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

Intracoronary pharmacological therapy versus aspiration thrombectomy in STEMI (IPAT-STEMI): A systematic review and meta-analysis of randomized trials

BACKGROUND

Thrombus load in STEMI patients remains a challenge in practice. It aggravates coronary obstruction leading to impaired myocardial perfusion, worsened cardiac function, and adverse clinical outcomes. Various strategies have been advocated to reduce thrombus burden.

OBJECTIVES

This meta-analysis aimed to evaluate the effectiveness of intracoronary-administered thrombolytics or glycoprotein IIb/IIIa inhibitors (GPI) in comparison with aspiration thrombectomy (AT) as an adjunct to percutaneous coronary intervention (PCI) among patients presenting with ST-segment elevation myocardial infarction (STEMI).

METHODS

A comprehensive literature search for randomized trials that compared intracoronary-administered thrombolytics or GPI with AT in STEMI patients who underwent PCI, was conducted using various databases (e.g., MEDLINE, EMBASE, CENTRALE). Primary outcome was procedural measures (e.g., TIMI flow grade 3, TIMI myocardial perfusion grade (TMPG) 3, Myocardial blush grade (MBG) 2/3, ST-segment resolution (STR)).

RESULTS

Twelve randomized trials enrolled 1,466 patients: 696 were randomized to intracoronary-administered pharmacological interventions and 553 to AT. Patients randomized to PCI alone were excluded. Thrombolytics significantly improved TIMI flow grade 3 (odds ratio = 3.71, 95% CI: 1.85-7.45), complete STR (odds ratio = 3.64, 95% CI: 1.60-8.26), and TMPG 3 (odds ratio = 5.31, 95% CI: 2.48-11.36). Thrombolytics significantly reduced major adverse cardiovascular events (MACE) (odds ratio = 0.29, 95% CI: 0.13-0.65) without increasing bleeding risk. Trial sequential analysis assessment confirmed the superiority of thrombolytics for the primary outcome. Intracoronary GPI, either alone or combined with AT, did not improve procedural or clinical outcomes.

CONCLUSIONS

Compared with AT, intracoronary-administered thrombolytics significantly improved myocardial perfusion and MACE in STEMI patients.

Perforated balloon technique: A simple and handy technique to combat no-reflow phenomenon in coronary system

OBJECTIVE

Examining the efficacy and outcomes of intracoronary (IC) instillation of adenosine using a novel perforated balloon technique (PBT) to combat no-reflow phenomenon during percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS).

BACKGROUND

Occurrence of no-reflow during PCI is a serious adverse prognostic event and inability to re-establish better flow is associated with poor outcomes. Several pharmacological and non-pharmacological interventions have been used to treat this situation. This series describes the use of PBT for IC adenosine administration and its effects on outcomes during real world interventional practice.

METHODS

Subjects comprised of 24 patients with ACS (out of a total of 1,634 patients undergoing PCI between January 2016 and June 2017) in whom we used PBT for IC administration of adenosine to treat coronary no-reflow.

RESULTS

PBT for IC adenosine instillation was used in 24 (1.5%) of 1,634 patients undergoing PCI. TIMI grade III flow was established in 21 patients (87.5%). In two patients (8.3%) TIMI grade II flow was established and in one patient (4.2%) we were unsuccessful.

CONCLUSION

We demonstrate the safety and efficacy of a novel strategy for adenosine instillation in the distal coronary bed, the PBT. This technique enables rapid and cost-effective treatment of no-reflow phenomenon during PCI for ACS.

Predictors of periprocedural complications in patients undergoing percutaneous coronary interventions within coronary artery bypass grafts

BACKGROUND

During the first decade following the coronary bypass grafting, at least ten percent of the patients require percutaneous coronary interventions (PCI) due to graft failure. Saphenous vein grafts (SVG) are innately at a higher risk of periprocedural complications. The present study aimed to investigate predictors of periprocedural complications of PCI within coronary artery bypass grafts.

METHODS

This study analyzed data gathered in the Polish National Registry (ORPKI) between January 2015 and December 2016. Of the 221,195 patients undergoing PCI, data on 2,616 patients after PCI of SVG and 442 patients after internal mammary artery (IMA) were extracted. The dissimilarities in periprocedural complications between the SVG, IMA and non-IMA/SVG groups and their predictors were investigated.

RESULTS

Patients in the SVG group were older (p < 0.001), with a higher burden of concomitant disease and differing clinical presentation. The rate of de-novo lesions was lower, while restenosis was higher at baseline in the SVG (p < 0.001). The rate of no-reflows (p < 0.001), perforations (p = 0.01) and all periprocedural complications (p < 0.01) was higher in the SVG group, while deaths were lower (p < 0.001). Among the predictors of no-reflows, it was found that acute coronary syndromes (ACS), thrombectomy and past cerebral stroke, while the complications included arterial hypertension, Thrombolysis in Myocardial Infarction (TIMI) flow before PCI and thrombectomy.

CONCLUSIONS

Percutaneous coronary interventions of SVG is associated with increased risk of specific periprocedural complications. The ACS, slower TIMI flow before PCI and thrombectomy significantly increase the periprocedural complication rate in patients undergoing PCI of SVG.

Intracoronary Bivalirudin Bolus in ST-Elevation Myocardial Infarction Patients Treated with Primary Angioplasty: Theoretical Bases, Clinical Experience, and Future Applications

Intracoronary thrombus is a common finding in acute coronary syndromes and often correlates with adverse prognosis and complications during percutaneous coronary interventions (PCIs). Bivalirudin, a direct thrombin inhibitor, is one of the recommended antithrombotic treatments for PCI in ST-elevation myocardial infarction (STEMI). The intracoronary administration of a bivalirudin loading dose, even if off-label, offers theoretical advantages over the standard intravenous route, providing a very high drug concentration in the infarct-related artery without increasing the total dose of the drug administered. After the description in case reports of such an approach, a larger scale experience was recently reported in a large cohort of patients with STEMI treated during primary PCI with a bivalirudin intracoronary loading dose followed by the standard intravenous maintenance infusion. As a control group, a propensity score-matched cohort of patients undergoing primary PCI treated with intravenous bivalirudin in the same institution was selected. Compared with the intravenous bolus, the intracoronary administration of bivalirudin was associated with improved ST-segment resolution, lower post-procedural peak CK-MB levels, and better Thrombolysis in Myocardial Infarction (TIMI) frame count values, without difference in bleeding rates. Thus, this new promising antithrombotic strategy, based on the intracoronary administration of a bivalirudin loading dose during primary PCI, appeared safe, improved myocardial reperfusion, and mitigated enzymatic myocardial infarct size compared with the standard intravenous protocol. Randomized trials are warranted to confirm these results and evaluate the possible long-term clinical benefits.

Endovascular thrombolysis for pediatric cerebral sinus venous thrombosis with tissue plasminogen activator and abciximab

Cerebral sinus venous thrombosis (CSVT) is a relatively rare but potentially devastating disease. Medical management of CSVT with systemic anticoagulation has been the mainstay treatment strategy with these patients. However, some patients may not respond to this treatment or may present with very severe symptoms indicating more aggressive management strategies. The authors present the case of a pediatric patient who presented with severe CSVT, who underwent successful recanalization with endovascular tissue plasminogen activator (tPA) and abciximab. To the authors' knowledge there are no cases of endovascular thrombolysis for CSVT described in the literature in which abciximab has been used in conjunction with tPA. The authors also review the literature regarding the agents used and outcome in pediatric patients with CSVT after endovascular thrombolysis. The use of abciximab in conjunction with tPA may be considered in patients whose blood is hypercoagulable and in whom the treatment strategy is to obtain acute recanalization and long-term venous patency. However, the use of adjunctive agents increases the risk of hemorrhagic complications and must be done judiciously.

Intracoronary Reopro during Percutaneous Coronary Intervention in Acute and Stable Patient can Influence Stent Thrombosis Formation (IRPASST) Study

BACKGROUND

In patients with acute myocardial infarction or unstable angina undergoing coronary angioplasty, abciximab reduces major adverse cardiac events (MACE). Most clinical trials have studied mainly intravenous administration. Intracoronary (IC) bolus application of abciximab causes very high local drug concentrations and may be more effective in reducing acute and sub-acute stent thrombosis (ST). We studied whether IC bolus administration of abciximab is associated with a reduced ST and target vessels revascularization (TVR); therefore, less MACE rate compared with the standard intravenous IV bolus and infusion application.

MATERIALS AND METHODS

This was a single-center observational study conducted between June 2007 and 2009. We studied a total of 447 patients admitted with either acute coronary intervention (PCI) and stenting. Patients with bleeding disorder, recent major surgery and high blood pressure were excluded. Patients were divided into two groups: Group I (n = 199) patient received IC bolus of abciximab (reopro) 0.25 μg/kg during the PCI in cath lab. Group II (n = 248) received the standard dose of reopro-a bolus intravenous 0.25 μg/kg and maintenance dose of 0.125 μg/kg over 12 h.

RESULTS

There were no differences between the groups with regard to diabetes mellitus, group I (56%) vs. group II (58%), P = 0.613; ACS, group I (38%) vs. group II (44%), P = 0.175; Dietthylstilbestrol Drug eluted stent (DES) in group I (66.5%) vs. (57.6%) group II, P = 0.056; Bare Metal Stent (BMS) in group I (33%) vs. (40.7%) group II, P=0.093; target vessel revascularization (TRV) was seen in 9 patients (4%) in group I vs. 16 patients (6%) in group II. ST elevation was seen in 4 patients (2%) in group I vs. 7 patients (2.8%) in group II, all presented with STEMI.

CONCLUSION

In this study, there was a trend toward less ST and TVR in patients who received IC reopro vs. intravenous route both in ACS and stable CAD. The percentage of DM was high in both groups (56%), especially in Saudi patients. In-stent restenosis (ISR) was less in group I than in group II, this was mainly associated with BMS usage. The percentage of BMS was more than 30% in both groups, either due to STEMI cases or large vessel size. Randomized controlled trials are warranted to further assess IC application of abciximab in reducing ST.

Current percutaneous treatment strategies for saphenous vein graft disease

Coronary artery bypass graft surgery remains one of the most widely performed surgical procedures in North America and aortocoronary saphenous vein grafts (SVG) are the most frequently used surgical conduits. SVG disease (SVGD) remains the leading cause of symptomatic coronary artery disease postcoronary artery bypass graft. When optimal medical therapy is ineffective, repeat surgery is associated with higher mortality combined with less favorable clinical and angiographic results, thus percutaneous revascularization on SVG is currently the standard of care for the revascularization of SVGD. Balloon angioplasty, bare metal stents, polytetrafluoroethylene-covered stents, and drug-eluting stents have been extensively investigated for SVG interventions. Multiple recent randomized trials and meta-analyses have confirmed the pathophysiologic and clinical differences between SVGD and coronary artery disease. Decisions such as patient selection, premedication, stent, and protection device characteristics should be carefully considered to achieve optimal procedural and clinical results. Acute coronary syndromes due to SVG involvement, chronic total occlusions, retrograde approaches, and SVG perforation management are newer fields requesting additional research.

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.

Pharmacotherapy During Saphenous Vein Graft Intervention

Coronary revascularization using saphenous vein grafts is an important treatment modality for patients with severe coronary artery disease. Percutaneous intervention of these grafts is often the best option for patients who develop severe stenosis of the vein grafts. Use of adjunctive glycoprotein IIb/IIIa inhibitors does not confer added benefit with ischemic endpoints as compared with heparin alone, but it increases the risk of bleeding. Bivalirudin used as the primary anticoagulant lowers the risk of bleeding. No-reflow frequently complicates vein graft interventions but can be treated with vasoactive agents such as calcium channel blockers, adenosine, and nitroprusside.

Intracoronary glycoprotein IIb/IIIa inhibitor infusion via a perfusion coronary catheter to decrease thrombus burden: results from the ClearWay™ Multicenter Registry

OBJECTIVES

This multicenter registry aimed to assess the ClearWay™ (CW) perfusion catheter in reduction of thrombus burden and improvement of the coronary flow during percutaneous coronary intervention (PCI).

BACKGROUND

The presence or development of thrombus during PCI is associated with poor prognosis.

METHODS

The utility of the CW perfusion catheter was assessed in patients who presented with intracoronary thrombus and were subjected to PCI. Data were collected by online survey from 15 US sites. Angiographic assessment of the coronary thrombus burden and the coronary flow after intracoronary infusion of glycoprotein (GP) IIb/IIIa inhibitors via the CW catheter was evaluated at baseline, immediately after infusion, and at the end of the procedure. The cohort included 102 patients; 71.6% presented with ST-elevation myocardial infarction (MI), 21.6% with non-ST-elevation MI, 5.9% with stable angina pectoris, and 2.9% with silent ischemia. The mean cohort age was 59.9±14.5years and comprised mostly of men (72.5%).

RESULTS

GP IIb/IIIa inhibitors were infused via the CW catheter on average 1.1±0.3 times, with a mean pressure of 4.2±2.7atm and a mean infusion time of 55±55s. Following the infusion, Thrombolysis In Myocardial Infarction (TIMI) flow improved by 1° in 71 patients (69.6%) and by 2° in 51 patients (50%), while visible thrombus was reduced by 52% (p<0.001). In the final angiogram, TIMI flow was restored in 90.2% and clearance of a visible thrombus was obtained in 91.8% of the lesions.

CONCLUSION

Intracoronary infusion of GP IIb/IIIa inhibitors via the perfusion CW catheter is associated with significant reduction in thrombus burden and with improvement of the coronary flow in patients presenting or developing thrombus burden during PCI.

The Optimal Route of Administration of the Glycoprotein IIb/IIIa Receptor Antagonist Abciximab During Percutaneous Coronary Intervention; Intravenous Versus Intracoronary

The use of the glycoprotein (GP) IIb/IIIa receptor antagonist Abciximab has over the years become an important part of the anticoagulant regimen in patients with acute coronary syndrome undergoing percutaneous coronary intervention. Abciximab is a potent inhibitor of platelet aggregation and thrombus formation, but other mechanisms, such as suppression of the inflammatory pathways, have also been proposed to contribute to the benefits of Abciximab.

The optimal route of administration, i.e. intravenous versus intracoronary, of the first dose has been questioned, but only tested in small, non-randomised and retrospective studies or studies with short follow-up. No definite conclusion can be made based on these studies.

In this review we present the current knowledge published about the intracoronary administration of Abciximab including the mechanisms behind the potential beneficial effects, and the safety. The emphasis will be on clinical trials rather than on studies on the pharmacological mechanisms, as the latter have been reviewed thoroughly elsewhere.

Our conclusion from this present review is that randomized trials of intracoronary versus intravenous bolus of Abciximab are needed.

Rationale and design of the INFUSE-AMI study: A 2 × 2 factorial, randomized, multicenter, single-blind evaluation of intracoronary abciximab infusion and aspiration thrombectomy in patients undergoing percutaneous coronary intervention for anterior ST-segment elevation myocardial infarction

BACKGROUND

Whether thrombus aspiration and local glycoprotein IIb/IIIa administration reduce infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) has not been established in multicenter studies.

DESIGN

INFUSE-AMI is a multicenter, open-label, controlled, single-blind randomized study enrolling 452 subjects with anterior STEMI and an occluded proximal or mid-left anterior descending artery with thrombosis in myocardial infarction 0, 1, or 2 grade flow undergoing primary PCI with bivalirudin anticoagulation. Subjects are randomized in a 2 × 2 factorial to one of the following 4 arms: (1) local infusion of abciximab using the ClearWay RX Local Therapeutic Infusion Catheter (ClearWay, Atrium Medical Corp, Hudson, NH) after aspiration with a 6F Export Aspiration Catheter (Medtronic, Inc, Minneapolis, MN), (2) local infusion of abciximab using the ClearWay RX Infusion Catheter and no aspiration, (3) no local infusion of abciximab and aspiration with a 6F Export Aspiration Catheter, or (4) no local infusion of abciximab and no aspiration. The primary end point is infarct size (percentage of total left ventricular mass) at 30 days measured by cardiac magnetic resonance imaging. Other secondary end points include microvascular obstruction by cardiac magnetic resonance imaging at 5 days, ST-segment resolution, angiographic myocardial perfusion, thrombus burden, angiographic complications, and clinical events through 1-year follow-up. Safety end points include major and minor bleeding.

SUMMARY

INFUSE-AMI is testing the hypothesis that the intracoronary administration of an abciximab bolus with or without thrombus aspiration before stent implantation compared to no infusion with or without thrombus aspiration reduces infarct size among patients undergoing primary PCI for anterior STEMI who are treated with bivalirudin.

Intracoronary compared with intravenous bolus abciximab application in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention: the randomized Leipzig immediate percutaneous coronary intervention abciximab IV versus IC in ST-elevation myocardial infarction trial

BACKGROUND

Abciximab reduces major adverse cardiac events in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI). Intracoronary abciximab bolus application results in high local drug concentrations and may be more effective than a standard intravenous bolus.

METHODS AND RESULTS

Patients undergoing primary PCI were randomized to either intracoronary (n=77) or intravenous (n=77) bolus abciximab administration with subsequent 12-hour intravenous infusion. The primary end point was infarct size and extent of microvascular obstruction as assessed by delayed enhancement magnetic resonance. Secondary end points were ST-segment resolution at 90 minutes, Thrombolysis in Myocardial Infarction flow and perfusion grades after PCI, and the occurrence of major adverse cardiac events within 30 days. The median infarct size was 15.1% (interquartile range, 6.1% to 25.2%) in the intracoronary versus 23.4% (interquartile range, 13.6% to 33.2%) in the intravenous group (P=0.01). Similarly, the extent of microvascular obstruction was significantly smaller in intracoronary compared with intravenous abciximab patients (P=0.01). Myocardial perfusion measured as early ST-segment resolution was significantly improved in intracoronary patients with an absolute ST-segment resolution of 77.8% (interquartile range, 66.7% to 100.0%) versus 70.0% (interquartile range, 45.2% to 83.5%; P=0.006). The Thrombolysis in Myocardial Infarction flow after PCI was not different between treatment groups (P=0.51), but there was a trend toward an improved perfusion grade (P=0.09). There also was a trend toward a lower major adverse cardiac event rate after intracoronary versus intravenous abciximab application (5.2% versus 15.6%; P=0.06; relative risk, 0.33; 95% CI, 0.09 to 1.05).

CONCLUSIONS

Intracoronary bolus administration of abciximab in primary PCI is superior to standard intravenous treatment with respect to infarct size, extent of microvascular obstruction, and perfusion.

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.

Rationale for intracoronary administration of abciximab

The present review aims to describe the pharmacological aspects as well as the available clinical data supporting the choice of intracoronary route of administration for abciximab, an antiplatelet drug used in patients with acute coronary syndromes undergoing percutaneous coronary interventions (PCI). Abciximab is a glycoprotein (GP) IIb/IIIa receptor antagonist which determines a potent inhibition of platelet aggregation and thrombus formation. These properties seem to prevent not only thrombus formation but also to promote (at higher drug concentration) lysis of fresh thrombus. Moreover, differently from the other GP IIb/IIIa inhibitors, abciximab also binds to the vitronectin receptor on endothelial, smooth muscle, and inflammatory cells and to an activated conformation of the aMb2 receptor on leukocytes. Such cross-reactivity raises the possibility that clinical benefits derived from its use may not be exclusively due to its anti-thrombotic effect, but may also be related to the suppression of inflammatory pathways involving platelets, white blood cells, and the vascular endothelium. On such basis, the local administration of abciximab at the site of coronary thrombosis may enhance, by increasing its local concentration, the binding to both platelet and endothelium receptors. The results of several angiographic studies assessing the effect of intracoronary abciximab administration support on clinical grounds its adoption in patients with fresh coronary thrombosis. Indeed, better post-angioplasty coronary flow, greater degree of myocardial salvage and a better left ventricular function recovery have been achieved as compared to the intravenous, systemic, administration of drug's bolus. Condensed Abstract Several studies have highlighted the benefits of abciximab, a potent antiplatelet agent, in patients with acute coronary syndromes undergoing percutaneous coronary interventions. Moreover, differently from the other glycoprotein IIb/IIIa receptor antagonists, abciximab also has non-IIb/IIIa-related properties raising the possibility that clinical benefits derived from its use may not be exclusively due to its anti-thrombotic effect, but may also be related to the suppression of inflammatory pathways. Several angiographic studies in patients with fresh coronary thrombosis and recent clinical studies in patients with acute coronary syndromes undergoing mechanical revascularization support the hypothesis that local administration of abciximab at the site of the culprit coronary artery may facilitate both the de-thrombotic and the non-GP IIb/IIIa-dependent properties of the drug. On such basis, the present review aims to describe the pharmacological aspects as well as the available clinical data supporting the choice of intracoronary route of administration for abciximab.

Drug-Eluting Coronary Stents

The introduction and widespread use of coronary stents have been the most important advancement in the percutaneous treatment of coronary artery disease since the introduction of balloon angioplasty. Coronary artery stents reduce the rate of angiographic and clinical restenosis compared to balloon angioplasty. This angiographic restenosis was further reduced with the introduction of drug-eluting stents and hence further reduction in the frequency of major adverse cardiac events. Herein we present a comprehensive and up-to-date review about the use of drug-eluting stents in the treatment of coronary artery disease.

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.

Procedural results and distal embolization after saphenous vein graft stenting and angioplasty for in-stent restenosis of grafts

Saphenous vein graft (SVG) angioplasty is associated with frequent periprocedural complications due to distal embolization and a high risk of restenosis. The purpose of this single-center, retrospective study was to determine the distal embolization incidences and outcomes of stenting for SVG lesions and percutaneous angioplasty for in-stent restenosis of these SVGs. We studied 48 consecutive patients (mean age, 62 +/- 7 years, 92% men) who had prior CABG and underwent stent deployment to SVG lesions detected at our institution over a period of 4 years. Mean lesion length was 12.4 +/- 3.2 mm. The minimal lumen diameter increased from 0.7 +/- 0.3 mm to 3.2 +/- 0.4 mm after stenting. Distal embolization as no reflow/slow flow phenomenon occurred in 5 (10%) patients. Angiographic success was achieved in 98% of the patients. Procedural success was achieved in 96% of the patients. No reflow/slow flow phenomenon was observed, particularly in patients with acute coronary syndrome. During the follow-up, 11 patients (23%) had angiographic evidence of restenosis. Lesions were treated with balloon angioplasty and the minimal lumen diameter increased from 2.6 +/- 1.1 mm to 3.1 +/- 0.3 mm. The angiographic and procedural success rates were both 100%. There were no cases of "no" reflow/slow flow. Restenosis was particularly frequent in patients with diabetes mellitus, hypercholesterolemia, and acute coronary syndrome. Stent implantation in patients with de novo SVG lesions can be achieved with a high rate of angiographic and procedural success. The distal embolization risk is lower during angioplasty of in-stent restenosis lesions of SVGs compared to de novo SVG lesions.

The anti-leukemic Bruton's tyrosine kinase inhibitor alpha-cyano-beta-hydroxy-beta-methyl-N-(2,5-dibromophenyl) propenamide (LFM-A13) prevents fatal thromboembolism

The leflunomide metabolite analog alpha-cyano-beta-hydroxy-beta-methyl-N-(2,5-dibromophenyl)-propenamide (LFM-A13) is a rationally-designed specific inhibitor of the TEC family protein tyrosine kinase, Bruton's tyrosine kinase (BTK) which plays an important role in platelet physiology by regulating the glycoprotein GPVI-FcRgamma-coupled collagen receptor signaling pathway. At low micromolar concentrations, LFM-A13 inhibited collagen-induced ultrastructural changes indicative of activation. LFM-A13 inhibited collagen (but not thrombin, TRAP-6, or ADP)-induced platelet aggregation in a concentration-dependent fashion with an IC50 value of 2.8 microM. LFM-A13 was not toxic to mice when administered systemically at dose levels ranging from 1 to 100 mg/kg. At nontoxic dose levels, LFM-A13 prolonged the tail bleeding times of mice and improved event-free survival in two mouse models of agonist-induced invariably fatal pulmonary thromboembolism. To our knowledge, LFM-A13 is the first anti-thrombotic agent which prevents platelet aggregation by inhibiting BTK.

Prolonged systemic delivery of tirofiban in a thrombus-laden saphenous vein graft

Results from previous trials have shown conflicting results from local delivery of thrombolytic agents to diminish thrombus burden before intervention in native coronary arteries and saphenous vein grafts. We described a patient with an acute coronary syndrome who was treated for 24 hours with systemic tirofiban (Aggrastat), a glycoprotein IIb/IIIa inhibitor, for the treatment of a degenerated saphenous vein graft with a TIMI grade 4 thrombus (large-sized thrombus). Angiographic evaluation 48 hours later revealed complete resolution of the thrombus with normal coronary blood flow.

Reduction of major adverse cardiac events with intracoronary compared with intravenous bolus application of abciximab in patients with acute myocardial infarction or unstable angina undergoing coronary angioplasty

BACKGROUND

In patients with acute myocardial infarction or unstable angina undergoing coronary angioplasty, abciximab reduces major adverse cardiac events (MACE). Clinical trials have studied intravenous administration only. Intracoronary bolus application of abciximab causes very high local drug concentrations and may be more effective. We studied whether intracoronary bolus administration of abciximab is associated with a reduced MACE rate compared with the standard intravenous bolus application.

METHODS AND RESULTS

We stratified 403 consecutive patients with acute myocardial infarction or unstable angina undergoing coronary angioplasty according to the type of application of abciximab. A 20-mg bolus of abciximab was given intravenously in 109 patients and intracoronarily in 294 patients. There were no differences between the groups with regard to diabetes mellitus, cardiogenic shock, successful intervention, or preprocedural and postprocedural TIMI flow. At 30 days, the incidence of MACE (death, myocardial infarction, urgent revascularization) was significantly lower in the patients with intracoronary compared with intravenous administration of abciximab (10.2% versus 20.2%; P<0.008), which was independent from stenting in multivariate analysis. The effect was most pronounced in patients with preprocedural TIMI 0/1 flow (MACE: intracoronary 11.8% versus intravenous 27.5%, P<0.002; n=273).

CONCLUSIONS

In patients with acute myocardial infarction or unstable angina undergoing emergency coronary angioplasty, intracoronary bolus application of abciximab is associated with a reduction of MACE compared with the standard intravenous bolus application of abciximab. Prospective, randomized trials are warranted to further assess intracoronary application of abciximab.

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.

Outcomes of patients with acute coronary syndromes and prior coronary artery bypass grafting: results from the platelet glycoprotein IIb/IIIa in unstable angina: receptor suppression using integrilin therapy (PURSUIT) trial

BACKGROUND

Patients with prior CABG with a subsequent non-ST-segment elevation acute coronary syndrome (ACS) pose an increasingly important clinical problem. Although GP IIb/IIIa inhibitors have improved the outcome of patients with ACS, their efficacy in patients with prior CABG has not been previously evaluated. Methods and Results- We analyzed the 30- and 180-day outcomes of patients with prior CABG enrolled in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial. In this trial, which evaluated the efficacy of eptifibatide in patients with ACS, 1134 patients (12%) with prior CABG and 8321 without prior CABG were enrolled. After adjusting for differences in baseline characteristics and treatment, patients with prior CABG had a significantly higher mortality rates at 30 days (hazard ratio [HR], 1.45 [95% CI, 1.06 to 1.98]; P=0.019) and at 180 days (HR, 1.32 [95% CI, 1.04 to 1.67]; P=0.021). At 30 days, there was a similar effect on the primary end point of death or myocardial infarction in the eptifibatide group versus the placebo group in prior CABG patients (unadjusted HR, 0.90 [95% CI, 0.67 to 1.20]) and in patients without a history of CABG (unadjusted HR, 0.89 [95% CI, 0.80 to 0.99]).

CONCLUSIONS

Patients with prior CABG with non-ST-segment elevation ACS have a significantly worse prognosis than do patients without a history of CABG. The treatment effect of eptifibatide in the prior CABG group was similar to the effect seen in patients without prior CABG.

Long-term clinical outcome and predictors of major adverse cardiac events after percutaneous interventions on saphenous vein grafts

OBJECTIVES

The purpose of this study was to examine the long-term clinical outcome after percutaneous intervention of saphenous vein grafts (SVG) and to identify the predictors of major adverse cardiac events (MACE).

BACKGROUND

Percutaneous interventions of SVGs have been associated with more procedural complications and higher restenosis rates compared with interventions on native vessels.

METHODS

From 1993 to 1997, 1,062 patients underwent percutaneous intervention on 1,142 SVG lesions. Procedural, in-hospital and long-term clinical outcomes were recorded in a database and analyzed.

RESULTS

In-hospital MACE occurred in 137 patients (13%) including death (8%), Q-wave myocardial infarction (MI) (2%) and coronary artery bypass surgery (3%). Late MACE occurred in 565 patients (54%) including death (9%), Q-wave MI (9%) and target vessel revascularization (36%). Any MACE occurred in 457 (43%) patients. Follow-up was available in 1,056 (99%) patients at 3 +/- 1 year. Univariate predictors were restenotic lesion (odds ratio [OR]: 2.47, confidence interval [CI]: 1.13 to 3.85, p = 0.0003), unstable angina (OR: 1.99, CI: 1.27 to 2.91, p = 0.04) and congestive heart failure (CHF) (OR: 1.97, CI: 1.14 to 3.24, p = 0.02) for in-hospital MACE, and peripheral vascular disease (PVD) (OR: 2.18, CI: 1.34 to 3.44, p = 0.002), intra-aortic balloon pump placement (OR: 2.08, CI: 1.13 to 3.85, p = 0.02) and previous MI (OR: 1.97, CI: 1.14 to 3.25, p = 0.007) for late MACE. Independent multivariate predictors for late MACE were restenotic lesion (relative risk [RR] 1.33, p = 0.02), PVD (RR: 1.31, p = 0.01), CHF (RR: 1.42, p = 0.01) and multiple stents (RR: 1.47, p = 0.004). Angiographic follow-up was available for 422 patients. Angiographic restenosis occurred in 122 (29%) of stented SVGs and 181 (43%) of nonstented SVGs (p = 0.04). Stent implantation did not confer a survival benefit.

CONCLUSIONS

Despite the use of new interventional devices, SVG interventions are associated with significant morbidity and mortality; SVG stenting is not associated with better three-year event-free survival. This may be due to progressive disease at nonstented sites.

Effect of abciximab on late adverse events in patients with diabetes mellitus undergoing stent implantation

Percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM) is associated with higher rates of adverse cardiac events. Recent data suggest that adverse events are reduced in DM after PCI using stents with abciximab. We performed a retrospective analysis of a prospective PCI registry for all patients with DM who underwent stent placement at the Mayo Clinic from 1995 to 1997 (n = 570), and divided them into 2 groups based on whether abciximab was administered. Characterization and comparison of the clinical and angiographic variables, procedural outcomes, and short- and long-term event rates between groups was performed. The baseline clinical characteristics of the groups were similar, but patients treated with abciximab were more likely to be men with a lower left ventricular ejection fraction. Patients treated with abciximab had more multivessel intervention, saphenous vein graft intervention, and thrombus before intervention. The 30-day mortality rate (0.6% vs 3.0%, p = 0.03) and repeat PCI (0% vs 1.1%, p = 0.03) was lower in patients treated with abciximab. The 30-day rates of bypass surgery, myocardial infarction (MI), and a composite of death, MI, and revascularization were similar. The 1-year event rates did not differ significantly between patients taking and not taking abciximab for the end points of death (8.9% vs 8.8%, p = 0.97), MI (13.3% vs 11.4%, p = 0.57), bypass surgery (10.3% vs 6.2%, p = 0.20), repeat PCI (14.7% vs 15.9%, p = 0.76), and a composite of death, MI, and revascularization (30.4% vs 26.7%, p = 0.43). After adjusting for baseline variables, abciximab did not influence the occurrence of late adverse events.