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.     

Intravascular Ultrasound Predictors of Angiographic Restenosis in Lesions Treated With Palmaz-Schatz Stents

Objectives. This study sought to evaluate the clinical, procedural, preinterventional and postinterventional quantitative coronary angiographic (QCA) and intravascular ultrasound (IVUS) predictors of restenosis after Palmaz-Schatz stent placement.Background. Although Palmaz-Schatz stent placement reduces restenosis compared with balloon angioplasty, in-stent restenosis remains a major clinical problem.Methods. QCA and IVUS studies were performed before and after intervention (after stent placement and high pressure adjunct balloon angioplasty) in 382 lesions in 291 patients treated with 476 Palmaz-Schatz stents for whom follow-up QCA data were available 5.5 ± 4.8 months (mean ± SD) later. Univariate and multivariate predictors of QCA restenosis (≥50% diameter stenosis at follow-up, follow-up percent diameter stenosis [DS] and follow-up minimal lumen diameter [MLD]) were determined.Results. Three variables were the most consistent predictors of the follow-up angiographic findings: ostial lesion location, IVUS preinterventional lesion site plaque burden (plaque/total arterial area) and IVUS assessment of final lumen dimensions (whether final lumen area or final MLD). All three variables predicted both the primary (binary restenosis) and secondary (follow-up MLD and follow-up DS) end points. In addition, a number of variables predicted one or more but not all the end points: 1) restenosis (IVUS preinterventional lumen and arterial area); 2) follow-up DS (QCA lesion length); and 3) follow-up MLD (QCA lesion length and preinterventional MLD and DS and IVUS preinterventional lumen and arterial area).Conclusions. Ostial lesion location and IVUS preinterventional plaque burden and postinterventional lumen dimensions were the most consistent predictors of angiographic in-stent restenosis.     

Balloon angioplasty for the treatment of coronary in-stent restenosis: immediate results and 6-month angiographic recurrent restenosis rate

Objectives. The purpose of this prospective study was to evaluate the immediate results and the 6-month angiographic recurrent restenosis rate after balloon angioplasty for in-stent restenosis.Background. Despite excellent immediate and mid-term results, 20% to 30% of patients with coronary stent implantation will present an angiographic restenosis and may require additional treatment. The optimal treatment for in-stent restenosis is still unclear.Methods. Quantitative coronary angiography (QCA) analyses were performed before and after stent implantation, before and after balloon angioplasty for in-stent restenosis and on a 6-month systematic coronary angiogram to assess the recurrent angiographic restenosis rate.Results. Balloon angioplasty was performed in 52 patients presenting in-stent restenosis. In-stent restenosis was either diffuse (≥ 10 mm) inside the stent (71%) or focal (29%). Mean stent length was 16 ± 7 mm. Balloon diameter of 2.98 ± 0.37 mm and maximal inflation pressure of 10 ± 3 atm were used for balloon angioplasty. Angiographic success rate was 100% without any complication. Acute gain was lower after balloon angioplasty for in-stent restenosis than after stent implantation: 1.19 ± 0.60 mm vs. 1.75 ± 0.68 mm (p = 0.0002). At 6-month follow-up, 60% of patients were asymptomatic and no patient died. Eighteen patients (35%) had repeat target vessel revascularization. Angiographic restenosis rate was 54%. Recurrent restenosis rate was higher when in-stent restenosis was diffuse: 63% vs. 31% when focal, p = 0.046.Conclusions. Although balloon angioplasty for in-stent restenosis can be safely and successfully performed, it leads to less immediate stenosis improvement than at time of stent implantation and carries a high recurrent angiographic restenosis rate at 6 months, in particular in diffuse in-stent restenosis lesions.     

Stenting of Nonacute Total Coronary Occlusions: Predictors of Late Angiographic Outcome

Objectives. This study was designed to determine and assess factors predictive of the intermediate-term outcome of stenting of nonacute total coronary occlusions.Background. Balloon angioplasty of recanalized coronary occlusions is associated with a combined restenosis/reocclusion rate of up to 65%. Adjunctive stenting holds the potential to reduce this rate significantly. However, variables affecting the late angiographic outcome of coronary stenting in the setting of a total occlusion have not been elucidated sufficiently.Methods. Coronary stenting was performed in 143 consecutive patients with a nonacute total occlusion; 120 of these patients (84%), with a total of 121 occlusions, underwent repeat angiography within 6 months and comprised the study group. High pressure stent implantation aimed to cover the site of the occlusion as well as adjacent diameter stenoses ≥70% and all possibly induced dissections. Pertinent angiographic and procedural variables obtained at the time of the intervention were entered into a multivariate logistic regression analysis model to assess their influence on the angiographic outcome at follow-up.Results. Mean preinterventional reference lumen diameter for the 121 vessels was 2.99 ± 0.53 mm (mean ± SD); occlusion length ranged from 4 to 44 mm (median of 7.7). After balloon angioplasty, dissections were found in 80% of patients. Lesions were covered with stents a median of 16 mm in length (range 8 to 53). The minimal lumen diameter (MLD) achieved after stenting was 2.89 ± 0.48 mm. After a median follow-up period of 4.5 months, mean MLD was assessed at 1.91 ± 0.90 mm, corresponding to a loss index of 0.34 ± 0.31. There were 27 vessels with a nonocclusive restenosis ≥50% and 8 with a reocclusion, for a combined restenosis/reocclusion rate of 29%. Factors found to adversely influence angiographic outcome were a post-stenting MLD ≤2.54 mm, a stented vessel segment length >16 mm, a balloon/vessel diameter ratio for final stent expansion ≤1.00 and the presence of a dissection after balloon angioplasty.Conclusions. Compared with previous reports on stand-alone balloon angioplasty, stenting of nonacute total coronary occlusions lowers the 6-month restenosis/reocclusion rate to ∼30%. The late procedural outcome is independently and statistically significantly influenced by the MLD after stenting, the length of the stented vessel segment, the balloon/vessel diameter ratio for final stent expansion and the incidence of dissections after balloon angioplasty.     

Rotational atherectomy (stentablation) in a lesion with stent underexpansion due to heavily calcified plaque.

We report treatment of a lesion with coronary stent underexpansion due to heavily calcified plaque. Conventional balloon angioplasty was attempted for in-stent restenosis, but the lesion was undilatable despite 25-atm inflation pressure. Intravascular ultrasound (IVUS) revealed stent underexpansion due to heavily calcified plaque. Rotational atherectomy was performed using a stepped burr approach, after which repeat IVUS revealed marked ablation of the stent-calcium complex. Adjunctive balloon angioplasty then easily resulted in full balloon and stent expansion, with an excellent angiographic and IVUS result. The patient's hospital course was uneventful.     

Impact of intravascular ultrasound guidance in stent deployment on 6-month restenosis rate: a multicenter,randomized study comparing two strategies—with and without intravascular ultrasound guidance

Objectives. We aimed to investigate the impact of intravascular ultrasound (IVUS)-guided stent implantation on the 6-month restenosis rate, which has not yet been fully established in randomized trials.Background. The 6-month angiographic restenosis rate was compared in patients with symptomatic ischemic heart disease who were randomly allocated to angioplasty and stent deployment, with versus without IVUS guidance.Methods. After successful stent implantation, patients were randomized into two groups: Group A had no further dilation, and Group B had additional balloon dilation until achievement of IVUS criterion for stent expansion. The study group consisted of 164 patients, assuming a 50% reduction of the restenosis rate in Group B (15% vs. 30%) (alpha = 10%, beta = 20%).Results. We enrolled 155 patients. Overdilation was carried out in 31 (39%) of 79 Group B patients, with the IVUS criterion being achieved in 63 (80%) of 79. No significant difference was observed in the minimal luminal diameter (MLD), but the stent lumen cross-sectional area (CSA) was significantly larger in Group B (mean ± SD) (7.16 ± 2.48 vs. 7.95 ± 2.21 mm², p = 0.04). At 6 months, there was no significant difference in the restenosis rate, (28.8% [21 of 73] in Group A vs. 22.5% [16 of 71] in Group B, p = 0.25), but according to the observed difference in the restenosis rate, the power of the study was only 40%. The difference in MLD was also nonsignificant (1.60 ± 0.65 mm in Group A vs. 1.70 ± 0.64 mm in Group B, p = 0.20), whereas the lumen CSA was 20% larger in the IVUS-guided group (4.47 ± 2.59 vs. 5.36 ± 2.81 mm², p = 0.03). Lumen CSA was the only predictor of restenosis by multivariate logistic regression analysis.Conclusions. A nonsignificant 6.3% absolute reduction in the restenosis rate and a nonsignificant difference in MLD were observed in this study. Nonetheless, we still cannot rule out a beneficial effect of IVUS guidance, although this may have gone undetected owing to a lack of statistical power. A significant increase was observed in immediate and 6-month lumen size, as detected by IVUS, indicating that ultrasound guidance in stent deployment may be beneficial.     

Safety and efficacy of angiography-guided stent placement in small native coronary arteries of < 3.0 mm in diameter

Background and hypothesis: Increased operator experience, greater insight in stent deployment techniques, and improved poststent medication regimen have significantly reduced the risk of thrombotic stent closure following stent placement in large coronary arteries ( 3.0 mm in diameter). Whether equally favorable results are afforded by stent placement in small vessels (> 3.0 mm), however, remains unclear. Accordingly, the aim of this study was the specific examination of the risk of stent placement in small native coronary vessels, using stent deployment technique consisting of supplementary dilatations with larger balloons or high-pressure inflations, and aggressive aspirin-ticlopidine and short-term oral anticoagulation poststent therapy. Methods: Forty-seven balloon-expandable stents (20 Gianturco-Roubin, 21 NIR, 6 Palmaz-Schatz) were successfully implanted without intravascular guidance in 45 native coronary arteries (mean reference diameter of 2.5 mm) in 44 consecutive patients (31 men, 13 women), the majority of whom (87%) were stented for the treatment of failed or suboptimal balloon angioplasty outcome. Results: Successful stent placement reduced the lesion diameter stenosis from 91 ± 9% to 3 ± 7% (p = 0.0001). There were no early stent thrombosis or major cardiovascular events prior to hospital discharge. During a 12-month follow-up period, most patients remained symptomatically improved and no myocardial infarction, stroke, or death was observed. Five-month angiographic reassessment revealed an in-stent restenosis rate of 41%, which was higher in vessels 2.5 mm in size (47 vs. 33% for vessels > 2.5 mm, p = 0.2747). Conclusions: In selected patients with small native coronary vessels < 3.0 mm in diameter, angiography-guided optimal stent placement is associated with a low risk of stent thrombosis and bleeding complications. However, the in-stent restenosis rate is high with the stents used in this study.     

A randomized comparison of repeat stenting with balloon angioplasty in patients with in-stent restenosis

OBJECTIVES: This randomized trial compared repeat stenting with balloon angioplasty (BA) in patients with in-stent restenosis (ISR). BACKGROUND: Stent restenosis constitutes a therapeutic challenge. Repeat coronary interventions are currently used in this setting, but the recurrence risk remains high. METHODS: We randomly assigned 450 patients with ISR to elective stent implantation (224 patients) or conventional BA (226 patients). Primary end point was recurrent restenosis rate at six months. Secondary end points included minimal lumen diameter (MLD), prespecified subgroup analyses, and a composite of major adverse events. RESULTS: Procedural success was similar in both groups, but in-hospital complications were more frequent in the balloon group. After the procedure MLD was larger in the stent group (2.77 +/- 0.4 vs. 2.25 +/- 0.5 mm, p < 0.001). At follow-up, MLD was larger after stenting when the in-lesion site was considered (1.69 +/- 0.8 vs. 1.54 +/- 0.7 mm, p = 0.046). However, the binary restenosis rate (38% stent group, 39% balloon group) was similar with the two strategies. One-year event-free survival (follow-up 100%) was also similar in both groups (77% stent vs. 71% balloon, p = 0.19). Nevertheless, in the prespecified subgroup of patients with large vessels (> or =3 mm) the restenosis rate (27% vs. 49%, p = 0.007) and the event-free survival (84% vs. 62%, p = 0.002) were better after repeat stenting. CONCLUSIONS: In patients with ISR, repeat coronary stenting provided better initial angiographic results but failed to improve restenosis rate and clinical outcome when compared with BA. However, in patients with large vessels coronary stenting improved the long-term clinical and angiographic outcome.     

Rotational atherectomy for in-stent restenosis: acute and long-term results of the first 100 cases

Objectives. This study evaluated the clinical safety and long-term results of rotational atherectomy (RA) followed by low-pressure balloon dilatation (percutaneous transluminal coronary angioplasty [PTCA]) for the treatment of in-stent restenosis (ISR).Background. In-stent restenosis is associated with a high incidence of recurrence after interventional treatment. Because ISR is due to neointimal hyperplasia, rotational ablation may be a more effective treatment than PTCA.Methods. Between November 1995 and November 1996, 100 consecutive patients with first-time ISR were treated by RA. Quantitative coronary angiography and intravascular ultrasound (IVUS) were used to analyze the acute procedural results. The incidence of repeat in-stent restenosis and target vessel revascularization (TVR) at follow-up was determined.Results. Procedural success without any major in-hospital complications was achieved in 100% of cases. Slow flow was observed in 3% and creatine kinase-MB enzyme elevation >3× normal occurred in 2%. The mean burr-to-artery ratio was 0.68 ± 0.18 and adjuvant balloon dilatation was performed at 4.2 ± 2.1 atm. Minimum luminal diameter increased from 0.86 ± 0.28 mm to 1.89 ± 0.21 mm after RA and to 2.56 ± 0.29 mm after adjunct PTCA. Quantitative IVUS analysis showed that 77% of the luminal gain occurred due to rotational ablation of the restenotic tissue and only 23% occurred after adjunct balloon dilation, and further stent expansion did not contribute to the luminal enlargement. At a mean follow-up of 13 ± 5 months, repeat in-stent restenosis occurred in 28% of patients with TVR of 26%. Univariate predictors of repeat restenosis were burr-to-artery ratio <0.6, ISR in <90 days of stenting, ostial lesion, stent for a restenotic lesion and diffuse type ISR.Conclusions. Rotational atherectomy is a safe and feasible technique for treatment of ISR and is associated with a relatively low recurrent restenosis in comparison to historical controls of balloon angioplasty.     

经皮切割球囊成形术治疗支架内再狭窄的研究

目的　研究切割球囊成形术对治疗支架内再狭窄的即刻和 6个月内随访效果。方法　 6 9例支架内再狭窄患者随机分配到切割球囊组 (38例 )和普通球囊治疗组 (31例 )。球囊扩张前及扩张后即刻在定量冠状动脉造影和冠状动脉内超声下 ,测定相关参数。观察随访 6个月内临床改善及冠状动脉造影结果。研究终点包括出现心肌梗死 ,需要冠状动脉搭桥或再介入治疗。结果　两组的手术成功率均为 10 0 %。切割球囊组 1例患者扩张后在支架的远端出现夹层。平均随访 (6 .7± 2 .3)个月。切割球囊组于术后 3和 6个月时的再狭窄率显著低于普通球囊组(15 %∶38%及 18%∶4 2 % ,P <0 .0 0 1)。扩张后即刻血管直径获得值在切割球囊组和普通球囊组分别为 (1.72±0 .5 2 )mm和 (1.15± 0 .5 4 )mm ,随访 3个月及随访终点时切割球囊组的血管直径晚期丢失分别为 (0 .2 6± 0 .0 5 )mm(3个月 )及 (0 .38± 0 .0 6 )mm ,同时的普通球囊组丢失值分别为 (0 .78± 0 .19)mm(3个月 )及 (0 .89± 0 .16 )mm。结论　切割球囊成形术治疗老年冠心病患者支架内狭窄效果可靠 ,安全 ,容易操作 ,再狭窄率低     

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.     

Sirolimus-eluting stent in chronic total occlusion: the SICTO study

Coronary stenting can significantly reduce the restenosis and reocclusion rates after successful balloon angioplasty for chronic total occlusions (CTO). Nevertheless, recanalization of CTO remains among the worst predictors for in-stent restenosis and reocclusion. This multicenter, nonrandomized study assessed the safety and effectiveness of the CYPHER sirolimus-eluting stent in reducing angiographic in-stent late loss in totally occluded native coronary arteries. A total of 25 eligible patients were treated with the CYPHER sirolimus-eluting stent. Baseline clinical and angiographic data were collected and 6-month follow-up angiography and intravascular ultrasound (IVUS) were performed. Clinical follow-up was required at 30 days, 6, 12, 18, and 24 months. Study stent implantation was successful in all patients, with a mean stent length of 28.4 +/- 11 mm. Six-month angiographic outcomes showed that mean lumen diameter stenosis did not change (2.22 +/- 0.56 mm postprocedure; 2.26 +/- 0.60 mm at 6 months follow-up; P = NS). Similarly, mean percent diameter stenosis did not change significantly (15.7 +/- 8.6% postprocedure, 19.3 +/- 11% at follow-up; P = NS). The absolute late lumen loss was -0.03 +/- 0.28 mm with a 6-month in-stent restenosis rate of 0%. IVUS follow-up revealed in-stent obstruction volume of only 4.9 +/- 6.8%. Long-term clinical follow-up showed target lesion revascularization at 12 months was only 4%, with target vessel revascularization of only 12%. The CYPHER sirolimus-eluting stent was safe and effective in the treatment of CTO compared to historical data with bare metal stents.     

Quantitative Coronary Angiographic Analysis of Spasm and Elastic Recoil After High Speed Rotational Atherectomy

This study evaluates the short-term changes in coronary artery segments treated with high speed rotational atherectomy (HSRA). Quantitative coronary angiographic (QCA) analysis indices, such as degree of expected ablation, elastic recoil, and segmental spasm, were examined in 133 patients and restudied 24 hours after HSRA. The study was also designed to compare the early results of three different HSRA strategies: stand-alone (SA) HSRA; HSRA with adjunctive high (≥ 4 atm) pressure (HP BA) and low (≥ 2 atm) pressure balloon angioplasty (LP BA). Previous studies have suggested negligible elastic recoil after HSRA as well as demonstrated the possibility of further continuous improvement in vessel patency up to 24 hours postprocedure. From a total of 656 patients treated with HSRA, a cohort of 133 patients with successful HSRA of 167 lesions were restudied angiographically at 24 hours. Serial QCA evaluation of the treatment site was performed. Analysis of the relative gain in minimal luminal diameter (MLD) assessed at 24 hours postprocedure showed that the highest gain group (> 40%) had narrower initial lesions compared to moderate gain (1%–40%), or MLD loss groups (MLD 0.5 ± 0.4 mm vs 1.0 ± 0.3 and 1.5 ± 0.4, respectively, P < 0.01). The initial percent diameter stenosis was also higher in the high gain group (77.1 ± 16.0 vs 61.9 ± 11.8 and 53.0 ± 11.9, P < 0.01). Immediately postprocedure there was a significant increase in MLD and a decrease in percent diameter stenosis. There was no difference in residual lesion characteristics postprocedure. While progressive MLD decrease was observed in the loss group (MLD postprocedure 1.6 ± 0.5 and 1.2 ± 0.6 at 24 hours, P < 0.01), a continuous increase in MLD was noted in the high gain group (MLD postprocedure 1.7 ± 0.5 mm vs at 24 hours 2.0 ± 0.5 mm, P < 0.01). The high gain group was characterized by the most lesion debulking, the most pronounced segmental spasm, and the least elastic recoil. Adjunctive HP BA was associated with the largest size vessels (D ref. in SA HSRA group was 2.6 ± 0.8 mm vs 2.9 ± 0.6 mm in LP BA and 3.0 ± 0.7 mm in HP BA groups, P < 0.01), the lowest elastic recoil (SA HSRA 23.8%± 20.9% vs LP BA 15%± 16.8% and HP BA 5.7%± 14.4%, P < 0.05), and the highest incidence of vessel dissection (SA HSRA 8.1% vs LP BA 14.7% and HP BA 34.0%, P < 0.05). However, these larger vessels underwent the least amount of lesion debulking (SA HSRA 46.4%± 27.2% vs LP BA 38.6%± 24.0% and HP BA 30.5%± 19.5%, P _{SA HSRA vs. HP BA} < 0.001). There are measurable degrees of elastic recoil and local spasm observed after HSRA. HSRA of the most severe lesions yields the highest procedural gain, the lowest elastic recoil and the highest index of lesion ablation. In addition, some late increase in the MLD due to the resolution of spasm is observed at 24 hours postprocedure. SA HSRA is associated with higher degrees of expected lesion ablation. This is comparable to the degree of improvement in MLD, where adjunctive percutaneous transluminal coronary angioplasty is utilized as assessed at 24 hours postprocedure. HSRA with adjunctive HP BA yields immediate results showing the least elastic recoil and spasm at the expense of the highest incidence of dissection and side branch loss.     

Role of vessel size as a predictor for the occurrence of in-stent restenosis in patients with diabetes mellitus

Intracoronary stents have been shown to reduce the rate of restenosis when compared with balloon angioplasty, but in-stent restenosis continues to be an important clinical problem. It was therefore the aim of this registry to identify procedural and angiographic predictors for the occurrence of in-stent restenosis. We analyzed 368 patients with 421 lesions who underwent coronary stent implantation between January 1998 and February 2000. Indications for the placement of a coronary stent were severe dissections (37%), suboptimal angiographic results (38%), restenotic lesions (20%), and graft lesions (4%). Angiographic follow-up was obtained in 270 patients (73%) with 293 lesions after 6 months. Clinical and angiographic variables were analyzed by univariate and multivariate models for the ability to predict the occurrence of in-stent restenosis, defined as a diameter stenosis >50%. In-stent restenosis was angiographically documented in 67 patients and 68 lesions (23%). Under all tested variables the reference luminal diameter before stent implantation (p = 0.006) and diabetes mellitus (p = 0.023) were identified as independent predictors for the occurrence of in-stent restenosis. The comparison of diabetic and nondiabetic patients according to vessel size revealed a 2 times higher rate of in-stent restenosis in small vessels (44% vs 23%, p = 0.002), whereas in vessels >3.0 mm the rate of in-stent restenosis was not significantly different between the 2 groups. In this registry, the clinical variable diabetes and the procedural variable reference vessel size were independent predictors for the occurrence of in-stent restenosis. In these patients, the rate of in-stent restenosis was as high as 45%.     

Clinical and angiographic follow-up after balloon angioplasty with provisional stenting for coronary in-stent restenosis.

The objective of this study was to assess the angiographic and clinical outcome of patients with coronary in-stent restenosis treated with balloon angioplasty with provisional stenting. The study included 375 consecutive patients with in-stent restenosis managed with balloon angioplasty alone or combined with stenting. Clinical events were recorded during a 1-year follow-up period and quantitative analysis was performed on 6-month angiographic data. Of the 373 patients (451 lesions) with a successful procedure, 273 were treated with angioplasty alone and 100 with additional stenting. Target lesion revascularization was required in 23.7% of the patients: 20.7% in patients with angioplasty and 31.0% in patients with stenting. Angiographic restenosis rate was 38.9%: 35.8% in the angioplasty group and 47.7% in the stent group. Stenting in small vessels was associated with a much higher restenosis rate than in larger vessels (65.6% vs. 37.5%, respectively; P = 0.01). Thus, repeat balloon angioplasty with provisional stenting for in-stent restenosis is a safe treatment strategy associated with a relatively favorable long-term outcome. However, the long-term results might be improved if additional stenting is avoided especially in small vessels. Cathet. Cardiovasc. Intervent. 48:151-156, 1999.     

Balloon angioplasty for treatment of in-stent restenosis: feasibility,safety, and efficacy

Sixty patients with 1 or 2 stainless steel intracoronary stents (Cook, Inc.) underwent balloon angioplasty for in-stent restenosis 1.5–13.5 months after stenting. Seventy-five in-stent redilatation procedures were performed. Seventy-three restenotic lesions (97%) were successfully recrossed and dilated, reducing the mean pre-angioplasty intrastent diameter stenosis from 77 ± 12% to 20 ± 11% residual. Although one angioplasty (1.3%) was complicated by non-Q-wave infarction, no angioplasty-related death, acute closure, need for additional stenting, emergent coronary bypass surgery, side branch occlusion, or vascular sequelae occurred. Post-procedure heparin was not used in 83% of successful cases. Most patients were discharged the day following redilatation (mean in-hospital stay 1.7 ± 1.3 days). At 5.4 ± 3.4 months following in-stent angioplasty, 84% of patients were in Canadian Cardiovascular Society class 0 or I. In conclusion, balloon dilatation in this stent for restenosis appears simple and efficacious in the short term, and may entail less risk than dilatation of unprotected coronary vessels. © 1994 Wiley-Liss,Inc..     

Efficacy of Coronary Stenting Versus Balloon Angioplasty in Small Coronary Arteries

Objectives. The goal of this study was to compare the efficacy of elective stent implantation and balloon angioplasty for new lesions in small coronary arteries.Background. Palmaz-Schatz stents have been designed and approved by the Food and Drug Administration for use in coronary arteries with diameters ≥3.0 mm. The efficacy of elective stent placement in smaller vessels has not been determined.Methods. By quantitative coronary angiography, 331 patients in the Stent Restenosis Study (STRESS) I–II were determined to have a reference vessel <3.0 mm in diameter. Of these, 163 patients were randomly assigned to stenting (mean diameter 2.69 ± 0.21 mm), and 168 patients were assigned to angioplasty (mean diameter 2.64 ± 0.24 mm). The primary end point was restenosis, defined as ≥50% diameter stenosis at 6-month follow-up angiography. Clinical event rates at 1 year were assessed.Results. Baseline clinical and angiographic characteristics were similar in the two groups. Procedural success was achieved in 100% of patients assigned to stenting and in 92% of patients assigned to angioplasty (p < 0.001). Abrupt closure within 30 days occurred in 3.6% of patients in both groups. Compared with angioplasty, stenting conferred a significantly larger postprocedural lumen diameter (2.26 vs. 1.80 mm, p < 0.001) and a larger lumen at 6 months (1.54 vs. 1.27 mm, p < 0.001). Restenosis (≥50% diameter stenosis at follow-up) occurred in 34% of patients assigned to stenting and in 55% of patients assigned to angioplasty (p < 0.001). At 1 year, event-free survival was achieved in 78% of the stent group and in 67% of the angioplasty group (p = 0.019).Conclusions. These findings suggest that elective stent placement provides superior angiographic and clinical outcomes than balloon angioplasty in vessels slightly smaller than 3 mm.     

Efficacy and feasibility of helixcision for debulking neointimal hyperplasia for in-stent restenosis.

The Helixcision system is a novel 6 Fr-compatible catheter designed to debulk tissue for in-stent restenosis lesions. The purpose of this study was to determine the efficacy and feasibility of this new system for removing neointimal hyperplasia. A total of 32 in-stent restenosis lesions in 32 patients were treated with helixcision followed by balloon angioplasty. Debulking efficacy was assessed with serial baseline intravascular ultrasound (IVUS) in a subset of 18 lesions. To investigate longitudinal efficacy, 3D analysis was also performed in 12 lesions with automated pullback to calculate average cross-sectional areas across the stent. Prior to procedure, the angiographic reference diameter was 2.60 +/- 0.46 mm. Immediately after procedure, minimum lumen diameter improved from 0.84 +/- 0.33 to 2.19 +/- 0.41 mm (P < 0.0001). IVUS showed a significant reduction of intimal area (IA) after helixcision (from 4.95 +/- 2.04 to 2.88 +/- 1.48 mm(2); P < 0.001). Adjunctive balloon angioplasty further improved lumen area (LA) mainly by stent expansion rather than IA reduction at the site of minimum lumen area. The degrees of IA reduction and LA improvement were closely similar in volumetric analysis. Thirty-day and 6-month clinical follow-up were available in 97% (n = 31) and 72% (n = 23) of the enrolled patients, respectively. At 30-day follow-up, no major adverse cardiac event was reported except for periprocedural CK elevation in two patients (6%). Target legion revascularization within 6 months was performed in six patients (26%). Preliminary results of helixcision indicate that this system is safe and feasible for the treatment of in-stent restenosis. The concordant results between 2D and 3D IVUS analyses suggest that this unique technology can achieve uniform longitudinal debulking throughout the stent. The long-term outcomes appeared to be favorable, considering the relatively diffuse lesion morphology.     

First clinical experience with the premounted balloon-expandable serpentine stent: Acute angiographic and intermediate-term clinical results

The beStent-Artist coronary stent is a newly developed, stainless steel coronary stent with a serpentine tubular design and terminal stent markers, premounted on a semicompliant balloon. During this pilot evaluation we aimed to test the acute clinical and angiographic results, short-term (30 days) and 6-month clinical results. A total of 57 stents were used to treat 43 lesions in 40 patients. Deployment strategy included predilatation, stent deployment, balloon repositioning to match the distal end of the balloon to the distal stent marker, and subsequent 12–14 atm postdilatation. There were two cases of stent dislodgment, but no procedural complications. In four cases, stent recrossing with another balloon was necessary. In two of these cases, distal dissections were observed and treated with another stent. The minimal lumen diameter (MLD) increased from 0.84 ± 0.52 mm at baseline to 2.7 ± 0.62 mm at the end of the procedure (a corresponding decrease in diameter stenosis from 78.6 > 16.4 to 18.2 ± 10.7%). The acute gain was 1.89 ± 0.61mm. No adverse events occurred by 30 days. During six months, 7/40 (18.5%) of patients required target vessel revascularization due to in-stent restenosis. In summary, the premounted beStent-Artist can be delivered and deployed with favorable immediate results and high success rate with favorable long-term recurrent event rates.Cathet. Cardiovasc. Intervent. 46:249–253, 1999. © 1999 Wiley-Liss, Inc.     

Does Carbofilm Coating Affect In‐Stent Intimal Proliferation? A Randomized Trial Comparing Rx Multi‐Link Penta and Tecnic Carbostent™ Stents: SIROCCO Trial

OBJECTIVES:To compare the volume of in-stent neointimal proliferation, assessed by intravascular ultrasound (IVUS), at 6-month follow-up after implantation of a coronary Carbofilm-coated stent (Tecnic Carbostent, Sorin Biomedica Cardio, Saluggia, Italy) versus a conventional 316 L stent (Rx Multi-Link Penta, Abbott Laboratories, Abbott Park, IL). BACKGROUND:Many trials suggest that stent characteristics and coating could be important determinants of restenosis. METHODS:From October 2004 to May 2005, 63 patients were randomized to Tecnic (T, n = 30) or Penta (P, n = 33). The primary end-point was in-stent volume of neointimal hyperplasia (NIH) measured by IVUS at 6 months. The secondary end-points included binary restenosis, minimal luminal diameter (MLD), target lesion revascularization, and major adverse cardiac events. RESULTS:There were no significant differences between T and P as to mean age, male gender, clinical status, complexity of the lesion, lesion length, reference vessel diameter before percutaneous coronary intervention (PCI), MLD pre-PCI, and stent-to-artery ratio. However, MLD poststenting was greater in P group than T group (2.81 +/- 0.45 mm vs. 2.49 +/- 0.33 mm, P < 0.002). At 6 months, angiographic late lumen loss (0.61 +/- 0.51 mm vs. 0.92 +/- 0.61 mm, P < 0.043), in-stent obstruction (25.86 +/- 16.48% vs. 38.33 +/- 19.56%, P = 0.021), and in-stent late loss volume (31.62 +/- 29.75 mm(3) vs. 57.28 +/- 37.16 mm(3), P = 0.016) were significantly lower in T group than in P group. CONCLUSION:Penta stent appears to offer a better deployment and a larger MLD post-PCI than Carbofilm-coated stent. However, a thicker NIH was observed on Penta stent at 6-month follow-up, when compared to Tecnic.