Incidence and predictors of recurrent restenosis following implantation of drug-eluting stents for in-stent restenosis.

OBJECTIVES: We investigated the incidence and predictors of recurrent restenosis after drug-eluting stent (DES) implantation for in-stent restenosis (ISR) in routine clinical practice. BACKGROUND: Although DESs have been increasingly used for treatment of ISR, little is known about the predictors of DES failure. METHODS: We determined the incidence of recurrent restenosis and major adverse cardiac events (MACE) in 224 consecutive patients with 239 lesions treated with sirolimus-eluting (n=217 lesions) or paclitaxel-eluting (n=22 lesions) stents for the first episode of ISR. RESULTS: The procedural success rate was 99.2%, and in-hospital complications did not occur in any patient. Follow-up angiography at 6 months was obtained in 73.7% of patients. Angiographic re-restenosis rate was 12.6%, and target lesion revascularization was required in 7.6% of patients. Of the 22 incidents of re-restenosis, 15 were focal (68.2%), 5 were diffuse (22.7%), and 2 were total (9.1%) restenosis. Univariate analysis showed that lesion length, use of paclitaxel-eluting stent, and number of stents per lesion were significant predictors of re-restenosis. In multivariate analysis, however, lesion length and use of paclitaxel-eluting stent were independent predictors of re-restenosis. During the follow-up (mean, 18.3+/-8.1 months), there were 4 deaths (1 cardiac, 3 noncardiac), but no nonfatal myocardial infarctions (MIs). MACE occurred in 18 patients. The cumulative probability of MACE-free survival was 92.9+/-1.8% at 1 year and 90.5+/-2.4% at 2 years. CONCLUSIONS: DESs are highly effective for treatment of ISR, with recurrent restenosis related to lesion length and type of DES.     

Drug-eluting stent implantation for treatment of recurrent renal artery in-stent restenosis.

Percutaneous renal artery stenting has become the treatment of choice for renal artery stenosis. In-stent restenosis (ISR) still remains a persistent problem. Drug eluting stents have significantly reduced the incidence of ISR in coronary arteries. We report a case in which recurrent renal ISR was successfully treated with paclitaxel-eluting stent implantation, using intravascular ultrasound guidance, with maintained stent patency at 6 months.     

ISR II study: a long-term evaluation of sirolimus-eluting stent in the treatment of patients with in-stent restenotic native coronary artery lesions.

The aim of this pilot study was to determine the safety and long-term efficacy of treating intrastent restenosis (ISR) with the slow-release sirolimus-eluting stent Bx Velocity (Cypher stent) without intravascular ultrasound (IVUS) guidance. Of patients who received a bare metal stent implantation and presented an ISR, 30-80% of the patients will develop a second restenosis within the stent, at the stent edges or both. To date, intravascular brachytherapy using beta- and gamma-radiation has been the only effective treatment for ISR. Twenty-three patients with ISR and evidence of ischemia were treated with Cypher stent. Clinical information was collected 1, 8, 12, and 24 months after stent implantation. During the first 8 months of the study, in-stent lumen diameter remained essentially unchanged from postprocedure in 80% of the case. The target lesion repeat revascularization (TLR) was 17%, of which 50% were oculostenotic reflexes. Only one patient presented a restenosis greater than 70%. During the 2-year study period, the TLR rate was 17%; the major adverse coronary event rate was 26%, and the non-Q-wave myocardial infarction (MI) rate was 9%. There were no reports of death, coronary artery bypass grafting, or Q-wave MI during the study. This study demonstrates the feasibility of using sirolimus-eluting stents without IVUS guidance for the treatment of ISR, providing long-term stability of immediate results.     

Usefulness of high-pressure post-dilatation to optimize deployment of drug-eluting stents for the treatment of diffuse in-stent coronary restenosis

Drug-eluting stents (DESs) may represent a simple, effective treatment for in-stent restenosis (ISR); however, the underexpansion of stents is a significant cause of target vessel failure. It was hypothesized that high-pressure postdilatation would be necessary to optimize DES expansion and minimize the risk for restenosis when treating patients with ISR. Fifteen patients with diffuse ISR were treated by predilatation (including cutting balloons), DES deployment, and high-pressure postdilatation, with the measurement of luminal and stent dimensions by intravascular ultrasound after each intervention. After initial deployment, DES underexpansion was present in 10 of 15 patients (66%); after high-pressure postdilatation, there was a significant increase in luminal dimensions, including minimum luminal area (4.3 +/- 0.3 to 5.6 +/- 0.4 mm(2), p <0.001) and a doubling in the proportion of patients with optimal stent expansion. At long-term follow-up (median 11 months), target lesion revascularization occurred in 1 patient (7%) because of edge restenosis; there was no restenosis within the DES.     

Angiographic and procedural correlates of stent thrombosis after intracoronary implantation of drug-eluting stents

BACKGROUND: Stent thrombosis (ST) following the implantation of drug-eluting stents (DES) remains the major limitation of this new technology. The identification of modifiable correlates of ST may help reduce this catastrophic event. METHODS: This was a retrospective, single-center, lesion-based study. A cohort of 45 consecutive lesions (35 patients) initially treated with successful DES implantation from May 2003 to February 2005 that re-presented with ST within 12 months was identified. This cohort was compared to a control group of 1,620 unselected lesions (1,187 patients) that were successfully treated with DES implantation and which remained free of ST. Comparison of angiographic and procedural features was made between the ST and no-ST groups, and logistic regression analysis was then performed to identify independent correlates of ST. For the purposes of the study only definite ST events (angiographically or autopsy proven) were considered. RESULTS: Independent angiographic predictors of cumulative ST at 12 months were left anterior descending (LAD) artery (OR: 1.91, CI: 1.01-3.59, P = 0.045), bifurcation (OR: 2.43, CI: 1.06-5.56, P = 0.035), and in-stent restenotic (OR: 2.64, CI: 1.12-6.25, P = 0.027) lesions. Procedural predictors were number of stents per lesion (OR: 2.30, CI: 1.29-4.11, P = 0.005) and intravascular ultrasound (IVUS) guidance (OR: 0.45, CI: 0.24-0.84, P = 0.013). Correlates of subacute events were LAD artery, proximal segment, and lack of IVUS guidance. Correlates of late ST were bifurcation and in-stent restenotic lesions. CONCLUSIONS: Angiographic and procedural correlates of subacute and late ST after DES implantation differ. Lack of IVUS guidance was the only modifiable predictor identified. Treatment of bifurcation and restenotic lesions was predictive of late events.     

Nonrandomized comparison of coronary stenting under intravascular ultrasound guidance of direct stenting without predilation versus conventional predilation with a semi-compliant balloon versus predilation with a new scoring balloon

This study was conducted to determine the influence of lesion preparation using the AngioSculpt balloon on final stent expansion. Stent expansion remains an important predictor of restenosis and subacute thrombosis, even in the drug-eluting stent (DES) era. In these patients, the role of different predilation strategies has yet to be established. Two hundred ninety-nine consecutive de novo lesions treated with 1 >2.5-mm DES (Cypher or Taxus) under intravascular ultrasound guidance without postdilation, using 3 implantation strategies, were studied: (1) direct stenting without predilation (n = 145), (2) predilation with a conventional semi-compliant balloon (n = 117), and (3) predilation with the AngioSculpt balloon (n = 37). Stent expansion was defined as the ratio of intravascular ultrasound-measured minimum stent diameter and minimum stent area to the manufacturer's predicted stent diameter and area. These ratios were larger after AngioSculpt predilation, and a greater percentage of stents had final minimum stent areas >5.0 mm(2) (another commonly accepted criterion of adequate DES expansion). Lesion morphology, stent and lesion length, and reference vessel size did not affect DES expansion. In conclusion, in this observational, nonrandomized study, pretreatment with the AngioSculpt balloon enhanced stent expansion and minimized the difference between predicted and achieved stent dimensions.     

Arterial remodeling patterns before intervention predict diffuse in-stent restenosis: an intravascular ultrasound study

OBJECTIVES: The aim of this retrospective study was to determine the predictors of diffuse in-stent restenosis (ISR) among the lesions causing the first ISR by intravascular ultrasound (IVUS) studies. BACKGROUND: Although some predictors of diffuse ISR have been reported, parameters on IVUS relating to diffuse ISR are not well characterized.METHODS: We classified 52 ISR lesions that had undergone successful stent implantation and led to restenosis into two types--focal and diffuse ISR--using quantitative coronary angiography. Restenosis was defined as > or =50% diameter stenosis, and diffuse ISR as lesion length > or =10 mm at follow-up. The remodeling index (RI) was defined as the vessel area at the target lesion divided by that of averaged reference segments. RESULTS: There were no significant differences in patient, angiographic, and procedural characteristics between the focal (n = 25) and diffuse (n = 27) ISR groups. Baseline RI was significantly greater in the diffuse ISR group (1.03 +/- 0.18 vs. 0.88 +/- 0.24, p = 0.0159). Negative remodeling, defined as RI <0.9, was detected in 60% of the focal ISR group and in only 26% of the diffuse ISR group. By logistic regression analysis, baseline RI was the only independent predictor of diffuse ISR (p = 0.0341). Moreover, volumetric analyses revealed that lesions developing into diffuse ISR had less capacity to compensate for further plaque growth. CONCLUSIONS: Among the first ISR lesions, baseline positive remodeling was the most powerful predictor of diffuse ISR. Measuring pre-interventional arterial remodeling patterns by IVUS may be helpful to stratify lesions at higher risk.     

Characterization of plaque prolapse after drug-eluting stent implantation in diabetic patients: a three-dimensional volumetric intravascular ultrasound outcome study.

OBJECTIVES: The aim of this research was to evaluate the plaque prolapse (PP) phenomenon after bare-metal (BMS) and drug-eluting stent (DES) implantation in patients with diabetes mellitus using 3-dimensional volumetric intravascular ultrasound (IVUS). BACKGROUND: Plaque prolapse has been observed in up to 22% of patients treated with BMS. Diabetic patients have a larger atherothrombotic burden and may be more prone to have PP. However, the incidence of PP and its clinical impact after DES implantation is unknown. METHODS: Three-dimensional IVUS was performed after intervention and at 9-month follow-up in 168 patients with diabetes (205 lesions) treated with bare BX Velocity stents ((BX Velocity/Sonic, Cordis, Johnson & Johnson) (BMS, n = 65), sirolimus-eluting stents (Cypher, Cordis) (SES, n = 69), and paclitaxel-eluting stents (Taxus, Boston Scientific, Natick, Massachusetts) (PES, n = 71). Intravascular ultrasound data at the sites of PP were compared with stented segments without PP in each lesion. Outcomes were evaluated at 9- and 12-month follow-up. RESULTS: There were 42 sites of PP (BMS = 11, SES = 11, PES = 20, p = NS) in 34 stented segments of 205 (16.6%) lesions. Plaque prolapse was more frequent in the right coronary artery and in chronic total occlusion lesions. Post-procedure PP volume was 1.95 mm3 in BMS, 2.96 mm3 in SES, and 4.53 mm3 in PES. At follow-up, tissue volume increased at PP sites in both BMS and PES, but not after SES. Neointimal proliferation was similar between PP and non-PP sites. Stent thrombosis and restenosis rates were similar between PP and non-PP lesions. CONCLUSIONS: The incidence of PP after implantation of new generation tubular stents in patients with diabetes remains high. Drug-eluting stent implantation was not associated with increased risk of PP. Plaque prolapse was not associated with stent thrombosis or increased neointimal proliferation.     

Results and predictors of angiographic restenosis and long-term adverse cardiac events after drug-eluting stent implantation for aorto-ostial coronary artery disease

The correlates of angiographic and clinical outcomes after drug-eluting stent (DES) implantation for aorto-ostial lesions remain unknown. This study evaluated long-term results of DES implantation for aorto-ostial lesions and determined risk factors for restenosis and adverse cardiac events. In total, 184 consecutive patients who underwent DES implantation for aorto-ostial lesions were investigated (DES group) compared with 172 consecutive patients treated with bare metal stents before the introduction of DESs (pre-DES group). Major adverse cardiac events (MACEs) were defined as death, Q-wave myocardial infarction, and need for target lesion revascularization. The DES group had significantly higher risk clinical and procedural profiles than the pre-DES group. Procedural success rates were 99.5% in the DES group and 100% in the pre-DES group (p = 1.0). The DES group had a significantly lower incidence of in-segment restenosis (10.5% vs 26.0%, p = 0.001) and target lesion revascularization (4.3% vs 11.6%, p = 0.011). Cumulative MACE rates at 1 year were 6.5% in the DES group and 13.4% in the pre-DES group (p = 0.03). By multivariate analysis, treatment of bypass graft, treatment of in-stent restenosis, and reference vessel diameter were predictors of restenosis, and only reference vessel diameter (hazard ratio 0.20, 95% confidence interval 0.05 to 0.75, p = 0.017) inversely correlated with 1-year MACEs after DES implantation. In conclusion, DES implantation for aorto-ostial lesions is associated with a significant decrease in restenosis and MACEs compared with the pre-DES phase. Treatment of bypass graft and in-stent restenosis and reference vessel size were identified as predictors of restenosis and/or long-term MACEs after DES implantation.     

Predictors of restenosis after placement of drug-eluting stents in one or more coronary arteries

Although drug-eluting stents (DESs) have been increasingly used in a wide variety of clinical and anatomic situations, limited data are available regarding the predictors of DES failure in unselected lesions. We investigated the incidence and predictors of restenosis after implantation of DESs in routine clinical practice. A total of 1,795 consecutive patients underwent successful implantation of sirolimus-eluting (1,374 patients, 1,788 lesions) or paclitaxel-eluting (421 patients, 517 lesions) stents. Of the 1,743 eligible patients (2,221 lesions), follow-up angiography at 6 months was obtained for 1,228 patients (70.5%, 1,577 lesions). All data were prospectively recorded and analyzed to predict the occurrence of restenosis, defined as a diameter stenosis of > or =50%. Restenosis was documented in 125 patients with 138 lesions (8.8%), and target lesion revascularization was required in 70 patients with 82 lesions (5.2%). The pattern of restenosis was 85 focal (62%), 29 diffuse (21%), 11 diffuse proliferative (8%), and 13 total (9%). Lesion length, stent length, postintervention minimal lumen diameter, preintervention minimal lumen diameter, reference artery size, complex lesions, and use of a paclitaxel-eluting stent were univariate predictors of restenosis. Multivariate analysis showed that the use of a paclitaxel-eluting stent (odds ratio [OR] 4.37, 95% confidence interval [CI] 2.90 to 6.58, p <0.001), postintervention minimal lumen diameter (OR 0.32, 95% CI 0.20 to 0.50, p <0.001), and lesion length (OR 1.02, 95% CI 1.01 to 1.04, p <0.001) were independent predictors of restenosis. In conclusion, the rate of restenosis after DES implantation in routine clinical practice was similar to the rate reported in clinical trials, confirming the efficacy of DES in routine clinical practice.     

Intravascular ultrasound-guided high-pressure balloon predilatation for optimal drug-eluting stent deployment in restenosis of a stent implanted 7 years earlier. Do we know the right technique for in-stent restenosis restenting?

Although off-label, drug-eluting stent (DES) implantation is a preferred intervention for in-bare metal stent restenosis (BMS ISR). Off-label DES implantation appears to be associated with a higher risk of stent thrombosis and lesion recurrence. Accordingly, routine BMS ISR restenting with DES is associated with more frequent subsequent thrombosis. Intravascular ultrasound (IVUS) studies point to stent underexpansion as the major mechanism of late DES failure. We report a case of a patient with BMS ISR in whom IVUS clarified initial BMS expansion; consequently, high-pressure predilatation with an angiographically oversized conventional balloon was applied prior to DES deployment; and finally, IVUS verified the stent expansion.     

Intravascular ultrasound evaluation after sirolimus eluting stent implantation for de novo and in-stent restenosis lesions.

AIMS: The aim of this study is to compare the efficacy of sirolimus-eluting stents (SES) on neointimal growth and vessel remodelling for in-stent restenosis versus de novo coronary artery lesions using serial intravascular ultrasound (IVUS). METHODS AND RESULTS: The study population consisted of 86 patients with in-stent restenosis (ISR) (n=41) or de novo lesions (n=45) treated with SES and evaluated by IVUS post-procedure and at follow-up. One 18-mm SES was used for de novo lesions while 16 patients with ISR received >1SES (total stented length 17.9 mm vs 22.0 mm respectively; P=0.004). At follow-up, no differences were observed between the ISR and de novo groups with respect to changes in the mean external elastic membrane (1.7% vs 1.3%; P=0.53), plaque behind the stent (1.2% vs 3.4%; P=0.49), and lumen areas (0.7% vs 1.9%; P=0.58). No positive remodelling or edge effect was observed. A gap between stents was observed in two patients with ISR, where more prominent, though non-obstructive, neointimal proliferation was noted. CONCLUSION: Sirolimus-eluting stenting is equally effective at inhibiting neointimal proliferation in de novo and ISR lesions without inducing edge restenosis or positive vascular remodelling.     

Variable histological and ultrasonic characteristics of restenosis after drug-eluting stents

Bare-metal stents have undergone intense pathological and clinical examination, but histological characterization of drug-eluting stent (DES) restenosis (ISR) remains unknown. We report a series of cases (n = 6) with intravascular ultrasound (IVUS) and pathological examinations over 8 months after DES deployment. Tissue samples were obtained using atherectomy devices in 5 cases and a thrombectomy catheter in 1 case. Histology revealed not only smooth muscle cell proliferation, which correlated with homogeneous hypoechoic tissue by IVUS in one case, but also demonstrated delayed healing features such as organized fibrin deposition in 3 cases (one with homogeneous echolucent tissue by IVUS), macrophage and T-lymphocyte infiltration in others. IVUS appearance of ISR components varied from echolucent to echodense images. This report suggests a variable histological and IVUS pattern of ISR after DES implantation. Further investigations are necessary to define the potentially pro-thrombotic histological features of ISR after DES implantation, and the relationship between the molecular mechanisms of thrombosis and DES restenosis.     

Drug-eluting stent-supported percutaneous coronary intervention for chronic total coronary occlusion.

OBJECTIVES: This study sought to determine the clinical and angiographic outcomes after drug-eluting stent (DES)-supported percutaneous coronary intervention (PCI) for chronic total coronary occlusion (CTO). BACKGROUND: There are few data about the efficacy of DES-supported PCI for CTO. METHODS: All consecutive patients who had a sirolimus-eluting stent or a paclitaxel-eluting stent implanted for CTO from December 2003 to December 2004 were analyzed. Clinical and angiographic outcomes of patients treated with DES were compared with a case-matched control group of patients treated with bare metal stents (BMS) in the 12 months before the routine use of DES. RESULTS: Successful DES-supported PCI was performed in 92 patients and 104 CTO. The case-matched control group consisted of 26 patients and 27 CTO successfully treated with BMS. There were no differences between groups in baseline clinical and angiographic characteristics. Stent length in the DES group was higher as compared with that of BMS group (51+/-28 mm vs. 40+/-19 mm, P=0.073). The 6-month major adverse cardiac event (MACE) rate was lower in the DES group as compared with that of BMS group (9.8% vs. 23%, P=0.072). The angiographic follow-rate was 80% in the DES group and 81% in the BMS group. The 6-month restenosis rate was 19% in the DES group and 45% in the BMS group (P<0.001). By multivariate analysis, it was found that in the DES group, the only predictors of restenosis were stented segment length (OR 1.031, 95% CI 1.01-1.06, P=0.009) and a target vessel reference diameter<2.5 mm (OR 6.48, 95% CI 1.51-27.83, P=0.012), while the only predictor of MACE was stent length (OR 1.04, 95% CI 1.01-1.08, P=0.006). CONCLUSIONS: DES implantation for CTO decreases the risk of mid-term restenosis and MACE. Small vessels and diffuse disease requiring the implantation of multiple stents and very long stents for full coverage of the target lesion are still associated with a relatively high risk of restenosis.     

Drug-eluting stent thrombosis: results from a pooled analysis including 10 randomized studies

OBJECTIVES: We compared the risk of stent thrombosis (ST) after drug-eluting stents (DES) versus bare-metal stents (BMS), and tested the hypothesis that the risk of DES thrombosis is related to stent length. BACKGROUND: Whether DES increase the risk of ST remains unclear. Given the very low restenosis rate after drug-eluting stenting, longer stents are frequently implanted for the same lesion length in comparison to BMS. METHODS: We included in a meta-analysis 10 randomized studies comparing DES and BMS. Overall, 5,030 patients were included (2,602 were allocated to DES and 2,428 to BMS). The risk of thrombosis after DES versus BMS was compared, and the relationship between the rate of DES thrombosis and stent length was evaluated. RESULTS: Incidence of ST was not increased in patients receiving DES (0.58% vs. 0.54% for BMS; odds ratio: 1.05; 95% confidence interval [CI]: 0.51 to 2.15; p = 1.000). The overall rate of ST did not differ significantly between patients receiving sirolimus- or paclitaxel-eluting stents (0.57% vs. 0.58%; p = 1.000). We found a significant relation between the rate of ST and the stented length (Y = -1.455 + 0.121 X; 95% CI for beta: 0.014 to 0.227; R = 0.716; p = 0.031). In patients with DES, mean stented length was longer in those suffering ST (23.4 +/- 8.1 mm vs. 21.3 +/- 4.1 mm, p = 0.025). CONCLUSIONS: Drug-eluting stents do not increase the risk of ST, at least under appropriate anti-platelet therapy. The risk of ST after DES implantation is related to stent length.     

The evolving role of inflammatory biomarkers in risk assessment after stent implantation

The main adverse reactions to coronary stents are in-stent restenosis (ISR) and stent thrombosis. Along with procedural factors, individual susceptibility to these events plays an important role. In particular, inflammatory status, as assessed by C-reactive protein levels, predicts the risk of ISR after bare-metal stent implantation, although it does not predict the risk of stent thrombosis. Conversely, C-reactive protein levels fail to predict the risk of ISR after drug-eluting stent (DES) implantation, although they appear to predict the risk of stent thrombosis. Of note, DES have abated ISR rates occurring in the classical 1-year window, but new concern is emerging regarding late restenosis and thrombosis. The pathogenesis of these late events seems to be related to delayed healing and allergic reactions to polymers, a process in which eosinophils seem to play an important role by enhancing restenosis and thrombosis. The identification of high-risk individuals based on biomarker assessment may be important for the management of patients receiving stent implantation. In this report, we review the evolving role of inflammatory biomarkers in predicting the risk of ISR and stent thrombosis.     

Intravascular ultrasound guidance in drug-eluting stent deployment

The role of routine intravascular ultrasound (IVUS) guidance during percutaneous coronary intervention (PCI) in the bare metal stent era remains controversial. The potential to reduce revascularization was reported without impacting non-fatal myocardial infarction and death. Drug-eluting stents (DES) have realized improved clinical results in patients undergoing PCI but are not free of restenosis and are limited by thrombosis, particularly in more complex lesion types. Stent under-expansion, malposition, and incomplete lesion coverage have been identified as the key mechanisms of DES failure. The identification of these features on IVUS and their subsequent treatment may lead to improved clinical outcomes. Though a clinical benefit is intuitive, results from randomized trials are still needed to justify routine IVUS guided DES implantation. The Authors provide a review of the currently available evidence pertaining to the potential clinical benefit of IVUS guidance in DES implantation.     

Incomplete expansion of Palmaz-Schatz stents despite high-pressure implantation technique: impact on target lesion revascularization.

Improved expansion of stents using high-pressure implantation technique with subsequent antiplatelet therapy has improved patient outcome regarding the incidence of subacute stent thrombosis, bleeding complications and restenosis. Whether high-pressure implantation per se guarantees adequate stent expansion remains unclear. The aim of the study was to determine (1) stent expansion after high-pressure implantation technique and (2) whether stent expansion influences rate of target lesion revascularization within 6 months of follow-up. One hundred Palmaz-Schatz stents were implanted in 98 lesions (91 native vessels, 7 graft vessels) of 94 patients using high-pressure implantation technique (balloon pressure 12-20 atm). Stent expansion was investigated using intravascular ultrasound imaging (IVUS). Clinical follow-up of the patients was performed for 6 months. After implantation, stent/mean reference ratio was 0.81 +/- 0.16. Noncompliant balloons used for implantation were chosen by angiographic criteria. Mean balloon/reference ratio was 1.08 +/- 0.22; therefore balloons were not undersized. Additional balloon dilataion using higher pressures and/or larger balloons based on IVUS criteria and subsequent IVUS measurements was performed in 52 patients (55%); in these patients, stent expansion improved from 79 +/- 16 to 91 +/- 15% (mean +/- SD) of average reference areas (p < 0.002). Within the 6 months' clinical follow-up, target lesion revascularization was performed in 19 patients (20%). The only prognostic factors for the development of in-stent restenosis requiring target lesion revascularization were the vessel size (p < 0.05) and the extent of plaque distal to the stents (p < 0.05). Implantation of Palmaz-Schatz stents using high-pressure technique does not guarantee adequate stent expansion. Additional dilatation with higher pressures and/or larger balloons improves stent expansion. The size of the stented vessel and the extent of plaque at the distal stent end (residual outflow stenosis) but not the degree of stent expansion were predictors for target lesion revascularization within 6 months' follow-up.     

药物洗脱支架治疗后冠状动脉再狭窄相关因素的分析

目的探讨药物洗脱支架治疗后冠状动脉再狭窄与临床和造影的相关因素。方法入选416例冠状动脉造影(CAG)资料完整的冠心病患者,男性328例,女性88例,共置入支架470枚,按照CAG结果分为再狭窄组59例和无再狭窄组357例,平均造影随访时间(7．91±2．37)个月。结果再狭窄组CAG示61枚支架发生再狭窄(13．0％),女性、既往冠状动脉旁路移植术(CABG)病史、慢性闭塞(CTO)病变病史、最大球囊释放压力、置入支架长度与术后再狭窄相关(P<0．05);置入支架血管直径与再狭窄高度相关(OR=0．61,95％CI:0．43～0．82,P< 0．01)。结论女性、既往CABG病史、CTO病变、血管直径、置入支架长度是支架术后再狭窄的危险因素,而糖尿病史等与再狭窄无关。     

Focal in-stent restenosis and in-stent thrombosis within the same bare-metal stent 5 years after deployment in a saphenous vein graft

Complications of percutaneous coronary intervention include in-stent restenosis (ISR) and in-stent thrombosis (IST) which have different underlying pathophysiological processes and different treatment strategies. ISR is primarily due to excessive neointimal growth and occurs in 20-30% of bare-metal stents (BMS). Drug-eluting stents (DES) have decreased the rates of ISR (< 10%), but are potentially associated with increased IST related to delayed arterial healing and stent strut exposure. ISR of BMS typically occurs within 6 months of stent deployment. IST usually occurs within 12 months of DES deployment. We present a case of focal ISR and IST within the same BMS, confirmed with intravascular ultrasound, 5 years after deployment in a saphenous vein graft.