Coronary stenting or balloon angioplasty for chronic total coronary occlusions: the Taiwan experience (a single-center report)

The authors conducted this study to compare the restenosis and reocclusion rates of primary balloon angioplasty alone versus angioplasty followed by stenting in Taiwanese patients with chronic total occlusions. They also evaluated whether stenting reduced the incidence of restenosis and improved left ventricular function in these patients. From October 1998 to April 2000, a total of 294 patients with chronic total occlusion (Thrombolysis in Myocardial Infarction grade 0 flow) underwent recanalization using balloon angioplasty alone or followed by stent implantation. Of these, only 129 patients were included after procedural failure and patients lost to follow-up; 62 patients were placed in the stent group, while 67 patients were assigned to the percutaneous transluminal coronary angioplasty (PTCA) group. Coronary angiography was performed at baseline and at 6 months follow-up or earlier if angina or objective evidence of ischemia involving the target vessel or other vessels was present. Procedural success was 60%. Minimal lumen diameter increased significantly after stenting: 2.97 +/-0.41 vs 2.24 +/-0.41 (p < 0.001); 60% of patients in the stent group were free of restenosis, whereas only 33% in the PTCA group were free of restenosis at follow-up. Only 1 patient in the stent group had reocclusion, as opposed to 17 (25%) patients in the PTCA group (p < 0.001). The follow-up minimal lumen diameter (MLD) at 6 months was significantly larger in the stent group: 1.80 +/-0.85 mm vs 1.08 +/-0.82 mm (p < 0.001). Left ventricular function improved in the stent group, but not in the PTCA group (58.44 +/-16.58% to 63.60 +/-14.59% [p < 0.001] vs 54.13 +/-15.66% to 54.31 +/-15.60% [p = 0.885]). More patients had angina in the PTCA group than in the stented group 43 vs 29 (p = 0.053). The postprocedural MLD and reference vessel diameter (RVD) were the strong predictors of restenosis and follow-up MLD (p < 0.001). Stenting of chronically occluded arteries significantly reduced the incidence of reocclusion and restenosis, at the same time improving left ventricular function in these patients. This should be the procedure of choice after successful angioplasty of chronically occluded vessels.     

One-Week and Six-Month Angiographic Controls of Stent Implantation After Occlusive and Nonocclusive Dissection During Primary Balloon Angioplasty for Acute Myocardial Infarction

We prospectively assessed in 124 consecutive patients by means of 1-week and 6-month follow-up angiograms the rate of reocclusion and restenosis of coronary stenting with Palmaz-Schatz stents after occlusive and nonocclusive dissection during primary balloon angioplasty for acute myocardial infarction (AMI). Patients were further evaluated clinically at 1 year. Stenting was performed on large (>3.2 mm) coronary arteries for suboptimal results (47%), occlusive (8%), or nonocclusive dissections (45%) after balloon angioplasty. Stents were delivered using the bare stent technique and high pressure inflations (>12 atm). All patients received ticlopidine 250 mg (500 mg if weight was >80 kg) and aspirin 100 mg for 1 month. No patient received warfarin. At 1 week, 6 patients died of cardiogenic shock and 2 of right ventricular infarction. One subacute occlusion occurred at day 14. At 6 months, in 95 patients, the angiographic restenosis rate (>50% diameter stenosis) was 19%. One-year clinical follow-up, available in 55 patients, indicated cardiac death in 5, and repeat revascularization in 3. Thus, coronary stenting on large (>3.2 mm) coronary arteries after occlusive and nonocclusive dissection during primary balloon angioplasty for AMI using bare Palmaz-Schatz stents, high pressures, ticlopidine, and aspirin is safe. Our reocclusion and restenosis rates are similar to those of trials on elective stenting in stable patients.

The reocclusion and restenosis rates of coronary Palmaz-Schatz stenting after occlusive and nonocclusive dissection during primary balloon angioplasty for acute myocardial infarction were assessed in 124 consecutive patients by performing 1-week and 6-month angiographic controls. No reocclusion was noted at 1 week, 1 subacute occlusion occurred at day 14, and the angiographic 6-month restenosis rate was 19%.     

Coronary stenting for acute coronary dissection after coronary angioplasty: Implications of residual dissection

Objectives. The aim of this study was to assess the implications of residual coronary dissections after stenting.Background. Coronary stenting is currently used in selected patients with coronary dissection after angioplasty. However, in some patients the total length of the dissection may not be completely covered with the device.Methods. Forty-two consecutive patients (mean [±SD] age 58 ± 11 years; 39 men, 3 women) undergoing stenting for a major coronary dissection after angioplasty were studied.Results. Thirty (67%) coronary dissections were small (≤15 mm), and 29 (64%) were occlusive (Thrombolysis in Myocardial Infarction [TIMI] flow grade ≤2). In 3 patients, coronary stenting was unable to open large occlusive dissections, but a good angiographic result was obtained in 39 patients (93%). After stenting, 22 of these patients (56%) had no visible residual dissections, and 13 (33%) had small and 4 (10%) had large residual dissections. These residual dissections were stable and did not compromise coronary flow. In a repeat angiogram (24 h later) the stent was patent in all 39 patients. However, two patients experienced a subacute stent occlusion. Of the remaining 37 patients, 36 (97%) had a late angiogram after stenting. Quantitative angiography revealed a reduction in minimal lumen diameter at the stent site (2.6 ± 0.4 vs. 2 ± 0.7 mm, p < 0.05) and a trend toward improvement in vessel diameter at the site of the previous residual dissection (1.7 ± 0.6 vs. 1.9 ± 0.5 mm, p < 0.1). The angiographic image of residual dissection disappeared in all patients. These factors provided a rather smooth angiographic appearance at follow-up. The four patients with large residual dissections after stenting did not have restenosis and were asymptomatic at last visit.Conclusions. Coronary stenting is effective in the management of acute coronary dissections after angioplasty. In this setting, small residual dissections are frequently seen but have a good outcome and disappear at follow-up. Large residual dissections may have a good outcome if coronary flow is not impaired and no residual stenosis is visualized.     

评价冠状动脉内支架对冠状动脉闭塞的临床及血管造影的远期疗效

目的　研究对完全闭塞的血管成功ＰＴＣＡ术后,选择性置入支架的近期及远期临床疗效及血管造影结果。方法４９８例完全血管闭塞的病人中,能成功进行ＰＴＣＡ并置入支架,完成临床及血管造影随访的８４例病人,共放置９８个支架,观察其术后近期及远期临床事件发生率及血管造影的特点。结果　置入支架后,住院期间,５％的病人出现亚急性血管闭塞,无死亡,１例发生心肌梗塞,至半年随访终点时,共有３０％的病人出现再狭窄,血管闭塞率１３％,重施血管再通术２０％,半年后的无心脏事件率为６８％。结论对完全血管闭塞病人,选择性支架术明显降低再狭窄及血管闭塞率,减少临床心脏事件的发生率。     

Safety and Efficacy of Angiographic Guided Elective Palmaz-Schatz Stent Implantation Without Coumadin: Comparison of Stent Implantation and Angioplasty

This study was designed to evaluate the safety and efficacy of routine high-pressure Palmaz-Schatz coronary stenting in patients with symptomatic coronary heart disease with only angiographic guidance without coumadin for poststenting treatment. Intracoronary stenting reduces restenosis rate after coronary angioplasty. High pressure stent deployment with intravascular ultrasound guidance reduces the incidence of stent thrombosis, despite reduction of anticoagulation. However, the feasibility of routine stent implantation with only angiographic guidance and without coumadin for poststenting treatment has not yet been determined. Patients undergoing coronary angioplasty for symptomatic coronary heart disease received stent implantation for abrupt or threatening vessel occlusion, vessel dissection without compromised antegrade blood flow (but at high risk for subacute occlusion and early restenosis), unsatisfactory angioplasty result with > 30% residual stenosis, and elective stent implantation in de novo lesions, restenotic lesions, and lesions in bypass grafts. Quantitative coronary analysis was performed before the procedure, immediately after, and at follow-up 6 ± 1 (SD) months later. This patient group was matched for clinical and angiographic characteristics with those patients who underwent balloon angioplasty during the same period. Patients who underwent coronary stenting had larger net gain (1.95 ± 1.0 vs 1.42 ± 0.9; P < 0.001) resulting in a larger minimal luminal diameter (2.48 ± 1.19 vs 1.78 ± 1.01; P < 0.001) at follow-up as compared with balloon angioplasty. Restenosis, defined as > 50% diameter stenosis at follow-up, occurred in 35.0% in the PTCA group and in 16.1% in the stent group (P < 0.001). Subacute stent thrombosis occured in one patient (0.8%) due to angiographically evident suboptimal stent expansion. Routine coronary high pressure Palmaz-Schatz stenting with angiographie guidance without coumadin for poststenting treatment represents a safe and effective option in patients with symptomatic coronary heart disease without increasing the incidence of (sub)acute stent thrombosis.     

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.     

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.     

Stents in total occlusion for restenosis prevention. The multicentre randomized STOP study. The Israeli Working Group for Interventional Cardiology.

AIMS: This multicentre randomized study set out to evaluate whether coronary stenting improves the results of successful balloon angioplasty for chronic total occlusion. Balloon angioplasty for chronic total occlusion has a high restenosis rate. Several reports have suggested that coronary stenting may decrease the likelihood of restenosis and reocclusion. METHODS AND RESULTS: Patients with total coronary artery occlusions who had an optimal PTCA result were randomized either to no further treatment or additional stent implantation. The AVE microstent was used and all patients were scheduled for a 1-, 3-, and 6-month clinical follow-up. Repeat coronary angiography to assess the rate and pattern of restenosis was performed at 6 months or earlier if clinically indicated. Ninety-six patients were enrolled in this study. The mean age was 59. 3+/-10.3 years and 15 were females. Forty-eight patients were randomized to the stent arm, receiving 52 stents (lengths 18-39 mm). Stent implantation was successful in all and there were no major procedure-related complications. Sixty-nine patients (72%) were restudied after 6 months. The binary restenosis rates (50%), in the PTCA arm were 70.9% with a minimal lumen diameter of 1.01+/-0.79 mm compared to 42.1% in the stent arm with a minimal lumen diameter of 1.63+/-1.02 mm (P=0.034). Reocclusion occurred in 7.9% in the stent group compared to 16.1% in the PTCA group. Restenosis in the PTCA group was focal in 88% of patients and occurred at the point of total obstruction (within 5 mm), compared to diffuse instent restenosis, which occurred in 54% of the patients in the stent group. CONCLUSION: Coronary stenting can significantly decrease the rate of restenosis and reocclusion of total occlusions. As restenosis in the stent group was more diffuse, care should be taken to implant short stents at the site of occlusion.     

Effectiveness of coronary stenting for the treatment of chronic total occlusion in angina pectoris

Percutaneous transluminal balloon angioplasty for chronic total occlusion of a coronary artery is associated with a primary success rate of about 60%.^1–3 This low success rate may be the result of failure in crossing the occlusion, or simply an unsatisfactory angiographic result after balloon inflation. In addition, patients with initial successful results have an increased propensity toward restenosis or reocclusion.^4,5 Stenting the recanalized segment in selected patients could theoretically improve the results of balloon angioplasty alone.⁶ This report evaluates the potential role of adjunctive coronary stenting after initial recanalization in 30 patients with nonacute coronary total occlusion.     

Bailout coronary stenting without anticoagulation or intravascular ultrasound guidance: Acute and six-month angiographic results in a series of 120 consecutive patients

The purpose of this study was to evaluate the feasibility, safety, and efficacy of bailout coronary stenting without anticoagulation or intravascular ultrasound guidance in patients with acute or unequivocal threatened closure after conventional angioplasty. One hundred twenty consecutive patients were prospectively enrolled according to the following criteria: 1) acute or threatened closure after balloon angioplasty; 2) reference vessel diameter ≥ 2.5 mm. All patients after stent implantation were on antiplatelet treatment with aspirin and ticlopidine. Four types of stents were used: Palmaz-Schatz (J&J), Gianturco-Roubin (Cook), Freedom (Global Therapeutics), and Microstent (AVE). Procedural results: a total of 206 stents were implanted in 134 target lesions with a stent deployment success rate of 100%; 44 target lesions were treated with multiple stent implantation; the mean luminal diameter after stenting was 3.14 ± 0.34 mm, and the mean final percent diameter stenosis was −2 ± 10%; the mean balloon to vessel ratio was 1.11 ± 0.15; the mean final pressure inflation was 13.9 ± 2.4 atm; an optimal angiographic result was achieved in 128 lesions (96%). In-hospital results: in-hospital recurrent ischemia occurred in 4 patients (3%); recurrent ischemia resulted directly in death in 1 patient, in nonfatal Q-waves infarction in 2 patients, and in emergency coronary artery surgery in 1 patient. Six-month clinical follow-up results: event free survival rate was 77%; 1 patient had non fatal infarction; the incidence of repeat revascularization procedures was 19%; there were no cardiac deaths. Angiographic follow-up results (follow-up rate 93%): the restenosis or reocclusion rate was 28%. Bailout coronary stenting without chronic anticoagulation treatment or intravascular ultrasound guidance may be considered a highly feasible and safe treatment for acute or threatened closure after failed angioplasty. Cathet. Cardiovasc. Diagn. 41:14–19, 1997. © 1997 Wiley-Liss, Inc.     

Determinants of stent restenosis in chronic coronary occlusions assessed by intracoronary ultrasound

Chronic coronary occlusions have a high recurrence rate that can be reduced by stenting, but this rate remains higher than in nonocclusive lesions. To analyze possible determinants of restenosis in these lesions, intracoronary ultrasound was performed during the recanalization procedure. A chronic coronary occlusion of > or = 1 month duration (range 1 to 33 months; median 3.3) was successfully recanalized in 41 patients. Quantitative ultrasound analysis was performed before and after stent placement, with measurement of the luminal area, the extent of the plaque burden at the site proximal and distal to the occlusion, and within the occlusion and the subsequent stent. The degree of compensatory enlargement of the coronary artery within the occlusion was determined by comparing the average of the total vessel area of the proximal and distal reference with the lesion site. Early reocclusion (subacute stent thrombosis) was observed in 1 patient (2.4%). The angiographic control after 6 months showed restenosis in 9 patients with 1 late reocclusion. The overall recurrence rate was 24%. There was no difference in clinical and procedural characteristics between lesions with restenosis and without restenosis. The latter had a larger minimum stent area (7.59 +/- 1.96 mm2 vs 5.71 +/- 0.90 mm2; p <0.01), and there was evidence for more compensatory vessel enlargement in lesions without restenosis. Thus, intracoronary ultrasound showed that a smaller minimum stent area was a major predictor of angiographic restenosis, and it occurred more often in occlusions without compensatory vessel enlargement.     

Treatment of in-stent restenosis with high speed rotational atherectomy and IVUS guidance in small <3.0 mm vessels

The management of in-stent restenosis remains a subject for debate because no one revascularization option is considered the most appropriate. Since a high restenosis rate still occurs after repeat balloon angioplasty, new techniques are attempted in order to reduce this rate. A combination of high speed rotational atherectomy (HSRA) and adjunctive balloon angioplasty is likely to achieve good results. In small (<3.0 mm diameter) vessels, the risk of interaction between the burr and the stent increases. We thus used intravascular ultrasound (IVUS) guidance in the treatment of in-stent restenosis with HSRA in small <3.0 mm small diameter vessels. Nine patients with in-stent restenosis in small vessels were referred for repeat angioplasty. Initial IVUS examination was used to assess the minimal stent struts diameter and to guide the burr size selection. A combination of HSRA and additional balloon angioplasty was performed under IVUS and angiographic guidance. Mean angiographic reference diameter was 2.25 ± 0.35 mm and mean stent struts diameter was 2.38 ± 0.20 mm. Burr size was selected ∼0.5 mm smaller than stent struts diameter and ranged from 1.75 to 2.5 mm, with a 0.88 ± 0.12 mean burr/artery ratio (range 0.71, 1.08). In two patients, a second larger burr was used. In 4/9 patients, the burr size chosen under IVUS guidance was close to angiographic MLD at stent implantation and thus larger than what would be used without IVUS guidance. Additional balloon angioplasty was decided in all cases, using a 1.1 ± 0.15 balloon/artery ratio. No complication occurred. Mean relative gain in minimal lumen diameter (MLD) was 94 ± 90% after HSRA and 54 ± 34% after balloon angioplasty (total relative gain 180 ± 100%). IVUS guidance allowed safe management of in-stent restenosis in small vessels using combination of HSRA and balloon angioplasty. Long-term follow-up and comparison with other techniques are necessary to assess whether this technique should be used routinely. Cathet. Cardiovasc. Diagn. 44:77–82, 1998. © 1998 Wiley-Liss, Inc.     

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.     

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.     

Initial clinical experience with the new EBI (BARD-XT) flexible coronary stent: Acute results and follow-up

The EBI (BARD-XT, C.R. Bard, Murray Hill, NJ) stent is a new radiopaque balloon expandable coronary stent with high resistance to external radial forces. It does not shorten significantly with expansion and allows stent implantation in bifurcation lesions. A total of 28 EBI stents were implanted in 23 lesions in 21 patients. Indications for stent implantation were acute closure in 1, threatened closure in 15, and electively in 7 lesions. In 2 cases, the lesion involved a bifurcation where a stent was implanted in both vessels. All patients received aspirin and ticlopidine. No anticoagulant therapy was given. The stenting procedure was successful in 22 of 23 lesions. No complications occurred with the exception of 1 patient with a thrombotic reocclusion within 1 hr after stent implantation and 1 patient with a temporary occlusion of a side branch. The mean minimal luminal diameter (MLD) increased from 0.74 ± 0.46 mm before balloon dilatation to 1.27 ± 0.62 mm before stent implantation and 2.32 ± 0.57 mm after stent implantation. Percent stenosis decreased from 71 ± 19% before angioplasty to 46 ± 25% after angioplasty to 5 ± 8% after stent implantation. MLD at the time of follow-up angiography after 4 months was 1.98 ± 0.77 mm and percent stenosis was 26 ± 21%. Restenosis of more than 50% occurred in 2 lesions. In these lesions, a second percutaneous transluminal coronary angioplasty was performed. Advantages of this stent are its flexibility together with an acceptable radial strength as well as enabling radiopacity without obscuring the arterial lumen. Stenting of bifurcation lesions is possible. Cathet. Cardiovasc. Diagn. 43:159–162, 1998. © 1998 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.     

Direct Stenting Application in Acute Coronary Syndromes

Although published reports about direct stenting in treating stable coronary artery disease have been increasing, the number of studies regarding direct stenting for acute coronary syndrome is limited. In this study, we report immediate and mid-term results of patients who underwent direct stenting for treating acute coronary syndrome. The average lesion length was 12.1 ± 3.3 mm. The preprocedure average minimum luminal diameter (MLD) was 0.67 ± 0.33 mm. Post-procedure average MLD was 3.19 ± 0.42 mm. In 35 of the 36 cases (97%), the stent delivery system crossed the lesion and was implanted successfully. In one case, an acute occlusion, which was treated by percutaneous transluminal coronary angioplasty (PTCA), occurred. The rate of procedure success was 94%. The amount of contrast media used was 88 ± 16 ml and duration of radiation exposure was 9 ± 2 min. Control angiography was performed in 28 out of 35 cases (80%). Seven patients who did not consent to coronary angiography were asymptomatic and had negative exercise tests. MLD was 2.66 ± 0.53 mm after a six month follow-up. The clinical and angiographic restenosis rates were 14% (5/35) and 18% (5/28), respectively. Three of the five cases of restenosis were treated by excimer laser coronary angioplasty (ELCA) and PTCA and the other two were treated with PTCA only. Target lesion revascularization rate was 14% (5/35). The rate of major adverse cardiac events (MACE) was 17% (6/35) after the six month follow-up period. Based on these results, we conclude that direct stenting for acute coronary syndrome is safe if the lesion is determined to be suitable.     

Revascularization of chronic coronary artery occlusions using laser debulking followed by stent implantation

OBJECTIVE: Chronic total occlusions are considered unfavourable for percutaneous balloon angioplasty because of the low rate of success and the high rate of restenosis. Stent implantation after recanalization of chronic total occlusions has been shown to reduce restenosis and reocclusion rates compared with balloon angioplasty in recently published randomized trials. However, it is not well known whether laser debulking before stent implantation would improve the benefit of stenting in chronic total occlusions. METHODS AND RESULTS: We analysed procedural and long-term clinical and angiographic follow-up results of 48 patients who underwent laser angioplasty followed by stent implantation for chronic total occlusions. The procedure was completed successfully in 46 patients (95.8%) in whom the lesion was crossed with a guidewire. We implanted 51 stents in 46 chronic total occlusions following laser debulking. During in-hospital follow-up 1 patient (2.1%) had Q wave, and 4 patients (8.7%) had non-Q wave myocardial infarction. Nine patients (19.5%) had repeat angioplasty for restenosis and one (2.1%) underwent coronary bypass operation at 6 months follow-up. Death or Q wave myocardial infarction did not occur during 6-month follow-up. Thirty-nine patients (85%) had angiographic follow-up at 6 months, and stent restenosis was found in 17 (44%) patients. CONCLUSION: These high rates of restenosis and target vessel revascularization in our study suggest that laser debulking before stent implantation does not improve clinical and angiogragic outcomes in chronic total occlusions.     

Optimal coronary balloon angioplasty with provisional stenting versus primary stent (OCBAS): Immediate and long-term follow-up results

Objective. This study sought to compare two strategies of revascularization in patients obtaining a good immediate angiographic result after percutaneous transluminal coronary angioplasty (PTCA): elective stenting versus optimal PTCA. A good immediate angiographic result with provisional stenting was considered to occur only if early loss in minimal luminal diameter (MLD) was documented at 30 min post-PTCA angiography.Background. Coronary stenting reduces restenosis in lesions exhibiting early deterioration (>0.3 mm) in MLD within the first 24 hours (early loss) after successful PTCA. Lesions with no early loss after PTCA have a low restenosis rate.Methods. To compare angiographic restenosis and target vessel revascularization (TVR) of lesions treated with coronary stenting versus those treated with optimal PTCA, 116 patients were randomized to stent (n = 57) or to optimal PTCA (n = 59). After randomization in the PTCA group, 13.5% of the patients crossed over to stent due to early loss (provisional stenting).Results. Baseline demographic and angiographic characteristics were similar in both groups of patients. At 7.6 months, 96.6% of the entire population had a follow-up angiographic study: 98.2% in the stent and 94.9% in the PTCA group. Immediate and follow-up angiographic data showed that acute gain was significantly higher in the stent than in the PTCA group (1.95 vs. 1.5 mm; p < 0.03). However, late loss was significantly higher in the stent than the PTCA group (0.63 ± 0.59 vs. 0.26 ± 0.44, respectively; p = 0.01). Hence, net gain with both techniques was similar (1.32 ± 0.3 vs. 1.24 ± 0.29 mm for the stent and the PTCA groups, respectively; p = NS). Angiographic restenosis rate at follow-up (19.2% in stent vs. 16.4% in PTCA; p = NS) and TVR (17.5% in stent vs. 13.5% in PTCA; p = NS) were similar. Furthermore, event-free survival was 80.8% in the stent versus 83.1% in the PTCA group (p = NS). Overall costs (hospital and follow-up) were US $591,740 in the stent versus US $398,480 in the PTCA group (p < 0.02).Conclusions. The strategy of PTCA with delay angiogram and provisional stent if early loss occurs had similar restenosis rate and TVR, but lower cost than primary stenting after PTCA.     

Randomized comparison of balloon angioplasty versus silicon carbon-coated stent implantation for de novo lesions in small coronary arteries

The objectives of this study were to compare the short- and long-term clinical and angiographic outcomes of conventional balloon angioplasty versus elective silicon carbide-coated stent implantation in de novo lesions in small coronary arteries (<3.0 mm). Angioplasty of small coronary arteries is associated with high restenosis rates. The beneficial effects of stent implantation on restenosis rates and clinical outcomes have been suggested by observational studies. However, randomized trials comparing balloon angioplasty with stenting show conflicting results. A total of 496 patients with a de novo stenosis in a coronary artery, with a diameter between 2.0 and 3.0 mm, were randomly assigned to balloon angioplasty (n = 246) or stent implantation (n = 250). One-year clinical and 6-month angiographic follow-up were performed. Baseline characteristics were similar for the 2 groups, with 16% having diabetes and 77% complex lesions (type B or C). Crossover to stents occurred in 29% of patients randomized to balloon angioplasty. At 6 months, angiographic restenosis rates were 25% versus 21% for the angioplasty and stent groups, respectively (p = NS). One-year clinical follow-up showed no difference in occurrence of major adverse cardiac events. Elective silicon carbon-coated stent implantation in small coronary arteries is safe and effective, with no beneficial effect on angiographic or clinical outcome compared with balloon angioplasty with provisional stenting.