Direct coronary stenting without balloon predilation in acute coronary syndromes

The impact of lesion complexity on no-reflow phenomenon and predictors of reversibility in patients treated with primary percutaneous intervention

OBJECTIVES

Complex coronary lesions are more prone to complications; however, the relationship between complex coronary lesions and no-reflow phenomenon in patients undergoing primary percutaneous intervention (pPCI) is still not clarified. Previous studies reported the association of total coronary artery complexity with no-reflow; however, impact of culprit lesion complexity on no-reflow is not known. In this study, we aimed to investigate the impact of culprit lesion complexity on no-reflow phenomenon. Furthermore, we aimed to investigate the factors that are related to reversibility of no-reflow.

METHODS

We prospectively included 424 patients treated with pPCI. Patients' baseline characteristics and clinical variables were recorded. Reversibility of no-reflow was decided according to final angiography or ST resolution during the first hour following pPCI. There were 90 patients with a diagnosis of no-reflow constituted group 1 and patients without no-reflow constituted group 2. Complexity of coronary artery disease was assessed with SYNTAX score and culprit lesion complexity was assessed with both American College of Cardiology/Society of Cardiovascular Angiography and Interventions lesion classification and SYNTAX score.

RESULTS

Complexity of culprit lesion was significantly higher in group 1 patients (type C lesion 76.6 vs. 27.8%; P < 0.001 and SYNTAX score 8.7 ± 3.0 vs. 6.2 ± 2.6; P < 0.001, respectively, group 1 vs. 2). Multivariate analyses revealed that lesion complexity is independently associated with no-reflow. Among 90 patients of group 1, 43 patients were classified as reversible no-reflow. Logistic regression analysis revealed that only ischaemia duration is independently associated with reversibility of no-reflow.

CONCLUSION

Our study demonstrated that culprit lesion complexity is independently associated with no-reflow phenomenon and short ischaemic duration is significantly associated with reversibility of no-reflow.

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.

To Whom Thrombus Aspiration May Concern?

BACKGROUND

Thrombus aspiration for ST-segment elevation myocardial infarction (STEMI) may improve myocardial perfusion. However, these favourable results called into a question by data indicating not only a lack of efficacy but a risk of potentially deleterious complications.

AIM

To assess the effect of thrombus aspiration during the primary percutaneous coronary intervention (PPCI) on procedural angiographic results, stent characteristics, and major adverse cardiac and cerebrovascular events (MACCE).

METHODS

All consecutive STEMI patients candidate for PPCI and admitted to Critical Care Department, Cairo University hospitals, managed either by thrombectomy before primary PCI (if thrombus score ≥ 3) or conventional PPCI, Six hundred seven subjects were enrolled in the study divided into Group with thrombectomy before PPCI (107 subjects, 18%), and group with Conventional PCI (500 subjects, 82%). ST-segment resolution, peak CK-MB, TIMI score, thrombus score, and MBG were assessed; stent number, diameter, length and stented segment were reported and follow up MACCE was reported (in hospital and 1-year post-intervention).

RESULTS

Mean values for peak CKMB were less in thrombectomy group (228 ± 174 I/U vs 269 ± 186 I/U, p = 0.04), ST segment resolution ≥ 70% occurred in {63 subjects (58.9%) vs 233 (46.6%), p = 0.001} in thrombectomy vs conventional group respectively. TIMI score pre procedure was zero in (102 subjects (95%) vs 402 (80.4%), p = 0.001), while TIMI III post procedure was reported in (100 subjects (93.4%) vs 437 (87%), p = 0.06), MBG mean values were (2.4 ± 0.6 vs 2.0 ± 1, p = 0.001), thrombus score was higher in thrombectomy group (4.6 ± 0.4 vs 0.8 ± 1.7, p = 0.001) in thrombectomy vs conventional group respectively. Direct stenting was { 34 patients (31%) vs 102 patients (20%), p = 0.05}, mean stent diameter (2.7 ± 1.3 mm vs 3.5 ± 1.3 mm, p = 0.3), mean stent length was (19.9 mm ± 10 versus 22.7 mm ± 8 in p 0.01). mean stent number was (1.0 ± 0.5 vs 1.2 ± 0.6, p = 0.001), mean stented segment was (22.5 ± 13.5 vs 28.5 ± 15.2 mm, p = 0.001) in thrombectomy vs conventional group respectively. MACCE in hospital were reported in {9 subjects (8.4%) vs 70 (14%), p = 0.07)}. Follow up MACCE after 1 year reported in {6 subjects (5.6 %) vs 80 (16 %), p 0.= 4} in thrombectomy vs conventional group respectively.

CONCLUSION

Thrombus aspiration before primary PCI (in a selected group with thrombus score ≥ 3) improves myocardial perfusion, suggested by better ST-segment resolution, TIMI flow, less peak CKMB and MBG, associated with a higher rate of direct stenting, shorter stent length, stented segments and less number of stents. Although thrombus aspiration was done in more risky patients (higher thrombus score) MACCE (in hospital and 1 year follow up) showed no statistical difference.

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.

New technologies aimed at percutaneous intervention in the small coronary artery

Percutaneous coronary intervention (PCI) of small vessels can be complicated by technically difficult access to the target lesion, an increased risk of major adverse cardiac events and in-stent restenosis requiring repeat revascularization. Conventional management of such lesions is with drug-eluting stent implantation; however, these have only partly attenuated the problem. In response, several medical device companies are competing to produce new technologies aimed at PCI in small coronary arteries. Such innovations include thin-strutted stents, stent-on-a-wire systems, drug-coated balloons, endothelial progenitor cell-catching stents and biodegradable stent systems. To date, none of these techniques have been sufficiently validated for use in small coronary arteries to justify a change in practice; however, small-vessel coronary artery disease is an increasingly common problem, and PCI of target lesions with reference vessel diameter <3.0 mm is likely to increase, especially in view of the increasing prevalence of diabetes, warranting further well-designed studies. The prospect of mounting a self-expandable biodegradable drug-eluting stent directly onto a guidewire could potentially be an exciting future development.

Comparison of outcomes of direct stenting versus stenting after balloon predilation in patients with acute myocardial infarction (DIRAMI)

Due to recent advances in stent design, stenting without balloon predilation (direct stenting) has become more extensively used in patients with acute myocardial infarction (AMI). We performed a randomized study with broad inclusion criteria and early randomization after presentation to compare direct stenting with stenting after balloon predilation in patients with AMI. A total of 248 patients was randomized. After exclusion of patients not suitable for stenting, the final study group comprised 217 patients. Direct stenting strategy was feasible in 88% of patients with no meaningful complications. Final Thrombolysis In Myocardial Infarction grade 3 flow (96% vs 94%), final Thrombolysis In Myocardial Infarction myocardial perfusion grade 2 or 3 (68% vs 61%), and average ST-segment resolution after the procedure (49% vs 51%) were similar in the direct stenting and predilation groups, respectively (p = NS). Rate of in-stent restenosis was higher in the direct stenting group (30% vs 16%, p = 0.024), which was due to a worse angiographic result after the procedure. At 5 years, a composite of cardiac death, reinfarction, and target lesion revascularization had occurred in 39% in the direct stenting group and 34% in the predilated group (p = 0.40). In conclusion, although at 5 years clinical outcome did not differ significantly between groups, direct stenting was associated with a higher incidence of in-stent restenosis at 1 year. Direct stenting did not improve epicardial and myocardial reperfusion indexes. Direct stenting strategy should not be recommended in all patients with AMI as an alternative strategy to stenting after predilation.

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 direct stenting versus conventional stent implantation on blood flow in patients with ST-segment elevation myocardial infarction

As compared with balloon angioplasty, stent implantation in treatment of acute myocardial infarction (AMI) reduces abrupt vessel closure, restenosis, and reocclusion rate. However, a few studies have demonstrated the safety and feasibility of direct stenting compared to conventional stent implantation technique. This study was designed to compare possible advantages of direct stenting with conventional stent implantation on immediate coronary blood flow and short-term clinical benefits in patients with AMI. Fifty patients with AMI who underwent mechanical revascularization were eligible for the study. The patients were randomly assigned to undergo either direct stenting (n = 25) or conventional stent implantation (n = 25). Before and after the procedure thrombolysis in myocardial infarction (TIMI) flow and postprocedural corrected TIMI frame count (cTFC) of the infarct-related artery were measured. There was no difference in TIMI flow distribution at baseline between the 2 groups. TIMI 3 flow rate significantly increased after procedure in both groups compared to baseline (p < 0.05). Postprocedural cTFC was found significantly lower in the direct stent arm compared to conventional stenting (p < 0.001). Both during and after the procedure the complication rate and procedural time were lower in the direct stenting arm. Direct stenting provides better immediate coronary blood flow and is a safe and feasible method compared with conventional stenting in patients with AMI. Improvement in coronary blood flow measured by the corrected TIMI frame count method may suggests a significant reduction of microvascular injury.

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.

Percutaneous coronary intervention: recommendations for good practice and training

Cardiologists undertaking percutaneous coronary intervention (PCI) are excited by the combination of patient and physician satisfaction and technological advance occurring on the background of the necessary manual dexterity. Progress and applicability of percutaneous techniques since their inception in 1977 have been remarkable; a sound evidence base coupled with the enthusiasm and ingenuity of the medical device industry has resulted in a sea change in the treatment of coronary heart disease (CHD), which continues to evolve at breakneck speed. This is the third set of guidelines produced by the British Cardiovascular Intervention Society and the British Cardiac Society. Following the last set of guidelines published in 2000, we have seen PCI activity in the UK increase from 33,652 to 62,780 (87% in four years) such that the PCI to coronary artery bypass grafting ratio has increased to 2.5:1. The impact of drug eluting stents has been profound, and the Department of Health is investigating the feasibility of primary PCI for acute myocardial infarction. Nevertheless, the changes in the structure of National Health Service funding are likely to focus our attention on cost effective treatments and will require physician engagement and sensitive handling if we are to continue the rapid and appropriate growth in our chosen field. It is important with this burgeoning development now occurring on a broad front (in both regional centres and district general hospitals) that we maintain our vigilance on audit and outcome measures so that standards are maintained for both operators and institutions alike. This set of guidelines includes new sections on training, informed consent, and a core evidence base, which we hope you will find useful and informative.

Comparison of the X-SIZER Thrombectomy Device with Adjunct Abciximab During Primary Angioplasty and Stenting for ST-Segment Elevation Myocardial Infarction

OBJECTIVE

To evaluate the safety and efficacy of the X-SIZER thrombectomy device versus the use of abciximab during primary angioplasty for acute ST-elevation myocardial infarction (STEMI).

DESIGN

Retrospective analysis of patients undergoing primary angioplasty for STEMI from October 2000 to December 2002 using the X-SIZER thrombectomy device versus abciximab.

SETTING

National University Hospital, Singapore.

PATIENTS

Out of 79 patients, 44 underwent X-SIZER use, while 35 received adjunct abciximab. Both groups were similarly represented with regards to age, gender, risk factors, target vessel site/diameter, cardiogenic shock, and onset of chest pain to procedure time. The infarct-related artery was occluded in 88.6% in both groups.

INTERVENTIONS

A 2-mm X-SIZER was used in 34/44 (77.3%), while a 1.5-mm device was used in the remainder. Final TIMI 3 flow was obtained in 38/44 (86.4%) in the X-SIZER group compared to 26/35 (74.3%) in the abciximab group (P = 0.175).

MAIN OUTCOME MEASURES

Coronary TIMI flow rate, electrocardiogram (ECG) resolution, slow flow/no reflow phenomenon, and patient outcome (death, cardiac failure, or repeat revascularization) at 1 month.

RESULTS

ECG resolution and slow flow/no reflow were better in the X-SIZER group (77.3% vs 54.3%, P = 0.031; 9.1% vs 25.7%, P = 0.047, respectively). Patient outcome at 1 month was, however, not significantly different (18.2% vs 17.1%, P = 0.904, respectively, for X-SIZER and abciximab).

CONCLUSION

X-SIZER thrombectomy during primary percutaneous coronary intervention for thrombus-laden STEMI is a safe and effective strategy. When compared to patients receiving abciximab, it was associated with improved ECG resolution, less slow flow/no reflow and a trend to better TIMI 3 flow.

Angiographic, intravascular ultrasound, and fractional flow reserve evaluation of direct stenting vs. conventional stenting using BeStent2 in a multicentre randomized trial

AIMS

Direct stenting (DS) may not be as safe and effective as conventional stenting. The objective was to demonstrate equivalence of post-procedural mean luminal diameter (MLD) by angiography after BeStent2 placement between DS and pre-dilatation (PD) strategy.

METHODS AND RESULTS

Two hundred and two patients with a single de novo lesion (diameter >/=3.0 mm and length </=13 mm) were randomized to DS (n=101) vs. PD. Stent deployment was guided by on-line quantitative coronary angiography (QCA). A second randomization assigned half of the patients to intravascular ultrasound (IVUS) and fractional flow reserve (FFR) assessment. QCA was repeated at 6 months. Baseline characteristics were similar. Crossover to PD was necessary in seven DS patients. Stent deployment was successful in 97% (DS) and 98% (PD). The post-procedural MLD was 2.79+/-0.45 mm (DS) and 2.76+/-0.40 mm (PD). The null-hypothesis of non-equivalence could be rejected (95% one-sided; P=0.0003). The minimum stent area (IVUS) was 7.89+/-1.75 mm(2) (DS) and 8.07+/-2.37 mm(2) (PD; P=0.69), with an FFR of 0.92+/-0.07 and 0.92+/-0.05, respectively (P=0.97). Major adverse cardiac event rates at 6 months were 9% (DS) and 11% (PD; P=0.93). Target lesion re-angioplasty was 6% (DS) and 5% (PD; P=0.77). The in-stent restenosis rate by QCA was 7.4% (DS) and 6.8% (PD; P=0.87).

CONCLUSION

DS with BeStent2 is equivalent to PD. Both strategies resulted in a low angiographic restenosis rate.

Angiographic and clinical outcomes associated with direct versus conventional stenting among patients treated with fibrinolytic therapy for ST-elevation acute myocardial infarction

The present study reports outcomes of direct stenting versus conventional stenting, which was performed during adjunctive/rescue percutaneous coronary intervention (n = 556) in the Integrilin and Tenecteplase in Acute Myocardial Infarction trial, the Enoxaparin as Adjunctive Antithrombin Therapy for ST-Elevation Myocardial Infarction-Thrombolysis in Myocardial Infarction 23 trial, and the Fibrinolytic and Aggrastat ST-Elevation Resolution trial of fibrinolytic therapy in ST-elevation myocardial infarction. Direct stenting was associated with a lower rate of death, myocardial infarction, or congestive heart failure during hospitalization and at 30 days and was independently associated with improved in-hospital outcomes (odds ratio 0.44, 95% confidence interval 0.23 to 0.85, p = 0.014).

Effectiveness of thrombectomy before stent implantation in acute myocardial infarction

Percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) may cause distal embolization, with deterioration of distal flow and further extension of the infarct. The purpose of the present study was to evaluate the effectiveness of pretreatment by thrombectomy on myocardial salvage after stent implantation in patients with AMI. From January 2000 to July 2002, 209 consecutive patients with AMI successfully underwent emergency stent implantation. They were divided into 2 groups: those treated in the year before the introduction of the thrombectomy device (Group A; n=109), and those treated the year after introduction of the device (Group B; n=100). Follow-up quantitative coronary angiography (QCA) and left ventriculography were carried out 6 months after PCI. Microvascular circulation after revascularization was assessed by Thrombolysis in myocardial infarction (TIMI) flow grade analysis, the maximum creatine kinase concentration was recorded, and the follow-up left ventricular ejection fraction and ST segment score were assessed on the 12-lead electrocardiography just before revascularization and on return to the coronary care unit. The QCA data, rate of restenosis (% restenosis) and rate of target lesion revascularization were also compared between the 2 groups. The results demonstrated that the introduction of thrombectomy had increased the number of patients who displayed blush-3 after primary angioplasty, which suggests that thrombectomy before stent implantation has the potential to minimize myocardial ischemic insult, presumably by protecting the coronary microvasculature.

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.

Direct stenting with 3000 i.u. heparin

In order to reduce vascular complications, the authors assessed safety and feasability of a new percutaneous transluminal coronary angioplasty (PTCA) strategy consisting of direct stenting with 3000 i.u. heparin and immediate sheath removal. Predicting factors of vascular complications during PTCA include heparin dosages, sheath dwell time and use of anti-glycoprotein (GP) IIb/IIIa. A simplified PTCA with direct stenting technique may allow the use of very low doses of heparin without anti-GPIIb/IIIa in selected cases. From April 1999 to April 2000 all patients who underwent PTCA in the authors' center were screened. Exclusion criteria comprised a contraindication for direct stenting, primary PTCA for acute myocardial infarction (MI) and a TIMI (thrombolysis in myocardial infarction) grade zero flow. All other patients were included. They received 3000 i.u. heparin before direct stenting whatever their current anticoagulation and their weight. The sheath was immediately removed using manual compression. Out of 716 consecutive PTCA patients, 171 (24%) were enrolled in the study (198 sites). Complete protocol was achieved in 150 patients (88%). Activated clotting time during the procedure was 179 +/- 32 seconds. No subacute thrombosis or creatine kinase elevation was observed before discharge. Only two uncomplicated groin hematomas and two false aneurysms (one surgical repair) were noted. This study shows that direct stenting with 3000 iu heparin is safe. Immediate sheath removal can be performed with a low rate of major vascular complications.

Effect of direct stenting on clinical outcome in patients treated with percutaneous coronary intervention on saphenous vein graft

BACKGROUND

Percutaneous coronary intervention (PCI) of saphenous vein graft (SVG) is associated with frequent postprocedural enzyme elevation and late cardiac events. New strategies are proposed to minimize distal embolization and to improve the outcome of patients treated with stenting for SVG lesions. The objectives of the current study were to examine direct stenting (DS) strategy of PCI in SVG lesions and its effects on creatine-kinase (CK) release, major adverse cardiac events (MACE), and late outcome when compared to conventional stenting (CS).

METHODS

A consecutive series of 527 patients treated with stent implantation for SVG stenosis was analyzed. In this cohort, 170 patients with 229 lesions were treated with DS and 357 patients with 443 lesions were treated with CS. The inhospital and 12-month follow-up events were recorded and reported.

RESULTS

Baseline clinical and postprocedural angiographic characteristics were similar between the 2 groups except for higher preprocedural prevalence of thrombus-containing lesions in the DS group. Patients in the DS group had less CK-MB release (P <.001), and less non-Q-wave myocardial infarction (P =.024). Multivariate analysis detected unstable angina (odds ratio [OR] = 1.8, P =.03) as a correlate for non-Q-wave MI; DS was inversely associated with non-Q-wave myocardial infarction (OR = 0.65, P =.04). At 1 year, the target lesion revascularization-MACE was significantly lower in the DS group (P =.021). Multivariate analysis showed that DS (OR = 0.47, P =.007) was associated with reduction of the target lesion revascularization-MACE.

CONCLUSIONS

When feasible, DS may be the best approach for treating SVG stenosis.

Direct stenting with the Bx VELOCITY balloon-expandable stent mounted on the Raptor rapid exchange delivery system versus predilatation in a European randomized Trial: the VELVET trial

AIMS

This study examined the six-month angiographic results of direct coronary stenting, and compared the nine-month safety, efficacy and cost of this strategy versus stenting after balloon predilatation.

METHODS

In phase I of VELVET, 122 patients (mean age = 62.3 +/- 10.1 years, 77% male, 11% with diabetes) with angina pectoris or myocardial ischemia resulting from a single de novo 51% to 95% coronary stenosis underwent direct stenting. The endpoints of phase I included angiographic findings and rates of major adverse cardiac events up to six months of follow-up. In phase II, 401 patients (mean age = 61.3 +/- 10.8 years, 79% male, 16% with diabetes) with angina pectoris or documented myocardial ischemia resulting from single or multiple, de novo or restenotic, coronary lesions were randomized between direct stenting and stenting after predilatation. The immediate angiographic results, and clinical outcomes and costs associated with the two treatment strategies up to nine months of follow-up were compared.

RESULTS

In phase I the mean diameter stenosis immediately before and after the procedure, and at six months was 61.7+/-9.4%, 13.5+/-6.3%, and 33.6+/-16.2%, respectively. The six-month binary restenosis rate was 11%. The overall rate of major adverse cardiac events, including two non-cardiac deaths, was 9.8%. In phase II, the success rates of the intended delivery strategies were 87.9% and 97.9% for direct stenting and predilatation, respectively (p < 0.001), while the procedural success rates were similar (93.9% vs 96.5%). Over a follow-up period of nine months, major adverse cardiac events rates were 12.0% and 10.9% in patients randomized to direct stenting and predilatation, respectively (non-significant). Analyses of the costs incurred up to nine months in each treatment group revealed a mean saving of e362 per patient in favor of the direct stenting strategy (non-significant).

CONCLUSIONS

Compared with a strategy of stenting preceded by balloon dilatation, direct stenting was associated with an equivalent procedural success rate, equivalent clinical results up to nine months of follow-up, and a reduction in procedural and in-hospital costs (p < 0.0001 and p < 0.001, respectively), that was no longer significant after nine months.

Multicenter randomized comparison of direct vs. conventional stenting: the DIRECTO trial

With conventional stenting, predilatation frequently induces dissections that require deploying stents longer than originally planned. To assess whether direct stenting is safe and may prevent dissections and reduce the length of stents implanted, we conducted a randomized study comparing direct (n = 73) and conventional (n = 78) stenting. Direct stenting was successful in 89% of cases, 11% crossed over to predilation without complications. Dissections occurred more frequently in conventional stenting group (10.3% vs. 1.4%; P = 0.034), but did not translate to a significant stent length difference (16.31 +/- 7.6 vs. 15.31 +/- 5.5; P = NS). Periprocedure creatine kinase elevation and number of balloons utilized were lower with direct stenting.

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.

Direct coronary stenting versus predilatation followed by stent placement

Direct stenting without antecedent dilatation may reduce procedural time, costs, and radiation exposure, and may result in less vessel injury. The purpose of this investigation was to compare immediate and long-term clinical and angiographic outcomes of direct stenting with stent placement after initial balloon dilation. Three hundred thirty-five symptomatic patients with single or multiple coronary lesions (diameter reduction 60% to 95%) of < or =30 mm length and with a vessel diameter of 2.5 to 4.0 mm were randomized either to direct stenting (group A, n = 171) or stenting after predilation (group B, n = 164). Patients with vessels with excessive calcification, severe proximal tortuosity, or occlusion were excluded. All patients were asked to return for routine repeat angiography at 6 months, irrespective of symptoms. Feasibility of direct stenting was 95% in group A, with 5% requiring crossover to predilation. Successful stent placement after predilation was performed in all 164 patients in group B. Direct stenting was associated with less procedural duration (group A 42.1 +/- 18.7 minutes vs group B 51.5 +/- 23.8 minutes, p = 0.004), radiation exposure time (group A 10.3 +/- 7.7 minutes vs group B 12.5 +/- 6.4 minutes, p = 0.002), amount of contrast dye used (group A 163 +/- 69 ml vs group B 197 +/- 84 ml, p <0.0001), and lower procedural costs (group A 845 +/- 167 vs group B 1,064 +/- 175, p <0.0001). Immediate angiographic results and in-hospital clinical outcomes (death, Q-wave myocardial infarction, repeat revascularization) were not significantly different between both strategies. However, at 6-month follow-up, direct stenting was associated with a lower angiographic restenosis (group A 20% vs group B 31%, p = 0.048) and target lesion revascularization rates (group A 18% vs group B 28%; p = 0.03). This study demonstrates the feasibility, safety, and outcomes of direct stenting in eligible coronary lesions. In appropriately selected cases, direct stenting has a lower rate of angiographic restenosis up to 6 months after the procedure, resulting in fewer coronary reinterventions compared with the conventional strategy of stenting with antecedent dilatation.

Clinical and angiographic outcome after conventional angioplasty with optional stent implantation compared with direct stenting without predilatation

OBJECTIVE

To compare in a randomised trial the procedural and clinical outcome and long term patency of conventional angioplasty with optional stent implantation versus direct stenting without predilatation.

METHODS

Patients undergoing coronary intervention for symptomatic coronary artery disease were randomly assigned to conventional angioplasty with optional stenting or to direct stent implantation without predilatation. The post-stent treatment consisted of antiplatelets. Follow up angiography was performed six months after the initial procedure.

RESULTS

Between December 1998 and August 1999, 181 of 190 eligible patients were randomly assigned to either optional stenting (n = 92) or direct stenting (n = 89). The procedural success was similar in both groups (87 (97.8%) in the optional v 87 (94.6%) in direct stenting group, p = 0.88). There were five cases of crossover from the direct stenting to the optional stenting group. Six patients experienced a Q wave myocardial infarction without further complications (4 in the optional v 2 in the direct stenting group, p = 0.36). One patient in whom coronary angioplasty failed underwent elective bypass surgery. No patients required urgent bypass surgery and no patients died. The reduction in late luminal loss (mean (SD) 1.19 (0.87) mm in the optional v 0.62 (0.69) mm in the direct stenting group, p = 0.004) led to a significant improvement in minimal luminal diameter at follow up (1.87 (0.93) mm in the optional v 2.56 (0.86) mm in the direct stenting group, p = 0.002), resulting in a significant reduction in restenosis rate, defined as > 50% diameter stenosis at follow up 6.5 (2.1) months after the initial procedure (28 (30.4%) in the optional v 14 (15.7%) in the direct stenting group, p = 0.019). Direct stenting significantly reduced the overall procedure and fluoroscopy times, the amount of contrast medium used, and the number of angioplasty catheters needed. The incidence of clinical events during the six month follow up did not differ significantly between the groups. No patient died during follow up.

CONCLUSIONS

Direct stent implantation without predilatation significantly reduced late luminal loss, giving a better improvement in minimal luminal diameter and restenosis rate than with optional stenting. There were five patients in whom direct stenting failed who needed predilatation followed by stent implantation. However, in most patients direct stent implantation without predilatation is a feasible treatment option with a favourable long term outcome and a low incidence of complication. The procedure may help to reduce the cost of coronary interventions by reducing overall procedure and fluoroscopy times, the amount of contrast medium used, and the number of angiography catheters needed.

Treatment of no-reflow phenomenon with verapamil after primary stent deployment during myocardial infarction

No-reflow phenomenon is the absence of myocardial perfusion despite adequate dilatation of the infarct related coronary artery during percutaneous coronary intervention. It predicts severe left ventricular dysfunction and poor prognosis in acute myocardial infarction (AMI). The present case is a 54 year old Turkish female who presented with chest pain that had started 2.5 hours earlier. The clinical and laboratory findings were consistent with AMI and the coronary angiogram performed for primary angioplasty revealed a 95% thrombotic occlusion with a TIMI grade I flow in the left anterior descending (LAD) coronary artery. A TIMI grade III flow was achieved with direct stent deployment. However, after the placement of a second stent for severe ostial stenosis more proximally and adjacent to the first one, the antegrade flow became TIMI grade O. As the intracoronary medications did not improve the flow, a mechanical occlusion was considered and a third stent was deployed covering the first two stents. A control angiogram revealed the persistence of TIMI grade O flow. A severe and persistent vasospasm was considered at this point and accordingly, intracoronary verapamil was administered in high concentrations by an infusion catheter to the distal LAD which was followed by the immediate achievement of TIMI grade III flow. Intracoronary administration of high dose verapamil can be performed to prevent vasospasm in resistant no-reflow cases with no evidence of mechanic occlusion.

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.

T-cell-mediated lysis of endothelial cells in acute coronary syndromes

BACKGROUND

CD4 T lymphocytes accumulate in unstable plaque. The direct and indirect involvement of these T cells in tissue injury and plaque instability is not understood.

METHODS AND RESULTS

Gene profiling identified perforin, CD161, and members of the killer-cell immunoglobulin-like receptors as being differentially expressed in CD4(+)CD28(null) T cells, a T-cell subset that preferentially infiltrates unstable plaque. Frequencies of CD161(+) and perforin-expressing CD4 T cells in peripheral blood were significantly increased in patients with unstable angina (UA). CD161 appeared on CD4(+)CD28(null) T cells after stimulation, suggesting spontaneous activation of circulating CD4 T cells in UA. Perforin-expressing CD4(+) T-cell clones from patients with UA exhibited cytotoxic activity against human umbilical vein endothelial cells (HUVECs) in redirected cytotoxicity assays after T-cell receptor triggering and also after stimulation of major histocompatibility complex class I-recognizing killer-cell immunoglobulin-like receptors. HUVEC cytolysis was dependent on granule exocytosis, as demonstrated by the paralyzing effect of pretreating CD4(+)CD28(null) T cells with strontium. Incubation of HUVECs with C-reactive protein (CRP) increased HUVEC lysis in a dose-dependent fashion.

CONCLUSIONS

In patients with UA, CD4 T cells undergo a change in functional profile and acquire cytotoxic capability. Cytotoxic CD4 T cells effectively kill endothelial cells; CRP sensitizes endothelial cells to the cytotoxic process. We propose that T-cell-mediated endothelial cell injury is a novel pathway of tissue damage that contributes to plaque destabilization. The sensitizing effect of CRP suggests synergy between dysregulated T-cell function and acute phase proteins in acute coronary syndromes.

Visualized plaque debris as a cause of distal embolization after percutaneous coronary intervention in patient with unstable angina

Procedural complications of percutaneous transluminal coronary angioplasty for unstable angina are higher than for stable angina. We report a case in which coronary angioscopy proved the dislodgment of a large plaque fragment after Cutting Balloon angioplasty and confirmed our suspicion that plaque fragmentation can cause distal embolization.

Percutaneous intervention of old degenerated saphenous vein grafts

The treatment of failing bypass grafts is difficult because repeat surgery carries a higher mortality rate than a first operation. Percutaneous intervention is more difficult because mechanical manipulation of these soft, friable atherosclerotic plaques have been associated with a significant rate of distal embolization, myocardial infarction, late restenosis and death. Balloon angioplasty alone has proven to have serious limitations in the treatment of older degenerated saphenous vein grafts (SVG). Although directional atherectomy yielded a higher angiographic success in a randomized trial, the restenosis rate was similar, and the procedural complications higher. The transluminal extraction catheter (TEC) has also shown significant limitations for the treatment of degenerated or thrombotic vein grafts with a significant procedural complication rate. A randomized trial comparing stenting versus balloon angioplasty in focal SVG lesions showed a higher freedom from major adverse cardiovascular events in the stent group, but there was no significant difference in the angiographic restenosis rates. More recently, rheolytic thrombectomy and mechanical thrombolysis have proven useful in treating thrombotic lesions in SVG. In addition, the recent development of distal protection devices appears very promising and will probably contribute to decreased distal embolization during percutaneous revascularization of these conduits.

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.

Direct coronary stenting without balloon or device pretreatment: acute success and long-term results

Improvements in coronary stents have made planned direct coronary stenting technically feasible, though safety, acute success, cost-effectiveness, and long-term results remain to be determined. Sequential patients eligible for direct stenting were prospectively characterized and treated with either direct or secondary stenting. Major adverse cardiovascular events (MACE) such as cardiac death, myocardial infarction (MI), target vessel ischemia, or revascularization (TVR) were followed for 6 months post-PCI. Enrollment included 128 direct (1.38 lesions/patient) and 69 secondary (1.39 lesions/patient) stented patients. Direct stenting was successful in 99% (with 5% crossover to secondary stenting) without major procedural complications and with a similar rate of vessel wall dissection or no-reflow phenomenon (2.3% vs. 2.1%; P > 0.05) as the secondary stenting group. There was a trend toward less postprocedural CPK-MB elevation in the nonacute MI patients with direct vs. secondary stenting (3% vs. 11%, respectively). At 6 months, there were no statistically significant differences in overall MACE. Direct stenting has a high success rate, low complication rate, and durable long-term results. Procedural cost and time savings, less contrast use and radiation exposure make direct stenting attractive in properly selected patients.

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.

[Initial results and 6 month clinical follow-up after implantation of a silicon carbide coated coronary stent]

INTRODUCTION AND OBJECTIVES

To present the initial Spanish experience with the Tenax coronary stent, a laser sculpted from high-precision 316L stainless steel coated with hydrogen rich amorphous silicon carbide that reduces thrombogenecity and improves biocompatibility.

PATIENTS AND METHODS

From July 1998 to July 1999, 206 patients (62 +/- 5 years) underwent implantation of 231 Tenax stents in 9 centers as the only revascularization procedure. The most frequent clinical indication was unstable angina (66%), and most of the lesions were complex (class B2 and C). The target vessels were the left anterior descending (51%) and right coronary arteries (36%). The ejection fraction was < 0.5 in 19% cases.

RESULTS

Revascularization was complete in 70%, elective in 80%, and the implantation was direct in 25% of the cases. The procedure was successful in all the lesions, reducing stenosis from 62 +/- 16 to 16 +/- 10% and increasing the minimal luminal diameter from 0.81 +/- 0.40 to 2.61 +/- 0.59 mm. The TIMI flow was reduced in 30%, but normalized after the stent in all but one case. The incidence of cardiac events was minimal: 1 acute thrombosis (0.5%) resolved by a new angioplasty and 1 non-Q myocardial infarction (0.5%). At the 6-month clinical follow-up 10% of the patients presented complaints of angina greater than class II, and a new angioplasty was carried out in 1.9% of these cases.

CONCLUSION

Clinical and angiographic data suggest that the hydrogenated silicon carbide coating of the Tenax coronary stent may indeed play a beneficial role in patient outcome, and should therefore be evaluated by prospective clinical trials.

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.

Clinical and technical determinants of the complexity of percutaneous transluminal coronary angioplasty procedures: analysis in relation to radiation exposure parameters

Few data are available on the quantitative assessment of complexity (C), especially in relation to a patient's exposure to radiation. The relationship between several clinical (CFs), anatomic (AFs), and technical factors (TFs) versus fluoroscopy time (FT) was evaluated in 402 random percutaneous transluminal coronary angioplasty (PTCA) procedures. CFs were age, sex, single or multivessel disease, ejection fraction, and previous coronary artery bypass graft. AFs were assessed based on the American Heart Association / American College of Cardiology classification. TFs were multivessel PTCA, use of the double wire or double balloon technique, stenting, ostial stenting, bifurcation stenting, and intravascular ultrasonography. No CFs significantly influenced FT, whereas all AFs and TFs (except multivessel PTCA) did significantly influence FT. A scoring system was developed, and two complexity indexes (CI) were conceived, based on which the procedures were divided into three groups: simple, medium, and complex. The mean FTs were 471+/-289, 805+/-532, and 1,190+/-641 (P <0.0001), respectively. Total cine frame recordings were 1,119+/-572, 1,265+/-644 (P = 0.0355), and 1,418+/-785 (P<0.0001 vs. simple; P = NS vs. medium). The dose/area product measurement was 65.8+/-41.4, 93 +/-58.5 (P<0.0001), and 116.7+/-72.8 (P<0.0001 vs. simple; P = 0.00159 vs. medium), respectively. In our series, CI was directly related to AF and TF, but not to CF. Comparison of PTCA procedures and definition of appropriate FT should consider CIs.

Novel method of coronary stent delivery

Occasionally a coronary stent cannot be delivered. In this case, a dislodged stent was purposely pushed forward by the delivery balloon into position; a smaller, compliant balloon was used for initial deployment; and the original stent-delivery balloon was used for subsequent final deployment.