Direct stenting versus predilatation and stenting technique when using paclitaxel-eluting stents

Direct stenting without predilatation is a well-defined, feasible method with bare metal stents. Direct stenting has also been shown to be safe and feasible with drug-eluting stents, however, there is much less evidence with this type of device when compared with bare metal stents. Three hundred and sixty-four coronary lesions in 257 consecutive patients (mean age, 57.4 +/- 9.8 years; 63 women) who had undergone elective stenting either with or without predilatation via a paclitaxel-eluting stent between March 2003 and March 2006 were retrospectively analyzed. Quantitative coronary angiography analysis was compared between the two groups of procedures; stenting with predilatation and direct stenting. All procedures were uneventful. No deaths occurred during the follow-up period. Direct stenting when compared with the predilatation technique, significantly decreased both procedure time (32.1 +/- 17.9 minute versus 41.2 +/- 18.6 minute, P < 0.0001) and fluoroscopy time (10.6 +/- 7.8 minute versus 15.5 +/- 7.6 minute, P < 0.0001). There was no difference in quantitative analysis parameters of coronary angiography during follow-up or the rates of stent thrombosis and restenosis. Direct stenting seems to be as feasible and safe as conventional predilatation and stenting in selected cases. Direct stenting seems to decrease procedural time and radiation exposure without any negative effect on quantitative analysis parameters of coronary angiography with approximately a one-year follow-up period.     

直接冠状动脉内支架置入术治疗急性心肌梗死

目的观察急性心肌梗死(AMI)时行无球囊预扩张直接置入冠状动脉内支架治疗的临床效果.方法对22例AMI患者在发病12小时内,未经球囊预扩张而直接置入冠状动脉内支架.梗死相关血管(IRA)(共22支血管),左前降支12例(54.5%),左回旋支5例(22.7%),右冠状动脉5例(22.7%).心肌梗死溶栓试验(TIMI)血流1级5例(22.7%),2级13例(59.1%),3级4例(18.2%).结果 22例患者共置入22个支架,支架置入后 TIMI血流3级21例(95.5%),2级1例(4.5%),残余狭窄为3.2±2.9%,支架置入成功率100%.住院期间无一例死亡、再次心肌梗死及再次靶病变需重复再通治疗.结论急性心血肌梗死(AMI)时行无球囊预扩张直接置入冠状动脉内支架治疗,成功率高、并发症少,TIMI血流3级达到率高.     

直接支架术治疗左冠状动脉主干病变(附三例报告)

目的评估直接支架术治疗左冠状动脉主干病变的可行性及其术后即刻与远期疗效。方法选择性对３例左主干病变患者进行不预扩左主干的支架直接置入术,其中２例置入ＭｕｌｔｉＬｉｎｋ支架,一例置入ＢｅＳｔｅｎｔ支架。每例均采用高压（１６至２２个大气压）扩张１至２次,持续时间１０至２０秒。结果３例左主干病变直接支架置入术均获成功,术中未发生并发症,术后临床随访６、７及１２个月均无心绞痛症状复发。结论选择性左主干病变直接置入支架术安全、有效、可行。该方法对左主干病变治疗较其他部位及方法可能更为有利,但此需得到大组病例及随机对比试验证实。     

Direct stenting without predilatation: a new approach to coronary intervention

BACKGROUND: Implantation of coronary stents after predilatation is a standard approach in the treatment of most coronary lesions. Stenting without predilatation could be a possible alternative way of treating a certain subset of patients. OBJECTIVE: To identify a group of patients suitable for this optional method, to evaluate their immediate clinical and angiographic outcomes and to test the feasibility and safety of this new therapeutic concept. METHODS: Ninety selected patients with 91 lesions were treated by implantation of coronary stents without predilatation. RESULTS: The mean duration of this procedure was 12.3 +/- 9.1 min and the fluoroscopic time was 3.6 +/- 2.9 min. The stenoses before and after this procedure were 77 +/- 10 and 5 +/- 9%, respectively. Predilatation, postdilatation or implantation of an additional stent was necessary for seven patients. Primary success rate was 92% with an excellent immediate clinical and angiographic outcome. No major complications occurred during direct stenting. CONCLUSION: Direct stenting is feasible using commercially available stents and could be performed for about 20% of patients for whom coronary intervention is indicated. The proper selection of lesions is of crucial importance. Lesions eligible for direct stenting should be without visible calcifications and on vessels without proximal tortuosity. This procedure proved to be safe and successful in this series of coronary interventions.     

Direct stenting without predilatation: influence of stent diameter on the immediate results

The influence of stent diameter in a direct stenting technique was analyzed. We retrospectively identified 987 consecutive lesions in 773 patients in whom direct stenting was attempted. Lesions were divided into two groups: group 1, nominal stent diameter 2.5 mm (237 lesions) and group 2, > or =2.75 mm (n=750). Differences between groups were found in age (64.4 [10.4] vs 62.3 [11] P=.009), female sex (33.2% vs 17%; P<.0001), diabetes (44% vs 33.1%; P=.003), tortuosity (5.4% vs 2.5%; P=.034), reference diameter (2.5 [0.3] vs 3.3 [0.6]; P<.0001) and location in distal segments (44.5% vs 29.4%; P<.0001). Primary deployment (85.5% vs 95.5%; P<.0001) and postdilatation success rates (1.9% vs 4.8%; P=.039) were higher in group 2, with no differences in vessel dissection rate (4.7% vs 4.4%; P=.85). Direct stenting with 2.5 mm stents was associated with a lower success rate than larger stents. Vessel tortuosity, angulation, calcification, lesion severity and distal location were also associated with a higher failure rate. The predictive power of our model was 0.87 (95% CI, 0.82-0.92).     

Impact of operator volume on overall major adverse cardiac events following direct coronary stent implantation versus stenting after predilatation

OBJECTIVES: To determine the impact of operator experience on procedural, clinical and angiographic outcome after (direct) coronary stent implantation.

BACKGROUND: Although for other forms of percutaneous coronary interventions an inverse relationship between operator volume and patient outcomes has been shown, the impact of operator volume on outcome after direct stenting has never been investigated.

METHODS: A retrospective analysis was performed on data from a prospective randomized trial comparing direct stenting with that after predilatation. The trial consisted of 400 patients with stable and unstable angina pectoris and/or myocardial ischemia due to a coronary stenosis of a single native vessel eligible in 1999–2001 for direct stenting. For a single‐center high‐volume clinic (>1500 cases/year), the authors compared the most experienced operators (case load: >4000) with well trained practitioners (case load: 175). One hundred and fifteen patients were identified who were treated by high‐volume and 180 who were treated by medium‐volume operators.

RESULTS: Baseline patient characteristics were evenly distributed among groups. High‐volume, compared with medium‐volume operators, were faster (30.8 versus 42.2 minutes, p?<?0.001), needed less frequent postdilatation (15% versus 24%, p?=?0.06) and had lower fluoroscopy times (7.5 versus 11.2 minutes, p?<?0.001), lower contrast usage (180 versus 228?ml, p?<?0.001), lower procedural costs (€1982 versus €2164, p?=?0.05) and reduced rates of major adverse cardiac and cerebral event (MACCE) at six months (12.2 versus 21.1%, p?=?0.03). The medium‐volume operator group experienced higher angiographic binary restenosis rates after direct stenting compared with stenting after predilatation (31.5 versus 14.9%, p?=?0.005).

CONCLUSIONS: Stenting performed by high‐volume operators resulted in a 50% reduction in MACCE as compared with medium‐volume physicians, which also had twice as much restenosis when using direct stenting. Hence, the more demanding technique of direct stenting should not be performed by unsupervised operators who have not yet completed their training. Furthermore, prolonged training periods and even more intensive supervision by experienced operators seems mandatory. (Int J Cardiovasc Intervent 2004; 1:?5–12)     

Direct stent implantation without predilatation using the multilink stent

The standard coronary stent implantation technique requires routine predilatation of the target lesion with a balloon catheter. In this study, we prospectively studied the feasibility and efficiency of elective coronary stent implantation without predilatation. In 94 patients who presented with various ischemic syndromes, direct implantation of 100 balloon expandable ACS MultiLink stents (7 over-the-wire, 93 rapid exchange) was attempted in 100 coronary lesions selected to have favorable characteristics. The stent crossed the lesion without predilatation in 97 cases (97%) and was successfully deployed in 93 (95.8%). In 4 patients, adjunctive high-pressure postdilatation was necessary to achieve optimal stent expansion. Reference vessel diameter was 3.12 ± 0.77 mm and lesion length 8.8 ± 2.7 mm. Minimal luminal diameter increased from 0.95 ± 0.38 mm to 2.98 ± 0.28 mm and diameter stenosis decreased from 71 ± 11% to 8 ± 11% after stenting. One occlusive dissection was treated by a second stent. There were no major in-hospital complications. At 1 month follow-up, 1 subacute thrombotic occlusion occurred. These results indicate that in a carefully selected coronary lesion subset, elective stent implantation without predilatation can be safely and effectively performed. The long-term results of this approach and possible advantages over the conventional implantation techniques remain unclear and need to be evaluated in further clinical studies.     

Randomized comparison of direct stenting with predilatation followed by stenting on vessel trauma and restenosis

Background

Direct stenting may reduce trauma to the vessel wall, thereby having a positive impact on acute and long-term results. This study evaluated acute vessel trauma and acute and follow-up angiographic and intravascular ultrasound (IVUS) results after direct stenting in comparison to conventional stenting.

Methods

Two hundred forty-nine patients were randomly assigned to direct stenting (n = 124) or stenting after predilatation (n = 125) and were followed up by angiography at 6 ± 2 months. Intracoronary serum endothelin (ET-1) levels were determined distal to the lesion before and after coronary intervention to define vessel trauma, and IVUS was performed before and after intervention and at follow-up to determine induced changes in vessel morphology and intimal hyperplasia in a subgroup of 40 patients.

Results

Feasibility of direct stenting was 91%, with 9% requiring crossover to predilatation. There were no differences between the 2 groups in immediate clinical, angiographic, and intravascular ultrasound results. Intracoronary ET-1 levels increased significantly after intervention, without differences between the 2 groups (increase in ET-1 level, 0.79 ± 1.06 vs 0.96 ± 1.22 fmol/L, P = .206). At 6-month follow-up, angiographic late loss (0.76 ± 0.86 vs 0.69 ± 1.09 mm, P = .788) and restenosis rate (21% vs 20%, P = 1.000) were similar for direct stenting versus conventional stenting, respectively. IVUS demonstrated comparable intimal hyperplasia areas for direct versus conventional stenting (2.0 ± 1.5 mm² vs 2.2 ± 1.6 mm², respectively, P = .243).

Conclusions

Direct stenting is highly feasible and results in similar vessel trauma and change in vessel morphology and acute lumen dimensions compared with stenting after predilatation. Similar acute angiographic and IVUS results persist at 6-month follow-up.     

直接支架术治疗急性冠状动脉综合征

目的本研究评价直接支架术治疗急性冠脉综合征的成功率、病变选择特征及并发症的发生情况.方法 92例急性心梗和不稳定心绞痛患者分为直接支架植入组(32例)和球囊预扩后植入支架组(常规支架植入组,60例),比较两组一般临床资料、靶血管造影特征、操作成功率及并发症.结果直接支架组年龄较常规支架治疗组小(53.14±9.18 vs 64.28±12.36,P<0.01),罪犯血管A型和B1型病变占病变率明显高于常规支架治疗组(79% vs 45%,P<0.01),操作时间直接支架组明显短于常规支架组(19.16±10.28 vs 27.29±7.69,P<0.01),操作成功及并发症发生率两组无明显差异.结论 A型及B1型病变为主的急性冠脉综合征病人,选择直接支架植入术治疗,操作时间短,而成功率及并发症的发生与常规支架治疗组无明显差异.     

直接冠状动脉支架置入术的临床应用及影响因素

目的 探讨选择性直接冠状动脉支架置入术应用的可行性及影响因素。方法 对237例直接支架置入术患的病变特点及临床预后了分析,并与367例预扩张后支架置入术患进行了比较。结果 对筛选的254例患尝试直接支架置入术,237例（93．4％）获成功,其中A型病变52．7％,B1型病变40．1％,17例（6．7％）直接支架置入术失败,其中血管内超声肯定的钙化病变7例,斑块纤维化4例,血管严重成角6例（血管多个弯曲＞45度）。结论 对有经验的心脏介入医生筛选的病变,并避开钙化病变,严重成角血管和长病变,可考虑行直接冠状动脉动脉支架置入术。     

Direct coronary stenting without predilatation: A new therapeutic approach with a special balloon catheter design

Coronary stenting is the primary therapeutic option for many coronary lesions, after the risk of subacute stent thrombosis and bleeding complications has been reduced by antithrombotic regimens and improved stent expansion. It would be desirable to shorten the procedure and the duration of ischemia, and to reduce the risk of ischemic complications during balloon inflation by implanting the stent without previous dilatation of the lesion. This is not possible with the presently available stent delivery systems. This new therapeutic concept was tested with a specially designed balloon catheter, on which slotted-tube stents can be fixed between two conical radiopaque markers. Sixty-one patients elegible for angioplasty underwent direct stent implantation without predilatation. Four procedures were performed for acute myocardial infarction, and two as high-risk PTCA. Single slotted-tube stents (Palmaz-Schatz, NIR, or JOStent) of 14–16-mm length were mounted between the conical radiopaque markers of a special balloon which provided a fixation for the crimped stent. The direct implantation was successful in 80% of all patients, while in 10% the stent could be deployed after predilatation of the lesion. In 10% of lesions a stent could not be implanted with this and any other delivery system. When patients with successful direct stenting were compared with those with indirect (after predilatation) or unsuccessful stent deployment, the presence of angiographically visible calcification was higher in the unsuccessful cases (75% vs. 19%; P < 0.01), and the patients were older (72 ± 8 vs. 61 ± 12 years; P < 0.01). Radiation exposure time was only 8.7 ± 5.1 min as compared with 12.6 ± 7.6 min in conventional stent procedures with predilatation (P < 0.05). The number of balloons used per lesion was also lower than with conventional stenting. Stent dislocation was observed in 5%, and no embolization occurred. The new therapeutic approach of direct stenting without predilatation proved to be a safe and successful procedure in this initial series of coronary angioplasties. When calcified coronary lesions are avoided, it provides a way to rationalize stent implantation with shorter radiation exposure times, fewer balloons, and the potential advantage of fewer ischemic complications as no balloon predilatation is required. Cathet. Cardiovasc. Diagn. 43:245–252, 1998. © 1998 Wiley-Liss, Inc.     

Neointimal tissue proliferation after coronary stent implantation without predilatation

INTRODUCTION AND OBJECTIVES: Intravascular ultrasound (IVUS) studies in conventional stent angioplasty with predilatation have demonstrated that late luminal narrowing is caused by neointimal proliferation. In the present study, we analyzed the degree and distribution of in-stent neointimal proliferation after direct stent implantation and aimed to identify variables that predict a proliferative response. MATERIAL AND METHOD: We studied 45 patients who underwent successful stent implantation without predilatation and 23 patients with similar clinical and angiographic characteristics who underwent conventional stent angioplasty with predilatation. IVUS imaging was performed at 7.85+/-2.81 months. The cross-sectional area was measured at five predetermined points in the stented coronary segment. The inflation pressure used in patients who underwent direct stent implantation was higher than that employed in those who underwent conventional angioplasty with predilatation (13+/-3 atm vs 10+/-2 atm; P=.005). RESULTS: Luminal and stent cross-sectional areas were greater in the group that did not undergo predilatation than in the group that did. Neointimal proliferation in the 5 sections analyzed along the axis of the stent was similar in the 2 groups. There was a weak linear relationship between the amount of plaque outside the stent and neointimal proliferation in both the group that underwent predilatation (r=0.37; P=.005) and the group that did not (r=0.33; P=.005). CONCLUSIONS: As with conventional angioplasty, the neointimal proliferation that occurred after direct stent implantation showed a diffuse homogeneous pattern along the length of the stent. There was a weak correlation between this proliferative response and the amount of plaque outside the stent.     

A randomized study of direct coronary stent delivery compared with stenting after predilatation: The NIR future trial

This randomized trial compared a strategy of direct stenting without predilatation (n = 39) with conventional stenting with predilatation (n = 42) in patients with suitable lesions in native vessels ≥ 2.5‐mm diameter to be covered by either a 9‐ or 16‐mm‐length NIR Primo stent. Equipment cost [mean (median) ± SD] was less in those with direct stenting [$1,199 (979) ± 526] than in those with predilatation [$1,455 (1,285) ± 401, P < 0.001]. There was no significant difference in contrast use or fluoroscopy time. Procedural time was shorter in the direct stenting group. The clinical outcome at 1 month was satisfactory in both groups. In selected patients, a strategy of direct stenting is feasible, costs less, and is quicker to perform than the conventional strategy of stenting following predilatation. Cathet. Cardiovasc. Intervent. 50:377–381, 2000. © 2000 Wiley‐Liss, Inc.     

Long-term follow-up after angiographically successful coronary stenting: direct stent versus conventional stent implantation

The purpose of the study was to compare the impacts of angiographically successful direct stent implantation and conventional stent implantation (stent implantation following predilatation) on long-term major cardiac events. The authors prospectively studied 40 patients who had successful direct stent implantation and 46 patients who had successful conventional stent implantation. The end-point of the study was defined as the occurrence of a major cardiac event, including recurrent angina, acute myocardial infarction, death, and target vessel revascularization. The demographic and clinical characteristics of the study groups were similar, except the indication of percutaneous angioplasty, which was more frequently unstable angina in the conventional stent group (63% vs 38%, P: 0.03). Procedural minor complications were more frequent in conventional stent implantation, and there was also a positive correlation between the conventional stent implantation and procedural minor complications (r = 0.231, P: 0.03), and postprocedural troponin elevation (r = 0.221, P: 0.04). The incidences of major cardiac events including recurrent angina, acute myocardial infarction, death, death or myocardial infarction, and target vessel revascularization were not different between the study groups during the long-term follow-up period (21 +/- 7.1 months for direct stent group and 20 +/- 7.5 months for conventional stent group). Overall end-points occurred in 9 patients (22%) in the direct stent group and in 9 patients (19%) in the conventional stent group. Kaplan-Meier survival analysis showed that there was no difference in event-free survival between the patients treated with direct stent implantation and conventional stent implantation (log-rank: 1.52, P = 0.21). Two-vessel intervention and hypertension were found to be related with long-term major cardiac events (r = 0.214, P: 0.048, r = 0.206, P: 0.04, respectively). In addition to the procedural advantages, direct stent implantation may also provide comparable results with conventional stent implantation concerning the late cardiac events following successful percutaneous coronary angioplasty.     

In-hospital and mid-term adverse clinical outcomes of a direct stenting strategy versus stenting after predilatation for the treatment of coronary artery lesions

Background

Direct stenting without balloon dilatation may reduce procedural costs and duration, and hypothetically, the restenosis rate. This study was designed to compare the in-hospital and long-term outcomes of direct stenting (DS) versus stenting after pre-dilatation (PS) in our routine clinical practice.

Methods

The 1 603 patients treated with stenting for single coronary lesions were enrolled into a prospective registry. Patients with acute myocardial infarction (MI) within the preceding 48 hours, and those with highly calcified lesions, total occlusions, or a lesion in a saphenous graft were excluded. The baseline, angiographic and procedural data, inhospital outcomes and follow-up data were recorded in our database and analysed with appropriate statistical methods.

Results

Eight hundred and fifty-seven patients (53.5%) were treated with DS and 746 (46.5%) underwent PS. In the DS group, lesions were shorter in length, larger in diameter and had lower pre-procedural diameter stenosis. Type C and diffuse lesions and drug-eluting stents were found less often (p < 0.001). With univariate analysis, dissection and non-Q-wave MI occurred less frequently in this group (0.2 and 0.6% vs 3.9 and 2.1%, p < 0.001 and p = 0.01, respectively). However, the cumulative major adverse cardiac events (MACE) did not differ significantly (4.9 vs 4.6%, p = 0.79). With multivariate analysis, direct stenting reduced the risk of dissection (OR = 0.07, 95% CI: 0.01–0.33, but neither the cumulative endpoint of MACE (OR = 1.1, 95% CI = 0.58–2.11, p = 0.7) nor its constructing components were different between the groups.

Conclusions

Direct stenting in the real world has at least similar long-term outcomes in patients treated with stenting after pre-dilatation, and is associated with lower dissection rates.     

A randomized comparison of direct stenting versus stenting with predilatation in native coronary artery disease: results from the multicentric Crosscut study

Stenting without predilatation has become possible due to the availability of a new generation of flexible, low-profile, securely crimped, balloon-expandable stents. This study compared the feasibility, efficacy and cost-effectiveness of direct stenting (DS) to the standard predilatation technique (PS) using the premounted Crossflex LC stent (Cordis Corporation, Miami Lakes, Florida). The study is a randomized prospective multicenter evaluation including 271 patients (140 patients in the DS group and 131 patients in the PS group) with 1 or 2 de novo or restenotic lesions located in native coronary arteries. Procedural success was 98.9% and 98.7% in the DS and PS groups, respectively (p = NS); crossover to PS was required in 22/166 lesions (13.2%) enrolled in the DS group because of inability to cross the target lesion without predilatation. Nonsignificant reductions in procedural time (-10.5%), fluoroscopy time (-4.7%) and amount of contrast (-3.8%) were observed in the DS group in comparison to the PS group. The number of balloons used (-76.6%) and the global cost of the procedure (-18.8%) were significantly lower in the DS group (p < 0.01 for both comparisons). After 6 months, no differences were observed in the restenosis rate between the two groups (22.0% for DS group versus 18.1% for PS group; p = NS) and in the incidence of major adverse clinical events (5.0% for DS group versus 3.0% for PS group; p = NS). Direct stenting is safe and feasible for the treatment of lesions in native coronary arteries and obtains a significant reduction in procedural cost, mainly due to the lower number of balloons used. Clinical and angiographic results at 6 months are comparable to those obtained after a conventional predilatation-stenting strategy.