Stent implantation without predilation in patients with a single, noncalcified coronary artery lesion

The OPTIMIZE randomized trial to assess safety and efficacy of the Svelte IDS and RX Sirolimus-eluting coronary stent Systems for the Treatment of atherosclerotic lesions: Trial design and rationale

Coronary stenting without angioplasty pretreatment (direct stenting) may simplify procedures in appropriate lesions. Direct stenting is facilitated by smaller profile coronary stent platforms. The present study was designed for regulatory approval of a novel drug-eluting coronary stent and incorporates both randomized comparison for non-inferiority to an approved predicate device as well as a nested evaluation of subjects eligible for direct stenting. STUDY DESIGN AND OBJECTIVES: Prospective, single-blind, randomized, active-control, multi-center study designed to assess the safety and efficacy of the novel Svelte sirolimus-eluting stent (SES) systems. A total of 1630 subjects with up to 3 target lesions will be randomized 1:1 to the Svelte SES versus either the Xience or Promus everolimus-eluting stents (control). Randomization will be stratified by whether or not a direct stenting strategy is planned by the investigator. The primary endpoint is target lesion failure (TLF) at 12 months post index procedure, defined as cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization, and the primary analysis is a non-inferiority test with a non-inferiority margin of 3.58%. Secondary clinical endpoints include individual components of TLF, stent thrombosis and measures of procedural resource utilization including contrast administration, fluoroscopy exposure and procedural resource utilization as well as costs. CONCLUSION: The OPTMIZE Trial will evaluate the safety, efficacy and clinical value of the novel Svelte SES in subjects with up to 3 lesions, and will provide a comparison of direct stenting between randomized devices.

Microcatheter-Facilitated Primary Angioplasty in ST-Segment Elevation Myocardial Infarction

BACKGROUND

Direct stenting is the best method for achieving reperfusion in primary percutaneous coronary intervention (PPCI). We hypothesized that the use of a microcatheter (MC) during PPCI when Thrombolysis in Myocardial Infarction (TIMI) flow ≤ 1 after wire crossing would allow visualization of the downstream artery with an optimal TIMI 3 flow at the end of the procedure.

METHODS

In this pilot study, PPCI patients with TIMI flow ≤ 1 after wire crossing formed the MC group (n = 60); the MC was positioned in the distal part of the culprit artery and a small amount of contrast was injected through it to determine stent size and length to treat the culprit lesion. The MC group was compared with previous consecutive patients treated using standard PPCI (n = 94; similar characteristics except for the rate of previous percutaneous coronary intervention).

RESULTS

In the MC group, downstream arteries were visualized in 98% of cases and direct stenting was achieved in 72% vs 31% (P < 0.0001). Final TIMI 3 flow was similar in both groups (97%). There was less manual thrombectomy (20% vs 63%; P < 0.001) and bailout glycoprotein IIb/IIIa inhibitor use (6.7% vs 29.8%; P < 0.002). The incidence of major adverse events (death, shock, severe arrhythmia) and left ventricular ejection fraction were similar. The peak cardiac enzymes level was significantly lower in the MC group.

CONCLUSIONS

The MC strategy appears feasible and safe. It could allow exploring new strategies on the basis of more systematic direct stenting and prepared reperfusion by injecting drugs through the MC before reperfusion.

The independent value of a direct stenting strategy on early and late clinical outcomes in patients undergoing elective percutaneous coronary intervention

OBJECTIVES

This study aimed to compare percutaneous coronary intervention (PCI) with direct stenting (DS) to balloon predilatation (PD) for patients undergoing elective PCI to determine whether there is an independent value for DS with regard to clinical outcomes.

BACKGROUND

The safety of PCI with DS has been established, but the independent advantages of this technique are not entirely clear.

METHODS

Patients undergoing elective PCI from January 2000 to December 2010 were included. The postprocedural and late clinical outcomes of 444 patients who underwent PCI with DS were compared with a propensity-matched population of 444 subjects treated with PD.

RESULTS

The two groups were well matched to 27 baseline clinical, procedural, and angiographic characteristics, thus allowing for a more accurate evaluation of the independent value of the stenting technique. Intravascular ultrasound was used in more than 60% of interventions in both groups. PCI performed with PD were longer (DS 45 ± 19.28 vs. PD 56 ± 23.72 minutes, P = 0.001), used more contrast (DS 154 ± 65.88 vs. PD 186 ± 92.84 cc, P = 0.001), and more frequently used balloon postdilation (DS 0% vs. PD 27.3%, P = 0.001). The incidence of periprocedural myocardial infarction (PPMI) was similar between DS- and PD patients (5.3% vs. 5.4%, P = 0.91). Likewise, the 1-year rates of major adverse cardiac events (8.4% vs. 6.3%, P = 0.25), target lesion revascularization (3.9% vs. 2.5%, P = 0.24), and definite stent thrombosis (0.2% vs. 0.9%, P = 0.37) were similar among DS and PD patients, respectively.

CONCLUSION

During elective PCI, DS decreases overall procedure time and resource utilization, but fails to reveal an independent clinical advantage as there is no demonstrable benefit in regard to the incidence of PPMI, restenosis, or overall clinical outcomes up to 1-year of follow-up.

The SIRIUS-DIRECT trial: A multi-center study of direct stenting using the sirolimus-eluting stent in patients with de novo native coronary artery lesions

OBJECTIVE

To assess the safety and efficacy of direct stenting using the sirolimus-eluting BX Velocitytrade mark stent in patients with coronary lesions.

BACKGROUND

Although direct coronary stenting has become a widespread practice, there have been no systematic assessments of direct stenting with drug-eluting stents.

METHODS

Total of 225 patients with identical inclusion and exclusion criteria as the original SIRIUS trial were enrolled in this prospective single-arm study. They were compared in a no-inferiority design with 412 similar patients from the SIRIUS trial who had sirolimus-eluting stents deployed after predilatation and were preassigned to angiographic follow-up evaluation.

RESULTS

Direct stenting was successful in 85.8% of the patients. Compared with the predilatation group, direct stenting was associated with shorter median procedure duration (33 min vs. 45 min, P < 0.001). Angiographic follow-up at 8 months revealed similar late loss (in-stent-0.19 +/- 0.47 mm vs. 0.17 +/- 0.44 mm, and in-lesion-0.23 +/- 0.41 mm vs. 0.24 +/- 0.47 mm) and similar frequency of binary restenosis (in-stent-4.6% vs. 3.2% and in-lesion-6.1% vs. 8.9%) between the two treatment strategies. However, stent-edge restenosis was lower with direct stenting than in the predilatation control group (2.1% vs. 6.9%, P = 0.02). At 12-months, there were no significant differences in target lesion revascularization (3.7% vs. 5.1%, P = ns) or composite major adverse cardiac events (7.0% vs. 8.3%, P = ns).

CONCLUSIONS

In patients similar to those treated in the SIRIUS trial, direct stenting using sirolimus-eluting stents achieves excellent short- and long-term clinical and angiographic results with shorter procedure time and less frequent stent edge restenosis compared with predilation stent implantation techniques.

Comparison of the efficacy of direct coronary stenting with sirolimus-eluting stents versus stenting with predilation by intravascular ultrasound imaging (from the DIRECT trial)

A direct coronary stenting technique using drug-eluting stents may decrease drug-eluting stent efficacy due to possible damage to the surface coating of the stent. The DIRECT is a multicenter, prospective, nonrandomized trial designed to evaluate the direct stenting strategy for the sirolimus-eluting Bx-Velocity stent compared with the historical control (SIRIUS trial, stenting with predilation). Volumetric and cross-sectional intravascular ultrasound analyses at 8-month follow-up were performed in 115 patients (DIRECT n= 64, control n = 51). Patient and lesion characteristics were comparable between groups. The DIRECT group achieved an equivalent uniform expansion index, defined as minimum stent area/maximum stent area x 100, compared with the control group (65.9 +/- 11.7 vs 63.1 +/- 12.7, p = NS). At 8-month follow-up, vessel, stent, lumen, and neointimal volume index (volume in cubic millimeters/length in millimeters) and percent neointimal volume were similar between the DIRECT and control groups (vessel volume index 13.9 +/- 4.40 vs 15.0 +/- 3.83; stent volume index 6.83 +/- 2.02 vs 6.94 +/- 2.04; lumen volume index 6.71 +/- 2.04 vs 6.81 +/- 2.07; neointimal volume index 0.14 +/- 0.24 vs 0.16 +/- 0.23; percent neointimal volume 3.73 +/- 6.97 vs 3.14 +/- 5.32, p = NS for all). In addition, in-stent neointimal hyperplasia distribution was significantly smaller near the distal stent edge (0.22 vs 0.098 mm(3)/mm, p = 0.01 for an average neointimal volume index within 3 mm from the distal stent edge). In conclusion, direct coronary stenting with the sirolimus-eluting Bx-Velocity stent is equally effective in terms of uniform stent expansion and long-term quantitative intravascular ultrasound results compared with conventional stenting using predilation. This strategy appears to be associated with less neointimal hyperplasia near the distal stent edge.

Effectiveness of "direct" stenting without balloon predilatation (from the Multilink Tetra Randomised European Direct Stent Study [TRENDS])

The purpose of the TRENDS trial was to assess the safety, efficacy, and cost effectiveness of a no-predilatation ("direct") stenting strategy in the treatment of de novo native coronary artery lesions using the Multilink Tetra stent system. In this multicenter, prospective clinical trial, 1,000 patients were randomized (1:1) to receive a Multilink Tetra stent with or without balloon predilatation. The primary outcome measurement was major adverse cardiac events (MACEs) at 30 days; secondary end points included resource utilization (including procedural duration, equipment use, and length of hospital stay), MACEs, and angiographic binary restenosis at 180 days. In the predilatation group, 587 stents were implanted in 499 patients; in the direct group, 579 stents were implanted in 501 patients. In the direct group, stents in 31 lesions (5.7%) required predilatation and multivariate analysis identified calcification (odds ratio 5.81), angulation (odds ratio 5.34), and preprocedural minimal lumen diameter (odds ratio 0.09) as direct stenting failure. MACEs at 30 days were similar in the 2 groups, with 19 (3.8%) in the predilatation group and 13 (2.6%) in the direct group (p = NS). Resource utilization favored the direct strategy, with decreases in balloon use, contrast media, and procedure time, but a larger number of guiding catheters was used. The 180-day MACE rate of 9.8% in the direct group was not significantly less than the rate of 10.8% in the predilatation group (p = NS). Quantitative angiographic follow-up at 6 months demonstrated in-stent binary restenotic rates of 11.4% in the predilatation group (late loss 0.88 +/- 0.53 mm) and 12.3% in the direct group (late loss 0.82 +/- 0.51 mm, p = NS) and in-segment restenosis rates of 12.2% and 13.4%, respectively (p = NS). In conclusion, a direct stenting strategy with the Multilink Tetra stent was feasible and safe in 94% of lesions and associated with lower resource utilization compared with a predilatation approach. Direct stenting was not associated with significantly lower MACE and target lesion revascularization rates and had no effect on late angiographic follow-up, with similar late loss reflecting an identical biologic response to bare metal stent placement.

Early results of direct coronary stenting in consecutive patients when multivessel, complex, long lesions, and small vessels are included

BACKGROUND

Direct coronary stenting is the dominant technique for coronary stent implantation, but previous randomized studies have strongly selected lesions to treat. To evaluate whether the results can be generalized to routine clinical practice, all consecutive patients with direct stenting in 15 hospitals were entered into a prospective registry. Single vessels and simple lesions, but also multivessel, complex and long lesions, and small vessels size (< or =2.5 mm) were included. Immediately results as well as clinical events within 30 days after the procedure were evaluated.

METHODS

Between April and November 2002, direct coronary stenting was performed in 452 consecutive patients (559 lesions) at 15 sites. Stents edge-protected by "sleeves" (SOX technology, NIR Stent, Boston Scientific) or with short transitional edge protection (STEP technology, Multilink Stents, Guidant) were selected to minimize vessel injury outside the stent edges during balloon inflation/deployment.

RESULTS

Stents were successfully implanted in 96% of lesions. Lesions were multivessel in 27%, type B2-C in 40%, very angulated in 28%, calcified in 18%, and longer than 20 mm in 10% of patients. Vessels were smaller than < or =2.5 mm in 27% of patients. Direct coronary stenting was unsuccessful in 25 lesions (24 patients) characterized by more unstable angina (p=0.07), more treated lesions (p<0.01), and more distal locations (p=0.001). Dissection occurred in 6% of patients, and one stent embolised. The 30-day follow-up period included 1 death (due to subacute occlusion), 11 (2.4%) acute myocardial infarctions (8 non-Q wave), and one stroke (following carotid surgery).

CONCLUSIONS

Direct coronary stenting yielded excellent results at 30 days although some expanded indications will be included.

Direct stenting with sirolimus-eluting stents

The sirolimus-eluting stent has been studied extensively in randomized controlled trials of patients with native de novo coronary lesions. Lesion predilation before stent placement has been the predominant implantation strategy in these trials. Direct implantation of the sirolimus-eluting stent without lesion predilation has been undertaken at the investigators' discretion in certain trials as well as in patients enrolled in a post-marketing surveillance registry, and was the intended implantation strategy in the DIRECT trial. Comparisons with patients receiving sirolimus-eluting stents after lesion predilation in the trials and the registry were all confounded by imbalances in patient, lesion, and/or procedural characteristics and point to the highly selective nature of the direct-stenting strategy. At present, direct implantation of the sirolimus-eluting stent appears to be safe and as effective as conventional (predilated) stenting, provided that the targeted coronary lesion is amenable to the direct approach. Since a randomized trial of implantation strategies is lacking, there is no conclusive evidence as to the hypothesized superiority of direct over predilated stenting in suitable coronary lesions.

Angiographic and volumetric intravascular ultrasound comparison between direct sirolimus-eluting stent implantation versus predilation

Conventional sirolimus-eluting stent (SES) implantation typically follows balloon predilation. The impact of direct SES implantation on in-stent neointimal hyperplasia and the adjacent reference segments has not been evaluated. The aim of this study was to analyze direct and conventional SES implantation techniques by angiography and serial intravascular ultrasound. Fifty-three patients with single de novo coronary lesions underwent successful conventional (n = 26) and direct (n = 27) SES implantation. At 6-month follow-up, similar in-stent late luminal loss and decreased neointimal hyperplasia volume were seen in the 2 groups, preserving the luminal dimensions at the edges of the stents.

Direct coronary stenting compared with stenting after predilatation is feasible, safe, and more cost-effective in selected patients: evidence to date indicating similar late outcomes

OBJECTIVES

To review the currently available data from studies assessing feasibility, safety, clinical outcome and cost-effectiveness of direct stenting.

BACKGROUND

With technical advances of stent designs and their delivery systems a new strategy has become increasingly popular: direct stent implantation without prior balloon dilatation.

METHODS

The Medline database was searched from January 1996 to March 2001 for clinical trials investigating direct stenting using the index terms direct stenting, coronary intervention, percutaneous transluminal coronary angioplasty (PTCA), PCI, angioplasty and ischemic heart disease. Studies were chosen based on the number of patients involved and endpoints mentioned. Data not yet published but presented at recent international meetings were also included. A comparison between direct stenting and stenting with predilatation was performed using for the latter results of the randomized trials supplemented with Benestent II data.

RESULTS

At least 26 studies have investigated direct stenting, showing high primary and final success rates with few complications. Direct stenting provides a way to reduce costs, shorten procedural and fluoroscopy times and lower material consumption. Immediate and long-term clinical outcomes appear to be similar to stenting with predilatation. Preliminary results of large randomized trials with angiographic follow-up indicate that restenosis rates are similar to those of conventional stenting strategies.

CONCLUSIONS

Direct stenting compared with stenting with predilatation is feasible, safe, faster and more cost-effective. The evidence to date shows similar late outcomes.

Direct Stent Implantation Using the EXPRESStm Coronary Stent System:. Results of a Multi-Center Feasibility Study

The aim of this prospective, multicenter, single arm study was to assess the safety and feasibility of EXPRESS Coronary Stent implantation in native coronary arteries without balloon predilatation. Forty-two patients with de novo or restenotic lesions were enrolled, of which 38 were eligible for analysis. The coronary lesions were predominantly complex, occurring in arteries with a mean reference diameter of 2.80 +/- 0.49 mm. Technical and procedural success were achieved in 89.5% and 84% of the cases respectively. The mean minimal lumen diameter increased from 1.08 +/- 0.26 mm to 2.55 +/- 0.44 mm and diameter stenosis decreased from 61 +/- 7% to 13 +/- 8%. The primary endpoint of major adverse cardiac events at 30 days was 2.6% and was limited to only one event (target vessel revascularization, nontarget lesion). No other MACE were observed during the three-month follow-up period. Based on the findings of this study, direct stenting with the EXPRESS Stent appears feasible and is well tolerated.

Nonionic low-osmolar contrast media have no impact on major adverse cardiac events in patients undergoing coronary stenting with appropriate antiplatelet therapy

The aim of this study was to assess the impact of two nonionic low-osmolar monomers (iopamidol and iopromide) and one ionic low-osmolar dimeric contrast medium (ioxaglate) on 30-day major adverse cardiac events in patients undergoing coronary interventions involving the use of new-generation stents and appropriate antiplatelet agents. Thirteen hundred and eight patients treated with stent implantation were randomized to receive ioxaglate (438 patients), iopamidol (442 patients), or iopromide (428 patients). Most of them (55%) had an acute coronary syndrome. Glycoprotein IIb/IIIa inhibitors were used in 37% of cases. All of the patients were on aspirin and ticlopidine for 1 month after the procedure. There was no significant between-group difference in the incidence of the primary composite endpoint of major adverse cardiac events 30 days after stenting (ioxaglate 3.6%; iopamidol 2.3%; iopromide 4.2%; P = 0.27). Adverse drug reactions were more frequent in the ioxaglate group (4.6% vs. 1.1% vs. 0.5%; P = 0.001). Multivariate analysis showed that intracoronary thrombus (P = 0.002), diabetes mellitus (P = 0.01), and postprocedure minimum lumen diameter (P = 0.04) independently correlated with an adverse outcome after 1 month. In conclusion, no significant differences in 30-day major ischemic complications were observed in this unselected population of patients undergoing coronary stenting who received ioxaglate, iopamidol, or iopromide. These data seem to suggest that the use of nonionic low-osmolar contrast media does not adversely affect stent patency.

Safe and effective direct implantation of a new stent through 5 F. guiding catheters with delivery from the radial artery: initial results of a prospective registry

OBJECTIVES

To evaluate the safety and efficacy of the direct implantation of a new stent via the radial artery through a 5 F. guiding catheter. Background advances in the design of stents and stent delivery systems have facilitated the performance of direct stenting and the use of thinner guiding catheters.

METHODS

This registry enrolled prospectively 125 patients (147 lesions, 20.4% AHA/ACC class B2/C) who underwent elective percutaneous coronary revascularization procedures for stable or unstable angina between November 2000 and March 2001.

RESULTS

Cannulation of the radial artery was attempted in 92.7% and was successful in 91.0% of cases. Direct stenting was successful in 88.7% of lesions and procedural success was 99.3%. In-hospital major adverse cardiac events occurred in 1.6% of cases (one death, one semi-urgent coronary artery bypass operation). The final rate of successful stent implantation through 5 F. guiding catheters was 96.7%. There were no access-site-related complications. Failure to cross the lesion occurred in 10% of attempts. At a mean follow-up of 7 +/- 2.8 months after discharge from hospital, 79% of patients had remained free of angina, and 89% had remained free of ischemic events.

CONCLUSIONS

Direct stenting with a new stent design was safe, effective, and could be accomplished through 5 F. guiding catheters with favorable long-term clinical outcomes.

Factors influencing fluoroscopy time and dose-area product values during ad hoc one-vessel percutaneous coronary angioplasty

X-ray exposure during radiologically guided interventional procedures may have some deleterious effects. The aim of our study was to analyse the factors affecting patient dose during percutaneous coronary angioplasty (PTCA). We evaluated radiation dose during coronary angiography followed by one-vessel PTCA in 402 consecutive patients who were treated by three experienced physicians using both femoral and radial techniques. Fluoroscopy time (t) and patient dose measured by a dose-area product (DAP) meter were recorded. A good correlation was observed between t and the DAP (r=0.78, p<0.001). To assess the factors affecting radiation exposure, we studied the differences between operators, arterial catheterization access and stenting strategy. Median (25th to 75th percentiles) values for t were 19 (13 to 26) min and for DAP were 191 (145 to 256) Gy cm(2) for operator 3 compared with t=12 (9 to 18) min and DAP=137 (91 to 208) Gy cm(2) for operator 2 (p<0.005 versus operator 3) and t=13 (9 to 17) min, and DAP=134 (93 to 190) Gy cm(2) for operator 1 (p<0.001 versus operator 3). Differences between the radial and the femoral techniques were: t=17 (13 to 24) min versus 12 (8 to 17) min, (p<0.001) and DAP=175 (128 to 246) Gy cm(2) versus 138 (93 to 197) Gy cm(2), (p<0.001). In comparison with stenting without pre-dilation, direct stenting significantly reduced t and DAP [t=12 (9 to 16) min versus 16 (11 to 22) min, (p<0.001) and DAP=130 (95 to 186) Gy cm(2) versus 163 (119 to 230) Gy cm(2), respectively, (p<0.01)]. Radiation exposure to patients and staff are strongly dependent on operators, stenting strategy and the arterial access chosen for ad hoc one-vessel PTCA.

[Nonselected use of direct coronary stenting. The DISCO 2 trial]

INTRODUCTION AND OBJECTIVES

Direct coronary stenting yields immediate long-term clinical results similar to those obtained with balloon predilation, with the advantage of lower costs and procedural times. Until now, direct stenting has been attempted only for selected lesions, so that the potential scope of its use in everyday practice remains unknown. The DISCO 2 trial was designed to identify the number and type of lesions that could be safely treated by direct stenting. Patients and method. 1,269 lesions (886 patients) were treated consecutively in 7 different hospitals. Direct stenting was attempted in all cases, except for total chronic occlusions, severe tortuosity or calcification of the vessel, lesions in the sinus ostium, or bifurcated lesions and vessel diameter < 2.4 mm. If the procedure failed, the stent was recovered and the lesion dilated with a balloon before a second attempt at stenting.

RESULTS

Direct stenting was attempted in 585 lesions (54.9% of all electively implanted stents and 46.1% of all angioplasties). This was successful in 553 (94.6%) and failed in 32 (5.4%). In 30 of these latter patients a stent was implanted after predilation. Predictors of failure were tortuosity, location in the nonproximal right coronary artery, age > 65 years and type B2 or C lesion. After 6 months of follow-up the total incidence of major adverse cardiovascular events in patients treated with direct stenting was 6.2%, with a target lesion revascularization rate of 4.45%.

CONCLUSIONS

In a mostly nonselected sample of coronary lesions, direct stenting was as safe as stenting with predilation. More than half of all elective stenting procedures can be attempted safely without balloon predilation. Greater need for predilation was associated with tortuosity, nonproximal right coronary artery location, older age and lesion complexity (B2, C). The 6-month clinical outcome was excellent, with a low rate of repeat revascularization.

Comparison of outcomes (early and six- month) of direct stenting with conventional stenting (a meta-analysis of ten randomized trials)

Although direct stenting (DS) is increasingly used in clinical practice instead of stent implantation after predilatation (conventional stenting [CS]), its impact has not been scientifically proved. We therefore performed, using Mantel-Haenszel analysis, a meta-analysis of the published randomized studies comparing DS with CS. Furthermore, all the key procedural data were systematically sought out and pooled. Ten trials (2,650 coronary lesions, 2,576 patients) were identified and entered into the analysis. Adopted angiographic exclusion criteria were homogeneous. DS, compared with CS, was found to have a similar success rate (98.7% vs 98.9%) and no specific complications. Across the studies, the mean rate of crossover to predilatation in the DS arm was 5.9%. Overall, DS was associated with a 17% procedural time (95% confidence interval [CI] 14% to 20%), a 18% fluoroscopic time (95% CI 15% to 21%), a 11% contrast volume (95% CI 9% to 14%), and a 22% cost reduction (95% CI 16% to 28%). In the early postintervention period, DS was associated with a trend toward reduction of each of the major adverse events (MACEs) and with a significant reduction of myocardial infarction (MI) + death (odds ratio [OR] 0.57, 95% CI 0.35 to 0.95). However, at 6 months, the OR (95% CI) for death, MI, target lesion revascularization, and MACEs were 0.47 (0.19 to 1.27), 0.72 (0.45 to 1.25), 1.07 (0.77 to 1.46), and 0.82 (0.63 to 1.08), respectively. In the subgroup of studies providing quantitative angiographic data, all the parameters were found to be similar between the CS and DS groups. In conclusion, the present meta-analysis shows that DS compared with CS, in selected coronary lesions, is safe, optimizes equipment use, and may enhance the early results of coronary interventions while warranting similar late clinical outcomes.

Direct coronary stenting without balloon predilation of lesions requiring long stents: immediate and 6-month results of a multicenter prospective registry

To assess the outcomes of direct coronary stenting (DS) using long stents and examine predictive factors of DS failure, this prospective multicenter registry included 128 consecutive patients who underwent the implantation of stents >or= 18 mm in length without balloon predilation for de novo coronary artery stenoses. Mean lesion and stent lengths were 20.7 +/- 5.4 and 21.4 +/- 3.8 mm, respectively. Rates of DS success, lesion success, and primary success were 82%, 99%, and 97.7%, respectively. At 6 months, rates of MACE and TVR were 12.5% and 6.3%, respectively. In multivariate analysis, factors predictive of DS failure vs. DS success were presence of calcifications (78% vs. 45%; P = 0.004) and reference vessel diameter (2.77 +/- 0.4 vs. 3.13 +/- 0.42 mm; P = 0.0002). DS of complex lesions with stents >or= 18 mm in length was performed safely and with a high success rate. This strategy was less successful in the treatment of small vessels and in presence of calcifications.

Is coronary stent deployment and remodeling affected by predilatation? An intravascular ultrasound randomized study Stenting with or without predilation: an IVUS study

In this intravascular ultrasound (IVUS) randomized trial we compared a strategy of direct stenting (DS) without predilation (n = 30) vs. conventional stenting with predilation (SWP) (n = 30) in patients with suitable type A or B non-calcified lesions in native vessels > or = 3 mm. Optimal deployment was achieved using angiographic criteria without interactive IVUS. The goal of our study was to determine whether stent expansion and coronary remodeling were similar. Maximal pressure inflation was comparable in the two groups (11.4 +/- 2.2 vs. 11.8 +/- 1.9 atm; NS). Stent deployment was obtained in all patients with complete apposition to the vessel wall. DS and SWP resulted in comparable lumen enlargement (5.4 +/- 2.5 vs. 5.5 +/- 2.1 mm2) with an identical mechanism: 66% of lumen enlargement was due to increased enlarged elastic membrane (EEM)-cross sectional area (CSA) (delta = 3.7 +/- 2.1 mm2 and delta = 2.4 +/- 6.8 mm2, respectively, p < 0.49) and 34% was due to a reduced P + M-CSA (delta = 0.02 +/- 6.9 mm2 and delta = 1.2 +/- 6.3 mm2, respectively, p < 0.50). We conclude that at the same maximal pressure inflation the mechanisms of stent expansion are similar in both DS and SWP groups. In this observational study, the IVUS data showed clearly under-expansion of stents in both groups in comparison with previously published CSA values (minimum stent CSA of 7.5 mm2).

Could direct stenting reduce no-reflow in acute coronary syndromes? A randomized pilot study

OBJECTIVES

Recently, direct stenting has been shown in retrospective and randomized studies to be feasible and safe in highly selected patients, with a potential interest to reduce the cost of the procedure and the rate of no-reflow. This randomized pilot study was designed to compare the incidence of no-reflow after direct stenting or conventional stenting after balloon predilation in acute coronary syndrome-related lesions.

METHODS AND RESULTS

Between December 1998 and October 1999, 130 patients in our center with acute coronary syndromes were included in this study and randomized in 2 groups. In group A (n = 65), direct stent implantation was performed without balloon predilation. In group B (n = 65), conventional balloon predilation was carried out before stent implantation. Baseline clinical and angiographic characteristics before the procedure were similar in the 2 groups of patients. No-reflow was observed in 7.7% after direct stenting and in 6.1% after conventional stent implantation (P = not significant). The immediate clinical success rate was similar in the 2 groups. Among the procedural data, only duration of the procedure (shorter in the direct stenting group), the number of balloons used, and the quantity of contrast agent (lower in the direct stenting group) were significantly different between the 2 groups (P <.05). The 6-month clinical outcome was similar in the 2 groups.

CONCLUSION

This randomized study confirms the promising results of previous studies that show the feasibility and the safety of direct coronary stenting in highly selected acute coronary syndrome-related lesions. The major impact of this strategy is the improvement of the cost-benefit ratio, with no major influence on the acute complications and especially on the occurrence of no-reflow in this high-risk population.

Mini-invasive strategy in acute coronary syndromes: direct coronary stenting using 5 Fr guiding catheters and transradial approach

The purpose of this study was to assess the feasibility and safety of direct coronary stenting in acute coronary syndromes using 5 Fr guiding catheters by transradial approach. A series of 119 patients with an acute coronary syndrome (unstable angina, n = 55; acute myocardial infarction, n = 45; recent acute myocardial infarction, n = 19) explored by transradial approach and eligible for direct stenting were included. A large proportion of patients (52%) was treated during the procedure by platelet IIb/IIIa receptor blockade. Only Medtronic 5 Fr guiding catheters were used in this study. Direct coronary stenting was attempted in all 119 highly selected patients. Failure of direct stenting was observed in only five cases (3.9%) and the stent successfully retrieved in each case in the 5 Fr guiding catheter. In these five cases, balloon predilation was performed and then the stent implanted successfully. Different stents were used: ACS stent (54%), AVE stent (33%), Velocity stent (10%), Nir stent (3%), with diameter ranging from 2.5 to 4 mm. In four cases, the dilation was finally performed using 6 Fr guiding catheters because the backup of the 5 Fr catheter was considered to be too low (3%). No vascular access site complications occurred in this series of patients. We conclude that direct coronary stenting using transradial approach and 5 Fr guiding catheters yields excellent procedural success rate. In the setting of acute coronary syndromes requiring platelet IIb/IIIa receptor blockade or after failure of thrombolysis, this mini-invasive strategy is very attractive because of the low risk of access site complications.

Comparison of direct stenting versus stenting with predilation for the treatment of selected coronary narrowings

Direct stenting may reduce costs, procedure times, and injury to the vessel wall, positively influencing acute and late results. This study was designed to demonstrate 6-month clinical outcome equivalence between direct and standard stenting techniques. Four hundred eleven patients (425 lesions) were randomized in 7 sites to undergo direct (210 patients, 216 lesions) or conventional (201 patients, 209 lesions) stent implantation. Lesions with severe calcification were excluded. Angiographic success rate was 100% in the direct stent group (2.8% requiring balloon predilation) and 98.6% in the predilation group (p = 0.12). Direct stenting was associated with decreased use of balloons (0.15 vs 1.09 balloons/lesion treated) and with a trend toward a reduction of procedure time (22.7 +/- 15.0 vs 25.6 +/- 18.2 minutes; p = 0.073). Fluoroscopy time and contrast volume were not different between groups. At 6-month follow-up, the incidences of death (direct [1.4%] vs predilation [2.5%]), myocardial infarction (5.3% vs 5.0%), and target vessel revascularization (8.2% vs 10.5%) were similar in both groups. Major adverse cardiac event-free survival rate was 87.5% for those who underwent the direct stent technique and 85.5% for patients who underwent predilation (p = 0.0002 for equivalence). In conclusion, direct stenting is at least equivalent to the standard technique in terms of 6-month clinical outcomes when performed on selected coronary lesions without significant calcification. This strategy is associated with decreased use of balloons, but, in general, does not significantly reduce procedure times.

A randomized trial of stenting with or without balloon predilation for the treatment of coronary artery disease

BACKGROUND

Stent placement has historically been preceded by predilation of the target lesion with percutaneous transluminal coronary angioplasty. Direct stent implantation, without predilation, has the potential to have a favorable impact on procedure cost by reducing the number of devices used, contrast administered, and procedure time.

METHODS AND RESULTS

We conducted a prospective randomized trial to compare the economic outcome of stenting with or without predilation. Inclusion criteria included intention to treat a single lesion with a coronary stent in a vessel with a reference diameter >2.4 mm. Exclusion criteria included total occlusions, culprit lesion within a saphenous vein graft, lesion length >25 mm, patients within 48 hours of an acute myocardial infarction, and patients unable to be treated with aspirin and clopidogrel. From September 1999 to March 2000, 77 patients were randomized to direct stent implantation (n = 37) or balloon-facilitated stenting (n = 40). Stent placement was successful in all patients. Crossover to predilation was required in 2 patients in the direct stent group because of inability to deliver the stent. Compared with balloon-facilitated stenting, direct stenting used fewer catheter devices (1.4 +/- 0.7 vs 2.5 +/- 0.8, P <.001), less contrast (92.7 +/- 43.1 mL vs 117.4 +/- 61.0 mL, P =.04), and less fluoroscopy time (7.5 +/- 3.9 minutes vs 11.6 +/- 8.3 minutes, P =.006). No difference in procedural complications or predischarge outcome was found. No difference in major adverse cardiovascular events was found at 6-month follow-up.

CONCLUSION

Direct stenting is a safe and successful procedure that reduces the number of devices used, fluoroscopy time, and contrast administration.

Direct infarct artery stenting without predilation and no-reflow in patients with acute myocardial infarction

BACKGROUND

In patients with acute myocardial infarction (AMI), the rate of microvascular embolization and no-reflow promoted by coronary stenting with the use of conventional techniques (CS) appears to be greater than the one that occurs with balloon angioplasty. The minor invasiveness of direct stenting (DS) of the infarct artery without predilation could be expected to reduce embolization in the coronary microvasculature and no-reflow in patients with AMI.

METHODS

In a cohort of 423 consecutive patients with AMI who underwent infarct-artery stenting, we compared CS and DS in terms of angiographic no-reflow rate and 1-month clinical outcome.

RESULTS

At baseline patients who underwent DS (n = 110) had a better risk profile compared with the use of CS (n = 313). The incidence of angiographic no-reflow was 12% in the CS group and 5.5% in the DS group (P =.040). The 1-month mortality rate was 8% in the CS group and 1% in the DS group (P =.008). The mortality rate was 11% in patients with no-reflow and 5.6% in patients with a normal flow. Multivariate analysis showed that age, preprocedure patent infarct artery, and lesion length were related to the risk of no-reflow. In the subset of patients with a target lesion length </=15 mm, the variables independently related to the risk of no-reflow were age, DS, and final balloon inflation pressure.

CONCLUSIONS

DS in patients with AMI may reduce the incidence of angiographic no-reflow, thereby increasing ultimate effective myocardial reperfusion.

Feasibility, safety, cost-effectiveness and 1 year follow-up of coronary stenting without predilation: a matched comparison with the standard approach

BACKGROUND

We evaluated the feasibility, safety, procedural cost-effectiveness, radiation dose and time and 1-year target vessel revascularization rate of direct unprotected mounted stenting without previous balloon dilatation (DS) in native coronary artery lesions.

METHODS

DS was attempted in 119 patients; 39 had a recent myocardial infarction, 62 had unstable angina, and 18 had stable angina. The clinical follow-up was obtained at 14+/-5 months (range 6 to 24 months). These results were compared with those for a consecutive group of 160 patients matched for type and length of lesions and who had a stent only if the post-balloon residual stenosis was >30%.

RESULTS

The feasibility of DS was 112/119 (94%). The number of inflations, the length of the stent/length of the lesion ratio, the time and the dose of radiation were dramatically lower in the DS group (P<0.001). DS conferred a slight reduction in procedure-related cost [$820+/-157 for DS vs. 894+/-427 for standard dilatation (SD) per patient]. The 1-year target vessel revascularization rate was similar in both groups [nine (8%) for DS vs. 17 (11%) patients for SD, ns].

CONCLUSIONS

DS is feasible and safe in selected coronary lesions. This method provides a low rate of repeat revascularization and reduces the time and the dose of radiation compared with the standard approach.

Randomised comparison of coronary stenting with and without balloon predilatation in selected patients

BACKGROUND

The SWIBAP (stent without balloon predilatation) prospective randomised trial was designed to compare direct coronary stenting with stenting preceded by lesion predilatation with an angioplasty balloon.

OBJECTIVE

To determine the feasibility and safety of direct stenting in non-complex coronary lesions in a prospective study.

PATIENTS AND DESIGN

All patients < 76 years of age scheduled to undergo angioplasty of a non-complex, non-calcified lesion in a coronary artery of > 3.0 mm, who granted their informed consent, were randomised into the trial. In group I, the stent was placed without balloon predilatation, while in group II stent implantation was preceded by balloon predilatation. The primary end point was the angiographic result according to procedure assigned by randomisation. An intravascular ultrasound substudy was performed in 60 patients.

RESULTS

Stent implantation was successful without predilatation in 192 of the 197 group I patients (97.5%), and with predilatation in 197 of the 199 group II patients (99%) (NS). No in-hospital stent thrombosis or death occurred. Overall procedural times, fluoroscopy times, and volumes of contrast agent given (mean (SD)) in group I v group II were 23.50 (13.54) min v 27.96 (15.23) min (p = 0.002), 6.04 (4.13) min v 6.67 (3.65) min (NS), and 135 (65) ml v 157 (62) ml (p < 0.001), respectively. No major adverse cardiovascular events had occurred by 30 days.

CONCLUSIONS

The feasibility and safety of direct stenting of selected and non-complex coronary lesions is confirmed. This technique was as successful as the conventional approach and was associated with a minor reduction in fluoroscopic exposure and procedure time and the administration of less contrast agent.

Direct coronary stenting: effect on coronary blood flow, immediate and late clinical results

Direct stenting (DS) was attempted in 99 coronary lesions in 94 patients while standard stenting (SS) was attempted in 113 lesions in 103 patients matched for clinical characteristics, stenosis type, and location and stent type. The angiographic result was also evaluated according to TIMI frame count method (TFC) before and after procedure. A clinical follow-up was performed 1 year after the procedure. Before the procedure, TIMI grade 3 flow was detected in 42 cases (42.4%), grade 2 in 40 cases (40.4%), grade 1 in 5 cases (5.1%), and grade 0 in 12 cases (12.1%) in the DS group; these data were similar in SS group. After the procedure, TIMI grade flow was 3 in 90 cases (92.8%) in DS group and in 87 (77.0%) in SS group (P < 0.005); grade 2 was observed in 7 case (7.2%) in DS group and in 25 (22.1%) in SS group (P < 0.005). Major adverse cardiac events during hospitalization and at follow-up were similar in two groups. Radiation exposure time and procedure costs per lesion were significantly reduced in DS group compared to SS group (10.1 +/- 8 min vs. 13.9 +/- 4.7 min, P < 0.001; and 1901 +/- 687 Euro vs. 2352 +/- 743 Euro, P < 0.001, respectively). This study confirms that, in selected patients, direct stenting is a safe and successful procedure, allowing a significant reduction in radiation exposure time and procedural costs compared to standard stenting technique. The angiographic success is confirmed by the improvement in TFC in all cases.

Comparison of direct coronary stenting with and without balloon predilatation in patients with stable angina pectoris. BET (Benefit Evaluation of Direct Coronary Stenting) Study Group

The purpose of this study was to compare the effects of stent placement with and without balloon predilatation on duration of the procedure, reduction of procedure-related costs, and clinical outcomes. Although preliminary trials of direct coronary stenting have demonstrated promising results, the lack of randomized studies with long-term follow-up has limited the critical evaluation of the role of direct stenting in the treatment of obstructive coronary artery disease. Between January and September 1999, 338 patients were randomly assigned to either direct stent implantation (DS+; 173 patients) or standard stent implantation with balloon predilatation (DS-; 165 patients). Baseline clinical and angiographic characteristics were similar in the 2 groups. Procedural success was achieved in 98.3% of patients assigned to DS+ and 97.5% of patients assigned to DS- (p = NS), with a crossover rate of 13.9%. Compared with DS-, DS+ conferred a dramatic reduction in procedure-related cost ($956.4 +/- $352.2 vs $1,164.6 +/- $383.9, p <0.0001) and duration of the procedure (424.2 +/- 412.1 vs 634.5 +/- 390.1 seconds, p < 0.0001). At 6-month follow-up, the incidence of major adverse cardiac events including death, angina pectoris, myocardial infarction, congestive heart failure, repeat angioplasty, or coronary artery bypass graft surgery was 5.3% in DS+ and 11.4% in DS- (p = NS). Multivariate analysis demonstrated that major adverse cardiac events rates were related to stent length of 10 mm (relative risk [RR] 3.25, 95% confidence intervals [CI] 1.36 to 7.78; p = 0.008), stent diameter of 3 mm (RR 2.69, 95% CI 1.03 to 7.06; p = 0.043), and complex lesion type C (RR 2.83, 95% CI 1.02 to 7.85; p = 0.045). Thus, in selected patients, this prospective randomized study shows the feasibility of DS+ with reduction in procedural cost and length, and without an increase in in-hospital clinical events and major adverse cardiac events at 6-month follow-up.

Acute stent recoil: in vivo evaluation of different stent designs

This study sought to investigate the degree of acute recoil of four different stents by means of quantitative coronary angiography. Four hundred and six patients underwent stent implantation for single discrete coronary artery lesion: 105 received a 16 mm Paragon stent, 112 an 18 mm Multilink Duet, 97 a 16 mm NIR Primo stent, and 92 a 15 or 18 mm NIR Royal Advance. Elastic recoil was defined as the difference between mean balloon cross-sectional area (CSA) at the highest pressure and mean CSA after PTCA. The mean stent recoil was 13% +/- 10% CSA (P < 0.001), being statistically greater for the nitinol Paragon stent (21% +/- 11%), intermediate for the multicellular Multilink Duet stent (14% +/- 7%), and minimum for the NIR family (9% +/- 6% and 8% +/- 7%, respectively). The recoil was not homogeneously distributed along the stent length but was lower at the two ends (11% +/- 12% and 13% +/- 11%) and highest in the central part (15% +/- 12%)(P < 0.001). Thus, acute recoil is a significant phenomenon regardless of the mechanical properties and design of new-generation tubular stents.