Intravascular ultrasound predictors of angiographic restenosis after sirolimus-eluting stent implantation.

AIMS: In many countries, drug-eluting stent implantation is the dominant interventional strategy. We evaluated the clinical, angiographic, procedural, and intravascular ultrasound (IVUS) predictors of angiographic restenosis after sirolimus-eluting stent (SES) implantation. METHODS AND RESULTS: SES implantation was successfully performed in 550 patients with 670 native coronary lesions. Six-month follow-up angiography was performed in 449 patients (81.6%) with 543 lesions (81.1%). Clinical, angiographic, procedural, and IVUS predictors of restenosis were determined. Using multivariable logistic regression analysis, the only independent predictors of angiographic restenosis were post-procedural final minimum stent area by IVUS [odds ratio (OR)=0.586, 95% confidence interval (CI) 0.387-0.888, P=0.012] and IVUS-measured stent length (OR=1.029, 95% CI 1.002-1.056, P=0.035). Final minimum stent area by IVUS and IVUS-measured stent length that best separated restenosis from non-restenosis were 5.5 mm2 and 40 mm, respectively. Lesions with final minimum stent area<5.5 mm2 and stent length>40 mm had the highest rate of angiographic restenosis [17.7% (11/62)], P<0.001 compared with other groups. CONCLUSION: Independent predictors of angiographic restenosis after SES implantation were post-procedural final minimum stent area by IVUS and IVUS-measured stent length. The angiographic restenosis rate was highest in lesions with stent area<5.5 mm2 and stent length>40 mm.     

Intravascular ultrasound-guided stenting in long lesions: an insight into possible mechanisms of restenosis and comparison of angiographic and intravascular ultrasound data from the MUSIC and RENEWAL trials

The high restenosis rates in long stents may be related to suboptimal stent deployment. In an attempt to understand the potential components associated with restenosis in long stents, this study compares angiographic and intravascular ultrasound (IVUS) data from the MUSIC and RENEWAL studies where IVUS was used to optimize stent deployment in short (< 15 mm) and long (> 20 mm) coronary lesions, respectively. The RENEWAL study, a randomized trial, compared the NIR stent and Wallstent in long (> 20 mm) coronary lesions and used on-line visual IVUS criteria to optimize stent expansion. Detailed analysis of IVUS data was performed off line. Angiographic and IVUS data from this study was compared to that from the MUSIC study. Initial stent deployment was deemed optimal by the operator after visual angiographic and IVUS assessment in 50 of 70 lesions. In the remaining 20 lesions further balloon inflations were required to optimize stent apposition that led to an average gain in minimal in-stent luminal area (MISA) of 15.9% (P < 0.01). Off-line IVUS data analysis showed that the number reaching "MUSIC criteria" for optimal stent deployment preredilatation was 8 (11.4%) of 70 and 14 (20%) of 70 postredilatation. The ratio of MISA/MRAprox (mean proximal reference area) was 0.69 in RENEWAL. At 6-month follow-up, the angiographic restenosis rate in RENEWAL was 36% and target lesion revascularization (TLR) rate was 7.8%, compared with MUSIC's 9.7% and 4.5%, respectively. In conclusion, angiographic assessment of stent deployment in long lesions is limited. On-line visual IVUS with further balloon inflations to improve stent apposition led to a significant gain in MISA, but the MISA/MRAprox ratio remained suboptimal. Therefore, suboptimal stent deployment due to constraint by lesion resistance may be an important mechanism underlying the high restenosis rates in long stents.     

Comparison of the effectiveness of sirolimus- and paclitaxel-eluting stents for small coronary artery lesions.

BACKGROUND: The sirolimus-eluting stent (SES) and the paclitaxel-eluting stent (PES) reduce restenosis in small coronary artery lesions. However, it is not clear which of these stents is superior in terms of clinical outcomes. METHODS: The authors retrospectively examined 197 patients with 245 de novo small coronary artery lesions (相似文献   

Predictors of target lesion revascularization and documented stent thrombosis beyond 30 days after sirolimus-eluting stent implantation: retrospective analysis in consecutive 1,070 angiographic follow-up lesions.

BACKGROUND: Outcomes after sirolimus-eluting stent (SES: Cypher) implantation remained to be elucidated in Japan. METHODS AND RESULTS: Among 1,070 consecutive angiographic follow-up lesions, 99 lesions underwent target lesion revascularization (TLR) with in-stent restenosis (ISR). Retrospective estimation by multivariate analysis including 50 variables showed that the ostiums of right coronary and left circumflex arteries, hemodialysis, calcification, non-direct stenting, ISR of SES, and non-eccentric lesion were the predictors of TLR. There was no documented late stent thrombosis (LST) among 2,166 lesions and very LST (VLST) among 1,423 lesions. CONCLUSION: Further revises are needed to implant SES to these predictive lesions. LST and VLST were very rare.     

Late target lesion revascularization after implantation of sirolimus‐eluting stent

Objectives : We evaluated the incidence, clinical presentation, and angiographic in‐stent restenosis (ISR) pattern of late target lesion revascularization (TLR) after sirolimus‐eluting stent (SES) implantation. Background : Late TLR is an unusual finding beyond 6–9 months after bare‐metal stent implantation. However, late TLR after SES implantation has not been sufficiently evaluated. Methods : The study population consisted of 804 patients with 1,020 native lesions that were patent at 6‐month follow‐up angiogram after SES implantation. Results : Late TLR was performed in 18 patients with 18 lesions (1.8%) at 24.1 ± 2.6 months (range; 18–30 months) after SES implantation. Clinical presentation of late TLR patients was silent ischemia in eight patients and recurrent angina in 10 patients, but none had an acute coronary syndrome. Angiographic ISR pattern of late TLR lesions were focal ISR in 12 lesions (67%) and diffuse ISR in six lesions (33%). Serial quantitative coronary angiographic analysis of these lesions showed a minimal lumen diameter of 2.6 ± 0.5 mm immediately after SES implantation, 2.4 ± 0.4 mm at 6‐month follow‐up and 0.7 ± 0.6 mm at 24‐month follow‐up (ANOVA P < 0.001). By stepwise multiple logistic regression analysis, the only independent predictor of late TLR was stent length (P < 0.001, OR = 1.040, 95% CI = 1.019–1.061). Conclusions : Late TLR was performed in 1.8% of 1,020 native lesions that were patent at 6‐month follow‐up angiogram. Clinical presentations of late TLR was either silent ischemia or recurrent angina, but not acute coronary syndrome. Two‐thirds of late TLR lesions had a focal angiographic ISR pattern. © 2007 Wiley‐Liss, Inc.     

Optimal final lumen area and predictors of target lesion revascularization after stent implantation in small coronary arteries

Despite similar early clinical events, patients who undergo treatment of small vessels are at an increased risk for target lesion revascularization (TLR) after coronary artery stenting. We sought to determine predictors of TLR after stent implantation in small coronary arteries. We identified 423 consecutive patients who underwent intravascular ultrasound (IVUS)-guided small vessel stenting procedures in 465 coronary lesions with an angiographic reference vessel diameter of <2.75 mm. Patients were divided into 2 groups based on a final IVUS lumen area of < or =6.0 mm2 (n=345 lesions, group I) and >6.0 mm2 (n=115, group II). Baseline patient characteristics and in-hospital outcomes were similar between the 2 groups, except for a higher rate of restenotic lesions in group I and bifurcation lesions in group II. Group I had higher TLR rates at 1 year compared with group II patients (39% vs 26%, p = 0.02). The TLR rate appeared to decrease with greater stent expansion, especially at >90% of the reference vessel area, as assessed by IVUS. By multivariate analysis, an IVUS final stent area of < or =6 mm2, diabetes, absence of prior myocardial infarction, and history of intervention were independent predictors of 1-year TLR in this population. Final stent area of >6.0 mm2 and greater stent expansion were associated with a decrease in TLR. Therefore, there does not appear to be any "downside" to aggressive stent implantation strategies in small vessels. In contrast, IVUS allows maximization of final lumen dimensions to minimize clinical restenosis.     

Impact of vessel size, lesion length and diabetes mellitus on angiographic restenosis outcomes: insights from the NIRTOP study

BACKGROUND: The primary objective of the current analysis was to define the impact of vessel size, lesion length, and diabetes on clinical and angiographic restenosis following implantation of the NIRFLEX stent. METHODS AND RESULTS: Clinical and angiographic restenosis outcomes and multivariate predictors were compared between patients treated in 'small' (<3 mm, n=113 pts/133 lesions) versus 'large' (> or =3 mm, n=41 pts/53 lesions) vessels; between 'tubular' (10-20 mm lesion length n=49 pts/51 lesions) versus 'discrete' (<10 mm lesion length n=103 pts/133 lesions) lesions; and between 'diabetic' (n=30/35 lesions) versus 'non-diabetic' (n=128/156 lesions) patients using the flexible closed-cell design 'bare-metal' NIRFLEX stent in patients with native coronary artery disease. At six month follow-up, target vessel revascularization (TVR) and target lesion revascularization (TLR) rates were significantly less frequent in the 'large' versus 'small' vessel group (2.4% versus 16.8% for TVR, P=0.016, 0% versus 12.4% for TLR, P=0.022). Likewise, angiographic late loss was lower in 'large' versus 'small' vessels (0.54 versus 0.70 mm, P=0.05). Lesion length affected MACE rates but not angiographic restenosis. Angiographic late loss was greater in diabetics compared to the non-diabetic group (0.89 versus 0.60 mm, P=0.003). Using a multivariate model, diabetes mellitus (odds ratio=2.65, P=0.047) and post-procedure in-stent MLD (mm) (odds ratio=0.178, P=0.0019) were major determinants of restenosis. CONCLUSION: Clinical and angiographic restenosis outcomes following NIRFLEX stent implantation were dependent upon vessel size, lesions length, post-procedural stent lumen dimensions, and the diabetic status.     

血管内超声指导对于冠状动脉真性分叉病变介入治疗长期预后的影响

目的研究血管内超声（intravascular ultrasound,IVUS）指导对于冠状动脉真性分叉病变植入药物洗脱支架（drug eluting stent,DES）长期预后的影响。方法通过分析2005年10月至2010年3月DK—Crush系列随机对照研究入选735例原位冠状动脉真性分叉病变植入DES患者,应用倾向评分匹配临床和造影特征,165例IVUS指导和165例冠状动脉造影指导患者纳入研究,比较两组患者的长期预后。结果两组临床基线资料和造影特征比较,差异无统计学意义（P〉0．05）。IVUS指导组更常见选择双支架策略（P=0．007）,IVUS指导组主支血管（MV）和分支血管（SB）的最大支架直径和支架总长度以及分支血管支架个数显著超过常规造影指导组;介入治疗后QCA分析显示,IVUS指导组分支血管参考血管直径（RVD）和即刻获得以及主支血管近端和分支血管最小管腔直径（MLD）显著超过造影指导组。12个月随访发现两组心脏死亡、靶病变重建（TLR）和主要心血管事件（MACE）比较,差异无统计学意义（P〉0．05）。然而,IVUS指导组晚期支架内血栓和急性心肌梗死发生率显著低于造影指导组,差异有统计学意义（0．6％ vs.4．8％。P=0．04;1．8％ vs.6．7％,P=0．03）。结论IVUS指导冠状动脉真性分叉病变植入DES可以显著减低晚期支架内血栓和由此引起急性sT段抬高心肌梗死发生率而改善长期预后。     

Predictive Factors of Re-restenosis after Repeated Sirolimus-Eluting Stent Implantation for SES Restenosis and Clinical Outcomes after Percutaneous Coronary Intervention for SES Restenosis

Sirolimus-eluting stent (SES) is established to be effective in reducing restenosis. Repeat revascularization, however, is still required in up to 5–8% of patients. In this study, we analyzed clinical and angiographic variables that might be related with SES re-restenosis and variables related with re-restenosis after repeat SES implantation for SES restenosis. We also assessed clinical outcomes at 2-year follow-up after percutaneous coronary intervention (PCI) for SES restenosis. Repeat revascularization for SES restenosis was performed in 113 patients with 140 lesions. Of the 140 lesions, follow-up coronary angiography (CAG) was performed on 117 lesions (101 patients) and revealed 46 SES re-restenotic and 71 non-re-restenotic lesions. In multivariate analysis, SES-in-SES-strategy and reference diameter before the second PCI were independent predictors of re-restenosis after PCI for SES restenosis. However, the reference diameter was the only independent predictor of re-restenosis after SES-in-SES. Major adverse cardiac events (MACE) at 2 years were found in 44 patients (43.5%), and target lesion revascularization (TLR) was performed in 33.7% of patients after SES restenosis. In conclusion, the incidence of MACE and TLR was relatively high in patients with SES restenosis, but the placement of another SES on larger-diameter vessels may be an effective strategy for the second PCI .     

Clinical outcomes for sirolimus-eluting stent implantation and vascular brachytherapy for the treatment of in-stent restenosis.

The purpose of this study was to compare the mid-term clinical outcome of sirolimus-eluting stent (SES) implantation and vascular brachytherapy (VBT) for in-stent restenosis (ISR). We assessed the 9-month occurrence of major adverse cardiac events (MACE) in 44 consecutive patients with ISR treated with SES implantation and 43 consecutive patients treated with VBT in the period immediately prior. Baseline clinical and angiographic characteristics of the two groups were similar. During follow-up, three patients (7%) died in the VBT group and none in the SES group. The incidence of myocardial infarction was 2.3% in both groups. Target lesion revascularization was performed in 11.6% of the VBT patients and 16.3% of the SES patients (P = NS). The 9-month MACE-free survival was similar in both groups (79.1% VBT vs. 81.5% SES; P = 0.8 by log rank). The result of this nonrandomized study suggests that sirolimus-eluting stent implantation is at least as effective as vascular brachytherapy in the treatment of in-stent restenosis.     

Impact of highly asymmetric stent expansion after sirolimus-eluting stent implantation on twelve-month clinical outcomes

OBJECTIVES: This study investigated the impact of highly asymmetric stent expansion after sirolimus-eluting stent(SES)implantation on clinical outcomes from post procedure to 12 months later. METHODS: Subjects were 118 patients with 171 lesions who underwent SES implantation for angina pectoris and were studied by intravascular ultrasound (IVUS) following the procedure. The stent symmetry index (minimal stent diameter/maximal stent diameter) at the minimal stent area was calculated by IVUS analysis. The patients were divided into two groups for comparative study: those with stent symmetry index > or = 0.7 were classified into the optimal (O) group (93 patients; 145 lesions, mean age 66 +/- 12 years) and those with stent symmetry index < 0.7 were the sub-optimal (S) group (25 patients; 26 lesions, mean age 67 +/- 10 years). RESULTS: Angiographic follow up after 8 months showed no differences in target lesion revascularization (TLR) (O group: 3.1% vs S group: 3.8%, p = 0.833). Multivariate analysis identified the post minimal stent diameter as the independent predictor of TLR (p = 0.038). The stent symmetry index < 0.7 was not a predictor of TLR (p = 0.887). Clinical outcomes after 12 months showed both groups had 0% stent thrombosis and there were no differences in deaths (O group: 2.1% vs S group: 4.0%, p = 0.602). CONCLUSIONS: Highly asymmetric stent expansion after SES implantation may not have a negative impact on clinical outcomes at 12 months.     

Comparable clinical outcomes with paclitaxel- and sirolimus-eluting stents in unrestricted contemporary practice.

OBJECTIVES: This study was designed to compare the outcomes of paclitaxel-eluting stents (PES) and sirolimus-eluting stents (SES) in a contemporaneous cohort of real-world patients. BACKGROUND: A number of randomized comparisons of PES and SES have shown unequivocal advantages for SES in angiographic end points such as late loss. However, the data on clinical outcomes are less consistent. METHODS: All consecutive patients successfully treated with only SES or PES in de novo native vessel lesions between March 2003 and March 2005 were analyzed. Our end points were major adverse cardiac events (MACE), a composite of death, myocardial infarction (MI), target vessel revascularization (TVR), and target lesion revascularization (TLR). We also analyzed late loss and angiographic restenosis. RESULTS: There were 609 patients (1,064 lesions) treated with PES and 674 patients (1,205 lesions) treated with SES. Diabetes mellitus was present in 26.8% of patients and multivessel disease in 75% of patients. Bifurcations made up 16.3% of lesions, chronic occlusions 9.5%, left main 4.8%, and American Heart Association/American College of Cardiology type B2/C 75.4%. Despite a higher late loss in the PES group (p = 0.0001), there were no differences in angiographic restenosis (PES 18% vs. SES 17.8%, p = 0.95), TLR (PES 11.9% vs. SES 11%, p = 0.47), or MACE (PES 21.3% vs. SES 21.1%, p = 0.95). The relative risk of MACE for the PES group was 1.02 (95% confidence interval [CI] 0.78 to 1.33). Multivariable analysis confirmed the lack of association of stent type with MACE (odds ratio 1.03 [95% CI 0.77 to 1.38], p = 0.83) and TLR (odds ratio 1.08 [95% CI 0.81 to 1.44], p = 0.61). CONCLUSIONS: In this complex cohort, both stent platforms demonstrated similar clinical outcomes despite different late loss.     

Effectiveness of sirolimus-eluting stent implantation for the treatment of ostial left anterior descending artery stenosis with intravascular ultrasound guidance

OBJECTIVES: This study was designed to evaluate the clinical and angiographic outcomes of sirolimus-eluting stent (SES) implantation for ostial left anterior descending (LAD) lesions compared with bare-metal stent (BMS) implantation. BACKGROUND: The effectiveness of SES implantation for ostial LAD lesions is currently unknown. METHODS: Sirolimus-eluting stents were implanted in 68 consecutive patients with ostial LAD stenoses. The control group was composed of 77 patients treated with BMS during the preceding two years. In the SES group, for complete lesion coverage, stent positioning was intentionally extended into the distal left main coronary artery (LMCA) in 23 patients (34%) with intermediate LMCA narrowing. RESULTS: Compared with the BMS group, the SES group had more multivessel involvement, received fewer debulking atherectomies, underwent more direct stenting, had a greater number of stents, and had more segments stented. The procedural success rate was 100% in both groups. The six-month angiographic restenosis rate was significantly lower in the SES group than in the BMS group (5.1% vs. 32.3%, p < 0.001). During the one-year follow-up period, neither death nor myocardial infarction occurred in either group, but target lesion revascularization was less frequent in the SES group than in the BMS group (0% vs. 17%, p < 0.001). In the SES group, there were no restenoses in cases with LMCA coverage, compared with three restenoses (7.9%) in cases with precise stent positioning (p = NS). CONCLUSIONS: Sirolimus-eluting stent implantation in ostial LAD lesions achieved excellent results regarding restenosis and clinical outcomes compared with BMS implantation. This finding may be associated with reduced neointimal hyperplasia and complete lesion coverage.     

Restenosis and stent fracture following sirolimus-eluting stent (SES) implantation.

BACKGROUND: Restenosis still occurs, even with the sirolimus-eluting stent (SES), and the precise mechanisms and the impact of stent fracture on restensosis have not yet been elucidated. METHODS AND RESULTS: Intravascular ultrasound (IVUS)-guided SES implantation was performed in 184 lesions in 151 patients with stable and unstable angina. Serial (pre-, post- and follow-up) quantitative coronary angiography analysis was obtained in 169 lesions in 138 patients (angiographic follow-up rate: 91%) and 12-month clinical follow-up was done in all patients. Restenosis occurred in 13 (7.7%) of 169 lesions. Stent fracture occurred in 4 (2.4%) of 169 lesions at follow-up. Of the 13 restenotic lesions, 8 had intimal hyperplasia, 4 had stent fracture, and 1 had late stent thrombosis at 7 months. Although multivariate logistic regression analysis revealed that minimal lumen area (min-LA) post (p=0.027), total stent length (p=0.003) and diabetes (p=0.032) were significant independent predictors of restenosis, univariate analysis showed that stent fracture was more common in the restenosis than in the non-restenosis groups (p=0.001). CONCLUSIONS: Although min-LA post by IVUS, total stent length by QCA and diabetes are independent predictors for angiographic restenosis, stent fracture occurred in 4 lesions (2.4%) and all of them resulted in restenosis (31% of the restenosis). The impact of stent fracture and its potential role in the development of restenosis deserves further study.     

Impact of lesion calcification on clinical and angiographic outcome after sirolimus-eluting stent implantation in real-world patients.

BACKGROUND: Previous studies have demonstrated similar efficacy of the drug-eluting stent (DES) in patients with and without calcified lesions. However, most of the randomized trials have excluded patients with severe calcified lesions. This study aimed to examine the impact of lesion calcium on clinical and angiographic outcome after sirolimus-eluting stent (SES) implantation in real-world patients. METHODS: Consecutive 380 patients with 556 lesions treated with SES were enrolled. Lesions were divided into Calc lesions (moderate or sever calcification; 195 lesions) and non-Calc lesions (none or mild calcification; 361 lesions) according to the lesion calcium. Quantitative coronary angiography (QCA) parameters, binary restenosis rate (%restenosis), target lesion revascularization (TLR) rate, and major adverse cardiac events (MACE) during follow-up were compared between the two groups. All patients were contacted at 1, 6, and 12 months after the procedure. RESULTS: Lesion success rate was similar in the two groups. %Restenosis (9.2% vs. 3.6%; P<.05) and TLR (7.3% vs. 2.8%; P<.05) were significantly higher in Calc lesions. Stent thrombosis was observed in 0.7% of overall lesions with no difference between the two groups. The MACE rate in Calc patients (13.8%) was significantly higher than in non-Calc patients (6.1%). By multivariate analysis, hemodialysis (HD) and requirement of rotational atherectomy (RA) were predictive factors of TLR in the Calc lesions. CONCLUSIONS: Coronary lesions with calcification comprise a high-risk cohort and are associated with a higher TLR and binary restenosis rates in real-world patients treated with SES. Moreover, patients with calcified lesions and on HD are associated with higher MACE rate.     

Angiographic and intravascular ultrasound predictors of in-stent restenosis

Objectives. This study was performed to determine predictors of in-stent restenosis from a high volume, single-center practice.Background. Intracoronary stents have been shown to reduce the restenosis rate as compared with balloon angioplasty, but in-stent restenosis continues to be an important clinical problem.Methods. Between April 1993 and March 1997, 1,706 patients with 2,343 lesions were treated with a variety of intracoronary stents. The majority of stents were placed with high pressure balloon inflations and intravascular ultrasound (IVUS) guidance. Angiographic follow-up was obtained in 1,173 patients with 1,633 lesions (70%). Clinical, angiographic and IVUS variables were prospectively recorded and analyzed by univariate and multivariate models for the ability to predict the occurrence of in-stent restenosis defined as a diameter stenosis ≥50%.Results. In-stent restenosis was angiographically documented in 282 patients with 409 lesions (25%). The restenosis group had a significantly longer total stent length, smaller reference lumen diameter, smaller final minimal lumen diameter (MLD) by angiography and smaller stent lumen cross-sectional area (CSA) by IVUS. In lesions where IVUS guidance was used, the restenosis rate was 24% as compared with 29% if IVUS was not used (p < 0.05). By multivariate logistic regression analysis, longer total stent length, smaller reference lumen diameter and smaller final MLD were strong predictors of in-stent restenosis. In lesions with IVUS guidance, IVUS stent lumen CSA was a better independent predictor than the angiographic measurements.Conclusions. Achieving an optimal stent lumen CSA by using IVUS guidance during the procedure and minimizing the total stent length may reduce in-stent restenosis.     

Success rate of implantation and mid-term outcomes of the sirolimus-eluting stent.

BACKGROUND: The sirolimus-eluting stent (SES) is currently the sole drug-coated stent approved for use in Japan, but there are few reports on its safety and outcomes in Japan. METHODS AND RESULTS: From May 2004 to February 2005, a total of 297 patients with 402 lesions were treated with SES at 6 hospitals in the Kansai district. Follow-up angiography was performed in 82% of the patients and 80% of the lesions at 182+/-35 days after stenting. Coronary stenosis was evaluated using quantitative coronary angiography. Clinical and angiographic data were analyzed. Minimum lesion diameter was 0.75+/-0.52 mm and the reference diameter was 2.81+/-0.47 mm before stenting. The SES successfully dilated 99.5% of the lesions with few major adverse cardiac events. Restenosis occurred in 4.0% and the target lesion revascularization rate was 3.7%. Restenosis correlated with chronic hemodialysis, calcification, occlusion, ostial lesions, lesions kinked>45 degrees, right coronary artery (RCA) lesions and lesions at the ostium of the RCA. CONCLUSION: SES demonstrated a high rate of successful implantation with few complications, and mid-term outcomes were excellent. Patients with lesions at the ostium of the RCA or under chronic hemodialysis developed restenosis.     

Standardized angiographically guided over-dilatation of stents using high pressure technique optimize results without increasing risks

BACKGROUND: Routine angio-guided stent deployment results in a relatively high restenosis rate, which is mostly due to stent sub-expansion. Several different intravascular ultrasound (IVUS) criteria for optimal stent deployment have been proposed. A minimal in-stent restenosis and a minimal in-stent lumen area of > or = 9 mm2 have been associated with low rates of restenosis and target lesion revascularization (TLR) at 6 months. The role of high-pressure stent deployment and/or upsizing the post-dilatation balloon has not yet been clarified. The aim of this study was to evaluate the possibility of achieving accepted IVUS criteria safely without IVUS guidance with the combination of high-pressure deployment and post-dilatation with a 0.25 mm oversized balloon. METHODS: Thirty-four stents (26 NIR, 3 AVE GFX, 3 ACS GFX, 1 Bard, 1 Jostent) were implanted in 30 patients until optimal angiographical results were obtained (< 10% residual stenosis visually). Forty percent of the patients had unstable angina pectoris, forty-four percent had complex lesions (B2 and C) and 29% were occlusions. Mean inflation pressure was 12.6 +/- 1.6 atm, mean stent diameter was 3.2+/- 0.4 mm and mean stent length was 15.1+/- 5.4 mm. Post-dilatation was performed with the same stent using a short (compared to the angiographic reference segment), 0.25 mm oversized Scimed Maxxum Energy 3.5 +/- 0.4 mm balloon using high pressure (16.1 +/- 1.7 atm) followed by an off-line IVUS examination of the stents. There was clinical follow-up for 1 year. Results in patients with single-vessel disease were compared with those of non-randomized controls, who were stented with high pressure but without over-dilatation. RESULTS: No stent achieved the nominal diameter, in spite of over-dilatation. Mean minimal stent diameter (MLD) according to IVUS was 2.9 +/- 0.4 mm (92% of the angiographic reference diameter). Mean minimal lumen area (MLA) was 7.7 +/- 2.2 mm2. An in-stent MLA > or = 90% of the distal reference segment (AVID criteria) and an MLA > or = 100% or > or = 90% of the smallest/average reference segment (MUSIC criteria) was found in 67% and 57%, respectively. MLA > or = 9 mm2 was achieved in 38%. All stents had good apposition and obtained a symmetry index > or = 0.7 mm. No acute perforations, dissections or other serious complications occurred during the over-dilatation. At 1 year, five patients had re-angina leading to a new coronary angiography; only 1 patient had a significant in-stent restenosis requiring re-PTCA. Compared to non-overdilated historical controls, the standardized over-dilatation seemed to give a larger MLD (3.0 +/- 0.4 mm vs. 2.7 +/- 0.4 mm; p = 0.03), more patients who fulfilled AVID criteria (70% vs. 32%; p = 0.048) and more stents with MLA > or = 9 mm2 (46% vs. 11%; p = 0.02). CONCLUSION: A standardized 0.25 mm over-dilatation of stents never achieved nominal stent size, but did improve lumen gain and was associated with low target vessel revascularization without adding complications to the routine stenting procedure.     

Comparison of sirolimus versus paclitaxel eluting stents for treatment of coronary in-stent restenosis

In patients with in-stent restenosis (ISR) inside bare metal stents, drug-eluting stents reduce the recurrence of restenosis compared with balloon angioplasty. However, few data are available about this therapeutic modality in the case of diffuse restenosis. The aim of this study was to evaluate the immediate and mid-term outcome of sirolimus- and paclitaxel-eluting stent implantation in diffuse ISR and determine the predictors of clinical and angiographic restenosis recurrence. A series of 161 consecutive patients with 194 diffuse ISR lesions (>10 mm) treated with drug-eluting stent implantation were evaluated. Major adverse cardiac events were defined as death, myocardial infarction, and the need for target lesion revascularization. During a mean follow-up of 8.2 +/- 3.4 months, the cumulative incidence of major adverse cardiac events was 19% in the SES group and 24% in the PES group (p = 0.56). Angiographic follow-up was performed in 80% of the lesions. The overall restenosis rate was 22% and was not significantly different between lesions treated with sirolimus-eluting (20%) or paclitaxel-eluting (25%, p = 0.55) stents. The incidence of restenosis was higher in diabetics (32%) than in nondiabetics (16%, odds ratio 2.5, 95% confidence interval 1.1 to 5.5, p = 0.02). By multivariate analysis, diabetes was confirmed to be the only independent predictor of recurrent restenosis (odds ratio 3.53, 95% confidence interval 1.39 to 9.02, p = 0.008). In conclusion, drug-eluting stent implantation for diffuse ISR is associated with acceptable clinical and angiographic results. The association of diffuse restenosis and diabetes mellitus is an unfavorable condition leading to a high risk of recurrence.     

Impact of intravascular ultrasound guidance in patients with acute myocardial infarction undergoing percutaneous coronary intervention

Objectives: The aim of this study was to examine the utility of routine intravascular ultrasound (IVUS) guidance in patients with acute myocardial infarction (MI) undergoing percutaneous coronary intervention (PCI) with stent implantation. Background: Stent thrombosis (ST) is a serious complication of PCI with stent implantation for patients presenting with acute MI. Mechanical factors such as incomplete stent expansion and smaller stent diameters are known to correlate with ST and restenosis. IVUS guidance for stent deployment is reported to reduce these events in stable patients. Methods: We analyzed a cohort of 905 consecutive patients who underwent primary PCI for acute MI and were discharged alive. The clinical outcomes of 382 patients who underwent IVUS‐guided PCI were compared to those of 523 patients who did not. Patients who presented with cardiogenic shock and rescue PCI were excluded. The primary composite endpoint of death, MI, and target lesion revascularization at 1‐year follow‐up was systematically indexed and a propensity score was performed with regard to the use of IVUS‐guided PCI. Results: Patients undergoing IVUS‐guided PCI were older, more diabetic and hypertensive, but presented with less history of previous MI. The severity of coronary artery disease was balanced between both groups. The number of treated lesions and stents used was higher in the IVUS‐guided group, with a longer procedural duration. The overall rates of the composite primary outcome were similar (14.5% vs. 14.3%, P = 0.94) as were the rates of definite and probable stent thrombosis at 1 year (2.1% vs. 2.1%, P = 0.99) in the IVUS‐guided and no‐IVUS groups, respectively. After multivariate and propensity score adjustment, IVUS guidance was not an independent predictor for the primary endpoint. Conclusion: This study does not support the routine use of IVUS guidance for stent deployment in patients who present with acute MI and undergo primary PCI. © 2009 Wiley‐Liss, Inc.