"Rescue" utilization of abciximab for the dissolution of coronary thrombus developing as a complication of coronary angioplasty

[Our enemy : the clot. Coronary thrombosis : strategy and therapeutic arsenal]

Intra coronary thrombus is  frequently encountered during acute coronary syndromes revascularisation procedures. It can also be encountered during angioplasty procedures in a stable angina context, although at a much lesser frequency.In both situations, it harbors a risk of poor angiographic result and poor prognosis. Intracoronnary thrombus may cause coronary occlusion at the angioplasty site or distal embolic  flow obstruction. Per procedure thrombus prevention rests on an prior optimal anti thrombotic treatment and in some circumstances the choice to defer the revascularisation procedure in the complex high risk setting. Treating the initiated thrombus remains controversial concerning thrombectomy and GPIIBIIIa inhibitors which are still in use in common practice. No reflow phenomenon is a particularly complex setting during cornary angioplasties, partially but not solely related to a thrombotic complication. It's treatment remains unclear in the absence of related oriented studies.The current mechanical and pharmacological antithrombotic therapies must remain common practice and used appropriately as of the clinical and angiographic setting, until further scientific outbrakes.

Large intracoronary thrombus and its management during primary PCI

Large intracoronary thrombus has been reported in significant number of patients with STEMI. Primary PCI is the current standard of care in patients of STEMI. Despite the availability of dual antiplatelets, GP IIb/IIIa inhibitor and effective anticoagulation regimens, large intracoronary thrombus remains one of the biggest challenge to interventional cardiologists during primary PCI. Large intracoronary thrombus may lead to distal embolization, no/slow reflow or embolization into a non-culprit vessel and is associated with adverse cardiovascular outcome. There is no ideal management strategy. We hereby discuss the current available methods/strategies to deal with large thrombus burden encountered during primary PCI, in the current manuscript.

Safety and Efficacy of Periprocedural Heparin Plus a Short-Term Infusion of Tirofiban Versus Bivalirudin Monotherapy in Patients Who Underwent Percutaneous Coronary Intervention (from the Intermountain Heart Institute STAIR Observational Registry)

Glycoprotein IIb/IIIa inhibitors, used as a standard intravenous bolus followed by a prolonged infusion for 12 to 18 hours, reduces ischemic complications during percutaneous coronary interventions (PCI) but often at a cost of increased bleeding. Today, when dual oral antiplatelet therapy is routine, heparin use plus short-term (bolus alone or with a <6 hours infusion) glycoprotein IIb/IIIa inhibitors, or bivalirudin monotherapy, have been proposed as potentially superior alternatives. This observational study evaluated the safety and efficacy of heparin plus short-term tirofiban versus bivalirudin monotherapy during PCI. Patients with successful PCI and no cardiogenic shock who were anticoagulated with either of the above regimens were followed for 30-day major bleeding and major adverse cardiovascular events (death, nonfatal myocardial infarction, and urgent target vessel revascularization) at 30 days, 1 year, and long term. A total of 727 patients receiving tirofiban (age = 63 ± 13 years, males = 76%, ACS presentation = 75%, radial access = 51%) and 459 patients receiving bivalirudin, (age = 65 ± 13 years, males = 71%, ACS presentation = 78%, radial access = 18%) were included. Thirty-day major bleeding was 0.7% and 4.1% for tirofiban and bivalirudin, respectively (adjusted odds ratio = 0.17 [0.06, 0.46], p = 0.001). During 30-day, 1-year, and long-term (1.7 ± 0.9 years) follow-up, major adverse cardiovascular events risk did not differ significantly between tirofiban and bivalirudin. However, long-term death was significantly lower in those receiving tirofiban (adjusted hazard ratio = 0.58 [0.34, 1.00], p = 0.05). In conclusion, in this observational study, PCI patients receiving heparin plus short-term tirofiban experienced significantly lower 30-day major bleeding, and improved long-term survival, than those receiving bivalirudin monotherapy.

Adjunctive Pharmacotherapy for Thrombotic Coronary Lesions

Patients with unstable coronary syndromes are often found to have intracoronary thrombus on angiography. Despite advancements in catheter-based treatments for coronary disease, these lesions remain challenging, as percutaneous coronary intervention of thrombus-containing lesions may be associated with worse outcomes. This article reviews the literature on adjunctive pharmacotherapy in the treatment of thrombotic coronary lesions with special focus on ST-segment elevation myocardial infarction, lesions with high thrombus burden, and saphenous vein graft intervention.

A multicenter randomized study to evaluate intracoronary abciximab with the ClearWay catheter to improve outcomes with Lysis (IC ClearLy): trial study design and rationale

BACKGROUND

Percutaneous coronary intervention (PCI) is a highly effective therapy for acute ST-elevation myocardial infarction. Adjunctive therapy with platelet glycoprotein (GP) IIb/IIIa inhibitor can result in increased vessel patency and improved outcomes in ST-elevation myocardial infarction patients undergoing PCI. The investigation of novel dosing and delivery strategies of this therapy may help to further improve outcomes.

METHODS

IC-Clearly is a randomized, open-label, multicenter trial, with the purpose of evaluating the effectiveness of an intracoronary bolus dose of abciximab delivered using the ClearWay RX catheter vs. an intravenous bolus of abciximab for ST-elevation myocardial infarction with angiographically visible thrombus (thrombus grade >or=2). A total of 150 patients will be randomized 1: 1 to treatment of the culprit artery with intracoronary abciximab (75 patients) or intravenous abciximab (75 patients) in addition to a maintenance infusion regimen of abciximab administered intravenously for 12 h after PCI. The number of patients included in this study is based on the estimation of sample size needed to identify a statistically significant difference in the primary endpoints between the two groups. The primary endpoint chosen to evaluate this hypothesis is infarct size assessed by cardiac magnetic resonance. Clinical outcomes will be assessed for each patient through hospital discharge and at 30-day follow-up.

CONCLUSION

The purpose of this study is to evaluate whether an intracoronary bolus of abciximab delivered with the ClearWay RX catheter prior to the 12 h post-PCI intravenous infusion regimen of abciximab will result in significant additional clot resolution in vivo and improved myocardial perfusion when compared with an intravenous bolus of abciximab on top of the 12 h post-PCI intravenous infusion regimen of abciximab as per standard practice. The primary endpoint chosen to evaluate this hypothesis is infarct size as assessed by cardiac magnetic resonance.

Role of thrombectomy in acute myocardial infarction

Acute ST elevation myocardial infarction results from atherosclerotic plaque rupture with subsequent thrombus formation, leading to complete or near complete occlusion of an epicardial coronary artery. Minimization of the mechanical obstruction from this thrombus remains the main goal of therapy in ST elevation myocardial infarction. Primary percutaneous coronary intervention for an ST elevation myocardial infarction appears to be the preferred mode of revascularization over thrombolytic therapy if the door-to-balloon time target of 90 min is achievable. The idea of reducing the thrombus burden with the use of devices as an adjunct to percutaneous coronary intervention is an attractive one. Several thrombectomy devices have been studied in randomized clinical trials, but no definitive conclusions have emerged, owing to conflicting results and variable clinical end points. This article intends to shed further light on the potential role of thrombectomy in the treatment of acute myocardial infarction.

Intracoronary abciximab use in patients undergoing PCI at a community hospital: a single operator experience

OBJECTIVE

To evaluate the safety of intracoronary (IC) abciximab during percutaneous coronary intervention (PCI).

BACKGROUND

Adjunctive treatment with glycoprotein IIb/IIIa inhibitors, especially abciximab, during PCI has been shown to improve clinical and procedural outcomes in numerous studies. However, significant bleeding complications exist with its use and this has limited its standard use. Interest has grown in local (IC) use with studies showing safety and long-term effectiveness, especially in patients with high thrombus loads.

METHODS

A retrospective review of records in a database of patients who had PCI by a single operator at the Easton Hospital.

RESULTS

611 patients received IC abciximab, and there were no complications in 610 (98.3%) patients; only 1 had an allergic reaction.

CONCLUSIONS

IC abciximab is safe and has a unique role in the catheterization lab and in patients at high risk of bleeding complications who would benefit from its limited use.

Rheolytic Thrombectomy during Percutaneous Coronary Intervention Improves Long-Term Outcome in High-Risk Patients with Acute Myocardial Infarction

OBJECTIVES

Aim of the present study was to compare the immediate and long-term effects of AngioJet rheolytic thrombectomy performed in the setting of a percutaneous coronary angioplasty (PTCA) with those of conventional PTCA in patients with acute myocardial infarction (AMI) and angiographic evidence of high intracoronary thrombus burden.

BACKGROUND

Plaque rupture, with subsequent exposure to the flowing bloodstream of high thrombotic materials often leads to intravascular thrombosis, representing the main pathophysiological event of acute coronary syndromes. PTCA is the first-choice treatment for these patients in hospitals with cardiac catheterization facilities. However, distal embolization of thrombotic material, fibrin, and other fragments from atherosclerotic plaques might lead to procedural failure.

METHODS

Immediate and 1-year follow-up results of a group of 30 consecutive patients, presenting with AMI and angiographic evidence of high thrombus burden, who underwent rheolytic thrombectomy and PTCA were compared with those of 30 consecutive patients with similar clinical presentation, risk profile, and angiographic picture, and treated with standard PTCA procedure.

RESULTS

After the procedure, angiographic analysis showed a higher incidence of final thrombolysis in myocardial infarction (TIMI) flow grade 3 in the AngioJet group (93.3% vs 83.3%, P = 0.034). In addition, mean corrected TIMI frame count (cTFC) was significantly lower in the AngioJet group (22.4 vs 32.4, P = 0,0004). At 1-year follow-up, patients treated with AngioJet showed a significantly lower incidence of death (3.33% vs 13.33%,P < 0.001), major adverse cardiac events (MACE: 10% vs 30%, P = 0.026), and need of revascularization (6.67% vs 20%, P = 0.013).

CONCLUSIONS

Data of the present study highlight that AngioJet thrombectomy in selected AMI patients at high risk for distal thrombotic embolization results not only in immediately improved angiographic results as compared to conventional PTCA but, indeed, seems to be associated with a significantly better long-term clinical outcome.

Management of failed thrombolysis after acute myocardial infarction: An overview of current treatment options

Thrombolytic therapy remains the most commonly administered revascularization strategy for patients with ST-elevation myocardial infarctions (STEMI). However, many patients fail to have patent arteries or ST-segment resolution after these therapies. Multiple strategies have been examined to treat these patients with "failed thrombolysis." We examined the existing medical literature regarding treatment of failed thrombolysis including strategies testing repeat thrombolytic therapy and rescue percutaneous coronary intervention. Additional, we reviewed the literature regarding the efficacy of transferring patient for rescue percutaneous intervention and coronary stenting. The impact of contemporary antiplatelet strategies, cardiogenic shock, and coronary bypass surgery was examined. Overall, the management of patients with acute STEMI in whom thrombolytic therapy failed remains a challenging problem. As a result, many different strategies are currently in use. Among these therapeutic interventions, rescue PCI with coronary stenting appears to be superior when it is done in a timely manner by an experienced center.

Emergency Use of Stent and rtPA with Mechanical Cloth Defragmentation for a Thromboembolic Complication during GDC Coil Treatment of an Acutely Ruptured Basilar Tip Aneurysm

Thrombotic occlusion of both posterior cerebral arteries occurred during embolization of an acutely ruptured basilar tip aneurysm. Intracranial stenting and continuous superselective infusion of rtPA was administered combined with mechanical clot fragmentation to reestablish normal vessel flow. DSA disclosed that normal vessel patency was achieved within 30 min. There were no adverse events related to rtPA administration and the patient recovered from the embolization with minor neurologic deficit as present before the procedure.

Role of abciximab in the treatment of coronary artery disease

Glycoprotein IIb/IIIa complex is a crucial membrane receptor for platelet aggregation, binding platelets to fibrinogen and establishing interplatelet bridges. This receptor is the common end point of the multiple activation pathways of a platelet. Antiplatelet agents, such as aspirin or thienopyridines, including ticlopidine and clopidogrel, inhibit one or more but not all, of these pathways. Inhibitors of the receptor are powerful platelet antiaggregants and include two groups of agents: non-competitive receptor blockers, such as abciximab, and competitive antagonists, such as tirofiban and eptifibatide. Abciximab is a monoclonal antibody that binds to the glycoprotein IIb/IIIa complex, thus blocking the interaction with fibrinogen. It is used for treatment of coronary artery disease, being well-studied in the setting of acute coronary syndromes and percutaneous coronary intervention, in which a rapid and effective antiaggregation is clinically important.

Heterogeneity of Myocardial Perfusion in Distal Coronary Embolism with Different Particle Sizes

BACKGROUND

We hypothesized that altered myocardial perfusion distribution patterns could be seen with coronary distal emboli of different particle sizes using myocardial contrast echocardiography.

METHODS

In 16 open-chest anesthetized dogs, microsphere suspensions of 9 or 500 microm in diameter were injected into the left anterior descending coronary artery until the mean left anterior descending coronary artery flow rate was reduced to less than 30% of baseline flow. During baseline conditions and after maximal embolization, real-time myocardial contrast echocardiography was performed by intravenous infusion of an echocontrast agent.

RESULTS

In animals infused with 9-microm microspheres, a transmural perfusion defect was seen at the time of maximal embolization. In contrast, in animals infused with 500-microm microspheres, a subendocardial perfusion defect was observed.

CONCLUSIONS

The particle size of coronary distal emboli affects myocardial perfusion distribution.

Angiographic evaluation of the effect of intracoronary abciximab administration in patients undergoing urgent PCI

BACKGROUND

Recent data suggest that the intracoronary (i.c.) administration of a systemic bolus dose of abciximab during PCI may increase the efficacy of this antiplatelet drug. However, the effect of i.c. abciximab on coronary angiographic flow has been not clarified.

METHODS

We studied 37 consecutive patients with acute coronary syndromes (ACS) who underwent successful urgent PCI on the target vessel and were treated by an i.c. abciximab bolus (0.25 mg/kg) prior to the first balloon inflation (Group IC), and 37 matched controls who were treated by intravenous (i.v.) abciximab bolus at the same dose (Group IV). Corrected TIMI frame count (CTFC) in the culprit and in a non-culprit coronary artery branch was assessed before treatment, immediately after intracoronary administration of abciximab bolus and at the end of the procedure.

RESULTS

After administration of abciximab, CTFC significantly decreased from 48+37 to 33+30 (P=0.001) in the culprit vessel while in the non-culprit vessel it remained unchanged (16+7 pre-treatment and 16+7 post-treatment, P=0.68). Final CTFC was 12+4 in Group IC and 14+5 in Group IV (P=0.069). Post-treatment mean peak of the cardiac enzymes showed a trend toward reduction in Group IC compared with Group IV.

CONCLUSIONS

The i.c. administration of abciximab bolus acutely decreases CTFC through culprit vessels of patients with ACS undergoing urgent PCI. Further studies evaluating the potential clinical benefits associated with i.c. abciximab administration are warranted.

Acute left main occlusion during percutaneous coronary intervention associated with heparin induced thrombocytopenia with thrombosis syndrome

A 76-year-old male was admitted with Braunwald IIIB unstable angina and treated with intravenous heparin. Coronary angiography 20 days later revealed a severe stenosis in the left circumflex artery. During coronary angioplasty thrombus developed in the circumflex artery, extended in the left main and lead to its occlusion. Normal left coronary artery patency and flow were achieved after intracoronary and intravenous administration of abciximab, and multiple stenting. Platelet-count decrease and an ELISA assay documented the presence of heparin-induced thrombocytopenia with thrombosis syndrome (HITTS). HITTS should be suspected after acute thrombus formation during coronary angioplasty.

Novel method for extraction of a massive refractory coronary thrombus after stent implantation

Percutaneous treatment of thrombotic coronary lesions is associated with an increased incidence of complications. In particular, management of massive coronary thrombus refractory to traditional methods of removal may be especially problematic. We report a novel application of the FilterWire distal protection device to retrieve a massive refractory native coronary thrombus present after drug-eluting stent implantation.

Antithrombotic therapy during percutaneous coronary intervention: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy

This chapter about antithrombotic therapy during percutaneous coronary intervention (PCI) is part of the seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading, see Guyatt et al, CHEST 2004;126:179S-187S). Among the key recommendations in this chapter are the following: For patients undergoing PCI, we recommend pretreatment with aspirin, 75 to 325 mg (Grade 1A). For long-term treatment after PCI, we recommend aspirin, 75 to 162 mg/d (Grade 1A). For long-term treatment after PCI in patients who receive antithrombotic agents such as clopidogrel or warfarin, we recommend lower-dose aspirin, 75 to 100 mg/d (Grade 1C+). For patients who undergo stent placement, we recommend the combination of aspirin and a thienopyridine derivative (ticlopidine or clopidogrel) over systemic anticoagulation therapy (Grade 1A). We recommend clopidogrel over ticlopidine (Grade 1A). For all patients undergoing PCI, particularly those undergoing primary PCI, or those with refractory unstable angina or other high-risk features, we recommend use of a glycoprotein (GP) IIb-IIIa antagonist (abciximab or eptifibatide) [Grade 1A]. In patients undergoing PCI for ST-segment elevation MI, we recommend abciximab over eptifibatide (Grade 1B). In patients undergoing PCI, we recommend against the use of tirofiban as an alternative to abciximab (Grade 1A). In patients after uncomplicated PCI, we recommend against routine postprocedural infusion of heparin (Grade 1A). For patients undergoing PCI who are not treated with a GP IIb-IIIa antagonist, we recommend bivalirudin over heparin during PCI (Grade 1A). In PCI patients who are at low risk for complications, we recommend bivalirudin as an alternative to heparin as an adjunct to GP IIb-IIIa antagonists (Grade 1B). In PCI patients who are at high risk for bleeding, we recommend that bivalirudin over heparin as an adjunct to GP IIb-IIIa antagonists (Grade 1B). In patients who undergo PCI with no other indication for systemic anticoagulation therapy, we recommend against routine use of vitamin K antagonists after PCI (Grade 1A).

Utilization of eptifibatide for treatment of severe dissections as a bail-out procedure

BACKGROUND

It has been shown in several large trials that the inhibition of glycoprotein (GP) IIb/IIIa receptors of platelets can reduce the rate of ischemic complications following percutaneous transluminal coronary angioplasty (PTCA). We sought to determine the efficacy of eptifibatide in patients with severe dissections or threatened vessel closure after PTCA in small coronary arteries (< 2.5 mm).

METHODS

Eptifibatide was used in 51 patients after conventional balloon angioplasty complicated by severe dissections with or without threatened vessel occlusion. Eptifibatide was administered as a double-bolus of 180 microg/kg bodyweight, followed by a continuous infusion at a dosage of 2.0 microg/kg min over a time period of 20 h. In this situation, the implantation of a coronary stent was avoided if a prompt antegrade flow of contrast dye could be maintained.

RESULTS

Using the GP IIb/IIIa antagonist eptifibatide, it was possible to increase or to maintain antegrade blood flow in 28 (55%) patients. In 45% of the patient population, however, repeat PTCA was needed, and in four patients (7.8%) an intracoronary stent had to be implanted. During hospitalization three (6%) patients underwent target lesion revascularization (two Re-PTCAs, one coronary bypass graft operation). There were no myocardial infarctions and there was no intrahospital death. The cumulative event rate including acute and long term events was 25%.

CONCLUSIONS

The findings of our study indicate that eptifibatide is able to prevent vessel occlusion after PTCA complicated by severe dissections with or without threatened vessel occlusion associated with a low-in-hospital complication rate.

Outcomes following bail-out abciximab administration during primary intervention in acute myocardial infarction (The CADILLAC Trial)

The utility of glycoprotein IIb/IIIa receptor inhibitors as a "bail-out" modality after unsuccessful primary percutaneous coronary intervention for acute myocardial infarction is unknown. In the CADILLAC trial, of 1,030 control patients, 62 patients (6.0%) crossed over and received abciximab for procedural complications or suboptimal angioplasty results. Compared with patients who received routine upfront abciximab, those treated with bail-out abciximab had markedly lower rates of Thrombolysis In Myocardial Infarction grade 3 flow and increased rates of hemorrhagic and ischemic complications at 30 days and 1 year.

Abciximab, eptifibatide, and tirofiban exhibit dose-dependent potencies to dissolve platelet aggregates

Platelet GPIIb/IIIa antagonists are not only used to prevent platelet aggregation, but also in combination with thrombolytic agents for the treatment of coronary thrombi. Recent data indicate a potential of abciximab alone to dissolve thrombi in vivo. We investigated the potential of abciximab, eptifibatide, and tirofiban to dissolve platelet aggregates in vitro. Adenosine diphosphate (ADP)-induced platelet aggregation could be reversed in a concentration-dependent manner by all three GPIIb/IIIa antagonists when added after the aggregation curve reached half-maximal aggregation. The concentrations chosen are comparable with in vivo plasma concentrations in clinical applications. Disaggregation reached a maximum degree of 72.4% using 0.5 microg/ml tirofiban, 91.5% using 3.75 microg/ml eptifibatide, and 48.4% using 50 microg/ml abciximab (P < 0.05, respectively). A potential fibrinolytic activity of the GPIIb/IIIa antagonists was ruled out by preincubation with aprotinin or by a plasma clot assay. A stable model Chinese hamster ovary (CHO) cell line expressing the activated form of GPIIb/IIIa was used to confirm the disaggregation capacity of GPIIb/IIIa antagonists found in platelets. Not only abciximab, but also eptifibatide and tirofiban have the potential to disaggregate newly formed platelet clusters in vitro. Because enzyme-dependent fibrinolysis does not appear to be involved, competitive removal of fibrinogen by the receptor antagonists is the most likely mechanism.

[Angiographic results of thrombectomy performed with two new devices in lesions with intracoronary thrombus]

INTRODUCTION AND OBJECTIVE

The presence of intracoronary thrombus is associated with less favorable results of percutaneous coronary interventions. In recent years, new devices have been designed to improve the outcome of these procedures when an intracoronary thrombus is present. The results of two new systems of thrombectomy used in a single center are analyzed.

METHODS

Prospective observational registry of the use of two thrombectomy devices, X-SIZER (EndiCOR Medical Inc., San Clemente, California, USA) and RESCUE (Boston Scientific Scimed, Inc., Maple Grove, Minnesota, USA), between 1 June 2000 and 15 February 2002. RESULTS. One hundred thirty-nine devices were used in 137 patients (112 RESCUE and 27 X-SIZER). The main indication was primary angioplasty for acute myocardial infarction (80%). In 7 patients (5%), unscheduled thrombectomy was performed for unexpected complications that appeared during the procedure. In 75% of patients, IIb/IIIa inhibitors were given. In 10 cases (7%) the device did not reach the lesion. Complications derived from the use of the device were recorded in 3 cases (2.1%). TIMI flow improved from 1.28 1.1 before thrombectomy to 2.31 1.2 after the procedure. Improvement in the thrombus image was observed in 86%. The intervention was successful in 86%.

CONCLUSIONS

Thrombectomy with X-Sizer and Rescue improved the angiographic thrombus image in most cases and was associated to a low complication rate. Its efficacy compared to the conventional technique should be assessed in future trials.

Bivalirudin (Angiomax) use during intracoronary brachytherapy may predispose to acute closure

We describe two cases of intracoronary vascular brachytherapy where bivalirudin (Angiomax), employed as an anticoagulant, led to abrupt vessel closure or threatened abrupt closure. Use of bivalirudin (Angiomax) during intracoronary brachytherapy may predispose to the formation of intracoronary thrombus, related to the reversible binding kinetics of the bivalirudin to thrombin, and resulting in recovery of thrombin functional activity during periods of prolonged stasis that occur during intracoronary brachytherapy. Intracoronary abciximab administration may be a useful strategy in resolving the acute closure, since abciximab administered early during the formation of thrombus has been shown to facilitate clot lysis.

Glycoprotein receptor inhibitors in the management of acute coronary syndromes

Coronary thrombosis and the risk of clinical adverse events remains high despite considerable advances in the management of acute coronary syndromes (ACS) with the combined use of aspirin, heparin, fibrinolytic therapy, and percutaneous coronary intervention (PCI). Platelet aggregation and thrombosis play a key role in the pathogenesis of unstable coronary syndromes. Over the past several years, multiple placebo-controlled trials involving more than 50,000 ACS patients have shown that blockade of the platelet receptor glycoprotein (GP) IIb/IIIa, the final pathway in platelet aggregation, reduces the incidence of ischemic complications among patients with ACS. Three agents (abciximab, eptifibatide, and tirofiban) are currently approved for use with aspirin and heparin in the management of ACS or during percutaneous coronary intervention. They have consistently been shown to reduce the incidence of death or myocardial infarction in the ACS population including the patients not routinely scheduled for early revascularization. They provide an augmented treatment effect among high-risk ACS patients, particularly those who have a baseline troponin-t-positive status. Recently published practice guidelines have recommended their use in high-risk patients with ACS and all those undergoing PCI.

Abciximab is rapidly effective in preventing and arresting established platelet aggregation

BACKGROUND

Abciximab reduces the thrombotic complications of angioplasty. It is also used, as a 'bail out' treatment when angioplasty is complicated by thrombus but its speed of action is not known. This study sought to establish how quickly abciximab blocks the aggregation of both quiescent and activated platelets to explain this rapid efficacy.

METHODS

Optical aggregometry (OA) and whole blood electrical impedance platelet aggregometry (WBEA) were performed with blood from 10 healthy volunteers. Abciximab 5 microg/ml was added in each case with saline control 5 minutes before agonist, 10 seconds before agonist and during aggregation.

RESULTS

(1) Abciximab administered 5 minutes before agonist, completely inhibited aggregation with OA: (medians and ranges) 0% (all 0), control: 71% (50-95%) p < 0.001. and with WBEA: 0 omega (all 0 omega), control: 7.5 omega (4.8-12.5 omega) p = 0.016. (2) When administered 10 s before agonist with OA a small initial degree of aggregation occurred but this was rapidly reversed (time to reversal: 2 mins (1-4.5 mins) to low levels of aggregation 16.5% (0-22%), control 72.5% (55-95%) p = 0.002. With WBEA aggregation was completely inhibited: 0 omega (all 0 omega), control: 7.5 omega (4.8-12.3 omega) p = 0.016. (3) When administered during aggregation, with OA the rise in the aggregometry tracing was rapidly arrested (time to arrest: 1.5 mins (0.1-3 mins)) with no further aggregation occurring: 42% (30-57%), control: 80% (60-100%) p = 0.002. With WBEA the findings were similar: (time to arrest 1.5 mins (1-2 mins)) 6.3 omega (1.5-11.3 omega), control: 10 omega (3-12 omega) p = 0.031.

CONCLUSIONS

These data suggest that when administered during a procedure in which thrombus has occurred, aggregation may be rapidly arrested. This applies to quiescent platelets but also activated platelets undergoing aggregation.

Bivalirudin with planned or provisional abciximab versus low-dose heparin and abciximab during percutaneous coronary revascularization: results of the Comparison of Abciximab Complications with Hirulog for Ischemic Events Trial (CACHET)

BACKGROUND

The direct thrombin inhibitor bivalirudin has previously been associated with better efficacy and lower hemorrhage risk than heparin during balloon angioplasty. This agent has not yet been tested with stenting or in combination with platelet glycoprotein IIb/IIIa antagonists.

METHODS AND RESULTS

In a pilot trial, 268 patients who underwent coronary intervention were randomized in 3 sequential phases to treatment with bivalirudin (with or without abciximab) or the control regimen of low-dose weight-adjusted heparin with abciximab. Patients in the bivalirudin arms received bivalirudin (1.0 mg/kg bolus, infusion of 2.5 mg/kg/h for 4 hours) plus abciximab in phase A, bivalirudin (0.5 mg/kg bolus, infusion of 1.75 mg/kg/h for the procedure duration) plus provisional ("rescue") abciximab in phase B, or bivalirudin (0.75 mg/kg bolus, infusion of 1.75 mg/kg/h for the procedure duration) plus provisional abciximab in phase C. Abciximab was necessitated on a provisional basis in 24% of the patients in the bivalirudin arms of phases B and C. A composite clinical endpoint of death, myocardial infarction, repeat revascularization, or major bleeding by 7 days occurred in 3.3%, 5.9%, 0, and 10.6% of the patients in the bivalirudin phase A, bivalirudin phase B, bivalirudin phase C, and heparin plus planned abciximab arms, respectively (P =.018 for the pooled bivalirudin groups versus the heparin group).

CONCLUSION

Bivalirudin with planned or provisional abciximab may be at least as safe and effective as low-dose heparin plus abciximab during percutaneous coronary intervention.

The use of the glycoprotein IIb/IIIa receptor antagonists during percutaneous coronary intervention

Coronary thrombosis is the major cause of ischemic complications during percutaneous coronary interventions (PCI). The glycoprotein (GP) IIb/IIIa receptor plays a critical role in the process of platelet thrombus formation since it serves as the final common pathway for platelet aggregation. Presently, there are three commercially available intravenous GPIIb/IIIa inhibitors that block fibrinogen binding to its receptor. These agents significantly reduce the incidence of death and nonfatal myocardial infarction at 30 days in patients undergoing percutaneous coronary revascularization. In addition, the early benefits appear to be sustained at 6 months to 1 year. Increasing evidence shows that the predominant mechanism of benefit is due to a reduction in embolization to the microcirculation that occurs during PCI. While data regarding the comparative efficacy and cost-effectiveness of these agents are scarce, the magnitude of benefit appears to be greatest for abciximab. Furthermore, a mortality benefit has been demonstrated only for abciximab. Although high risk patients reap the greatest benefit from the use of these agents, it is clear that even patients who are classified as low-to-moderate risk still derive substantial benefit from their use. Finally, evidence indicates that the majority of patients with acute coronary syndromes without ST segment elevation who are scheduled to undergo PCI should be pretreated with a GPIIb/IIIa receptor antagonist.

Intra-arterial thrombin injection of an ascending aortic pseudoaneurysm complicated by transient ischemic attack and rescued with systemic abciximab

Thrombin injection as a means of inducing thrombus formation has recently received wide attention as an alternative treatment for pseudoaneurysm. We present a case of a 67-year-old man in whom a large mycotic pseudoaneurysm developed in the ascending aorta because of sternal osteomyelitis and mediastinitis after coronary artery bypass grafting. Transcatheter intra-arterial thrombin injection was performed, and it successfully induced pseudoaneurysm thrombosis. However, the procedure was complicated by a sudden transient ischemic attack caused by thrombus propagation into the cerebral circulation. Complete thrombus dissolution in the cerebral circulation with the resolution of neurologic symptoms was achieved by means of intravenous abciximab.

Abciximab for the treatment of acute distal embolization associated with internal carotid artery angioplasty

Carotid artery angioplasty and stent placement (CAS) can be complicated by procedure-related distal embolization and thrombus formation, potentially resulting in neurological sequelae. Patient A had CAS of left internal carotid artery and had loss of vision in the left eye with no flow in the left ophthalmic artery. Patient B had CAS of right internal carotid artery and developed left sided hemiparesis with total occlusion of the right middle cerebral artery. A selective intra-arterial injection of 5 mg of abciximab locally followed by a bolus of 5 mg of abciximab intravenously resulted in complete resolution of the filling defect on repeat angiography after 10 min in both patients.

Evaluation of the role of abciximab (Reopro) as a rescue agent during percutaneous coronary interventions: in-hospital and six-month outcomes

Abciximab is effective for the prevention of complications when administered prior to percutaneous coronary intervention (PCI). The efficacy and safety of abciximab as an unplanned or rescue agent for complications of PCI is unknown. Rescue versus planned use was compared in 186 consecutive patients. Primary or rescue PCI for acute myocardial infarction (MI) and shock were excluded. Rescue abciximab use was undertaken in 101 patients (54.3%) and planned abciximab was used in 85 (45.7%). The rescue abciximab patients had a lower incidence of previous MI, preprocedural thrombus, multivessel, and vein graft intervention. In-hospital endpoints in the rescue versus planned abciximab patients were death (1.0% vs. 1. 2%, P = 1.0), Q-wave MI (2.0% vs. 2.4%, P = 1.0), any MI (14.9% vs. 9.4%, P = 0.3), target vessel revascularization (TVR; 0% vs. 1.2%, P = 1.0), and composite (15.8% vs. 10.6%, P = 0.3). At 6 months, events were death (4.0% vs. 2.3%, P = 0.69), MI (14.9% vs. 9.4%, P = 0.26), TVR (20.8% vs. 4.7%, P = 0.001), and composite (30.7% vs. 15. 3%, P = 0.01). In-hospital complications between the rescue and planned abciximab patients of major bleed (1.0% vs. 1.8%, P = NS), stroke (0% vs. 1.8%, P = NS), and thrombocytopenia (3.0% vs. 1.8%, P = NS) were similar. There was a significantly higher procedural time (99.6 min vs. 86.1 min, P = 0.02), contrast volume (278.8 ml vs. 223. 5 ml, P = 0.04), and heparin use (8984 u vs. 6003 u, P = 0.0006) in the rescue group. In this nonrandomized comparison, rescue abciximab allowed for the safe discharge from hospital in the majority of patients. However, during a 6-month follow-up, more patients treated with rescue abciximab required TVR with either repeat PCI or CABG. Further studies are warranted to evaluate the overall strategy of rescue abciximab use in PCI.

Decreasing mortality with primary percutaneous coronary intervention in patients with acute myocardial infarction: the Mayo Clinic experience from 1991 through 1997

OBJECTIVE

To characterize and determine the overall impact of changes in primary percutaneous coronary intervention (PCI) on the clinical outcome of patients presenting within 24 hours of acute myocardial infarction (AMI).

PATIENTS AND METHODS

We retrospectively analyzed a prospective PCI registry for 1073 consecutive patients undergoing primary PCI for AMI at the Mayo Clinic in Rochester, Minn, from 1991 through 1997. The primary outcome measure was mortality from any cause within 30 days and 1 year.

RESULTS

The number of patients treated for AMI by primary PCI per year increased from 119 in 1991 to 193 in 1997. Intracoronary stent use increased from 1.7% in 1991 to 64.8% in 1997 (P < .001). This coincided with an increase in ticlopidine use from 3.6% in 1994 to 62.1% in 1997 (P < .001) and in abciximab use from 2.7% in 1995 to 63.2% in 1997 (P < .001). An increase in beta-blocker (58.3% to 75.3%; P < .001), angiotensin-converting enzyme inhibitor (0.9% to 40.0%; P < .001), and 3-hydroxy-3-methylglutaryl coenzyme A reductase use (1.9% to 40.5%; P < .001) as well as a decrease in calcium channel antagonist (34.3% to 8.4%; P < .001) use occurred on discharge. From 1991 through 1997, there was a significant decrease in the 30-day mortality rate (10.1% to 5.2%; P = .05). The 1-year mortality rate also decreased (13.4% in 1991 to 10.4% in 1997) (P = .09). After adjustment for other confounding variables, treatment in more recent years was associated with a significant decrease in death at 30 days (odds ratio, 0.89; 95% confidence interval, 0.79-1.00; P = .05) and during long-term follow-up (odds ratio, 0.93; 95% confidence interval, 0.87-1.00; P = .04).

CONCLUSIONS

Percutaneous coronary intervention methods of reperfusion for AMI, along with adjuvant pharmacotherapy, have changed over recent years and have been associated with improved short- and long-term survival.

Comparison of ReoPro((R)) (abciximab) versus intracoronary thrombolysis for early coronary stent thrombosis

AIMS: This study evaluated the treatment of early coronary stent thrombosis with intracoronary urokinase or the platelet glycoprotein IIb/IIIa receptor inhibitor ReoPro (abciximab). METHODS AND RESULTS: Seventy-four patients (126 stents) were treated immediately after identification of early (0-30 days) coronary stent thrombosis. Twenty-nine patients were treated with intracoronary urokinase (UK) (UK alone in 19; UK and additional balloon angioplasty in 10) and another 45 patients were given ReoPro((R)) (abciximab) (0.25 mg/kg as a bolus alone in 26, abciximab with additional balloon angioplasty in 19) within 30 days of stent implantation. TIMI grade 3 flow was obtained in 23 patients (79%) in the UK group and in 38 (84%) in the abciximab group (nonsignificant). Three patients (10%) in the UK group and one (2%) in the abciximab group underwent repeat percutaneous transluminal coronary angioplasty (PTCA) (nonsignificant). Five patients (17%) in the UK group and three (7%) in the abciximab group were referred for urgent coronary artery bypass graft surgery (CABG) because of residual thrombus and refractory ischemia (nonsignificant). Repeat revascularization was necessary in eight patients (28%) in the UK group versus four (9%) in the abciximab group (p < 0.05). Five patients (17%) in the UK group and eight (18%) in the abciximab group developed myocardial infarction (nonsignificant). Five patients (17%) in the UK group (cardiogenic shock (three), cerebral hemorrhage (one) and pneumonia (one)) and three (6.6%) in the abciximab group (cardiogenic shock (two), heart failure (one)) died within 30 days (nonsignificant). Overall, noncardiac complications (bleeding including surgical repair of groin) were observed in 11 patients (38%) in the UK group and three (7%) in the abciximab group (p < 0.001). CONCLUSION: Compared to urokinase, abciximab reduced the need for repeat revascularization procedures and the risk of noncardiac events, including bleeding complications in patients with early coronary stent thrombosis.

Reduced thrombus burden with abciximab delivered locally before percutaneous intervention in saphenous vein grafts

BACKGROUND

Existing thrombus can complicate percutaneous saphenous vein graft (SVG) intervention. Local delivery of thrombolytics has been used to reduce the thrombus burden often associated with these interventions. We sought to determine whether local delivery of a platelet glycoprotein IIb/IIIa inhibitor is feasible and can reduce thrombus burden before percutaneous SVG intervention.

METHODS

We performed a multicenter pilot study of abciximab (0.25 mg/kg) given by local delivery catheter before percutaneous intervention for de novo SVG stenoses followed by intravenous infusion. All patients (n = 58) had >/=60% stenosis and Thrombolysis In Myocardial Infarction (TIMI) grade >0 flow in an SVG of 3 to 4 mm in diameter. Percent diameter stenosis, TIMI thrombus grade, and TIMI flow grade were measured before and after delivery of abciximab and after intervention.

RESULTS

Median percent diameter stenosis improved from 69% to 45% (P =.0001) after local delivery, and TIMI thrombus grade >/=1 incidence reduced from 68% to 34% (P =.0001). TIMI flow grade was not significantly affected (P =.12). All patients had a successful intervention (</=50% residual stenosis).

CONCLUSIONS

Local abciximab delivery before percutaneous SVG intervention is associated with significantly reduced thrombus burden, significantly improved percent diameter stenosis, and excellent acute procedural results. Further studies of this approach are warranted to define its clinical utility.

Successful dissolution of occlusive coronary thrombus with local administration of abciximab during PTCA

Treatment of intracoronary thrombus poses difficult problems and may result in severe complications. We used a local delivery catheter (InfusaSleeve, LocalMed, Palo Alto, CA) to treat an occlusive coronary thrombus that was refractory to systemic thrombolysis and conventional angioplasty. After local administration of 10 mg of abciximab with this catheter there was successful resolution of coronary thrombus and vessel recanalization. Cathet. Cardiovasc. Intervent. 48:211-213, 1999.

The influence of abciximab use on clinical outcome after aortocoronary vein graft interventions

OBJECTIVES

The purpose of this study was to evaluate the effect of abciximab use on clinical outcome in aortocoronary vein graft interventions.

BACKGROUND

Although large randomized trials have demonstrated a significant benefit of abciximab use in the setting of percutaneous coronary interventions, there is relatively little data with respect to the use of this agent in percutaneous vein graft interventions.

METHODS

Three hundred and forty-three patients were identified; 210 undergoing vein graft intervention without abciximab and 133 patients with abciximab.

RESULTS

There were differences in baseline clinical and angiographic characteristics between the two groups; advanced age, unstable angina, older vein grafts and thrombus containing lesions were relatively common in both groups. Angiographic and procedural success rates were similar with or without the use of abciximab (89% vs. 92%, p = 0.15, and 85% vs. 91%, p = 0.12, respectively). The in-hospital composite end point of death/Q-wave myocardial infarction (QWMI)/repeat revascularization was similar between the two groups. Utilizing statistical modeling to adjust for baseline differences between the groups, abciximab use did not influence the cumulative long-term composite end point of death/MI/repeat revascularization.

CONCLUSIONS

This study demonstrates that in this relatively high-risk population undergoing aortocoronary vein graft interventions, the administration of abciximab periprocedurally does not appear to reduce major adverse clinical events.

Thrombectomy with AngioJet catheter in native coronary arteries for patients with acute or recent myocardial infarction

The AngioJet thrombectomy catheter removes thrombi by rheolytic fragmentation and suction. The purpose of this study was to identify the efficacy and safety of this new device. Myocardial infarction (MI) is associated with intracoronary thrombus. Intracoronary thrombus has been identified as a risk factor of unfavorable outcome after percutaneous transluminal coronary angioplasty. To what extent the AngioJet is applicable or effective for acute or recent MI in native coronary artery is not clear. Thrombectomy with the AngioJet was attempted in 31 patients with 31 native coronary arteries selected from 304 patients with acute or recent MI. Follow-up angiography was performed at 3 to 6 months. Procedure success was achieved in 29 patients (94%). Adjunctive balloon angioplasty was performed after AngioJet thrombectomy in 30 patients (97%), and in only 1 patient (3%) AngioJet thrombectomy was the sole procedure. Subsequent stenting after balloon angioplasty was attempted successfully in 12 patients (40%) without thrombotic complications. Thrombolysis In Myocardial Infarction trial flow grading increased from 0.70 +/- 0.97 before to 2.61 +/- 0.88 after AngioJet thrombectomy (p <0.0001), to 2.84 +/- 0.64 after adjunctive procedures (p = 0.070). At follow-up angiography restenosis rate was 21% but Thrombolysis In Myocardial Infarction flow 3 was present in all patients. The restenosis rate of stented patients was 8%. There were no major events during in-hospital and follow-up. The AngioJet can be used safely and successfully to remove thrombus from the native coronary artery of patients with MI. Thrombus removal makes subsequent stenting safe and uncomplicated. The restenosis rate was considered to be acceptable.

Associations between a polymorphism in the gene encoding glycoprotein IIIa and myocardial infarction or coronary artery disease

OBJECTIVES

The purpose of this study was to determine whether a common variant (PIA2) of the membrane glycoprotein (GP) IIIa gene is associated with myocardial infarction (MI) or coronary artery disease (CAD).

BACKGROUND

Platelet GP IIb/IIIa is believed to play a central role in MI, binding fibrinogen, cross-linking platelets and initiating thrombus formation. Genetically determined differences in binding properties of GP IIb/IIIa might result in changes in platelet activation or aggregation and affect the risk of MI or CAD.

METHODS

To determine associations (odds ratios [OR] > or =1.5 to 2.0) of genotype with MI or CAD, blood was drawn from 791 patients (pt) undergoing angiography. A 266 base pair fragment of the GP IIIa gene was amplified by the polymerase chain reaction and digested with the MspI restriction enzyme. Genotypes were identified after electrophoresis of digestion products in 1.5% agarose gel.

RESULTS

Of the 791 pt, 225 had acute (n = 143) or previous MI, and 276 did not have MI or unstable angina. The PI(A2) allele was carried by 33.8% of MI pt versus 26.9% of no-MI control subjects, OR = 1.39 (95% CI, 0.95 to 2.04, p = 0.09). Angiographically, 549 pt had severe (>60% coronary stenosis) CAD, and 170 had normal coronary arteries (<10% stenosis). The PI(A2) allele was found in 31.0% of CAD pt versus 28.2% of no-CAD control subjects, OR = 1.14 (CI, 0.78 to 1.67, p = 0.50). When adjusted for six standard risk factors, ORs were 1.47 (CI, 0.98 to 2.20, p = 0.062) for MI and 1.20 (CI, 0.80 to 1.81, p = 0.38) for CAD.

CONCLUSIONS

The PI(A2) variant of the gene encoding GP IIIa is modestly associated (OR approximately 1.5) with nonfatal MI but shows little if any association with CAD per se.

Frequency and efficacy of glycoprotein IIb/IIIa therapy for treatment of threatened or acute vessel closure in 1332 patients undergoing percutaneous transluminal coronary angioplasty

BACKGROUND

Glycoprotein (GP) IIb/IIIa antagonists are potent inhibitors of thrombocyte aggregation and thrombus formation. Several large-scale randomized studies for prevention of thrombotic complications have shown their potential to reduce these complications in patients undergoing percutaneous transluminal coronary angioplasty (PTCA). It was the purpose of this observational trial to assess the frequency and efficacy of primary GP IIb/IIIa antagonist therapy as a bailout procedure for the prevention of threatened or abrupt vessel closure in patients after conventional balloon angioplasty.

METHODS AND RESULTS

From January 1995 to December 1996, PTCA was performed in 1332 consecutive patients with coronary artery disease. Overall, threatened or abrupt vessel closure was observed in 63 (4.7%) patients of the patient population. In these patients, abciximab was administered (0.25 mg/kg body weight intravenous bolus, followed by a 12-hour infusion at 10 mg/min). Repeat PTCA was performed shortly after the administration of the abciximab bolus to achieve an optimal flow at the time of active GP IIb/IIIa therapy. One day after intervention, early follow-up angiography was performed. Follow-up after 1 year included the clinical status of all patients and, if possible, control angiography. Overall, the preintervention minimum lumen diameter (MLD) measured 0.74 +/- 0.27 mm and the diameter stenosis was 75% +/- 24%. The postintervention MLD increased to 2.60 +/- 0.55 mm, and the diameter stenosis decreased to 24% +/- 22%. At 24-hour angiographic follow-up, the MLD decreased to 2.47 +/- 0.49 mm and the diameter stenosis increased to 28% +/- 24%, correspondingly. The thrombus score decreased from 2.8 +/- 1.5 before abciximab treatment to 0.88 +/- 0.81 after abciximab treatment, and Thrombolysis In Myocardial Infarction flow grade increased from 2.1 +/- 1.1 to 2.9 +/- 0.3. In-hospital events occurred in 2 patients. Both patients had to undergo emergency coronary artery bypass grafting (1 of these patients died). During long-term follow-up, there were 10 clinical events (1 death, 3 repeat PTCA, and 6 coronary artery bypass graft operations for restenosis at the target lesion site). The cumulative event rate after 1 year (including acute and follow-up events) for both the total group and for the target vessel was 19%.

CONCLUSIONS

The results of this study demonstrate that GP IIb/IIIa antagonists are able to prevent vessel occlusion after PTCA complicated by subsequent threatened or abrupt vessel closure. In these situations, GP IIb/IIIa antagonists provide effective treatment for the reduction of thrombus at the target lesion site, which constitutes a second key element for threatened or abrupt vessel occlusion.

A risk-benefit assessment of abciximab in angioplasty

Advances in percutaneous coronary intervention (PCI) have allowed procedures to be performed on a variety of patients with a spectrum of challenging coronary anatomy. Abciximab has permitted further expansion and has made the procedure safer. Abciximab is a chimerised murine monoclonal antibody directed against the platelet glycoprotein (GP) IIb-IIIa receptor. Binding to this receptor inhibits platelet aggregation to a wide variety of biological agonists. It also binds to alphavbeta3 and leucocyte MAC-1 receptors; the biological significance of its affinity to these receptors is unclear. Abciximab has an extremely short plasma half-life. Since abciximab binds to the platelet GP IIb-IIIa receptor with great avidity it has an extremely long biological half-life. The use of abciximab is currently confined primarily to PCIs. The first large trial, EPIC, established that abciximab, given with aspirin (acetylsalicylic acid) and heparin, reduced the frequency of peri-procedural ischaemic events by 35% in high-risk patients. For this reduction a bolus of 0.25 mg/kg was followed by a 12-hour infusion of abciximab. However, the transfusion rate was doubled. A subsequent trial, EPILOG, indicated that reduction of the dose of heparin along with expeditious removal of arterial access sheaths, reduced the rate of haemorrhagic complications to a level comparable with placebo-treated patients. while also amplifying the reduction in ischaemic events. In a third trial, EPISTENT, this benefit was shown to include patients undergoing elective coronary stent implantation. Additional trials have demonstrated that the same effect is present in patients undergoing primary PCI for acute myocardial infarction and in patients undergoing PCI for refractory unstable angina pectoris. In the latter situation, treatment with abciximab for 18 to 24 hours preceding the intervention reduced the rate of myocardial infarction even before the procedure was begun. The rationale for the use abciximab is thus clearly established. Bleeding complications can be reduced by limiting the heparin dose, avoiding unneeded venous access site punctures, and expeditious removal of arterial sheaths. In emergency coronary artery bypass surgery, platelet transfusion reduces the number of receptors occupied per platelet and is likely to reduce the degree of postoperative bleeding. The cost of abciximab remains an issue; however, this is partially offset by the reduction in ischaemic complications and accompanying resource use. In patients undergoing elective coronary stenting, abciximab use reduced the long term rate of target vessel revascularisation. The degree to which this reduction results in further cost savings will require further analysis.

Abciximab in primary coronary angioplasty for acute myocardial infarction improves short- and medium-term outcomes

OBJECTIVES

The purpose of this study was to compare the outcome of primary percutaneous transluminal coronary angioplasty for acute myocardial infarction (MI) when performed with or without the platelet glycoprotein IIb/IIIa antibody, abciximab.

BACKGROUND

Abciximab improves the outcome of angioplasty but the effect of abciximab in primary angioplasty has not been investigated.

METHODS

Data were collected from a computerized database. Follow-up was by telephone or review of outpatient or hospital readmission records.

RESULTS

A total of 182 consecutive patients were included; 103 received abciximab and 79 did not. The procedural success rate was 95% in the two groups. At 30-day follow-up, the composite event rate of unstable angina, reinfarction, target vessel revascularization and death from all causes was 13.5% in the group of patients who did not receive abciximab, 4% (p < 0.05) in the abciximab group and 2.4% (p < 0.05) in the subgroup of patients (n = 87) who completed the 12-h abciximab infusion. At the end of follow-up (mean 7+/-4 months), the composite event rate was 32.4%, 17% (p < 0.05) and 13.1% (p < 0.01) in these three categories respectively. Abciximab bolus followed by a 12-h infusion was an independent predictor of event-free survival, in a Cox proportional hazards model (relative risk 0.49; 95% confidence interval 0.24 to 0.99; p < 0.05).

CONCLUSIONS

Abciximab given at the time of primary angioplasty may improve the short- and medium-term outcome of patients with acute MI, especially when a 12-h infusion is completed.