Combined antiplatelet therapy with ticlopidine and aspirin. A simplified approach to intracoronary stent management

Efficacy of aspirin, clopidogrel, and ticlopidine in stroke prevention: A population-based case-cohort study in Taiwan

Background

In real-world practice settings, there is insufficient evidence on the efficacy of antiplatelet drugs, including clopidogrel, aspirin, and ticlopidine, in stroke prevention.

Purpose

To compare the efficacies between aspirin and clopidogrel and aspirin and ticlopidine in stroke prevention.

Methods

This population-based case-cohort study utilized the data obtained from a randomized sample of one million subjects in the Taiwan National Health Insurance Research Database. Patients who were hospitalized owing to the primary diagnosis of ischemic stroke from January 1, 2000 to December 31, 2010 and treated with aspirin, ticlopidine, or clopidogrel were included in the study. Propensity score matching with a 1:4 ratio was performed to compare aspirin with ticlopidine and clopidogrel. The criteria for inclusion were the use of one of the three antiplatelet drugs for more than 14 days within the first month after the stroke and then continued use of the antiplatelet drugs until the study endpoint of recurrent stroke.

Results

During the 3-year follow-up period, the recurrent stroke rates were 1.62% (42/2585), 1.48% (3/203), and 2.55% (8/314) in the aspirin, ticlopidine, and clopidogrel groups, respectively. Compared with the patients treated with aspirin, those treated with clopidogrel and ticlopidine showed competing risk-adjusted hazard ratios of recurrent stroke of 2.27 (1.02–5.07) and 0.62 (0.08–4.86), respectively.

Conclusion

Compared with the patients treated with aspirin, those treated with clopidogrel were at a higher risk of recurrent stroke. For stroke prevention, aspirin was superior to clopidogrel whereas ticlopidine was not inferior to aspirin.

Prospective Evaluation of von Willebrand Factor Release After Multiple and Single Stenting

The hypothesis that von Willebrand factor (vWf) release after multiple coronary stenting may be higher than release after single coronary stenting was tested. Preliminary data suggest that multiple stenting is a predictor of thrombosis, and vWf levels in the coronary sinus reflect coronary endothelial injury. Therefore vWf as an indicator of thrombogenesis and endothelial injury was studied. vWf levels were obtained in the coronary sinus at the prestenting and poststenting period in 50 patients with ischemic heart disease who underwent elective coronary stenting (25 patients in single stent group and 25 patients in multiple stent group). Eight subjects who underwent diagnostic coronary angiography were used as controls. vWf levels increased significantly after multiple stenting and vWf levels were significantly different from vWf levels after single stenting. In single stent group, vWf levels in type C lesions were significantly different from levels detected in type A and B lesions. Multiple coronary stenting induces a rapid increase in vWf expression in the coronary circulation. These changes may contribute to the pathogenesis of acute or subacute stent thrombosis and restenosis after multiple stenting.

Pharmacology of antithrombotic drugs: an assessment of oral antiplatelet and anticoagulant treatments

Antithrombotic drugs, which include antiplatelet and anticoagulant therapies, prevent and treat many cardiovascular disorders and, as such, are some of the most commonly prescribed drugs worldwide. The first drugs designed to inhibit platelets or coagulation factors, such as the antiplatelet clopidogrel and the anticoagulant warfarin, significantly reduced the risk of thrombotic events at the cost of increased bleeding in patients. However, both clopidogrel and warfarin have some pharmacological limitations including interpatient variability in antithrombotic effects in part due to the metabolism, interactions (eg, drug, environment, and genetic), or targets of the drugs. Increased knowledge of the pharmacology of antithrombotic drugs and the mechanisms underlying thrombosis has led to the development of newer drugs with faster onset of action, fewer interactions, and less interpatient variability in their antithrombotic effects than previous antithrombotic drugs. Treatment options now include the next-generation antiplatelet drugs prasugrel and ticagrelor, and, in terms of anticoagulants, inhibitors that directly target factor IIa (dabigatran) or Xa (rivaroxaban, apixaban, edoxaban) are available. In this Series paper we review the pharmacological properties of these most commonly used oral antithrombotic drugs, and explore the development of antiplatelet and anticoagulant therapies.

Endovascular Treatment of Large Intracranial Aneurysms by Neuroform Stent-Assisted Coil Placement

Large intracranial aneurysms represent huge therapeutic challenges for neurosurgeons and endovascular therapists. Since they may involve entire vessels or be irregular in shape, the ratio of complete obliteration of these aneurysms with detachable coils is low and the incidence of recanalisation is very high. So the technique of stent-assisted coil placement was designed for the treatment of large intracranial aneurysms. We report our experience in the treatment of large or complex and wide-necked aneurysms using Neuroform stent-assisted coil placement. Thirty-six patients harboring large intracranial aneurysms were treated by Neuroform stent-assisted coil placement. Thirty-five Neuroform stents were delivered and deployed at the desired location. Of the 35 aneurysms successfully stented, all the aneurysms were occluded with stent-assisted coiling. Twenty-six were totally occluded, four achieved subtotal occlusion, and five incomplete occlusion at the end of the procedure. There were no complications related to the procedure except the migration of stents in two cases. All the patients recovered well. Though Neuroform stent-assisted coil placement may be a favorable technique for treatment of large intracranial aneurysms, further study is necessary to assess the long-term outcome.

In-vitro assays of polymer-coated stents eluting platelet glycoprotein IIb/IIIa receptor monoclonal antibody

The monoclonal antibody (mAb) to the platelet glycoprotein (GP) IIb/IIIa receptor has potent antiplatelet and antithrombotic characteristics shown to reduce thrombus-related major complications after coronary angioplasty. This mAb can be incorporated in drug-eluting stents capable of releasing single or multiple bioactive agents into the bloodstream and surrounding tissues. Stents eluting the monoclonal mouse anti-human platelet glycoprotein IIb/IIIa antibody SZ-262 were tested for their effectiveness in improving the blood compatibility and the antithrombotic characteristics by immunofluorescence and scanning electron microscopy (SEM). The SEM results convincingly demonstrated that the surface of the mAb eluting-stents was completely free of platelet uptake without any sign of cellular debris or proteinaceous deposits, compared with controls. The deformation index of platelets on the L-polylactic acid (L-PLA) coated stents were higher than bare Nitinol intravascular stents, as shown by SEM images. Monoclonal antibody to the platelet GP IIb/IIIa receptor, when eluting from L-PLA polymer-coated stents, effectively inhibits platelet aggregation in the stent microenvironment, thus demonstrating a potential capacity of reducing thrombosis, improving blood flow and arterial patency rates, and inhibiting cyclic blood flow variations. These results highlight the possibility of such monoclonal antibody-eluting stents to reduce or possibly eliminate thrombosis and in-stent restenosis.

Applying drug-eluting stents in clinical practice

The use of percutaneous coronary interventions has resulted in significant improvement in patient care; however, the risk for restenosis remains a major limitation. Drug-eluting stents represent an impressive breakthrough in the evolution of interventional cardiology, but it is important to understand the limits to their added benefit. Safety of the procedure must continue to be the first consideration, and technique must not be compromised to accommodate new technology.

[Late stent-thrombosis-related myocardial infarction]

The objective of the study was to assess the frequency of late stent-thrombosis-related acute myocardial infarction in patients with LAD stents. A series of 930 PCI procedures involving LAD stenting were performed in 920 patients (mean age: 63 years, 667 men) from January 1999 to December 2001. Among those 14 patients had late (> 30 days), thrombosis-related acute myocardial infarction after a mean delay of 135 +/- 131 days. Three-year thrombosis-free survival was 97.6%. By univariate analysis, risk of late thrombosis was associated with LAD-diagonal bifurcation stenting, placement of a stent on the ostium of a diagonal branch and number of stents implanted on the LAD. Patients with these risk factors might be appropriate candidates for long-term combined antiplatelet therapy.

Comparative Inhibitory Effects of Cilostazol and Ticlopidine on Subacute Stent Thrombosis and Platelet Function in Acute Myocardial Infarction Patients With Percutaneous Coronary Intervention

We compared the effects of ticlopidine and cilostazol on the prevention of subacute stent thrombosis (SAT) in acute myocardial infarction (AMI) patients with stenting. We also analyzed the cause of the difference by measuring platelet aggregation activity. Consecutive patients who underwent successful stenting for AMI between March 2001 and March 2004 were analyzed. In addition to aspirin (100 mg/day), cilostazol (200 mg/day) was administered to 99 cases between March 2001 and May 2002 and ticlopidine (200 mg/day) was administered to 85 cases between June 2002 and February 2004. The incidence of SAT within four weeks after stenting was analyzed. Thirty-eight AMI patients were randomized and their platelet aggregation activity was measured using a laser-scattered aggregometer (18 cases in the cilostazol group and 20 cases in the ticlopidine group). SAT did not occur in the ticlopidine group while 5 cases (5.1%) of SAT occurred in the cilostazol group (P < 0.05). The inhibitory activity of cilostazol for ADP-induced platelet aggregation was lower than that of ticlopidine (P < 0.05). Cilostazol with aspirin after stenting in AMI patients showed more frequent SAT than ticlopidine with aspirin. One of the causes for this difference was speculated to be the weaker inhibitory activity of cilostazol for ADP-induced platelet aggregation.

"Protected" wallstenting of atheromatous stenoses at the carotid bifurcation

SUMMARY

Atheromatous stenoses at the carotid bifurcation were treated by angioplasty and Wallstenting with cerebral protection obtained in most cases by temporary occlusion of the internal carotid artery. 287 carotid stenoses were treated in 233 patients. The stenosis was symptomatic in 79% of cases. All patients presented either a stenosis of >70% with significant impairment of the cerebral circulation (281 cases) or a symptomatic ulcerated plaque (six cases). A self-mounted protection system was used in 177 cases, the Percusurge Guardwire protection device in 98 cases an EPI filter in 12 cases. There was a contralateral internal carotid occlusion in 13% of cases. A combined stenting (vertebral, siphon, subclavian) was performed in 14% of cases. A Rolling membrane Wallstent was used in 84 patients, a first generation Easy Wallstent in 38 cases, a "Carotid" Easy Wallstent 35 in 55 cases and monorail 14 in 110 cases. Full opening of the stenosis was obtained in 98% of patients with correction of the arterial curve and improvement of the cerebral vascular supply. There were 0.7% cases with transient symptomatic neurological complications and 2% with permanent sequelae mainly related to avoidable inadequacy in flushing or to the insufficient radial force of the first generation Easy Wallstent. There were no per and one post-procedural cardiac complication (0.6%) in the s165 cases performed with the "Carotid" Easy Wallstent. Follow-up angiograms showed 0.7% of restenoses. Still in evolution, endovascular treatment of atheromatous stenoses at the carotid bifurcation with cerebral protection and stenting is a promising alternative technique to surgery. The association of Carotid Easy Wallstent 14 monorail and Percusurge Guardwire appears to be currently satisfactory.

Elective placement of covered stents in native coronary arteries

PURPOSE

To study the feasibility of placing a polytetrafluoroethylene (PTFE)-covered stent graft into native coronary arteries and assess the complications and the restenosis rate.

MATERIAL AND METHODS

Fifty consecutive patients with stable angina pectoris were included and the stent graft was placed into native coronary arteries. Clinical and angiographic follow-up were performed after 6 months.

RESULTS

The stent grafts were successfully placed in all patients. The mean reference diameter was 3.3 +/- 0.6 mm. During follow-up the stent grafts occluded in patients after 1, 2 and 2.5 months and one more was occluded at 6 months. Three patients experienced myocardial infarction, 2 Q wave and one non-Q wave. After 6 months 42 (84%) patients had angina NYHA class 0 or 1. Target vessel revascularization was done in 11 cases for restenosis in the graft (n = 4), outside the graft (n = 3) and both (n = 4), giving a restenosis rate of 24%. The total major adverse coronary events at 6 months was 24%.

CONCLUSION

The stent graft was deployed with a high success rate. The restenosis rate was not higher than expected for bare stents. However, this study showed that subacute occlusion may occur more frequently and we therefore recommend that ticlopidine or clopidogrel treatment should be prolonged to at least 3 months.

Late thrombotic occlusion of a malapposed stent 10 months after intracoronary brachytherapy

We report a patient who received a stent following intracoronary 3-irradiation. Despite a good initial angiographic result, the stent appeared to be not fully expanded on intravascular ultrasound imaging at 6-month follow-up. Four months later, sudden thrombotic occlusion occurred shortly after aspirin cessation.

Predictive value of preprocedural fibrinogen concerning coronary stenting

Elevated fibrinogen levels after coronary balloon angioplasty have been reported to be useful in predicting restenosis. Therefore, we sought to evaluate the relationship between preprocedural fibrinogen levels and the 6-12-month outcomes of patients undergoing coronary stenting. Plasma levels of fibrinogen were measured in 390 consecutive patients prior to coronary stenting. The primary end point was binary restenosis (percent diameter stenosis of >/=50%). The secondary combined end point was death due to cardiac causes, myocardial infarction related to the target vessel and target lesion revascularization. Patients were grouped into tertiles according to fibrinogen levels. Both at baseline and immediately after procedure, clinical and angiographic characteristics were almost identical in the fibrinogen tertiles. An increase in restenosis rate was observed across the tertiles (18.6, 23.9, 38.1%, P<0.001, respectively). In addition, the frequency of the secondary end point increased in the highest tertile (14.9, 21.5, 37.2%, P<0.001, respectively). Multivariate analysis revealed that high levels of fibrinogen (per 100 mg/dl, OR 1.82, P<0.001) and stent length (P=0.034) were independent predictors for restenosis. An elevated preprocedural fibrinogen level should be considered as a stronger predictor for restenosis after coronary stenting, which might be associated with coagulation and inflammation.

The effect of clopidogrel in combination with aspirin when given before coronary artery bypass grafting

OBJECTIVES

This study was designed to evaluate the effect of preoperative clopidogrel on coronary artery bypass graft surgery (CABG) outcomes.

BACKGROUND

Clopidogrel in combination with aspirin, given before percutaneous coronary intervention, has become the standard for stent thrombosis prevention. Some premedicated patients, however, are found to have surgical disease on angiography, and irreversible platelet inhibition becomes a concern for upcoming CABG.

METHODS

We prospectively studied 224 consecutive patients undergoing nonemergent first-time CABG, and compared those with preoperative clopidogrel exposure within seven days (n = 59) to those without exposure (n = 165).

RESULTS

The groups were comparable in age, gender, body surface area, preoperative hematocrit, preoperative prothrombin time and prior myocardial infarction. The clopidogrel group had higher 24-h mean chest tube output (1,224 ml vs. 840 ml, p = 0.001), and more transfusions of red blood cells (2.51 U vs. 1.74 U, p = 0.036), platelets (0.86 U vs. 0.24 U, p = 0.001) and fresh frozen plasma (0.68 U vs. 0.24 U, p = 0.015). Moreover, reoperation for bleeding was 10-fold higher in the clopidogrel group (6.8% vs. 0.6%, p = 0.018). The clopidogrel group also had less extubation within 8 h (54.2% vs. 75.8%, p = 0.002) and a trend towards less hospital discharge within five days (33.9% vs. 46.7%, p = 0.094).

CONCLUSIONS

Clopidogrel in combination with aspirin before CABG is associated with higher postoperative bleeding and morbidity. These findings raise concern regarding the routine administration of clopidogrel before anticipated coronary stent implantation.

Combined therapy with clopidogrel and aspirin significantly increases the bleeding time through a synergistic antiplatelet action

OBJECTIVE

Many thromboembolic events occur in patients taking aspirin. Dual therapy with aspirin and clopidogrel may prove effective at reduction of thromboembolic complications. However, the extent to which these two drugs interact may significantly increase the risk of bleeding in open surgery. Because of the increased use of combination antiplatelet therapy in populations with significant atherosclerotic disease, this risk needs to be evaluated by the assessment of the combined effect in vivo of clopidogrel and aspirin on bleeding time and platelet function.

OUTCOMES

In seven healthy subjects, addition of low dose clopidogrel (2 x 75 mg) to aspirin (150 mg) therapy significantly increased bleeding time (from 7.6 +/- 3.4 minutes to 17.5 +/- 8.6 minutes; P <.05), with concomitant falls in adenosine diphosphate (ADP)-induced platelet fibrinogen binding and aggregation (P <.05). Increasing the dose of clopidogrel to 300 mg increased bleeding time (to 24.9 +/- 8.5 minutes; P <.05) without significant additional platelet inhibition. There was considerable variability in the individual subject platelet response to the lower dose of clopidogrel. Those patients with the highest ADP response at baseline had the least response, and subjects with a weak response to ADP at baseline achieved maximal platelet inhibition with the low dose of clopidogrel.

CONCLUSION

The increases in bleeding times should be considered in combination antiplatelet therapy in patients who undergo open vascular surgery.

Staged versus one-step approach for multivessel percutaneous coronary interventions

BACKGROUND

Percutaneous coronary interventions (PCIs) in patients with multivessel coronary artery disease (CAD) may be staged or performed in a single session. No data exist about the relative safety and efficacy of these 2 strategies. Our aim was to compare short-term and long-term outcomes of patients with multivessel CAD who underwent PCI in 1 versus 2 sessions.

METHODS AND RESULTS

The study included 264 consecutive patients who underwent treatment in our center during 1997 and 1998. PCI was conducted in a single session in 129 patients and was staged in 135 patients. The mean interval between the sessions in the staged group was 45.6 +/- 22.3 days. The rates of major adverse cardiac events (MACEs) during in-hospital stay did not differ significantly between the staged (combined for both stages) and nonstaged groups (2.2% vs 4.6%; P =.28). A trend for lower event rates at 30-day (2.9% vs 6.9%; P =.13) and 1-year follow-up (26.1 vs 35.9; P =.08) favored the staged arm. Diameter stenosis > or =50% was found in 17% of patients in the staged group in the second session and was successfully retreated in most of them. No MACE occurred between the sessions. Multivariate analysis identified staging of the procedure as a single independent predictor of MACE at 1-year follow-up (P =.05).

CONCLUSION

Our results suggest that a practical staging strategy within 4 to 8 weeks is safe and allows for identification and treatment of potential excessive proliferative response in the previously intervened lesions during the second procedure.

The comparison of different clinical, laboratory, and angiographical parameters in diabetic stent restenosis

This investigation was undertaken to detect the midterm stent restenosis rate in diabetic patients and the important clinical, laboratory, and angiographic factors for in-stent restenosis in the same group. Our results found the real midterm stent restenosis rate to be 40.3% in 159 stents placed in 134 diabetic patients. For diabetic stent restenosis, the most important angiographic and clinical factors in univariate logistic regression analyses were the used stent diameter (P < 0.001), reference vessel diameter (P < 0.01); patient age (P < 0.01); duration of diabetes mellitus (P < 0.01); unstable angina prior to stenting (P < 0.05); dyslipidemia (P < 0.05); and diseased vessel number (P < 0.05). The most important factors in multivariate analysis were the used stent length (P < 0.05) and dyslipidemia (P < 0.05). Classic risk factors for nondiabetic stent restenosis were also found to be important for diabetic stent restenosis. The advanced age and duration of diabetes mellitus and the number of diseased coronary vessels and segments may be other specific risk factors for diabetic stent restenosis.

Clinical and angiographic outcomes of diabetic patients after coronary stenting: a comparison of native vessel stent restenosis rates in different diabetic subgroups

The main objectives of this study were to analyze the relationship between stent restenosis and microalbuminuria, which may express not only the glomerular vessels damage but also widespread microvascular dysfunction including coronary arterial disease, and to determine the angiographic and clinical outcomes of different diabetic subgroups after coronary stenting. Identification of the factors that may predict the outcome after coronary stent placement in diabetic patients could assist in deciding different stenting strategies in different diabetic subgroups. Control coronary angiographies were performed in 136 diabetic patients 6 months after coronary stent implantation. Patients were divided into 3 subgroups according to their microalbuminuria status. Clinical and angiographic outcomes and distribution of various risk factors were determined for these subgroups. Blood pressure and serum cholesterol concentrations were higher in the overt diabetic nephropathy group. The mean diseased vessel segment rate was lower in patients without microalbuminuria. Although the mean stent length and size were similar, patients without microalbuminuria had lower restenosis rates (23.9% vs 53.2% [microalbuminuria] and 46.2% [overt diabetic nephropathy] p<0.01). Insulin therapy or gender caused no difference in restenosis rate. Although stent lengths and diameters were not different, patients with microalbuminuria had higher restenosis rates. The authors suggest that microalbuminuria may be an independent risk factor for restenosis in patients with diabetes.

Can angiotensin receptor antagonists prevent restenosis after stent placement?

Restenosis rates after coronary stent implantation in complex lesions are between 30 and 50%. Neointimal hyperplasia promoted by complex interaction between cellular and acellular elements, such as cytokines and growth factors, is thought to be the primary process responsible for restenosis. The risk of in-stent restenosis is increased in patients with a history of restenosis after percutaneous transluminal coronary angioplasty, in long lesions, in total occlusions, in patients with diabetes mellitus, in small vessels, in the proximal parts of the left anterior descending coronary artery and in cases of stent oversizing. In-stent restenosis represents a serious economic burden on society because treatment strategies include expensive approaches such as cutting-balloon angioplasty, rotational atherectomy and brachytherapy. A number of pharmacological agents, including ACE inhibitors, have been unsuccessful in preventing restenosis. Alternative procedures such as brachytherapy, radioactive stents and drug-eluting stents are under evaluation. Although sirolimus- or paclitaxel-eluting stents have been associated with very low restenosis rates over durations of 6 to 12 months, the long-term efficacy and tolerability of this approach is currently being investigated. Although ACE inhibitors have failed in reducing restenosis rates, the selective angiotensin II type 1 (AT(1)) receptor antagonist valsartan has shown encouraging results in the single-center Valsartan for Prevention of Restenosis after Stenting of Type B2/C lesions trial (ValPREST). The ValPREST trial is the first randomized, placebo-controlled study to have evaluated the effect of an angiotensin receptor antagonist on in-stent restenosis in a moderate number of patients. Compared with ACE inhibitors, angiotensin receptor blockers exert additional effects on the pathophysiological processes which lead to restenosis. Angiotensin receptor antagonists may affect several mechanisms involved in neointimal hyperplasia such as decreasing circulating cytokine and growth factor levels and reducing neutrophil activation, especially after stenting in acute coronary syndromes, but the results need to be confirmed in a large multicenter trial. The question whether long-term therapy, with an oral angiotensin receptor antagonist, is cost-effective and whether angiotensin receptor antagonists should be used as an add-on therapy to drug-eluting stents, requires clarification.

Angiographic and clinical one-year follow-up of the Cordis tantalum coil stent in a multicenter international study demonstrating improved restenosis rates when compared to pooled PTCA and BENESTENT-I data: the European Antiplatelet Stent Investigation (EASI)

The Cordis tantalum coil stent was assessed in a nonrandomized multicenter trial: 275 patients with stable or unstable angina were entered. Clinical follow-up was for 1 year, with repeat angiography at 6 months. The major adverse cardiac event rates (MACE) were 3%, 14%, and 17% at 1, 7, and 13 months, respectively. The procedural success rate was 96% and the subacute occlusion rate 1.5%, in a group of patients over 60% of whom had ACC/AHA type B2 or C lesions. The binary restenosis rate at 6 months was 17.3%. Minimum lumen diameter increased from 1.07 +/- 0.28 mm preprocedure to 2.93 +/- 0.34 mm poststenting and at 6 months was 1.99 +/- 0.69 mm. These results demonstrate that the Cordis tantalum stent can be used to treat complex lesions with good procedural success and low rates of subacute thrombosis and restenosis at 6 months.

Ticlopidine versus oral anticoagulation for coronary stenting

BACKGROUND

A 2-4 week course of ticlopidine plus aspirin following coronary stenting is considered effective in preventing thrombotic occlusion of the stented vessel and safe in regards to bleeding and peripheral vascular complications. However, rare, although potentially life-threatening haematological complications have been reported with this drug regimen.

OBJECTIVES

To evaluate the efficacy and safety of ticlopidine plus aspirin versus oral anticoagulants after coronary stenting

SEARCH STRATEGY

Electronic search of the Cochrane Library, Medline, Embase from 1991 to June 1999; references from trials and experts.

SELECTION CRITERIA

Randomised controlled trials comparing ticlopidine plus aspirin versus oral anticoagulants (either with or without aspirin) after elective or bail out coronary stenting.

DATA COLLECTION AND ANALYSIS

Three reviewers assessed trial quality and compiled data on outcomes including: total mortality, non fatal myocardial infarction and revascularization occurring within the first 30 days after hospitalization, stent thrombosis on angiography, major and minor bleeding, neutropenia, thrombocytopenia, thrombotic thrombocytopenic purpura.

MAIN RESULTS

Four trials (n=2436 patients) were included. Ticlopidine plus aspirin compared to oral anticoagulants significantly reduced the risk of non-fatal acute myocardial infarction and revascularization at 30 days, combined negative events (mortality, myocardial infarction, revascularization at 30 days) (RR: 0.41; 95% CI: 0.25-0.69; NNT for 30 days: 22; 95% CI: 14-45), and major bleeding (RR in high quality studies: 0.24; 95% CI: 0.07-0.79). Ticlopidine plus aspirin compared to oral anticoagulants significantly increased the risk of eutropenia, thrombocytopenia and neutropenia (RR 5; 95% CI: 1.08-13.07; NNT for 30 days: 142; 95% CI: 76-1000). Ticlopidine plus aspirin vs oral anticoagulation did not affect all cause mortality. Ticlopidine plus aspirin significantly reduced the risk of stent thrombosis (angiography) which was seen only on studies with blinded outcome assessment (RR: 0.14; 95% CI: 0.03-0.60; NNT for 30 days: 33; 95% CI:16-166). Minor bleeding was reported only in one study and no studies recorded thrombotic thrombocytopenic purpura (TTP).

REVIEWER'S CONCLUSIONS

Ticlopidine plus aspirin after coronary stenting is effective in reducing the risk of the revascularization, non fatal myocardial infarction and bleeding complications when compared with oral anticoagulants. No effect is observed on total mortality. However, the haematological side effects of ticlopidine are still a matter of concern, and strict monitoring of blood-cell counts is recommended. Physicians should also be aware of the possibility of rare although potentially life-threatening complications such as TTP

Long-term outcome in patients treated by intracoronary stenting with ticlopidine and aspirin, and deleterious prognostic role of unstable angina pectoris

Compared with stable clinical conditions, unstable angina carries an increased risk of immediate and delayed cardiac adverse events after balloon coronary angioplasty. The influence of stent use in reducing these differences remains unknown. We analyzed the early (30 days) and late outcome of a cohort of 459 consecutive patients who underwent stent placement with ticlopidine and aspirin as antithrombotic regimen according to the presence (group 1, n = 151) or absence (group 2, n = 308) of unstable angina at rest (Braunwald classes II and III). Group 1 patients were older and more likely to be current or former smokers. In group 2, prior myocardial infarction was more frequent. Procedural, in-hospital results, and early outcome were similar in the 2 groups. However, over the long term, the incidence of myocardial infarction (11% vs 6%, p <0.04), target lesion revascularization (19% vs 13%, p <0.04), or any revascularization (30% vs 20%, p <0.01) was significantly higher in group 1. Kaplan-Meier probabilities of survival without myocardial infarction (85% vs 91%, p <0.05), survival without revascularization of the target lesion (73% vs 83%, p <0.01), survival without any revascularization (65% vs 77%, p <0.006), and survival without any events (61% vs 73%, p <0.009) were significantly worse in group 1. In addition, Cox multivariate analysis showed that unstable angina at rest was an independent predictor of target lesion revascularization, of survival without any revascularization, and without any events. Thus, unstable angina at rest remains an adverse prognostic indicator in patients treated with intracoronary stents, particularly with regard to subsequent requirement of revascularization procedures and event-free survival.

Antiplatelet is superior to anticoagulant treatment after coronary stenting: fewer coronary and other events within 30 days after stenting

Stent prosthesis is a high efficacious method with low complication rates. However, the ideal adjunctive therapy following stent implantation remains controversial. The authors compared the effectiveness and complication rates of aspirin-ticlopidine antiplatelet therapy vs. anticoagulant therapy with acenocoumarol within 30 days following stent prosthesis. They prospectively studied 404 patients following stent prosthesis while randomly receiving anticoagulant (Group A: 201 patients) vs. antiplatelet treatment (Group B: 203 patients). Groups A and B were similar in demographic data (age, gender), stent location, clinical presentation, indication of stenting, and type of implanted stent. Chi-square test, t test, and Wilcoxon test for two samples were used for statistical analysis of the results. Stent implantation was attempted in 434 cases. This was successful in 70/85 (82%) of the bailout, 122/135 (90%) of the suboptimal, and 212/214 (99%) of the elective cases. In 201 patients anticoagulant treatment with acenocoumarol was administered for 4 weeks (group A), while 203 received antiplatelet treatment with ticlopidine (group B). The need for reintervention was less and total cardiac events were fewer in group B than in group A: three (1.5%) and nine (4.4%) vs 18 (9%) and 29 (14.4%), p<0.0008 and p<0.006 respectively. Hemorrhagic complications and total noncardiac events were fewer in group B than in group A: six (3%) and six (3%) vs. 18 (9%) and 19 (9.5%), p<0.01 and p<0.007 respectively. The length of hospital stay was shorter in group B than in A, p<0.0001. In conclusion, in this study of intracoronary stenting the authors had a high success rate in 434 attempted cases. Antiplatelet therapy was accompanied by fewer cardiac and noncardiac 1 month events when compared with anticoagulant therapy, supporting its role as the adjunctive treatment of choice post-stenting for the time being.

Angiographic and clinical outcome of a new self-expanding intracoronary stent (RADIUS): results from multicenter experience in Japan

The RADIUS coronary stent featuring a multisegmented slotted tube design and self-expanding nitinol delivery system has a high radial force and flexibility, uniform expansion, and contours to the shape of the vessel. Successful stent deployment was achieved in 104 stable angina patients (106 lesions; 44% LAD, 19% circumflex, and 37% RCA). Mean minimal lumen diameter (MLD) increased from 0.77 +/- 0.46 mm to 2.88 +/- 0.61 mm and mean percent diameter stenosis (% DS) decreased from 73 +/- 14% to 6 +/- 13% immediately after the procedure. At 6-month follow-up, two patients (2%) underwent urgent target revascularization, and cerebral bleeding occurred in one patient (1%). Angiographic follow-up was performed in 94 lesions (89%) and mean MLD and mean % DS were 2.08 +/- 0.92 mm and 30% +/- 24%, respectively. Stent restenosis (>50% diameter stenosis at follow-up) was observed in 16 (17%) of all lesions. The high success rate for stent deployment, low incidence of major adverse cardiac event, and lower restenosis rate after stent implantation indicate that the RADIUS stent is useful for coronary intervention.

One-year clinical outcomes and relative costs of primary infarct artery stenting versus angioplasty following systemic thrombolysis for acute myocardial infarction

We investigated the clinical effectiveness and relative cost of two different infarct artery revascularization strategies in patients following systemic thrombolysis for acute myocardial infarction. The clinical efficacy and relative cost of stenting and angioplasty have not been investigated in patients requiring infarct artery revascularization after systemic thrombolysis for myocardial infarction. We prospectively enrolled 220 consecutive patients who received thrombolytic therapy for acute myocardial infarction and were subsequently treated with either angioplasty or primary stenting of the infarct artery. In-hospital and 1-year clinical outcomes, including death, myocardial infarction, and repeat revascularization, and total hospital costs over the 1-year study period were assessed. Compared to angioplasty, primary stenting resulted in lower in-hospital mortality (4% vs. 0%; P = 0.01) and reduced rates of repeat percutaneous or surgical revascularization (7% vs. 0%; P = 0.0009). At 1-year follow-up, stenting was associated with a lower death rate (6.25% vs. 0%; P = 0.002) and reduced repeat infarct artery revascularization (11% vs. 27%; P = 0. 001). Initial hospitalization costs were higher in the stent group ($11,818 +/- $3,377 vs. $9,723 +/- $8,661; P = 0.014) due primarily to catheterization laboratory-related expenditures ($7,346 +/- $2, 395 vs. $3,567 +/- $1,212; P = 0.0001). However, the cumulative 1-year medical cost difference between the two groups was not significant ($13,938 +/- $5,939 vs. $12,914 +/- $9,308; P = 0.33). Following thrombolytic therapy, primary infarct artery stenting reduced in-hospital and 1-year mortality and revascularization rates compared to angioplasty. Stenting was associated with higher initial hospital costs, which were off-set by lower revascularization rates, resulting in comparable total hospitalization costs after 1 year. These findings have important clinical and economic implications in an increasingly cost-conscious health care environment. Cathet. Cardiovasc. Intervent. 49:135-141, 2000.

The role of coronary angioplasty and stenting in acute myocardial infarction

Despite the improvements in the pharmacological treatment of acute myocardial infarction, it is recognised that thrombolysis fails to reproduce reperfusion in a significant proportion of patients. Coronary interventional techniques have been shown to offer an alternative reperfusion strategy. There is increasing evidence that mechanical reperfusion may offer significant advantages over established thrombolytic therapy.

Comparison of the efficacy and safety of aspirin alone with coumadin plus aspirin after provisional coronary stenting: final and follow-up results of a randomized study

BACKGROUND

The antithrombotic benefit of the conventional treatment with coumadin after coronary stenting is limited by bleeding complications. However, the superiority of an antiplatelet therapy with aspirin alone compared with coumadin plus aspirin has not been proven by randomized studies. The efficacy and safety of treatment with aspirin alone in comparison to coumadin plus aspirin were evaluated in this randomized study.

METHODS

Out of 164 patients aged 59.7 +/- 9.2 years, 79 patients were randomly assigned to receive 100 mg aspirin daily (group A) and 85 patients randomly assigned to coumadin plus aspirin (group CA) after provisional coronary stenting with a high-pressure technique. The primary end point was defined as the absence of death, subacute closure of the target vessel, myocardial infarction, urgent coronary bypass surgery, repeated coronary angioplasty, and peripheral vascular complications requiring transfusion or surgery. High-pressure inflation technique was used, but ultrasound guidance was not.

RESULTS

During hospitalization (median 8 days), 135 patients (82. 3%) were free of events (A, 84.8%; CA, 80.8%; P =.42). Eleven (6.7%) subacute closures occurred (A, 10.1%; CA, 3.5%; P =.09); 2 of them were lethal in the aspirin group. Emergency bypass surgery was performed in 1 patient in each group. Peripheral vascular complications were observed in 13 patients (7.9%) (A, 1.3%; CA, 14. 1%; P <.01). At 3-month follow-up, 15 (9.1%) elective revascularization procedures (A, 7.6%; CA, 10.6%; P =.51) were performed.

CONCLUSION

Aspirin alone at the low dose of 100 mg administered or the combination of coumadin and aspirin after high-pressure coronary stenting does not prevent adverse clinical events when ultrasound guidance is not used.

Intra-arterial thrombolysis for vertebrobasilar circulation ischemia

Acute basilar artery occlusion is usually associated with a poor prognosis despite therapy with antiplatelet and anticoagulant agents. The natural history of this disorder should be fully understood before clinicians make decisions on therapy. Recent advances in angiography technique and the use of newer mobile microcatheters have made intra-arterial thrombolysis therapy feasible. There have been several small, uncontrolled series of intra-arterial thrombolysis in basilar artery occlusion with promising results.

Results of coronary stenting after delayed angioplasty of the culprit vessel in patients with recent myocardial infarction

Little information is available concerning the effect of late coronary stenting in patients with recent myocardial infarction, especially long-term results. We retrospectively reviewed our results of 57 stent placements in 52 consecutive patients who received stents at an infarct-related lesion 24 hr to 30 days after an acute myocardial infarctions (median, 14 days). The average age was 67 years; 90% were male. Two patients who suffered from acute stent thrombosis received revascularization again and two early deaths were due to refractory cardiogenic shock before discharge. Mean patient clinical follow-up was 18.3 +/- 6.5 months. There were 1 subacute stent thrombosis, 1 cardiogenic death, and 10 patients (20.8%) in total suffering from angina class II to IV. Angiographic follow-up was performed in 36 patients (80%) at a mean of 7.5 +/- 3.1 months. Of these 36 patients, only 1 (3% of the total population undergoing follow-up angiography) had reocclusion at follow-up, but restenosis existed in 18 patients (50%). We conclude that there is still relatively high incidence of angiographic recurrence that is often silent in long-term follow-up, though the long-term result of late stenting in recent MI is low incidence of reocclusion.

Restenosis, late vessel occlusion and left ventricular function six months after balloon angioplasty in diabetic patients

OBJECTIVES

We studied angiographic outcome and its predictors after traditional coronary balloon angioplasty in diabetics. We further examined whether changes in ejection fraction were influenced by the status of the dilated site(s) at follow-up.

BACKGROUND

Recent studies have suggested that diabetics have a particularly poor outcome after balloon angioplasty. The reasons for this observation are not known.

METHODS

We investigated procedural and six-month angiographic outcome, analyzed by quantitative coronary angiography, and left ventricular function in 485 consecutive diabetics (627 lesions) treated by balloon angioplasty without stent implantation.

RESULTS

The procedure was successful in 455 (94%) patients; angiographic follow-up was available in 377 patients (83%). At follow-up, the rates of restenosis and total occlusion were 62% and 13%, respectively. Five independent predictors of restenosis were identified: the presence of organ damage, a saphenous vein graft (SVG) angioplasty, a bifurcation lesion, a Thrombolysis in Myocardial Infarction (TIMI) flow <3 preprocedure and the degree of residual stenosis. Four independent predictors of vessel occlusion were identified: treatment with insulin, a SVG angioplasty, a TIMI flow <3 preprocedure and the degree of residual stenosis after angioplasty. Late vessel occlusion at angioplasty site(s) was observed in 15% of patients, ranging from 11% for a one-site procedure to 37% for a three-site procedure. This complication was associated with a decrease in ejection fraction at follow-up (-6.2 +/- 9.9%, p = 0.0001), whereas no significant change was observed in patients without occlusion.

CONCLUSIONS

This study shows that late vessel occlusion is a frequent mode of restenosis in diabetic patients and is associated with a significant decrease in ejection fraction. This could partly explain the poor long-term clinical outcome reported in such patients after traditional balloon angioplasty.

The effect of antiplatelet drugs, heparin, and preanalytical variables on platelet function detected by the platelet function analyzer (PFA-100)

The platelet function analyzer (PFA)-100 is a newly developed instrument that provides a rapid, in vitro, quantitative measurement of platelet adhesion and aggregation in whole blood flowing through a small aperture under high shear conditions. Thirty patients undergoing percutaneous transluminal coronary angioplasty (PTCA) and ten normal individuals were included in this study. In vitro and in vivo studies were conducted to discern the effect of combinations of antiplatelet drugs (aspirin, ticlopidine, abciximab) and heparin on the performance of the device as well as the effects of preanalytical variables, such as method of sample collection and ex vivo anticoagulants. Studies were also conducted examining the effect of aperture size (standard 150 microns vs. smaller 120 microns) on the ability of the device to detect the effect of antiplatelet drugs. There was no difference in mean PFA-100 closure time with citrate versus PPACK anticoagulants or with venipuncture vs. sheath sampling. Closure times did not vary with heparin administration. Closure times were slightly longer for patients taking aspirin plus ticlopidine compared to aspirin alone (p = NS). In contrast adenosine disphosphate (ADP) induced platelet aggregation was significantly less in patients that took aspirin plus ticlopidine vs. aspirin alone (p = .0005). In vitro, there was a dose-dependent increase in closure time for both aperture sizes with increasing abciximab concentration. Although both cartridges showed infinite closure times at an abciximab concentration of 2.25 micrograms/mL, there was a slight benefit to using the 120 microns aperture cartridges at abciximab concentrations of 1.75 to 2.0 micrograms/mL. In ten patients who were followed during abciximab therapy to assess the effect of aperture size, the PFA-100 was able to detect in vivo platelet inhibition by abciximab, but detection of recovery from abciximab-induced platelet dysfunction was slightly better for the PFA-100 with the 120 microns aperture compared to the standard 150 microns aperture collagen/ADP cartridge.

Clinical pharmacology of the adenosine diphosphate (ADP) receptor antagonist, clopidogrel

Antiplatelet compounds interfere with the platelet activation cascade at different levels. The antiplatelet effect of the thienopyridine, clopidogrel, results from antagonism of a platelet ADP receptor, P2T, resulting in inhibition of platelet activation. This antagonism is non-competitive, irreversible, and results in a 50-70% inhibition of platelet fibrinogen binding. Additionally, clopidogrel may also antagonize the ADP-induced inhibition of adenylate cyclase, possibly resulting in an elevated platelet cyclic adenosine monophosphate level after stimulation by an appropriate agonist, such as prostacyclin. This spectrum of antiplatelet activities is different from that of aspirin. Further, clopidogrel is associated with a reduction in gastrointestinal hemorrhage, making it a valuable therapeutic alternative to aspirin in oral, long-term prevention of atherothrombotic vascular occlusion.

Stent thrombosis: incidence and related factors in the R.I.S.E. Registry(Registro Impianto Stent Endocoronarico)

Although stent thrombosis has been greatly reduced by adequate stent expansion with high-pressure balloon inflations and by the use of antiplatelet drugs, this event is still frightening, as it may lead to acute myocardial ischemia resulting in acute myocardial infarction or sudden death. Therefore, the definition of factors associated with stent thrombosis may provide a better understanding of the mechanisms underlying this phenomenon and may permit us to define therapeutic strategies to further reduce its occurrence. The purpose of this study was to assess factors responsible for the occurrence of stent thrombosis after coronary stent implantation in 939 consecutive patients enrolled in the Registro Impianto Stent Endocoronarico (R.I.S.E. Study Group). Consecutive patients undergoing coronary stent implantation at 16 medical centers in Italy were prospectively enrolled in the registry. Clinical data, and qualitative and quantitative angiographic findings were obtained from data collected in case report forms at each investigator site. The study group consisted of 781 men and 158 women with a mean age of 59 yr: 1,392 stents were implanted in 1,006 lesions and expanded at a maximal inflation pressure of 14.7 +/- 3 atm. The great majority of patients (92%) received only antiplatelet drugs after coronary stenting. During hospitalization there were 45 major ischemic complications in 39 patients (4.2%): 13 events were related to acute or subacute thrombosis (1.4%). Another stent thrombotic event occurred in the first month of follow-up. On multivariate logistic regression analysis, stent thrombosis was related to the following factors: unplanned stenting (OR 3.46, 95% CI 1.65-7.23), unstable angina (OR 3.37, 95% CI 1.11-10.14) and maximal inflation pressure (OR 0.83, 95% CI 0.75-0.93). In conclusion, this registry shows that in an unselected population of patients undergoing coronary stenting, stent thrombosis occurs in less than 2% of patients and is significantly related to unplanned stent implantation, unstable angina, and maximal inflation pressure. The incidence of this phenomenon is likely to be further reduced by the use of new potent antiplatelet drugs, such as platelet glycoprotein IIb/IIIa antagonists.

Randomized evaluation of anticoagulation versus antiplatelet therapy after coronary stent implantation in high-risk patients: the multicenter aspirin and ticlopidine trial after intracoronary stenting (MATTIS)

BACKGROUND

Although the association of ticlopidine and aspirin has been shown to be superior to anti-vitamin K agents and aspirin after coronary stent implantation in low-risk patients, the latter combination has remained an unproven reference regimen for high-risk patients until recently.

METHODS AND RESULTS

We randomized 350 high-risk patients within 6 hours after stent implantation to receive during 30 days either aspirin 250 mg and ticlopidine 500 mg/d (A+T group) or aspirin 250 mg/d and oral anticoagulation (A+OAC group) targeted at an international normalized ratio of 2.5 to 3. The primary composite end point was defined as the occurrence of cardiovascular death, myocardial infarction, or repeated revascularization at 30 days. Patients were eligible if (1) the stent(s) were implanted to treat abrupt closure after PTCA; (2) the angiographic result after implantation was suboptimal; (3) a long segment was stented (>45 mm and/or >/=3 stents); or (4) the largest balloon inflated in the stent had a nominal diameter of </=2.5 mm. The primary cardiac end point was reached for 10 patients (5.6%) in the A+T group and 19 (11%) in the A+OAC group (relative risk [RR], 1. 9; 95% CI, 0.9 to 4.1; P=0.07). Major vascular and bleeding complications were less frequent in the A+T group (3 patients, 1.7%) than in the A+OAC group (12 patients, 6.9%) (RR, 4.1; 95% CI, 1.2 to 14.3; P=0.02).

CONCLUSIONS

High-risk patients should be treated with A+T rather than A+OAC after coronary stenting because the bleeding and vascular complications are significantly reduced and there is a marked trend suggesting a decrease in cardiac events.

Combined endovascular stent implantation and endosaccular coil placement for the treatment of a wide-necked vertebral artery aneurysm: technical case report

OBJECTIVE AND IMPORTANCE

We describe a case in humans of the combined application of endovascular stent placement and Guglielmi detachable coil packing in the management of a wide-necked intracranial aneurysm.

CLINICAL PRESENTATION

A 56-year-old woman suffered a subarachnoid hemorrhage secondary to a large wide-necked left vertebral artery aneurysm. Because of the size of the neck of the aneurysm and the extent of its calcification evident on computed tomographic scans, it was deemed unsuitable for surgical intervention or for conventional endovascular coiling. Instead, a combined surgical and endovascular therapy was instituted.

INTERVENTION

The left vertebral artery was surgically exposed and cannulated to allow for the placement of an endovascular stent across the neck of the aneurysm to act as a buttress against which Guglielmi detachable coils could be packed. The patient suffered no ill effects as a result of this procedure and made a slow but steady recovery.

CONCLUSION

This report describes a case of a wide-necked intracranial artery aneurysm treated using a combination of endovascular stent implantation across an aneurysm neck and endosaccular coil placement to obliterate the aneurysm. The technique described provides another treatment to better manage the difficult entity of wide-necked intracranial aneurysms that may be unsuitable for clipping.

Antiplatelet therapy in atherosclerotic cardiovascular disease

Arterial thrombosis frequently leads to death or disability from stroke, peripheral arterial disease, or myocardial infarction (MI). Treating the underlying causes of these diseases is the key to producing significant reduction in morbidity, mortality, and health care costs. Prevention of arterial thrombosis is the primary indication for antiplatelet therapy, and intense research has been conducted in the past decade to develop novel antiplatelet agents with favorable safety profiles. The results of the Antiplatelet Trialists' Collaboration, which definitively established the rationale for antiplatelet agents in the prevention of death, MI, and stroke, were an important stimulus for this research. This large meta-analysis combined data from 145 randomized trials and showed that antiplatelet therapy (most commonly aspirin, 75 to 325 mg/d) reduced the risk of vascular events, including nonfatal MI, nonfatal stroke, and vascular death, by 25% in patients at high risk for occlusive vascular disease. The limitations and adverse effects associated with traditional antiplatelet agents such as aspirin have prompted the search for newer antiplatelet agents. Clinical trials such as the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) study, which was the first study to evaluate aspirin and clopidogrel in patients with cerebrovascular, cardiac, and peripheral arterial disease, have established the importance of newer antiplatelet effects in the management of patients with diseases associated with atherosclerosis. The pathophysiology of atherosclerosis, the mechanisms of action of antiplatelet agents, and the results of these and other clinical trials that document the value of antiplatelet agents in atherosclerosis are reviewed in this paper.

Predictors of restenosis after coronary stent implantation

OBJECTIVES

We sought to determine predictors of restenosis after coronary stenting (CS) in a consecutive series of patients.

BACKGROUND

Although stenting in highly selected patient groups reduces restenosis, the results of stenting in a heterogeneous patient group and the effects of clinical and procedural factors on stent restenosis are currently unclear.

METHODS

We analyzed the 6-month angiographic outcome of 500 lesions in 463 consecutive patients undergoing successful CS. Clinical, qualitative and quantitative angiographic variables were correlated with restenosis assessed as both a binary and a continuous variable.

RESULTS

Restenosis, defined as the presence of >50% diameter stenosis in the dilated segment, was present in 105 (26%) of the 405 lesions with angiographic follow-up. The mean late lumen loss during the follow-up period was 0.79+/-0.64 mm. Implantation of multiple stents (p < 0.0001) and a high acute gain (p < 0.0002) were independently associated with a higher late lumen loss. In contrast, the use of high inflation pressure (p < 0.02) and Palmaz-Schatz stents (p < 0.005) was independently associated with a lower late lumen loss. When restenosis was defined as a qualitative variable, implantation of multiple stents (p < 0.001), stenosis length (p < 0.01), small reference diameter (p < 0.02) and stent type other than Palmaz-Schatz (p < 0.01) were independent predictors of restenosis. None of the clinical variables tested was associated with restenosis.

CONCLUSIONS

Coronary stenting in an unselected patient group is associated with an acceptable restenosis rate. Although some risk factors were identified, the risk of restenosis was not related to most of the variables tested. This suggests that the superiority of CS over balloon angioplasty, in terms of restenosis, might also apply to subgroups of patients that were not included in the recent randomized studies.

Randomised comparison of Micro Stent I with Palmaz-Schatz stent placement for the elective treatment of short coronary stenoses

This randomised trial compared the Micro Stent I and the Palmaz-Schatz stent for the elective treatment of short (<8 mm long), new-onset coronary stenoses. The primary endpoints were restenosis rate and minimal luminal diameter at 6 mo angiographic follow-up. The secondary endpoints were angiographic and procedural success of stenting and a composite clinical endpoint at 6 mo (death, myocardial infarction, and target site revascularisation). A total of 93 patients were randomised. Clinical and angiographic characteristics of the two groups were comparable. Angiographic success of stenting was 96% in both groups, and there were no complications so that the procedural success was also 96% in both groups. The restenosis rate was 29% for Micro Stent I and 27% for the Palmaz-Schatz stent (P = NS). The minimal luminal diameter at 6 mo was 1.75 +/- 0.72 mm in the Micro Stent I group and 1.84 +/- 0.59 in the Palmaz-Schatz group (P = NS). At 6 mo, a clinical endpoint was reached by 21% of the patients in the Micro Stent I group and by 11% in the Palmaz-Schatz group (P = NS). In conclusion, the elective treatment of short coronary stenosis with the Micro Stent I or the Palmaz-Schatz stent resulted in similar early and late outcomes. In particular, the late angiographic results were very similar.

Enhanced onset of platelet inhibition with a loading dose of ticlopidine in ASA-treated stable coronary patients

Antiplatelet therapy reduces the rate of complications of coronary angioplasty. Ticlopidine, in addition to acetyl salicytic acid (ASA), improves the results after coronary stenting, but early complications still occur. Ticlopidine given in the standard way has a slow onset of action. Eighteen ASA-treated stable coronary patients were randomized to standard ticlopidine treatment (250 mg twice daily) or to a loading dose of 1500 mg followed by 250 mg twice daily. After one day, standard treatment had a very modest antiplatelet effect, as assessed by ADP-induced platelet fibrinogen binding, whereas the loading dose resulted in a considerably better platelet inhibition; relative inhibition, 5.6-10.6 vs. 24.9-35.3% (p<0.005) with final ADP concentrations 3 and 0.6 microM, respectively. It is possible that a loading dose of ticlopidine, given the day before the procedure, might reduce the complications related to angioplasty and stenting.

Six-month angiographic outcome after successful repeat percutaneous intervention for in-stent restenosis

BACKGROUND

In-stent restenosis is an increasing clinical problem. Discordant results have been published regarding the risk of recurrent restenosis after repeat angioplasty for the treatment of in-stent restenosis.

METHODS AND RESULTS

One hundred three consecutive patients (107 vessels) underwent repeat percutaneous intervention for the treatment of in-stent restenosis and were entered in a prospective angiographic follow-up program. Repeat balloon angioplasty was performed at 93 lesions (87%) and additional stenting at 14 lesions (13%). The primary success rate was 98%. Six-month angiographic follow-up was performed in 85% of eligible patients. Restenosis was determined by quantitative angiography. Restenosis defined as a >50% diameter stenosis at follow-up was observed at 22% of lesions. The rate of target-lesion revascularization at 6 months was 17%. Repeat intervention for diffuse in-stent restenosis and severe stenosis before repeat intervention were associated with significantly higher rates of recurrent restenosis.

CONCLUSIONS

The overall restenosis rate after repeat intervention for in-stent restenosis is low. The subgroup of patients with diffuse and/or severe in-stent restenosis, however, is at higher risk of recurrent restenosis and may benefit from alternative therapeutic strategies.

Effects of coronary stenting on restenosis and occlusion after angioplasty of the culprit vessel in patients with recent myocardial infarction

BACKGROUND

PTCA of an infarct-related lesion is associated with a high rate of restenosis and/or vessel occlusion. Recent studies have shown that coronary stenting in patients with stable or unstable angina is associated with a significant reduction in the restenosis rate compared with conventional balloon angioplasty. However, no information is available concerning the long-term effect of coronary stenting at infarct-related lesions compared with balloon angioplasty alone.

METHODS AND RESULTS

One hundred consecutive patients undergoing stent implantation at an infarct-related lesion and systematic 6-month angiographic follow-up were matched for major pre-PTCA clinical and angiographic variables with a group of patients undergoing conventional angioplasty. Preprocedural, postprocedural, and 6-month follow-up angiograms were analyzed with quantitative angiography. Coronary stenting was performed as a bailout procedure after failed balloon angioplasty in 20%, for a suboptimal result after balloon angioplasty in 71%, and electively in 9%. Stent implantation was associated with a higher acute gain than balloon angioplasty. At follow-up, the minimal lumen diameter was significantly (P<.0001) larger in the stent group (1.72+/-0.69 versus 1.23+/-0.72 mm). Restenosis (>50% DS at follow-up) occurred in 27% of the stent group versus 52% of the balloon group (P<.005). At follow-up, total occlusion at the dilated site occurred in 1% of the stent group versus 14% of the balloon group (P<.005).

CONCLUSIONS

Coronary stenting of infarct-related lesions is associated with a highly beneficial effect on 6-month angiographic outcome compared with balloon angioplasty alone. Further studies are needed to establish whether the beneficial effect of coronary stenting on long-term vessel patency is associated with an improvement in left ventricular function or in clinical outcome.

Early versus late coronary stenting following acute myocardial infarction: results of the STENTIM I Study (French Registry of Stenting in Acute Myocardial Infarction)

This study was undertaken to determine the feasibility and safety of coronary stenting in acute myocardial infarction (AMI). In AMI, primary percutaneous transluminal coronary angioplasty (PTCA) is accepted as the preferred method of reperfusion for patients presenting at highly experienced centres. Until recently, however, stenting has been avoided during AMI because of a potential high risk of thrombosis. This prospective observational study carried out in 20 centres and included 648 consecutive patients who underwent PTCA with stent implantation for AMI. Of these 648 patients, 269 (41.5%, Group 1) were dilated early (< 24 hr) after the onset of the symptoms (75% treated by direct PTCA) and 379 (58.5%, Group 2) were dilated between 24 hr and 14 days after AMI. Combined therapy with ticlopidin and aspirin was used after the procedure. Bailout stenting occurred more often in Group 1 than in Group 2 (17% vs. 9.5%)(P < 0.05). Angiographic successful stenting was similar in both groups of patients (96% vs. 97%). During the hospital follow-up period, stent thrombosis occurred in eight patients (3%) in Group 1 and in six patients (1.6%) in Group 2 (NS). There was 14 deaths (5.2%) in Group 1 and 11 deaths (3.9%) in Group 2 (NS). After multivariate analysis bailout stenting was identified as the sole predictor of stent thrombosis (P < 0.0001). Vascular access-site complications occurred in six patients (1%) with no difference between the two groups. This study indicates that patients who receive a coronary stent in AMI can be managed safely with antiplatelet therapy. Randomized studies are needed to determine the precise indication for coronary stenting as an adjunct to primary PTCA.

Coronary artery stenting in cardiac allograft vascular disease

Cardiac allograft vascular disease is characterized by diffuse and multifocal heterogeneous myointimal hyperplasia with or without vascular remodeling. Catheter-based interventions are indicated in selected patients. This study documents our experience with percutaneous transluminal coronary angioplasty and coronary stents (n = 48) in a group of 27 patients 5.7 +/- 2.9 years after heart transplantation. Early and intermediate results were controlled by angiography and intravascular ultrasound. Conventional percutaneous transluminal coronary angioplasty resulted in a mild and mostly inadequate gain in luminal dimensions (lumen area: 3.17 +/- 0.92 mm2 to 3.70 +/- 1.21 mm2; minimal lumen diameter: 1.84 +/- 0.23 mm to 2.04 +/- 0.36 mm). Coronary stenting led to a further improvement of luminal gain (lumen area: 3.70 +/- 1.21 mm2 to 5.86 +/- 1.76 mm2; minimal lumen diameter: 2.04 +/- 0.36 mm to 2.53 +/- 0.38 mm). These results were stabilized by application of aspirin and ticlopidine only. There were no stent thromboses or bleeding complications, and early hospital discharge of the patients was possible. At follow-up (mean follow-up period 7.72 +/- 5.45 months (range 0.50 to 23.13 months) all patients were clinically event free. In six of 24 stented vessels (25%) in 16 patients, significant restenosis (>50%) was found by intravascular ultrasound (n = 20) or by angiography (n = 4) 6 months after stent placement. We conclude that in eligible cardiac allograft vascular disease lesions primary stenting may be the method of choice. However, further evaluation of the modalities of stent application and different stent designs with respect to long-term survival is necessary.

Restenosis rates in diabetic patients: a comparison of coronary stenting and balloon angioplasty in native coronary vessels

BACKGROUND

Diabetes is a major risk factor for restenosis after coronary balloon angioplasty. Recent studies have shown that coronary stenting significantly reduces restenosis compared with balloon angioplasty alone. However, limited information is available on the effect of coronary stenting in diabetic patients.

METHODS AND RESULTS

We designed this study to analyze the effect of diabetes on restenosis in patients treated with either balloon angioplasty or coronary stenting who were enrolled in a 6-month angiographic follow-up program. Three hundred consecutive patients, 19% of whom were diabetics, who underwent coronary stent implantation during a single-vessel procedure on native coronary vessels and who had 6-month angiographic follow-up constituted the study group (stent group). Three hundred consecutive patients who underwent 6-month angiographic follow-up after single-vessel conventional balloon angioplasty served as control patients (balloon group). Preprocedural, postprocedural, and follow-up angiograms were analyzed with quantitative angiography. In the balloon group, the restenosis rate was almost twofold higher in diabetic than in nondiabetic patients (63% versus 36%; P=.0002) owing to both a greater late loss (0.79+/-0.70 versus 0.41+/-0.61 mm, respectively; P<.0001) and a higher rate of late vessel occlusion (14% versus 3%, respectively; P<.001). In the stent group, restenosis rates were similar in diabetics and nondiabetics (25% versus 27%, respectively). Furthermore, in the stent group, late loss (0.77+/-0.65 versus 0.79+/-0.57 mm, respectively) and the rate of late vessel occlusion (2% versus 1%, respectively) did not differ significantly between diabetic and nondiabetic patients.

CONCLUSIONS

Although diabetics have increased rates of restenosis and late vessel occlusion after simple balloon angioplasty, they have the same improved outcome with coronary stenting that has been documented in nondiabetic patients.

Changes in immediate outcome of percutaneous transluminal coronary angioplasty in multivessel coronary artery disease in 1990 to 1991 versus 1994 to 1995

Coronary angioplasty has undergone major technical changes since the period of inclusion in the randomized trials, comparing it with surgery, particularly with the increased use of coronary stents. This study shows improved in-hospital outcome in terms of primary success and complication rates in patients treated with coronary angioplasty for multivessel disease from 1994 to 1995, compared with the 1990 to 1991 period.