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

[Thrombectomy in the acute myocardial infarction: A success in the fight against incomplete myocardial perfusion]

Currently, the preferred treatment of persistent ST-segment elevation acute myocardial infarction is primary angioplasty. After successful primary angioplasty, up to 30% of patients develop left ventricular dilation and heart failure, as a result of incomplete microvascular reperfusion. The pathophysiology of the microvascular dysfunction in the setting of primary angioplasty is complex and not completely known. Distal embolization of necrotic and thrombotic material acts as a mayor factor. No treatment has so far demonstrated proven efficacy in this scenario. However, several prophylactic measures have been identified. Among them, the rheolytic trombectomy offers interesting benefits both in surrogate and clinical outcome variables.

Intracoronary Eptifibatide Bolus Administration During Percutaneous Coronary Revascularization for Acute Coronary Syndromes With Evaluation of Platelet Glycoprotein IIb/IIIa Receptor Occupancy and Platelet Function

Background— Eptifibatide reduces major adverse cardiac events in patients with acute coronary syndromes undergoing percutaneous coronary intervention (PCI). Intracoronary bolus administration of eptifibatide may result in higher levels of platelet glycoprotein IIb/IIIa receptor occupancy in the local coronary bed, disaggregate thrombus in the epicardial artery and microvasculature, and thereby improve coronary flow.

Methods and Results— Patients undergoing PCI for an acute coronary syndrome were randomized to either intracoronary or intravenous bolus administration of eptifibatide. The primary end point was the local glycoprotein IIb/IIIa receptor occupancy measured in the coronary sinus. There were no angiographic, electrophysiological, or other adverse findings attributable to intracoronary eptifibatide. Platelet glycoprotein IIb/IIIa receptor occupancy was significantly greater with intracoronary versus intravenous administration: first bolus, 94±9% versus 51±15% ( P <0.001); and second bolus, 99±2% versus 91±4% ( P =0.001), respectively. Microvascular perfusion was significantly improved as measured by the corrected thrombolysis in myocardial infarction frame count (cTFC) with intracoronary versus intravenous administration: pre-PCI, 36 (median) (25th and 75th percentiles, 16 and 64) versus 31 (25th and 75th percentiles, 23 and 45; P =0.8); and post-PCI, 18 (25th and 75th percentiles, 10 and 22) versus 25 (25th and 75th percentiles, 22 and 35; P =0.007), respectively. The only multivariate predictor associated with a post-PCI cTFC rank score was the first bolus glycoprotein IIb/IIIa receptor occupancy ( P <0.001).

Conclusions— Intracoronary bolus administration of eptifibatide during PCI in patients with acute coronary syndromes results in higher local platelet glycoprotein IIb/IIIa receptor occupancy, which is associated with improved microvascular perfusion demonstrated by an improved cTFC.

Intracoronary versus intravenous abciximab in ST-segment elevation myocardial infarction: rationale and design of the CICERO trial in patients undergoing primary percutaneous coronary intervention with thrombus aspiration

Background

Administration of abciximab during primary percutaneous coronary intervention is an effective adjunctive therapy in the treatment of patients with ST-segment elevation myocardial infarction. Recent small-scaled studies have suggested that intracoronary administration of abciximab during primary percutaneous coronary intervention is superior to conventional intravenous administration. This study has been designed to investigate whether intracoronary bolus administration of abciximab is more effective than intravenous bolus administration in improving myocardial perfusion in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention with thrombus aspiration.

Methods/Design

The Comparison of IntraCoronary versus intravenous abciximab administration during Emergency Reperfusion Of ST-segment elevation myocardial infarction (CICERO) trial is a single-center, prospective, randomized open-label trial with blinded evaluation of endpoints. A total of 530 patients with STEMI undergoing primary percutaneous coronary intervention are randomly assigned to either an intracoronary or intravenous bolus of weight-adjusted abciximab. The primary end point is the incidence of >70% ST-segment elevation resolution. Secondary end points consist of post-procedural residual ST-segment deviation, myocardial blush grade, distal embolization, enzymatic infarct size, in-hospital bleeding, and clinical outcome at 30 days and 1 year.

Discussion

The CICERO trial is the first clinical trial to date to verify the effect of intracoronary versus intravenous administration of abciximab on myocardial perfusion in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention with thrombus aspiration.

Trial registration

ClinicalTrials.gov NCT00927615

The pathogenesis and treatment of no-reflow occurring during percutaneous coronary intervention

No-reflow is one of the major causes of postinterventional rise of cardiac enzyme and myocardial infarction (MI). This complication is associated with substantial morbidity and mortality after percutaneous coronary intervention (PCI). During and after a no-reflow episode, the patient can suffer from severe chest pain, hypotension, bradycardia, hemodynamic collapse, MI, congestive heart failure, and death. Every effort should be taken to reduce the incidence of this complication. The distal embolic protection device has been shown to decrease this risk in saphenous vein graft (SVG) interventions but not in native coronaries. On the other hand, the use of glycoprotein IIb/IIIa receptor antagonists have been effective in reducing the occurrence of no-reflow during PCI of native coronaries but not during SVG interventions. The treatment of no-reflow is based on the intracoronary administrations of medications that induce maximal vasodilatation in small distal coronary vasculature. The most commonly used drugs in this setting are adenosine, nitroprusside, and verapamil. The goal of this study was to review the pathogenesis and treatment of no-reflow in patients undergoing PCI.

The GPIIb/IIIa (integrin alphaIIbbeta3) odyssey: a technology-driven saga of a receptor with twists, turns, and even a bend

Starting 90 years ago with a clinical description by Glanzmann of a bleeding disorder associated with a defect in platelet function, technologic advances helped investigators identify the defect as a mutation(s) in the integrin family receptor, alphaIIbbeta3, which has the capacity to bind fibrinogen (and other ligands) and support platelet-platelet interactions (aggregation). The receptor's activation state was found to be under exquisite control, with activators, inhibitors, and elaborate inside-out signaling mechanisms controlling its conformation. Structural biology has produced high-resolution images defining the ligand binding site at the atomic level. Research on alphaIIbbeta3 has been bidirectional, with basic insights resulting in improved Glanzmann thrombasthenia carrier detection and prenatal diagnosis, assays to identify single nucleotide polymorphisms responsible for alloimmune neonatal thrombocytopenia, and the development of alphaIIbbeta3 antagonists, the first rationally designed antiplatelet agents, to prevent and treat thrombotic cardiovascular disease. The future looks equally bright, with the potential for improved drugs and the application of gene therapy and stem cell biology to address the genetic abnormalities. The alphaIIbbeta3 saga serves as a paradigm of rigorous science growing out of careful clinical observations of a rare disorder yielding both important new scientific information and improved diagnosis, therapy, and prevention of other disorders.

Management of 'no-reflow' complicating reperfusion therapy

No-reflow phenomenon, defined as inadequate myocardial perfusion of the adequately dilated target vessel without evidence of angiographic mechanical obstruction. It is a multifactorial, well-recognised, secondary phenomenon following reperfusion therapy such as thrombolysis or percutaneous coronary interventions (PCI). The pathophysiological mechanisms leading to the no-reflow state are incompletely understood. Embolization of the atheromatous material to the distal vasculature and intense arteriole vasospasm caused by microembolization of platelet-rich thrombi that release vasoactive agents resulting in microvascular obstructions are likely mechanisms. Current prophylaxis and management strategies are derived from limited clinical data. Intracoronary verapamil, adenosine and nitroprusside have been most frequently studied and administered for angiographic no-reflow during PCI for acute myocardial infarction or saphenous vein graft (SVG) lesions and have been shown to improve epicardial flow and microvascular perfusion. The use of distal embolic protection devices in SVG interventions also provide microvascular protection and improve clinical outcomes. However, by far the most important measures are prevention and anticipation during PCI as once no-reflow established, complete reversal of the situation may not be possible.

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.

Abciximab: a reappraisal of its use in coronary care

Platelet reactivity plays a pivotal role in the pathogenesis of ischemic adverse events during and after acute coronary syndromes (ACS), and percutaneous coronary intervention (PCI). Glycoprotein (GP) IIb/IIIa inhibitors are the strongest antiplatelet agents currently available on the market and three different compounds, namely abciximab, tirofiban, and eptifibatide, have been approved for clinical use. Abciximab has been investigated in the clinical field far more extensively than the other GPIIb/IIIa inhibitors. Abciximab is an anti-integrin Fab fragment of a human - mouse chimeric monoclonal antibody with high affinity and a slow dissociation rate from the GP IIb/IIIa platelet receptor. Abciximab, given shortly before the coronary intervention, is superior to placebo in reducing the acute risk of ischemic complications (EPIC, EPISTENT, EPILOG trials); moreover, in the ISAR-REACT 2 study abciximab has been shown to reduce the risk of adverse events in patients with non ST-segment elevation ACS who are undergoing PCI even after optimal pre-treatment with 600 mg of clopidogrel. Finally, abciximab has been also used in abciximab-coated stent, with only bolus administration regimen and for direct intracoronary use with promising results that may extend and/or modify its current use in clinical practice in future.

Immediate and intermediate results of intracoronary stand-alone bolus administration of eptifibatide during coronary intervention (ICE) study

BACKGROUND

This study evaluated the immediate and intermediate results of intracoronary (i.c.) eptifibatide administration during percutaneous coronary intervention (PCI). Several studies tested intravenous (i.v.) bolus and continuous administration of eptifibatide during PCI. However, limited data are available regarding giving eptifibatide as i.c. bolus alone during PCI.

METHODS

We studied clinical outcomes of 376 patients who received coronary stent(s) and eptifibatide by 3 applications during PCI and were followed up over 24 months. Group A (119 patients) had i.c. eptifibatide bolus only, group B (119 patients) had i.c. bolus and i.v. infusion, and group C (138 patients) had i.v. bolus and infusion. The standard 2 boluses of eptifibatide 180 microg/kg were given either via i.c. or i.v. route, and only groups B and C received i.v. infusion at 2 microcg x kg(-1) x min(-1) for 18 to 24 hours.

RESULTS

There were 256 males and 120 females, with a mean age of 57 +/- 11 years. Among them, 52% were diabetic. The 6-, 12-, and 24-month cumulative composite end point of death and myocardial infraction was lower in group A (2.5%) compared with group C (10.8%, odds ratio [OR] 4.3, P = .029) and group B (5.8%, OR 2.6, P = .17). Compared with group A, target vessel revascularization was 3-fold in group C (OR 3.3, P = .001) and 2-fold in group B (OR 2.0, P = .061). Bleeding was significantly higher in group C (OR 5.4, P < .0001) and group B (OR 3.4, P = .007) compared with group A. Rehospitalization was significantly lower in group A (10.9%) compared with group B (16.8%) and group C (28%) (P = .0009).

CONCLUSION

The i.c.-bolus-alone application of eptifibatide may be safer and superior to the i.v. route, and continuous infusion may not be necessary. Large-scale prospective randomized trials are needed to further validate these findings.

Selective serotonin reuptake inhibitor use by patients with acute coronary syndromes

BACKGROUND

Selective serotonin reuptake inhibitors are commonly used to treat anxiety, depression, and other conditions that commonly affect patients with coronary artery disease. Selective serotonin reuptake inhibitors inhibit platelet activation and may, therefore, affect outcomes in patients with acute coronary syndromes.

METHODS

A retrospective study was performed of 1254 patients with acute coronary syndromes comparing in-hospital bleeding and cardiac event rates in 158 patients who received a selective serotonin reuptake inhibitor and a propensity score-matched group of patients who did not. All patients were treated with a glycoprotein IIb/IIIa inhibitor and almost all also received aspirin, clopidogrel, and heparin.

RESULTS

Patients who received a selective serotonin reuptake inhibitor were significantly more likely to experience any bleeding (37.3% vs 26.6%, OR 1.65, 95% confidence interval (CI), 1.02-2.66, P =.04) and significantly less likely to experience recurrent myocardial ischemia, heart failure, or asymptomatic cardiac enzyme elevation while in the hospital (7.0% vs 13.9%, OR 0.46, 95% CI, 0.22-0.99, P =.04). No differences were observed in death, myocardial infarction during the hospitalization, urgent revascularization, or major bleeding. Bleeding and cardiac events were not affected by antidepressants other than selective serotonin reuptake inhibitors.

CONCLUSIONS

Selective serotonin reuptake inhibitor use during a hospitalization for an acute coronary syndrome is associated with reduced rates of recurrent ischemia, heart failure, or cardiac enzyme elevation at the expense of increased bleeding in patients receiving maximal conventional antiplatelet medications and heparin. Clinicians should be aware of this association when treating patients with an acute coronary syndrome.

Assessment of myocardial perfusion for detection of coronary artery stenoses by steady-state, free-precession magnetic resonance first-pass imaging

OBJECTIVE

To evaluate the diagnostic impact of magnetic resonance imaging (MRI) first-pass perfusion using steady-state, free-precession (SSFP) sequences with parallel imaging (SENSE) for detection of coronary stenoses.

DESIGN

Prospective observational study.

SETTING

University hospital, cardiac MRI and catheterisation laboratories.

PATIENTS AND METHODS

228 patients were examined with coronary angiography and MRI (1.5 T Intera CV). A three-slice, short-axis SSFP perfusion scan with a saturation prepulse was performed during infusion of adenosine and at rest followed by myocardial scar (late enhancement) imaging. Gadolinium-DTPA was given at 0.1 mmol/kg body weight. Perfusion images were visually assessed. Analysis for myocardial hypoperfusion was done according to patient group and according to vessel.

RESULTS

Sensitivity, specificity and accuracy of MRI first-pass perfusion for detection of a coronary artery stenosis (>50% luminal narrowing) in the total patient group were 93.0%, 85.7%, 91.2% and for a significant lesion (>70% luminal narrowing) 96.1%, 72.0%, 88.2%, respectively. Based on 536 coronary artery territories without myocardial scar, the sensitivity of MRI perfusion analysis for detection of a significant lesion was for the left anterior descending artery 91.4%, for the circumflex artery 81.6% and for the right coronary artery 65.1% (p<0.001).

CONCLUSIONS

MRI first-pass perfusion analysis using an SSFP sequence with three myocardial slices was a highly accurate diagnostic method for detection of coronary artery stenoses. This MRI technique can be included in daily practice and has the potential to guide the indication for invasive coronary angiography.

A sequential approach to the management of a massive intracoronary thrombus in ST elevation myocardial infarction: a case report

Thrombus-laden coronary lesions present a particular challenge to the interventional cardiologist. Despite the development of multiple strategies to attack this problem, lesions with angio-graphically visible thrombus still carry a high risk of complications when coronary intervention is attempted. The authors present a case of acute inferior ST elevation myocardial infarction with a massive thrombus in an ectatic right coronary artery. Sequential treatment with intra-coronary glycoprotein IIb/IIIa inhibitor, rheolytic thrombectomy with 2 different-sized catheters, and transcatheter thrombus aspiration with a Pronto aspiration catheter was required to achieve a satisfactory result. This case illustrates the potential benefit of combining various mechanical strategies to treat intracoronary thrombus.

Advances in ischemic stroke treatment: neuroprotective and combination therapies

Thrombolysis with intravenous alteplase (recombinant tissue-type plasminogen activator) continues to be the sole recourse for acute ischemic stroke therapy, provided that patients seek treatment preferably within 3 h of stroke onset. The narrow window of efficacy, coupled with the significant risk of hemorrhage and the high mortality rate, preclude the use of alteplase beyond this time frame. Moreover, in part because of safety concerns, only a small percentage (6-15%) of eligible patients is treated with alteplase. Clearly, safer and more effective treatments that focus on improving the shortcomings of the present thrombolysis for stroke need to be identified. Therefore, newer thrombolytics are being developed with the goal of minimizing side effects, while also shortening the time of cerebral reperfusion and extending the therapeutic window of efficacy. Besides thrombolytics, new and potentially useful drugs and devices are also being studied either as monotherapeutic agents or for use in conjunction with alteplase. In animal models of stroke, neuroprotective agents that affect various components of the ischemic injury cascade that results in neurodegeneration have shown promise for the latter. Examples of such agents include spin traps that block oxidative stress, metalloprotease inhibitors that prevent vascular damage, anti-inflammatory drugs that suppress inflammation and transcranial infrared laser irradiation, which promotes recovery of function. Ideally, a successful combination of neuroprotectant (drug or device) and thrombolytic therapy for stroke would minimize the side effects of thrombolysis followed by supplementary neuroprotection thereafter.

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.

Instant dissolution of intracoronary thrombus by abciximab

Formation of intracoronary thrombus during percutaneous coronary intervention can lead to acute vessel closure and myocardial infarction if prompt action is not taken. Thrombus removal using mechanical thrombectomy is the common treatment approach. We report a rare case of thrombus formation immediately after guidewire advancement, causing acute myocardial ischemia. Intracoronary bolus of abciximab was given and this resulted in prompt dissolution of the thrombus. The procedure proceeded uneventfully and there was no myocardial damage. This is consistent with a recent report suggesting that intracoronary abciximab may be more beneficial than standard intravenous administration for patients undergoing emergency coronary intervention for acute coronary syndrome.

Intracoronary bolus administration of eptifibatide during percutaneous coronary stenting for non ST elevation myocardial infarction and unstable angina

BACKGROUND

Distal embolization of thrombotic debris may occur during and after percutaneous coronary intervention (PCI) for acute coronary syndromes. This may lead to impaired microvascular perfusion, myocardial infarction and increased morbidity and mortality. In vitro studies suggest that high local concentrations of a glycoprotein IIb/IIIa inhibitor may be effective in disaggregating thrombus and thereby prevent microvascular compromise. We hypothesized that intracoronary (IC) administration of eptifibatide during stent implantation for unstable angina/non ST elevation myocardial infarction (UA/NSTEMI) would be safe and would lead to an acceptable rate of normal myocardial perfusion.

METHODS

In 54 patients with UA/NSTEMI, 2 boluses of 180 mcg/kg of eptifibatide each were administered via the IC route during PCI. Data were retrospectively collected and reviewed by an independent core laboratory.

RESULTS

No adverse events including arrhythmias occurred during IC administration of eptifibatide. There were no deaths or urgent revascularizations among patients treated with IC eptifibatide. One patient (2.0%) sustained a post-procedure myocardial infarction. One patient sustained a TIMI major bleeding event due to a gastrointestinal bleed. There were no TIMI minor bleeding events. Normal post PCI TIMI Myocardial Perfusion Grade was observed in 54% of patients.

CONCLUSION

IC bolus administration of eptifibatide was feasible and safe among patients with UA/NSTEMI. Larger prospective and randomized studies are warranted to further explore the efficacy of this strategy. Intracoronary eptifibatide administration during PCI for UA/NSTEMI is feasible and safe.

Which strategy should be used for acute ST-elevation myocardial infarction in patients aged more than 75 years?

The optimal management of acute myocardial infarction in elderly people (>or= 75 years) is controversial because elderly patients have been excluded or are under-represented in most acute myocardial infarction trials. Randomized studies show that, also in the elderly, thrombolytic therapy is effective in reducing mortality after acute myocardial infarction but the benefit in terms of mortality, recurrent infarction and stroke is smaller compared to primary percutaneous coronary intervention. Among the available mechanical therapeutic strategies, stenting is found to be superior to balloon angioplasty, whereas the role of drug-eluting stents in this setting still remains to be evaluated. The standard use of intravenous unfractionated heparin is still recommended because of the increased risk of intracranial haemorrhage by a combination of low molecular weight heparin or IIb/IIIa inhibitors and thrombolytic agents. Dedicated randomized clinical trials are needed to establish the best reperfusion therapy for this expanding population, especially in patients admitted to hospitals without percutaneous coronary intervention facilities and in patients developing cardiogenic shock.

Percutaneous coronary intervention of or through saphenous vein grafts or internal mammary arteries: the impact of stents, adjunctive pharmacology, and multicomponent distal protection

We hypothesized that the use of stents and aggressive adjunctive pharmacotherapies has been associated with lower rates of complicating myocardial infarction (MI) and improved long-term outcomes compared to either previous balloon-only percutaneous coronary intervention (PCI) or atheroablative intervention for lesions of or through saphenous vein grafts (SVGs) and/or internal mammary arteries (IMAs). PCI of SVG has been complicated by relatively high rates of procedural MI and less favorable long-term outcomes than native vessel PCI, stimulating the development and application of an array of technologies. This study was based on retrospective review of stent-era (1999-2004) 5-year experience of a single center with 95 SVG procedures in 85 patients and 20 IMA procedures in 20 patients. These cases were compared with the previously published experience of one of the operators during the balloon-only period and literature review of the application of multiple technologies to SVG intervention, as well as consideration of the reoperation alternative. There was one in-hospital death each in the SVG cohort (1%) and in the IMA cohort (5%). There were SIX procedural MIs (6%), defined by total CK > normal, and 19 procedural MIs (20%) based on troponin-I > 1.0. Follow-up has been from 4 months to 5 years (average, 2.5 years), with 91% survival and one late CABG in the IMA group. SVG PCI with stents and adjunctive pharmacotherapies is associated with relatively low rates of procedural MI and favorable long-term outcomes.

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.

Administration of intracoronary eptifibatide during ST-elevation myocardial infarction

Distal embolization of atherothrombotic material during primary percutaneous coronary intervention (PCI) is associated with impaired myocardial perfusion, abnormal left ventricular function, and higher mortality. At high local concentrations, glycoprotein IIb/IIIa receptor antagonists have been demonstrated to promote clot disaggregation in vitro. Intracoronary administration of eptifibatide in vivo may increase local drug concentration by several orders of magnitude and promote clot disaggregation with a minimal increase in systemic drug concentrations. We hypothesized that intracoronary administration of eptifibatide before primary PCI for ST-elevation myocardial infarction would be safe and would be associated with high rates of normal myocardial perfusion. Clinical and angiographic data were pooled from patients who underwent primary PCI and received intracoronary eptifibatide as part of clinical practice. In-hospital adverse events were collected retrospectively. No deaths, urgent revascularizations, or reinfarctions were observed among the 59 patients who were treated with intracoronary eptifibatide. There were no Thrombolysis In Myocardial Infarction (TIMI) major bleeding events. Two TIMI minor bleeding events were noted. Normal TIMI myocardial perfusion grade 3 flow after PCI was noted in 54.4% of patients. No adverse events. including arrhythmias, were noted during intracoronary eptifibatide administration. In conclusion, intracoronary eptifibatide can be administered safely during primary PCI and is associated with few adverse events. Relatively high rates of normal myocardial perfusion were observed after primary PCI with adjunctive intracoronary eptifibatide. Further prospective randomized trials are warranted to evaluate the efficacy and safety of intracoronary eptifibatide.

Pioglitazone Reduces Neointima Volume After Coronary Stent Implantation

Background— Restenosis requiring reintervention limits the long-term success after coronary stent implantation. Thiazolidinediones, like pioglitazone or rosiglitazone, are oral antidiabetic drugs with additional antirestenotic properties. In a randomized, placebo-controlled, double-blind trial, we examined the effect of 6-month pioglitazone therapy on neointima volume after coronary stenting in nondiabetic coronary artery disease patients.

Methods and Results— Fifty nondiabetic patients after coronary stent implantation were randomly assigned to pioglitazone (30 mg daily; pio) or placebo (control) treatment in addition to standard therapy, and neointima volume was assessed by intravascular ultrasound at the 6-month follow-up. Both groups were comparable with regard to baseline characteristics, angiographic lesion morphology, target vessel, and length of the stented segment. In addition, there were no statistical differences in minimal lumen diameter before and after intervention, as well as reference diameter after stent implantation. In this study population of nondiabetic patients, pio treatment did not significantly change fasting blood glucose, fasting insulin, or glycosylated hemoglobin levels, as well as lipid parameters. In contrast, pio treatment significantly reduced neointima volume within the stented segment, with 2.3±1.1 mm 3 /mm in the pio group versus 3.1±1.6 mm 3 /mm in controls ( P =0.04). Total plaque volume (adventitia-lumen area) was significantly lower at follow-up in the pio group (11.2±3.2 mm 3 /mm) compared with controls (13.2±4.2 mm 3 /mm; P =0.04). Moreover, the binary restenosis rate was 3.4% in the pio group versus 32.3% in controls ( P <0.01).

Conclusions— Thus, 6-month treatment with pio significantly reduced neointima volume after coronary stent implantation in nondiabetic patients. These data bolster the hypothesis that antidiabetic thiazolidinediones, in addition to their metabolic effects, exhibit direct antirestenotic effects in the vasculature.

Interventional cardiovascular pharmacotherapy: current issues

In the last decade, a variety of novel anticoagulant and antiplatelet agents that improve outcomes in patients undergoing percutaneous coronary revascularization have emerged. During the next decade, continued refinements in catheter-based device technology should lead to further increases in the number of interventional procedures. The use of optimal antithrombotic strategies is pivotal in reducing adverse events among patients undergoing percutaneous coronary intervention (PCI). Our purpose is to review the current evidence regarding the efficacy of available adjunctive anticoagulant and antiplatelet agents in treating patients undergoing percutaneous coronary revascularization. It should be borne in mind that patients undergoing PCI in the midst of an acute coronary event require a different level of coagulation and platelet aggregation inhibition than low-risk patients undergoing elective PCI for stable angina pectoris. Similarly, generalizing antithrombotic regimen safety data to a wide spectrum of catheter-based therapeutic devices should be avoided. A level of anticoagulation that is safe and effective for angioplasty and stent placement may not be sufficient for devices with longer intracoronary dwell times such as brachytherapy catheters. In light of current evidence, activated clotting times should be targeted in the 200- to 250-second range during elective PCI and in the 250- to 300-second range when intervening on a higher-risk lesion, such as one with an angiographically visible thrombus or in patients presenting with an acute coronary syndrome (ACS).Low-dose enoxaparin sodium is an attractive antithrombin strategy in PCI because it is intrinsically adjusted for renal function, age, and concomitant glycoprotein (GP) IIb/IIIa antagonist use. Other low-molecular weight heparins have also been studied as adjunctive anticoagulants during cardiac catheterization. For example, in pilot studies, dalteparin sodium was shown to have a good safety profile when used alone or in combination with abciximab during PCI.A wealth of data supports the use of a GP IIb/IIIa antagonist in patients presenting with ACS, especially those with high-risk features such as elevated cardiac markers; the systematic use of GP IIb/IIIa inhibitors in this population is therefore encouraged. Overall, the use of GP IIb/IIIa inhibitors reduces the incidence of thrombotic complications following PCI, is associated with a mortality benefit, but has no impact on the risk of restenosis.

Sequelae of acute myocardial infarction regarding cardiac structure and function and their prognostic significance as assessed by magnetic resonance imaging

AIMS

Because of its high spatial resolution and tissue contrast, magnetic resonance imaging (MRI) was used to assess cardiac structure and function in a large population of patients with acute myocardial infarction (AMI).

METHODS AND RESULTS

One hundred and ten patients were studied by MRI 6.1 +/- 2.2 days after AMI. Infarct size (IS), persistent microvascular obstruction (PMO), left and right ventricular (LV/RV) volumes, and functions were measured. The same MRI measurements were repeated in 89 patients after a mean follow-up period of 225 +/- 92 days. IS was 11.9 +/- 7.3% of total LV muscle mass. PMO was detected in 51/110 (46.4%) patients and comprised 15.6 +/- 8.5% of IS and 2.8 +/- 2.3% of LV muscle mass. Papillary muscle infarct was seen in 26%, RV infarction in 16%, pericarditis in 40%, and pericardial effusion in 66% of the patients. During follow-up, there were 16 major adverse cardiac events (MACE) including seven deaths. IS, PMO, and amount of transmural infarction were predictive for LV adverse remodelling defined as > 20% increase in LV end-diastolic volume. Multivariable analysis revealed LV end-diastolic volume, LV ejection fraction, and PMO as significant predictors for the occurrence of MACE.

CONCLUSION

MRI is a highly sensitive and reliable tool to detect morphologic and functional sequelae of AMI providing baseline MRI parameters with relevant predictive power for LV adverse remodelling and occurrence of MACE.

Incidence and Management of "No-Reflow" Following Percutaneous Coronary Interventions

No-reflow is a complex condition associated with inadequate myocardial perfusion of the coronary artery in the absence of epicardial obstruction. It can occur in several settings, including percutaneous coronary intervention, especially in complex thrombotic lesions of native arteries and vein grafts and in primary angioplasty. The causes of no-reflow are not completely understood, and current treatments consist of intracoronary vasodilators, antithrombotic therapies, and mechanical devices (including aspiration thrombectomy catheters and embolic protection devices).

Rescue Revascularization Therapy With a Stent-in-Stent Technique for Acute Intracranial Internal Carotid Artery Occlusion-Case Report-

A 45-year-old woman presented with progressive stroke due to occlusion of the left internal carotid artery at the level of the cavernous portion (C3/C4). Revascularization was achieved by stent deployment following percutaneous transluminal angioplasty. Stent thrombosis occurred 7 days after primary stenting; it was successfully treated with the stent-in-stent technique. The patient was able to return to her independent life with no sequelae except for slight hemiparesis. In combination with appropriate antiplatelet treatment, the stent-in-stent technique should be considered as a rescue option in patients with re-occlusion of an intracranial stent.

The no-reflow phenomenon in coronary arteries

No reflow occurs when there is inadequate myocardial perfusion of a given segment of the coronary circulation without evidence of epicardial vessel obstruction. It is a rare but clinically significant condition associated with myocardial infarction and coronary interventions. Diagnosis is usually based on clinical signs of myocardial ischemia (symptoms and/or ECG changes) combined with coronary angiography. Management can be difficult and primarily consists of intracoronary administration of vasodilators. One interesting etiology is thromboembolism and this has become the focus for new potential treatments, including distal embolic protection devices.

Glycoprotein IIb-IIIa antagonists in non-ST elevation acute coronary syndromes and percutaneous interventions: from pharmacology to individual patient's therapy: Part 2: When and how to use various agents

Patients with high-risk characteristics admitted for non-ST elevation acute coronary syndromes benefit from an early invasive treatment, and in this case glycoprotein (GP) IIb/IIIa inhibitors appear effective in improving prognosis. There is however an ongoing debate on which of the currently available agents is the best in patients who are candidates for percutaneous coronary interventions. The dispute revolves on the optimal level of inhibition of platelet function and on whether the benefit is retained in the presence of pretreatment with thienopyridines. Especially the additional value of GP IIb/IIIa inhibition on top of an aggressive antithrombotic therapy (including aspirin, heparins, and clopidogrel) requires further clarification. Here we propose an algorithm for the practical use of available GPIIb/IIIa antagonists in relation with the patient's clinical presentation and concomitant use of other drugs and devices.

Role of the Abiomed BVS 5000 Device for Short-Term Support and Bridge to Transplantation

Over the last 10 years, we have gained experience implanting the Abiomed BVS 5000 (Abiomed, Inc., Danvers, MA) device for short-term mechanical support. We retrospectively reviewed our experience with this device. From April 1993 through January 2003, 71 patients underwent implantation of an Abiomed BVS 5000 device. This included 19 left ventricular assist devices (LVADs), 30 right ventricular assist devices (RVADs), and 22 biventricular assist devices (BIVADs). Demographics of device recipients, conditions for mechanical support, and outcome were evaluated for each device type. Devices were inserted for postcardiotomy cardiogenic shock in 53 (74.6%) patients and precardiotomy cardiogenic shock in 18 (25.4%) patients. Mean duration of support was 4.9+/-4.1 days, with 64 (90.1 %) patients supported for fewer than 10 days. Twenty-nine (40.8%) patients were successfully weaned from support after myocardial recovery: 7 (36.8%) LVADs, 13 (43.3%) RVADs, and 9 (40.9%) BIVADs. Eight (11.3%) patients received devices as a "bridge to bridge," undergoing implantation of a long-term HeartMate LVAD (Thoratec, Pleasanton, CA): six (31.6%) LVADs and two (9.1 %) BIVADs. Seven (9.9%) Abiomed patients were successfully bridged to transplantation: two (10.5%) LVADs, two (6.7%) RVADs, and three (13.6%) BIVADs. Overall, 44 (62.0%) patients survived support: weaned, "bridged to bridge," or transplanted. The Abiomed BVS 5000 can be used effectively for short-term stabilization and for bridging to transplant in select patients.

Increase of myocardial salvage and left ventricular function recovery with intracoronary abciximab downstream of the coronary occlusion in patients with acute myocardial infarction treated with primary coronary intervention

In this prospective randomized trial on patients with acute myocardial infarction (AMI) treated with primary percutaneous coronary intervention (PCI), we hypothesized that abciximab administered intracoronarily, downstream of the coronary occlusion, leads to a greater degree of myocardial salvage and better left ventricular function recovery compared with the usual abciximab administration. Forty-five consecutive patients with first AMI and infarct-related artery TIMI flow 0-1 undergoing primary PCI were enrolled. Twenty-two patients were randomly assigned to the intracoronary treatment and 23 to the usual treatment. The initial perfusion defect, final infarct size, myocardial salvage, salvage index, and left ventricular function recovery were assessed by serial scintigraphic scans performed at admission and 7 days and 1 month after PCI. Angiographic myocardial blush grade, corrected TIMI frame count, and electrocardiographic ST segment elevation reduction were also assessed as markers of myocardial reperfusion. Final infarct size was significantly smaller (P = 0.043) and salvage index significantly higher (P = 0.003) in the intracoronary treatment group as a result of a greater degree of myocardial salvage (P = 0.0001). The increase of left ventricular ejection fraction at 1 month was significantly higher in the intracoronary treatment patients (P = 0.013). The markers of myocardial reperfusion were also significantly better in the intracoronary treatment group. In patients with AMI and occluded infarct-related artery treated with primary PCI, intracoronary abciximab given just before PCI downstream of the occlusion is associated to a greater degree of myocardial salvage than the usual abciximab protocol. This benefit is mainly related to a substantial reduction in final infarct size, which leads to an improvement in left ventricular ejection fraction.

Comparison of intracoronary vs. intravenous administration of abciximab in coronary stenting

There have been animal and human studies looking at intracoronary (IC) use of abciximab with good short-term clinical outcomes. There exists no data comparing intracoronary with intravenous (IV) administration of abciximab beyond 30 days. We compared the clinical outcomes between the IC (n = 101) and IV (n = 72) group of patients. Patients who had coronary stenting and received abciximab were included in the study. All the patients received the standard systemic bolus dose of abciximab 0.25 mg/kg either via the IC or IV route, followed by a 12-hr IV infusion at 0.125 microg/kg/min. The 6-month composite endpoint of death or myocardial infarction was slightly higher in the IV (13.9%) than in the IC group (5.9%; P = 0.04). The frequency of bleeding complications was similar in both groups. The IC bolus route of abciximab may be superior to the intravenous route. Prospective randomized trials are warranted to validate these findings.

Effect of glycoprotein IIb/IIIa antagonist abciximab on monocyte-platelet aggregates and tissue factor expression

OBJECTIVE

Activated platelets rapidly adhere to monocytes and upregulate the expression of tissue factor (TF), the major trigger of the coagulation cascade. In this study, we examined the effect of abciximab, a nonselective glycoprotein IIb/IIIa-receptor antagonist, on monocyte TF expression in thrombin receptor activator-stimulated whole blood in vitro.

METHODS AND RESULTS

Abciximab (50 microg/mL) reduced the mass of platelets attached to monocytes, measured by the mean fluorescence intensity (MFI) of CD42b on CD14+ cells, 1 (CD42b, 471+/-197 versus 1073+/-217 MFI, mean+/-SD, P<0.05), 5, and 10 minutes after thrombin receptor activator stimulation of whole blood to the same extent as anti-P-selectin (50 microg/mL; 288+/-177 MFI, P<0.05) when determined by flow cytometry. In parallel, the expression of the platelet activation marker P-selectin colocalized with CD14+ monocytes was reduced up to 25% by abciximab at the same time points. Expression of monocyte TF antigen (CD14+/TF+, 39.9+/-8.7% versus 66.3+/-19.9%, P<0.05), chromogenic TF-activity (TF, 8.4+/-1.9 versus 13.2+/-2.8 U, arbitrary units, P<0.05), and TF mRNA was suppressed in the presence of abciximab as a consequence of reduced platelet mass attached to monocytes.

CONCLUSIONS

Our data suggest that heterotypic monocyte-platelet aggregates are a target for abciximab, which suppresses monocyte TF because of a reduction of monocyte-platelet cross talk.