Cutting balloon angioplasty for the prevention of restenosis: results of the Cutting Balloon Global Randomized Trial

The cutting balloon (CB) is a specialized device designed to create discrete longitudinal incisions in the atherosclerotic target coronary segment during balloon inflation. Such controlled dilatation theoretically reduces the force needed to dilate an obstructive lesion compared with standard percutaneous transluminal coronary angioplasty (PTCA). We report a multicenter, randomized trial comparing the incidence of restenosis after CB angioplasty versus conventional balloon angioplasty in 1,238 patients. Six hundred seventeen patients were randomized to CB treatment, and 621 to PTCA. The mean reference vessel diameter was 2.86 +/- 0.49 mm, mean lesion length 8.9 +/- 4.3 mm, and prevalence of diabetes mellitus in patients was 13%. The primary end point, the 6-month binary angiographic restenosis rate, was 31.4% for CB and 30.4% for PTCA (p = 0.75). Acute procedural success, defined as the attainment of <50% diameter stenosis without in-hospital major adverse cardiac events, was 92.9% for CB and 94.7% for PTCA (p = 0.24). Freedom from target vessel revascularization was slightly higher in the CB arm (88.5% vs 84.6%, log-rank p = 0.04). Five coronary perforations occurred in the CB arm only (0.8% vs 0%, p = 0.03). At 270 days, rates of myocardial infarction, death, and total major adverse cardiac events for CB and PTCA were 4.7% versus 2.4% (p = 0.03), 1.3% versus 0.3% (p = 0.06), and 13.6% versus 15.1% (p = 0.34), respectively. In summary, the proposed mechanism of controlled dilatation did not reduce the rate of angiographic restenosis for the CB compared with conventional balloon angioplasty. CB angioplasty should be reserved for difficult lesions in which controlled dilatation is believed to provide a better acute result compared with balloon angioplasty alone.     

Angiographic and histologic consequences of laser thermal angioplasty: comparison with balloon angioplasty

The angiographic and histologic consequences of laser thermal angioplasty were examined and compared with those of conventional balloon angioplasty in an atherosclerotic rabbit iliac artery preparation immediately and 4 weeks after the procedure. Nineteen vessels in 13 rabbits underwent either laser thermal or balloon angioplasty in random order. Laser thermal angioplasty was performed in a total of nine vessels with either a 1.5 or 2.0 mm laser-heated metallic-capped fiber by delivery of 6 or 8 W, respectively, of argon laser energy for 5 sec duration during continuous advancement through the stenosis. Balloon angioplasty was performed in a total of 10 stenotic lesions with a 2.5 mm balloon catheter. The immediate enlargement of the angiographic luminal diameters was similar for both procedures: from 1.0 +/- 0.2 to 1.9 +/- 0.2 mm for laser thermal angioplasty vs 1.0 +/- 0.1 to 2.0 +/- 0.2 mm for balloon angioplasty. However, 4 weeks later the vessels treated with laser thermal angioplasty had less restenosis, defined as a 20% or greater reduction in luminal diameter (two of nine vessels [22%] vs 10 of 10 vessels [100%]; p less than .001), and a significantly larger mean luminal diameter (1.6 +/- 0.5 vs 1.0 +/- 0.4 mm) than those treated with conventional balloon angioplasty (p less than .02). Histologic examination 4 weeks after the procedure revealed less fibrocellular proliferation after laser thermal angioplasty, whereas those vessels treated with balloon angioplasty demonstrated evidence of prior fracture and dissection of the vessel wall with more of a fibrocellular proliferative response.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

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.     

Laser balloon angioplasty: clinical, angiographic and histologic results

Laser balloon angioplasty combines conventional coronary angioplasty with laser energy to transiently heat vascular tissue. Laser balloon angioplasty, was performed in 21 patients (aged 56 +/- 13 years), including 10 patients treated urgently after acute failure of conventional angioplasty and 11 patients treated with elective laser balloon angioplasty. Immediately after conventional angioplasty, laser doses (1 to 10 doses of 205 to 380 J each) were delivered during inflation of the laser balloon to a pressure of 4 atm. Seven (70%) of 10 patients with acute failure of conventional angioplasty were successfully treated with laser balloon angioplasty, but 3 (30%) were unsuccessfully treated with the laser procedure and required emergency coronary artery bypass surgery. In all three failures, the 3 mm laser balloon angioplasty catheter was not the optimal size for the vessel. In the 11 patients treated with elective laser balloon angioplasty (reference diameter 2.94 +/- 0.22 mm), the minimal luminal diameter increased from 0.45 +/- 0.25 to 1.85 +/- 0.46 mm after conventional angioplasty and to 2.44 +/- 0.29 mm after laser balloon angioplasty (p less than 0.001). This corresponded to a decrease in diameter stenosis from 84 +/- 9% before to 35 +/- 16% after conventional angioplasty and to 15 +/- 10% after laser balloon angioplasty (p less than 0.001). There were no instances of myocardial infarction, emergency coronary artery bypass surgery or death and no acute complications related to delivery of laser energy in this group. Follow-up coronary angiography was performed 5.5 +/- 1.1 months after laser balloon angioplasty in 18 patients discharged from the hospital after a successful procedure. Ten patients (56%) had angiographic restenosis, defined as recurrent diameter stenosis greater than 50%. Six patients were subsequently treated by directional coronary atherectomy, which revealed intimal proliferation indistinguishable from that in patients with restenosis after conventional angioplasty. In conclusion, laser balloon angioplasty may be effective in sealing severe coronary dissections and reversing abrupt closure associated with failed conventional angioplasty. After uncomplicated conventional angioplasty, laser balloon angioplasty improves immediate luminal dimensions, but restenosis appears to be mediated by intimal hyperplasia, similar to that seen after conventional angioplasty.     

Influence of residual stenosis in determining restenosis after cutting balloon angioplasty.

The cutting balloon is a new device for coronary angioplasty, which, by the combination of incision and dilatation of the plaque, is believed to minimize arterial wall trauma, the neoproliferative response, and subsequent restenosis. In this study, we sought to determine predictors of the restenosis using this technique. Seventy-seven patients underwent successful coronary angioplasty with cutting balloon alone. In 67 of these patients (87%), we performed a control angiogram at 6-month follow-up. Pre-, post-, and late angiographic results were evaluated by quantitative coronary analysis. Clinical and angiographic variables were correlated with restenosis as a binary variable and a continuous variable (late loss and late minimum luminal diameter). Univariate analysis showed that the immediate postprocedure minimum luminal diameter (MLD) was smaller in the restenotic group (defined as MLD > 50% by quantitative coronary angiography) than in the nonrestenotic group (1.90 +/- 0.47 mm vs. 2.19 +/- 0.56 mm, P < 0.05). In addition, the immediate percentage of stenosis was higher in the restenotic group than in the nonrestenotic group (37% +/- 10% vs. 27% +/- 11%, P < 0. 003). Multivariate analysis identified the immediate postcutting balloon percentage of stenosis as an independent determinant of binary restenosis (P < 0.008). When restenosis was defined as a continuous variable, the immediate postprocedure MLD was an independent predictor of late loss (P < 0.02) and of late MLD (P < 0. 0002). No clinical, preprocedure angiographic, or technical variables tested were associated with restenosis. The degree of postprocedural residual stenosis after cutting balloon angioplasty is predictive of late restenosis.     

A randomized comparison of the value of additional stenting after optimal balloon angioplasty for long coronary lesions: final results of the additional value of NIR stents for treatment of long coronary lesions (ADVANCE) study

OBJECTIVES: We sought to investigate the clinical benefit of additional stent implantation after achieving an optimal result of balloon angioplasty (BA) in long coronary lesions (>20 mm). BACKGROUND: Long coronary lesions are associated with increased early complications and late restenosis after BA. Stenting improves the early outcome, but stent restenosis is also related to both lesion length and stent length. METHODS: A total of 437 patients with a single native lesion 20 to 50 mm in length were included and underwent BA, using long balloons matched to lesion length and vessel diameter (balloon/artery ratio 1.1) to achieve a diameter stenosis (DS) <30% by on-line quantitative coronary angiography (QCA). "Bail-out stenting" was performed for flow-limiting dissections or >50% DS. Patients in whom an optimal BA result was achieved were randomized to additional stenting (using NIR stents) or no stenting. The primary end point was freedom from major adverse cardiac events (MACE) at nine months, and core laboratory QCA was performed on serial angiograms. RESULTS: Bailout stenting was necessary in 149 patients (34%) and was associated with a significantly increased risk of peri-procedural infarction (p < 0.02). Among the 288 randomized patients, the mean lesion length was 27+/-9 mm, and the vessel diameter was 2.78+/-0.52 mm. The procedural success rate was 90% for the 143 patients assigned to BA alone (control group), as compared with 93% in the 145 patients assigned to additional stenting (stent group), which resulted in a superior early minimal lumen diameter (0.54 mm, p < 0.001) and led to reduced angiographic restenosis (27% vs. 42%, p = 0.022). Freedom from MACE at nine months was 77% in both groups. CONCLUSIONS: A strategy of provisional stenting for long coronary lesions led to bailout stenting in one-third of patients, with a threefold increase in peri-procedural infarction. Additional stenting yielded a lower angiographic restenosis rate, but no reduction in MACE at nine months.     

Pullback atherectomy. An alternative procedure in the treatment of coronary stenosis and in-stent restenosis

Optimized directional coronary atherectomy (DCA) has shown significantly superior acute and long-term results compared to conventional balloon angioplasty (BA). Nevertheless DCA has remained a niche application due to specific procedural aspects. The pullback atherectomy catheter (PAC), developed to retrieve atheromatous plaque material, is an alternative debulking device. We report on clinical and angiographic experience in 55 consecutive patients, in whom de novo lesions (35 pts) as well as instent restenoses (17 pts) were treated. The minimal luminal diameter (MLD, mm) rose after PAC and additional BA from 1.06 +/- 0.53 to 2.68 +/- 0.48 and from 1.10 +/- 0.48 to 2.55 +/- 0.49 mm, respectively. A stenosis reduction from 69 +/- 13 to 19 +/- 16 and from 64 +/- 15 to 16 +/- 10%, resp., could be documented. After 3-6 months a complete angiographic follow-up showed MLD values of 2.01 +/- 0.69 and 1.88 +/- 0.61 mm. Nine of 35 (26%) vs. 5 of 17 (29%) pts developed significant restenosis at the treated site (diameter stenoses > 50%). Stent implantation was necessary to achieve an optimal acute angiographic result or due to dissection in 17 vs. 5 pts. Major cardiac events did not occur; however, two restenosed coilstents were removed by PAC. With the pullback atherectomy catheter, a safe and effective alternative device is available for the treatment of coronary lesions and also of in-stent restenosis. Promising short and acceptable long-term results are comparable to those of other debulking procedures.     

The clinical and angiographic evolution of dilated lesions in the proximal segment of the anterior descending coronary artery: stent versus balloon

INTRODUCTION AND OBJECTIVES: The restenosis rate after coronary balloon angioplasty of lesions located in the proximal segment of the left anterior descending coronary artery is high, having been recommended elective stent implantation in order to improve the outcomes. The aim of this study was to analyze clinical, anatomic and angiographic factors related to the short-term outcome after angioplasty of severe lesions in the proximal segment of the left anterior descending artery, with and without stent implantation. MATERIAL AND METHODS: We study 87 patients with severe stenosis (> or = 70%) of the proximal segment of left anterior descending artery treated successfully with angioplasty. In 54 patients (62%) a conventional balloon was used (group A) and in 33 (38%) a stent was implanted (group B). RESULTS: Mean age of patients was 61.9 +/- 12 years old, 74% were male and angioplasty was performed because of unstable angina in 72%. At the end of the follow-up (mean 6.3 +/- 1.5 months), 21% of patients in group B had angina vs 54% in group A (p = 0.03). Group B patients experienced a lower restenosis rate (30% vs. 50%; p = 0.07) and less repeat angioplasty procedures (33% vs 21%; p = NS) than group A. These results were maintained independently of the vessel diameter (< 3 mm or > or = 3 mm) or when an optimal result (< 25%) after balloon angioplasty was obtained. CONCLUSIONS: In our experience, stenting of lesions located in the proximal segment of the left anterior descending artery appears imply a better short-term clinical, angiographic outcome and a lower restenosis rate than lesions treated with conventional balloon angioplasty, even despite an optimal result after balloon angioplasty or independently of the vessel diameter. Future studies will be necessary to confirm these results.     

Randomized comparison of coronary stenting with optimal balloon angioplasty for treatment of lesions in small coronary arteries.

AIMS: Angioplasty of lesions in small coronary arteries remains a significant problem because of the increased risk of restenosis. The aim of this study was to compare the efficacy of elective coronary stent placement and optimal balloon angioplasty in small vessel disease. METHODS: One hundred and twenty patients with lesions in small coronary arteries (de novo, non-ostial lesion and reference diameter <3 mm) were randomly assigned to either balloon angioplasty or elective stent placement (7-cell NIR stent). The primary end-point was restenosis at 6 months follow-up. Optimal balloon angioplasty was defined as diameter stenosis less than or = 30% and the absence of major dissection after the angioplasty, and crossover to stenting was allowed. RESULTS: Baseline clinical and angiographic characteristics were similar in the two groups. Procedure was successful in all patients, and in-hospital events did not occur in any patient. However, 12 patients in the angioplasty group were stented because of suboptimal results or major dissection. Postprocedural lumen diameter was significantly larger in the stent group than in the angioplasty group (2.44 +/- 0.36 mm vs 2.14 +/- 0.36, P<0.05, respectively), but late loss was greater in the stent group (1.12 +/- 0.67 mm vs 0.63 +/- 0.48, P<0.01, respectively). The angiographic restenosis rate was 30.9% in the angioplasty group, and 35.7% in the stent group (P = ns). Clinical follow-up was available in all patients (15.9 +/- 5.7 months) and clinical events during the follow-up were similar in both groups. CONCLUSIONS: These results suggest that optimal balloon angioplasty with provisional stenting may be a reasonable approach for treatment of lesions in small coronary arteries.     

Growth of stenotic lesions after balloon angioplasty for pulmonary artery stenosis after arterial switch operation

Little is known about the growth potential of pulmonary stenotic lesions after balloon angioplasty (BA) in patients after the arterial switch operation. The aim of this study was to evaluate the growth potential of pulmonary stenotic lesions after BA and assess the midterm results of BA for pulmonary artery stenosis after the arterial switch operation. Thirty-seven patients who had undergone 52 procedures had repeat catheterization at a median of 43 years (range 1.2 to 9.3 ys) after BA. To adjust growth-related changes in the size of the pulmonary artery, the stenotic diameter was expressed as a percentage of normal (%N). An immediate increase of 63 +/- 45% in the stenotic diameter and a reduction of 51 +/- 33% in the pressure gradient occurred across the stenotic lesions after BA. The right ventricular-aortic systolic pressure ratio decreased from 0.67 +/- 0.24 to 0.51 +/- 0.12 after BA (p <0.0001). Compared with immediate data after BA, there was no significant change in the growth-adjusted diameter of the stenotic lesions (68 +/- 26 %N after BA vs 65 +/- 25 %N at follow-up, p = 0.08), and the pressure gradient (16 +/- 13 mm Hg after BA vs 20 +/- 21 mm Hg at follow-up, p = 0.10). The ventricular-aortic systolic pressure ratio also did not change (0.51 +/- 0.12 after BA vs 0.50 +/- 0.21 at follow-up, p = 0.57). Restenosis occurred in 3 of 26 vessels (12%) after successful BA in which the diameter increased >50% after BA. Our data suggest that pulmonary stenotic lesions after BA develop with age in growing children after the arterial switch operation, and the efficacy of the BA may be long lasting.     

The safety and feasibility of transradial cutting balloon angioplasty: immediate results,benefits, and limitations

Cutting balloon angioplasty can reduce the restenosis rate more than conventional balloon angioplasty, but is traditionally performed through a femoral artery. However, it is not clear how useful a transradial approach would be for cutting balloon angioplasty. This study was conducted to examine the safety, feasibility, and limitations of transradial as opposed to transfemoral cutting balloon angioplasty. From November 1999 to August 2001, 177 patients underwent cutting balloon coronary angioplasty. We compared the success rate, angiographic results, and complication rates of two groups of patients, those undergoing transradial (168 lesions from 153 patients) and those undergoing transfemoral (24 lesions from 24 patients) cutting balloon angioplasty. In both groups of patients who had similar clinical and target lesion characteristics. the percentage of lesions that required balloon predilation (27.4% vs 29.2%). stenting (7.7% vs 4.2%), and adjunct balloon dilation (28.0% vs 33.3%) due to dissection (35.7% vs 33.3%) or suboptimal results were comparable. Both approaches achieved a 100% primary success rate with similar acute gain (2.02 +/- 0.68 mm vs 1.94 +/- 0.70 mm), residual (luminal) diameter stenosis (19.2 +/- 11.7% vs 17.0 +/- 12.7%). proportion of lesions that achieved TIMI 3 flow (98.8% vs 100%), and clinical success rate (98.8% vs 95.8%). However, patients undergoing transradial cutting balloon angioplasty had earlier ambulation and a significantly shorter hospital stay than those undergoing a transfemoral approach (2.80 +/- 2.67 days vs 4.75 +/- 5.44 days, P = 0.005). We conclude that the transradial approach is a feasible and safe alternative to the transfemoral approach for cutting balloon angioplasty. In addition, it offers patients early ambulation and a short hospital stay.     

Therapeutic implications of in-stent restenosis located at the stent edge. Insights from the restenosis intra-stent balloon angioplasty versus elective stenting (RIBS) randomized trial.

AIMS: In patients with in-stent restenosis (ISR) several anatomic subgroups have been identified. ISR affecting the stent edge (EDG) is a poorly characterised subgroup with undefined therapeutic implications. We sought to determine the implications of ISR affecting the stent EDG. METHODS AND RESULTS: 450 patients included in the "Restenosis Intra-stent: Balloon angioplasty vs elective Stenting" (RIBS) randomized study, were analysed. EDG ISR was predefined in the protocol and the pattern of ISR analysed in a centralized core-lab. Fifty-two patients (12%) had EDG ISR (29 stent group, 23 balloon arm). Patients with EDG ISR had less severe [minimal lumen diameter (MLD) (0.78+/-0.3 vs 0.66+/-0.3 mm, p=0.05)] and shorter lesions (lesion length 10.2+/-6 vs 13.2+/-7 mm, p=0.003). Patients with EDG ISR more frequently required crossover (12% vs 3%, p=0.006) but eventually the immediate angiographic result and the long-term clinical and angiographic outcome was similar to that found in patients without EDG ISR. Patients with EDG ISR treated in the balloon and stent arms had similar baseline characteristics. However, after intervention, the immediate angiographic result was better in the stent arm (MLD 2.79+/-0.4 vs 2.35+/-0.3 mm, p=0.001). This difference persisted at late follow-up: MLD (1.93+/-0.7 vs 1.39+/-0.7 mm, p=0.01), recurrent restenosis (20% vs 50%, p=0.03). In addition, the 1-year event-free survival was significantly better (83% vs 52%, log rank p=0.01; Cox HR 0.28, 95%CI 0.09-0.79) in the stent arm. Moreover, stent implantation was an independent predictor of freedom from target vessel revascularization (HR 0.15, 95%CI 0.03-0.67, p=0.003). CONCLUSIONS: EDG ISR constitutes a specific subgroup with relevant therapeutic implications. In patients with EDG ISR, repeat stent implantation provides better clinical and angiographic outcome than conventional balloon angioplasty.     

Latin American randomized trial of balloon angioplasty vs coronary stenting for small vessels (LASMAL): immediate and long-term results

PURPOSE: To assess the potential role of coronary stent to improved acute success and reduce late restenosis in lesions with reference diameter <2.9 mm using a bare metal stent specifically designed for small coronary vessels. There is controversy on the results among previous studies comparing bare metal stent implantation with conventional balloon percutaneous transluminal coronary angioplasty (PTCA). Differences in baseline characteristics, inclusion and exclusion criteria, and stent design may account for these discrepancies. METHODS: The population of this multicenter, multinational randomized study (LASMAL) consisted of 246 patients undergoing percutaneous coronary intervention of small vessel reference diameter. They were randomized into 2 strategies of percutaneous revascularization: elective primary stent (n = 124) or conventional balloon PTCA with provisional stenting (n = 122) in the presence of acute, threatened closure or flow-limiting dissections. RESULTS: The clinical success rate was significantly better for the stent group (98.3% vs 91.8%; P = 0.038). At 30 days follow-up, requirements of target vessel revascularization (TVR) (6.6% vs 0.8%; P = 0.018) and incidence of major adverse cardiac and cerebrovascular events (MACCE) (9.8% vs 2.4%; P = 0.01) was significantly lower in the stent strategy. Postpercutaneous coronary intervention minimal luminal diameter (MLD) was significantly larger in the stent group (2.3 +/- 0.2 mm vs 2.2 +/- 0.2 mm; P = 0.003). At follow-up, MLD in the stent group was larger than with PTCA (1.7 +/- 0.7 mm vs 1.5 +/- 0.7 mm, respectively; P = 0.035). Net gain was also significantly better with stent strategy (1.1 +/- 0.7 mm vs 0.8 +/- 0.7 mm, respectively; P = 0.002). Stenting resulted in a significant lower angiographic binary restenosis (20% vs 31%; P = 0.02) than PTCA. Furthermore, patients treated with stent were more frequently free from MACCE at 9-month follow-up (death, acute myocardial infarction [AMI], stroke, repeat revascularization procedures) than those treated initially with PTCA (82.2% vs 72% of PTCA, P = 0.046). CONCLUSIONS: The use of a specifically designed bare metal coronary phosphoril choline-coated stent as primary device during percutaneous interventions in small coronary arteries was associated with high procedural success and low in-hospital and 30-day follow-up complications. At long-term follow-up, patients initially treated with stents had lower angiographic restenosis rate and were more frequently free from major adverse cardiac events.     

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     

Effect of intracoronary stenting on intimal dissection after balloon angioplasty: results of quantitative and qualitative coronary analysis

The effect of the Palmaz-Schatz stent on the angiographic appearance and residual luminal stenosis in patients with intimal dissection after balloon angioplasty was evaluated in 84 consecutive patients (90 lesions). Coronary angiography was performed before angioplasty, after conventional angioplasty and after stent implantation. The degree of intimal disruption was assessed as follows: grade 0, no dissection; grade 1, simple dissection (intraluminal linear defect or extraluminal cap extravasation); or grade 2, complex dissection (nonlinear spiral defect or luminal defect with multiple irregular borders). Quantitative coronary analysis of digitized cineangiograms was performed with use of a computerized automatic edge detection algorithm. After balloon angioplasty, 31 (34%) of 90 lesions demonstrated intimal dissection (18 simple, 13 complex). After stent implantation, intimal dissection improved by greater than or equal to 1 grade in 29 (94%) of the 31 lesions with 27 (87%) reduced to grade 0 (that is, no dissection). Dissection grade improved after stenting in 16 (89%) of 18 simple dissections and in all 13 complex dissections. Mean diameter stenosis was 77 +/- 17% before angioplasty, 47 +/- 17% after angioplasty and 14 +/- 10% after stenting (before angioplasty vs. after angioplasty and after angioplasty vs. after stenting, p less than 0.0001). In conclusion, intracoronary stenting is effective in reducing the residual luminal stenosis and in improving the angiographic appearance of intimal dissections after conventional balloon angioplasty.     

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.     

Comparison of Restenosis Rate in Various Devices for Coronary Intervention: Analysis Using Vessel Diameter and Lesion Length

The purpose of this study was to retrospectively compare the restenosis rates related to vessel diameter and lesion length among plain old balloon angioplasty (POBA), cutting balloon (CB) angioplasty, Palmaz-Schatz (PS) stems, Gianturco-Roubin (GR) stents, and directional coronary atherectomy (DCA). In 909 consecutive successfully treated cases, target lesion dimensions were divided into diameters of ± 2.5 mm and lengths of ± 20 mm to compare the restenosis rates obtained by the individual devices. Quantitative angiographic analysis was performed before the procedure, after the procedure, and at FU angiography at a mean FU time of 6 ± 3 months. Restenosis was defined as %DS > 50 at FU angiography. Patients with acute myocardial infarction, chronic total occlusions, left main lesions, ostial as well as venous graft lesions, severe calcifications, severe coronary thrombosis, and bleeding complications were excluded. The overall restenosis rate was 32%, with the CB it was 29%, with the PS stent it was 27%, and with DCA it was 39%. Each of these restenosis rates was significantly lower than that with POBA. The overall restenosis rate with short lesions at small vessels was 35%, while CB angioplasty yielded 29%, being significantly lower compared to that obtained by POBA. The overall restenosis rate with long lesions at small vessels was 53%. With those lesions there was no significant difference among the devices. The overall restenosis rate with short lesions at large vessels was 27%, with CB angioplasty it was 24%, with the PS stent it was 22%, and with DCA it was 25%. These restenosis rates were significantly lower compared to POBA. With long lesions at large vessels, the overall restenosis rate was 44%. In this subgroup, there was again no significant difference among the devices. Our study suggests that restenosis rates with short lesions are lower after CB angioplasty, stenting, and DCA, when compared to POBA. However, in the presence of long lesions, no difference was found among the devices.     

Standalone cutting balloon angioplasty for the treatment of stent-related restenosis: acute results and 3- to 6-month angiographic recurrent restenosis rates.

Despite excellent acute reperfusion results, 20%-30% of patients who undergo coronary stent implantation will develop angiographic restenosis and may require same additional treatments. Cutting Balloon angioplasty (CBA) causes less histological damage outside of the incised area than a regular balloon. However, regular plain old balloon angioplasty is sometimes required before CBA, as is adjunctive stenting and adjunctive angioplasty. These adjunctive strategies may negate the advantages of CBA. There is little data available on CBA as a standalone therapy for stent-related restenosis (SRS). The aim of this study was to evaluate the acute and 3- to 6-month angiographic recurrent restenosis rates following standalone CBA in a patient population treated for SRS and in whom optimal acute results were obtained. In this study, 40 patients with SRS (54 lesions) underwent standalone CBA with optimal acute results. For all lesions, coronary angiography was conducted before and after a standalone CBA procedure for SRS and systematically during 3-6 months to assess recurrent angiographic restenosis rates in the study population. In the study lesions, SRS was either diffuse disease (> 15 mm; 52%) or focal type (48%). Cutting Balloon diameter was 3.20 +/- 0.44 mm and maximal inflation pressure 8.7 +/- 1.2 atm. Ratio of Cutting Balloon diameter to restenotic stent diameter was 0.996 +/- 0.487. Multiple inflations (6 +/- 3 times) were performed. Number of used Cutting Balloon was 1.02 +/- 0.14. Complications were as follows; one non-Q-wave MI (1.9%); 0 death (0%), and 17 repeat target lesion revascularizations (TLRs; 32%). Follow-up coronary angiography (CAG) was not attained for one patient. The angiographic recurrent restenosis rate was 34%, with a higher rate observed when the SRS was diffuse type, 50% vs. 16% for focal-type SRS (P < 0.01). The recurrent restenosis rate for smaller vessels (vessel diameter < or = 3.0 mm) was the same as for larger ones. At follow-up CAG, diffuse-type recurrent restenosis (56%) presented nearly as frequently as that presenting in the original SRS lesions (52%). But four diffuse-type SRS (29%) changed into focal-type recurrent stenosis. In this study, standalone CBA for SRS with optimal acute results was associated with an angiographic restenosis rate of 34%. Diffuse-type disease had a higher recurrent restenosis rate. When CBA achieves acute optimal results, adjunctive stenting or adjunctive PTCA are not always necessary, particularly when the SRS is focal. As a result of CBA, some diffuse-type SRS may change into focal-type recurrent stenosis by the time of the next intervention.     

Influence of inflation pressure and balloon size on the development of intimal hyperplasia after balloon angioplasty. A study in the atherosclerotic rabbit

To evaluate the effect of balloon size and inflation pressure on acute and subsequent outcome following balloon angioplasty (BA), 70 New Zealand White rabbits with bilateral femoral atherosclerosis were assigned to four groups: group 1, oversized balloon, low inflation pressure (n = 35 vessels; balloon size, 3.0 mm/inflation pressure, 5 atm); group 2, oversized balloon, high inflation pressure (n = 36; 3.0 mm/10 atm); group 3, appropriate size, low inflation pressure (n = 17; 2.5 mm/5 atm); and group 4, appropriate size balloon, high inflation pressure (n = 19; 2.5 mm/10 atm). Angiograms were obtained before, 10 minutes after, and 28 days after BA and read by two blinded observers using electronic calipers. The in vivo balloon-to-vessel ratio was measured for each group. There were eight non-BA controls. Rabbits were sacrificed either immediately (n = 34) or at 28 days after BA (n = 36), with the femoral vessels pressure perfused for histologic and morphometric analysis. The latter was performed at 28 days only. Absolute angiographic diameters increased in all groups immediately after BA (p less than 0.01). Acute angiographic success, defined as greater than 20% increase in luminal diameter, was higher using high inflation pressure (group 2, 32/36 [89%] and group 4, 16/19 [84%] vs. group 1, 23/35 [66%] and group 3, 9/17 [53%]; p less than 0.05). A 3.0-mm balloon resulted in significant oversizing irrespective of inflation pressure (balloon-to-vessel ratio, 1.5 +/- 0.1 vs. 1.1 +/- 0.1 to 1, for the 2.5-mm balloon). Vessels exposed to high inflation pressure had a significantly higher incidence of mural thrombus, dissection (p less than 0.01), and medial necrosis versus low pressure (p less than 0.05). At 28 days, the rates of restenosis (defined as greater than 50% loss of initial gain) were 14/20 (70%), 11/16 (69%), 5/10 (50%), and 5/10 (50%) for groups 1 through 4 (p = NS; a trend in favor of the groups using an oversized balloon). There was an increase in the degree of intimal hyperplasia by morphometric analysis in all groups, being most marked in group 2 (oversized balloon and high inflation pressure, 1.7 +/- 0.9 vs. 0.5 +/- 0.2 mm for controls, p less than 0.001). We reached two conclusions. First, all protocols resulted in a significant increase in luminal diameter immediately after angioplasty with the highest success rate in vessels subjected to high pressure dilatation.(ABSTRACT TRUNCATED AT 400 WORDS)