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Introduction: Patients with non-O blood groups have higher plasma von Willebrand factor (vWF) levels than those with type O. vWF mediates platelet adhesion, aggregation and thrombosis. These considerations likely explain the prior observations that non-O patients have higher rates of arterial and venous thromboembolic events. However, the effect of blood group status on size of MI, procedural findings and outcomes after PCI for MI have not been reported., Methods: We analyzed 1198 patients who underwent percutaneous coronary intervention for acute myocardial infarction between 10/03 and 8/06, and who had ABO blood group status and clinical follow-up., Results and Conclusions: Patients with O blood type were slightly older (62 +/- 13 vs. 60 +/- 13 years; p = 0.017) had a higher prevalence of hypercholesterolemia (67% vs. 58%; p = 0.002), and had a higher burden of atherosclerosis with more vascular disease (17% vs. 13%; p = 0.017) and higher prevalence of previous PCI (22% vs. 17%; p = 0.025). Non-O blood group patients had larger infarcts as measured by median peak troponin (33 vs. 24; p = 0.037), total CK (721 vs. 532; p = 0.012) and CK-MB (101 vs. 68; p = 0.010). At PCI, non-O patients had increased visible thrombus and reduced TIMI flow pre-procedure. However, there were no differences in procedural success, in-hospital blood transfusion or occurrence of MACE at 1 year follow-up. Our data demonstrate that non-O compared to O blood groups patients have higher thrombus burden despite less extensive atherosclerosis. Nevertheless, outcomes at 1 year were similar.

Background: Abciximab is often used to treat high-risk patients during percutaneous coronary intervention (PCI). Recent data indicate, however, that upstream and postprocedural treatment with low-dose glycoprotein (GP) IIb/IIIa inhibitors may be more beneficial than abciximab during and after PCI. Whether abciximab can be used safely or effectively during PCI for high-risk patients after upstream treatment with eptifibatide in patients with acute coronary syndromes (ACS) is not known., Methods: Clinical outcomes were evaluated in 289 patients with ACS who had upstream treatment with eptifibatide, and abciximab (EA) during PCI, and compared to 560 ACS patients who had both upstream and interventional treatment with eptifibatide (EE)., Results: Bleeding and vascular complications of the two groups were similar. Overall, 1-year major adverse cardiac event (MACE) rates were similar: 26.0% in the EA group and 25.2% in the EE group; p = 0.82. In patients with unstable angina, the hazard of MACE at 1 year was higher with EA than EE, 1.98 (1.23-3.18), due to significantly higher rates of repeat revascularization in the EA group. In patients with myocardial infarction (MI), the hazard of MI or death at 1 year was lower in the EA than the EE group, 0.50 (0.27-0.93)., Conclusion: In this single-center observational study, the use of abciximab for PCI after upstream use of eptifibatide for ACS was safe. Abciximab was of no benefit in patients with unstable angina, but was associated with lower MI or death in patients with MI. These observations are consistent with recent findings indicating that abciximab is of benefit in patients with NSTEMI, but not lower-risk patients.

In 29 patients undergoing percutaneous coronary intervention (PCI), we obtained blood samples at baseline, 10 minutes after standard weight-based abciximab (n=15) or double-bolus eptifibatide (n=14) and 5 minutes after unfractionated heparin (UFH; 70 U/kg bolus). The median percent inhibition was significantly higher in the eptifibatide group compared with the abciximab group both before (96.5% [94-100] vs. 85% [77-89.5] [adenosine diphosphate; ADP]; 89.5% [84-95] vs. 59% [37.5-76.5] [thrombin receptor agonist peptide; TRAP], p<0.001 for both) and after UFH (95% [93-100] vs. 79% [68.8-87.5] [ADP]; 82% [77-93] vs. 51% [34.5-71.3] [TRAP], p<0.001 for both). Addition of UFH significantly reduced platelet inhibition in the abciximab group (85% [77-89.5] vs. 79% [68.8-87.5] [ADP]; 59% [37.5-76.5] vs. 51% [34.5-71.3] [TRAP], p<0.05 for both) but not in the eptifibatide group (96.5% [94-100] vs. 95% [93-100] [ADP]; 89.5% [84-95] vs. 82% [77-93] [TRAP], p=ns for both). Eptifibatide achieved superior platelet inhibition before but especially after UFH compared with abciximab.

Elevation of white blood cells (WBCs) is associated with worse outcomes in patients with coronary artery disease (CAD), including patients undergoing percutaneous coronary intervention (PCI) of native coronary arteries, but this relation has not been studied in patients with saphenous vein graft disease undergoing PCI. A total of 530 patients who underwent PCI of saphenous vein grafts from May 1997 to July 2002 were followed for >3 years. Major adverse coronary events (MACEs) were assessed as a composite of death, myocardial infarction, or revascularization during follow-up (mean 2.7 years). Patients with MACEs (n = 287) were younger and had more thrombotic and ostial lesions (p < 0.05) than those without MACEs (n = 243). The preprocedural WBC count was also significantly higher in the MACE group than in the non-MACE group (8.1 x 10(3)/mul, range 6.6 to 10.1, vs 7.0 x 10(3)/mul, range 5.6 to 8.2; p < 0.001). After adjusting for covariates, multiple logistic regression analysis revealed the preprocedural WBC count to be an independent predictor for MACEs (odds ratio 1.2; 95% confidence interval 1.1 to 1.3, p < 0.001). Patients in the highest quartile of the preprocedural WBC level had a significantly increased risk of MACEs (lowest vs highest quartile, 41.3% vs 72.4%; odds ratio 3.7; 95% confidence interval 2.2 to 6.3). Thus, an elevated preprocedural WBC count is associated with increased risk of MACEs in patients undergoing PCI for saphenous vein graft lesions.

Objectives: To examine the frequency of cerebrovascular complications among patients receiving abciximab (AB) undergoing PCI with prior intracranial hemorrhage (ICH) or recent (< 2 years) ischemic strokes., Background: AB improves clinical outcomes in high-risk patients undergoing percutaneous coronary intervention (PCI); however, the safety of AB in patients with prior stroke has not been adequately studied., Methods: A database review of 7,244 consecutive PCIs, from 7/97 to 10/01, identified 6,190 PCIs performed with AB among which 515 interventions were performed in patients with prior stroke history [ICH or recent ischemic stroke, (n = 101) and remote (> 2 years) ischemic stroke, (n = 414)]., Results: The post-PCI stroke rate was significantly higher in patients with prior stroke (2.06% vs. 0.35%, p < 0.001 for all stroke; 0.38% vs. 0.03%, p = 0.023 for ICH). The incidence of ICH among the AB-treated group was 0.065%; a history of prior stroke did not increase the incidence of ICH in the AB-treated group (0.39% vs. 0.0%, p = ns). Moreover, the post-PCI stroke rate was similar between the prior ICH or recent ischemic stroke-group and remote ischemic stroke-group (2 vs. 1.9%; OR: 1.03; 95% CI: 0.21-4.90; p = ns for all strokes; 2% vs. 1.5%; OR: 1.4; 95% CI: 0.27-6.91; p = ns for ischemic stroke). Importantly, no ICH occurred in patients with recent ischemic or any prior ICH stroke., Conclusions: Abciximab, in addition to aspirin, heparin and ADP-inhibitors does not increase the risk of stroke in patients with prior stroke undergoing PCI.

Background: Percutaneous coronary intervention (PCI) is increasingly used in patients with high-risk baseline characteristics. A prior stroke may identify patients who have a higher risk for post-PCI complications. However, no comparative data exist on post-PCI outcomes of patients with or without prior stroke., Methods: Review of a PCI database of 9,088 consecutive PCIs from July 1997 to December 2002 identified 812 PCIs in patients with a history of prior stroke and 8,044 PCIs without prior stroke., Results: Patients with prior stroke had high-risk baseline characteristics [diabetes, hypertension, hyperlipidemia, smoking, peripheral arterial disease, congestive heart failure, chronic renal failure, history of prior myocardial infarction and prior coronary artery bypass graft (CABG)] and high-risk coronary anatomy (p < 0.001 for each one). The triple composite (death, myocardial infarction and emergent CABG) and the triple composite plus post-PCI stroke were higher in patients with prior stroke (11.2% vs. 4.8%; p < 0.001; z = 7.617 and 12.1% vs. 5.0%; p < 0.001; z = 8.271, respectively., Conclusion: Patients with prior stroke constitute a high-risk PCI cohort with higher rates of in-hospital adverse events. A prior stroke history should be considered in evaluating potential candidates for PCI.

Background: Despite the proven benefit of glycoprotein IIb/IIIa inhibitors during percutaneous coronary intervention, significant interpatient variability exists in antiplatelet response. Furthermore, a diminished degree of platelet inhibition is an independent predictor of adverse cardiac events, highlighting the need for accurate and precise monitoring of platelet function., Methods: Patients (n = 192) who underwent elective percutaneous coronary intervention at 4 centers were enrolled. The following 3 time points were studied: 1, baseline, before abciximab bolus administration; 2, during, within 1 hour of abciximab bolus administration; and 3, post, 24 hours after abciximab bolus administration or at the time of patient discharge, whichever occurred first. The following 3 assays were compared at all time points: Ultegra rapid platelet-function assay (Ultegra RPFA), conventional turbidometric platelet aggregometry, and receptor binding assay with [125I]-abciximab. Variability in Ultegra RPFA measurements between operators was determined with performance of the assays at the point of care and in the laboratory. A sub-study of 22 patients at 1 center was performed in which the laboratory scientist performed all 3 assays in duplicate at each time point., Results: Comparison with the receptor binding assay and conventional platelet aggregometry in 120 patients showed that the Ultegra RPFA correlated with aggregometry (r = 0.89) and with the receptor binding assay (r = 0.89). There was good agreement (r = 0.80) between values obtained by intended users and those obtained by laboratory scientists. Furthermore, Ultegra RPFA values had equivalent precision to the standard assays., Conclusion: The Ultegra RPFA has equivalent accuracy and precision when compared with the 2 reference assays studied. Ultegra RPFA measurements are not operator-dependent and are not influenced by concomitant medications, hematologic parameters, or demographics.

Background: Platelet glycoprotein IIb/IIIa blockade with abciximab (ReoPro) improves the clinical outcomes of percutaneous coronary intervention. This registry was conducted to characterize the effects of repeated administration of abciximab during intervention., Methods and Results: We recruited 500 consecutive patients at 22 centers in the United States who were receiving abciximab for at least a second time during percutaneous coronary intervention. Safety was measured as the incidence of hypersensitivity reactions, major bleeding, and thrombocytopenia. Efficacy was assessed as event-free clinical success. Human antichimeric antibody (HACA) responses were also characterized. There were no cases of hypersensitivity (95% upper confidence bound, 0.3%), major bleeding, or death. Clinical success was 94.4%. Thrombocytopenia occurred in 23 patients (4.6%; 95% CI, 2.8% to 6.4%), including 12 (2.4%; 95% CI, 1.1% to 3.7%) who developed profound thrombocytopenia (<20x10(9) cells/L). In 2 patients (0.4%), profound thrombocytopenia did not develop until after hospital discharge; in 4 (0.8%), profound thrombocytopenia recurred despite platelet transfusion. Before a first readministration, a positive HACA titer was present in 22 of 454 patients (4.8%); after a first readministration, an additional 82 of 432 (19.0%) became HACA-positive. HACA did not neutralize the in vitro inhibition of platelet aggregation by abciximab or correlate with clinical events., Conclusions: The results, including overall rates of thrombocytopenia, were consistent with randomized clinical trials of first abciximab treatment. However, there was a shift from mild to profound thrombocytopenia, and cases of delayed presentation and of recurrent thrombocytopenia were seen. These findings suggest that indications and guidelines for first-time use apply to retreatment, particularly the systematic monitoring for thrombocytopenia.

Background: The optimal level of platelet inhibition with a glycoprotein (GP) IIb/IIIa antagonist necessary to minimize thrombotic complications in patients undergoing a percutaneous coronary intervention (PCI) is currently unknown., Methods and Results: Five hundred patients undergoing a PCI with the planned use of a GP IIb/IIIa inhibitor had platelet inhibition measured at 10 minutes, 1 hour, 8 hours, and 24 hours after the initiation of therapy with the Ultegra Rapid Platelet Function Assay (Accumetrics). Major adverse cardiac events (MACES: composite of death, myocardial infarction, and urgent target vessel revascularization) were prospectively monitored, and the incidence correlated with the measured level of platelet function inhibition at all time points. One quarter of all patients did not achieve >/=95% inhibition 10 minutes after the bolus and experienced a significantly higher incidence of MACEs (14.4% versus 6.4%, P=0.006). Patients whose platelet function was <70% inhibited at 8 hours after the start of therapy had a MACE rate of 25% versus 8.1% for those >/=70% inhibited (P=0.009). By multivariate analysis, platelet function inhibition >/=95% at 10 minutes after the start of therapy was associated with a significant decrease in the incidence of a MACE (odds ratio 0.46, 95% CI 0.22 to 0.96, P=0.04)., Conclusions: Substantial variability in the level of platelet function inhibition is achieved with GP IIb/IIIa antagonist therapy among patients undergoing PCI. The level of platelet function inhibition as measured by a point-of-care assay is an independent predictor for the risk of MACEs after PCI.

Heparin-induced thrombocytopenia (HIT) is a well-documented complication of heparin anticoagulation therapy. Heparin's frequent use in the cardiovascular population poses a significant challenge for managing patients with HIT in need of percutaneous coronary intervention (PCI). We describe four patients with HIT who successfully underwent PCI without thrombotic or hemorrhagic complications while on lepirudin.

Objectives: This study sought to determine the frequency of thrombocytopenia and its relation with clinical outcomes in high risk patients undergoing percutaneous coronary revascularization who received either the platelet glycoprotein (GP) IIb/IIIa receptor antagonist abciximab (ReoPro, c7E3 Fab) or conventional therapy., Background: The development of thrombocytopenia on exposure to GPIIb/IIIa antagonists threatens the utility and economic viability of this drug class for patients with vascular disease., Methods: We analyzed data from the Evaluation of c7E3 for the Prevention of Ischemic Complications trial (EPIC), a 2,099-patient, randomized trial of placebo, abciximab bolus or abciximab bolus plus a 12-h infusion during high-risk coronary revascularization., Results: Thrombocytopenia (nadir platelet count <100 x 10(9)/ liter) developed in 81 patients (3.9%) during their hospital stay, with 19 (0.9%) developing severe (<50 x 10(9)/liter) thrombocytopenia. Both thrombocytopenia and severe thrombocytopenia were more frequent in the bolus-plus-infusion arm (5.2% and 1.6%, respectively) than in the bolus-only and placebo arms combined (p = 0.020 and p = 0.025, respectively). Acute profound thrombocytopenia developed in two patients in the bolus-plus-infusion arm. Patients with thrombocytopenia experienced more unfavorable clinical outcomes than those who did not develop thrombocytopenia, regardless of treatment assignment, but those with thrombocytopenia who received abciximab had fewer worse outcomes at 30 days. Multivariable logistic modeling revealed a lower baseline platelet count, older age and lighter weight to be important predictors of thrombocytopenia. In a logistic regression model, bolus-plus-infusion treatment was a significant predictor of thrombocytopenia (p = 0.016) and remained so after adjustment for procedures and baseline risk factors (p = 0.0077)., Conclusions: Thrombocytopenia was associated with adverse clinical outcomes and excessive bleeding, but patients receiving abciximab fared better than those receiving placebo.