assessment before stent implantation, the selection of stent length was facilitated by accurately measuring the lesion length. After stenting, 3-D ICUS modified the management strategy in 21 of 36 patients (58%), triggering additional high-pressure dilatations in 13 patients (36%) and additional stent deployment in 8 (22%). In conclusion, on-line 3-D ICUS facilitates stent selection and strongly modifies the revascularization strategy by accurately detecting stent underexpansion and presence of uncovered lesions.