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J E Tcheng

Publications and source records attributed to J E Tcheng.

At least 19 recordsLinked to original sources

Clinical pharmacology of higher dose eptifibatide in percutaneous coronary intervention (the PRIDE study).

This study describes the dose-exploration phase of the PRIDE trial, an investigation of the clinical pharmacology of higher dose eptifibatide in patients who underwent elective percutaneous coronary intervention (PCI). Outcomes of treatment with the platelet glycoprotein IIb/IIIa inhibitors were dependent upon proper dosing selection. In this multicenter, placebo-controlled clinical study, 127 patients were randomized 1:1:2:2 into 1 of the following treatment groups: placebo; eptifibatide as a 135 microg/kg bolus followed by a 0.75 microg/kg/min infusion; eptifibatide as a 180 microg/kg bolus with a 2.0 microg/kg/min infusion; or eptifibatide as a 250 microg/kg bolus with a 3.0 microg/kg/min infusion. Light transmission aggregometry was used to determine platelet aggregation in response to 20 microM adenosine diphosphate, and platelet receptor occupancy was also determined. Eptifibatide exhibited linear pharmacokinetics over the dose range studied. Inhibition of platelet aggregation was greater in samples collected in sodium citrate compared with those collected in D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone. The 180/2.0 dosing regimen achieved 90% inhibition of platelet aggregation immediately (5 minutes) and at steady state (8 to 24 hours). At 1 hour, mean inhibition of platelet aggregation was 80%. Eptifibatide exhibited dose-dependent pharmacodynamics that were dependent upon choice of anticoagulant. A 180 microg/kg bolus followed by a 2.0 microg/kg/min infusion at steady state achieved >80% inhibition of platelet aggregation. With the single-bolus regimen, however, there was an early loss of the inhibition of platelet aggregation before steady state was reached. Additional dose-exploration studies may further optimize eptifibatide dosing.

Amino Acid Chloromethyl Ketones↗

Effect of eptifibatide on angiographic complications during percutaneous coronary intervention in the IMPACT--(Integrilin to Minimize Platelet Aggregation and Coronary Thrombosis) II Trial.

We sought to determine whether eptifibatide reduces elevation of creatine kinase (CK)-MB isoenzyme release during coronary intervention by preventing angiographic complications, by minimizing the sequelae of angiographic complications once they occur, or by other mechanisms. In the Integrilin to Minimize Platelet Aggregation and Coronary Thrombosis trial, patients underwent coronary intervention during treatment with placebo versus the glycoprotein IIb/IIIa receptor inhibitor eptifibatide. Eptifibatide decreased ischemic complications at 24 hours and 30 days. CK-MB elevations and in-laboratory angiographic complications (including major dissection, distal embolization, residual thrombus, abrupt closure, residual stenosis >50%, and side branch occlusion) were prospectively recorded. The incidence of any angiographic complication was lower in eptifibatide-treated patients (33%) than in placebo-treated patients (38%, p = 0.019). For patients with angiographic complications, there was a trend toward a reduced incidence of any elevation in CK-MB in the first 24 hours (29%, 135/0.75 eptifibatide dose; 33%, 135/0.5 eptifibatide dose; 37%, placebo). Among patients without angiographic complications, there was a similar trend toward fewer abnormal CK-MB levels in patients receiving eptifibatide (17% and 18% in eptifibatide arms vs 21% placebo). Thus, eptifibatide reduces angiographically evident complications during coronary intervention, but this effect accounts for only 1/3 of the reduced frequency of CK-MB elevations observed with eptifibatide. When angiographic complications occur, eptifibatide reduces rates of subsequent CK-MB elevation, accounting for another 1/3 of the reduction in CK-MB elevations. Finally, eptifibatide reduces the incidence of periprocedural CK-MB elevations in patients without angiographically evident complications, accounting for 1/3 of eptifibatide's overall effect in reducing of CK-MB elevations in patients undergoing percutanous coronary intervention.

Angioplasty, Balloon, Coronary↗

Abciximab readministration: results of the ReoPro Readministration Registry.

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.

Abciximab↗

Pharmacodynamics and pharmacokinetics of higher-dose, double-bolus eptifibatide in percutaneous coronary intervention.

BACKGROUND: Pharmacodynamics of eptifibatide, a cyclic heptapeptide antagonist of platelet glycoprotein IIb/IIIa, are substantially altered by anticoagulants that chelate calcium, resulting in overestimation ex vivo of the in vivo effects of this agent. We conducted a dose-ranging study to characterize the pharmacodynamics and pharmacokinetics of eptifibatide under physiological conditions. METHODS AND RESULTS: Patients (n=39) undergoing elective percutaneous coronary intervention were randomly assigned to an eptifibatide bolus followed by an infusion (180-microgram/kg bolus followed by 2 microgram/kg per minute or 250-microgram/kg bolus followed by 3 microgram/kg per minute) for 18 to 24 hours. In a 2:1 ratio, these patients received either a second bolus of eptifibatide (90 microgram/kg or 125 microgram/kg for the initial 180-microgram/kg or 250-microgram/kg groups, respectively) or placebo 30 minutes after the initial bolus. Bleeding times, ex vivo platelet aggregation, receptor occupancy, and plasma eptifibatide levels at baseline and at 1, 2, 3, 4, 6, and 8 hours were evaluated. Platelet inhibition was dose dependent and >80% in all groups by steady state. The single-bolus regimens had a transient loss of inhibition at 1 hour, consistent with rapid distribution and drug elimination. Pharmacokinetic modeling suggested that optimal dosing of eptifibatide would be obtained with a 180-microgram/kg bolus and a 2-microgram/kg per minute infusion followed by a second 180-microgram/kg bolus 10 minutes later. CONCLUSIONS: A novel higher-dose, double-bolus regimen of eptifibatide in coronary intervention attains and maintains >90% inhibition of platelet aggregation in >90% of patients, providing the pharmacodynamic construct for the design of the Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial of adjunctive eptifibatide in coronary stent implantation.

Angioplasty, Balloon, Coronary↗

Risk of stroke associated with abciximab among patients undergoing percutaneous coronary intervention.

CONTEXT: Abciximab, a potent inhibitor of the platelet glycoprotein IIb/IIIa receptor, reduces thrombotic complications in patients undergoing percutaneous coronary intervention (PCI). Because of its potent inhibition of platelet aggregation, the effect of abciximab on risk of stroke is a concern. OBJECTIVE: To determine whether abciximab use among patients undergoing PCI is associated with an increased risk of stroke. DESIGN: Combined analysis of data from 4 double-blind, placebo-controlled, randomized trials (EPIC, CAPTURE, EPILOG, and EPISTENT) conducted between November 1991 and October 1997 at a total of 257 academic and community hospitals in the United States and Europe. PATIENTS: A total of 8555 patients undergoing PCI with or without stent deployment for a variety of indications were randomly assigned to receive a bolus and infusion of abciximab (n = 5476) or matching placebo (n = 3079). One treatment group in EPIC received a bolus of abciximab only. MAIN OUTCOME MEASURE: Risk of hemorrhagic and nonhemorrhagic stroke within 30 days of treatment among abciximab and placebo groups. RESULTS: No significant difference in stroke rate was observed between patients assigned abciximab (n = 22 [0.40%]) and those assigned placebo (n = 9 [0.29%]; P =.46). Excluding the EPIC abciximab bolus-only group, there were 9 strokes (0.30%) among 3023 patients who received placebo and 15 (0.32%) in 4680 patients treated with abciximab bolus plus infusion, a difference of 0.02% (95% confidence interval [CI], -0.23% to 0.28%). The rate of nonhemorrhagic stroke was 0.17% in patients treated with abciximab and 0.20% in patients treated with placebo (difference, -0.03%; 95% CI, -0.23% to 0.17%), and the rates of hemorrhagic stroke were 0.15% and 0.10%, respectively (difference, 0.05%; 95% CI, -0.11% to 0.21%). Among patients treated with abciximab, the rate of hemorrhagic stroke in patients receiving standard-dose heparin in EPIC, CAPTURE, and EPILOG was higher than in those receiving low-dose heparin in the EPILOG and EPISTENT trials (0.27% vs 0.04%; P =.057). CONCLUSIONS: Abciximab in addition to aspirin and heparin does not increase the risk of stroke in patients undergoing PCI. Patients undergoing PCI and treated with abciximab should receive low-dose, weight-adjusted heparin.

Abciximab↗

Achieving optimal results with standard balloon angioplasty: can baseline and angiographic variables predict stent-like outcomes?

OBJECTIVES: To predict which patients might not require stent implantation, we identified clinical and angiographic characteristics associated with repeat revascularization after standard balloon angioplasty. BACKGROUND: Stents reduce the risk of repeat revascularization but are costly and may lead to in-stent restenosis, which remains difficult to treat. Identification of patients at low risk for repeat revascularization may allow clinicians to reserve stents for patients most likely to benefit. METHODS: Data from five interventional trials (5,146 patients) were pooled for analysis. We identified patients with optimal angiographic results (final diameter stenosis < or =30% and no dissection) after balloon angioplasty and determined the multivariable predictors of repeat revascularization. RESULTS: Optimal angiographic results were achieved in 18% of patients after angioplasty. The repeat revascularization rate at six months was lower for patients with optimal results (20% vs. 26%, p < 0.001) but still higher than observed in stent trials. Independent predictors of repeat revascularization were female gender (odds ratio [OR] 1.67, p = 0.01), lesion length > or =10 mm (OR 1.62, p = 0.03) and proximal left anterior descending coronary artery lesions (OR 1.62, p = 0.03). For the 8% of patients with optimal angiographic results and none of these risk factors, the repeat revascularization and target vessel revascularization rates were 14% and 8% respectively, similar to rates after stent implantation. Cost analysis estimated that $78 million per year might be saved in the U.S. with a provisional stenting strategy using these criteria compared with elective stenting. CONCLUSIONS: A combination of baseline characteristics and angiographic results can be used to identify a small group of patients at very low risk for repeat revascularization after balloon angioplasty. Provisional stenting for these low risk patients could substantially reduce costs without compromising clinical outcomes.

Angioplasty, Balloon↗

Point-of-care measured platelet inhibition correlates with a reduced risk of an adverse cardiac event after percutaneous coronary intervention: results of the GOLD (AU-Assessing Ultegra) multicenter study.

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.

Abciximab↗

Platelet glycoprotein IIb/IIIa integrin blockade with eptifibatide in coronary stent intervention: the ESPRIT trial: a randomized controlled trial.

CONTEXT: The Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial showed the efficacy of adjunctive, double-bolus eptifibatide therapy in reducing ischemic complications of nonurgent coronary stent implantation at 48 hours and at 30 days. OBJECTIVE: To determine whether the beneficial effects of eptifibatide persist at 6 months after treatment. DESIGN: Follow-up study of a randomized, double-blind, placebo-controlled, crossover-permitted trial conducted from June 1999 through February 2000. SETTING: Ninety-two tertiary care centers in the United States and Canada. PARTICIPANTS: A total of 2064 patients scheduled to undergo nonurgent percutaneous coronary intervention with stent implantation. INTERVENTION: Patients were randomly assigned to receive placebo or eptifibatide (two 180-microg/kg boluses 10 minutes apart and continuous infusion of 2.0 microg/kg per minute), started immediately before stent implantation and continued for 18 to 24 hours. Complete follow-up data were available for 988 (95.0%) of 1040 patients given eptifibatide and 977 (95.4%) of 1024 patients given placebo. MAIN OUTCOME MEASURES: Composite rates of death or myocardial infarction (MI); death, MI, or target vessel revascularization; and their individual components 6 months after enrollment, compared between the 2 groups. RESULTS: By 6 months, the composite end point of death or MI had occurred in 7.5% of eptifibatide-treated patients and in 11.5% of placebo-treated patients (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.47-0.84; P =.002). The composite of death, MI, or target vessel revascularization was 14.2% in eptifibatide-treated patients vs 18.3% in placebo-treated patients (HR, 0.75; 95% CI, 0.60-0.93; P =.008). Most of this benefit accrued early (<48 hours after initiation of therapy) and was maintained through 6 months. Six-month mortality in the eptifibatide group was 0.8% vs 1.4% in the placebo group (HR, 0.56; 95% CI, 0.24-1.34; P =.19) and target vessel revascularization occurred in 8.6% of the eptifibatide group vs 9.4% of the placebo group (HR, 0.91; 95% CI, 0.68-1.22; P =.51). CONCLUSION: Adjunctive eptifibatide therapy during coronary stent implantation provides benefit through 6-month follow-up.

Aged↗

Current multicentre studies with the excimer laser: design and aims.

Excimer laser ablation to remove atherosclerotic plaque has been used for over a decade as a methodology to treat cardiovascular disease. Improvements in the technique and technology of excimer laser angioplasty, coupled with the recognition of new clinical opportunities for this treatment modality, have resulted in a resurgence of interest in the laser. Three clinical trials are now being conducted to explore potential applications, including the LARS trial of excimer laser versus balloon angioplasty to treat in-stent restenosis, the PELA trial of excimer laser angioplasty in occluded superficial femoral artery disease, and the LACI trial of excimer laser angioplasty in limb-threatening ischaemia. This article describes the rationale and objectives of these new approaches to some of the more challenging problems in cardiovascular disease.

Angioplasty, Laser↗

Effect of glycoprotein IIb/IIIa receptor inhibition on angiographic complications during percutaneous coronary intervention in the ESPRIT trial.

OBJECTIVES: We sought to determine whether eptifibatide decreases the incidence of in-laboratory angiographic complications and to determine the relationship of angiographically evident complications to elevations of creatine kinase-MB (CK-MB) enzyme levels during percutaneous coronary intervention. BACKGROUND: In the Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial, eptifibatide during coronary intervention was associated with decreased ischemic complications at 48 h and 30 days. METHODS: Patients (n = 2,064) were randomized to placebo versus eptifibatide (two 180 microg/kg boluses 10 min apart and as a continuous infusion of 2 microg/kg per min) during percutaneous coronary stenting. Angiographic complications including major dissection, distal embolization, residual thrombus, abrupt closure, residual stenosis >50% and side-branch occlusion were prospectively recorded by the operator. Creatine kinase-MB levels were measured after the procedure and every 6 h thereafter. The incidence of angiographic complications and CK-MB elevation was determined for eptifibatide versus placebo groups. RESULTS: Eptifibatide-treated patients demonstrated nonsignificant trends toward fewer angiographic complications (10 vs. 12% for placebo patients, p = 0.13) and, for patients with angiographic complications, fewer subsequent CK-MB elevations (43 vs. 50% for placebo patients, p = 0.31). In patients without any angiographic complications, the incidence of CK-MB elevation >3 times the normal was 7% with placebo and 4% with eptifibatide (p = 0.003). CONCLUSIONS: Eptifibatide during nonurgent coronary stent intervention only minimally (and insignificantly) reduces the incidence of angiographic complications and subsequent CK-MB elevations in patients developing an angiographic complication. The greater effect is to reduce myocardial infarction in patients undergoing otherwise uneventful coronary stent implantation as well as in the overall study population.

Angioplasty, Balloon, Coronary↗

Rapid assessment of glycoprotein IIb/IIIa blockade with the platelet function analyzer (PFA-100) during percutaneous coronary intervention.

BACKGROUND: The platelet function analyzer PFA-100 (Dade Behring, Miami, Fla) evaluates platelet function by determining the time to occlusion of an aperture in a membrane coated with collagen and adenosine diphosphate or epinephrine as whole blood flows under shear stress conditions. Platelet aggregation causes aperture occlusion, and results are reported as closure time (CT). Interindividual variability is observed in the level of platelet inhibition achieved with use of the current abciximab dosing regimen (0.25-mg/kg bolus + 10-microg/min infusion for 12 hours). The relationships between specific levels of platelet inhibition and clinical efficacy and safety have not been fully established. METHODS AND RESULTS: We prospectively studied platelet function in 27 patients receiving abciximab during percutaneous coronary intervention. This evaluation included determinations of platelet-rich plasma aggregometry, receptor occupancy studies (D3 assay), and CT measurements at baseline and 10 minutes, 4 hours, 12 hours, and 24 hours after the bolus. All patients received abciximab, aspirin, and heparin; patients undergoing coronary stent implantation received aspirin and ticlopidine after the procedure. CT results were reported within 10 minutes after initiation of testing. For 96% of patients, CT was 300 seconds (maximum CT) immediately after abciximab bolus and remained so throughout the infusion. At 24 hours we observed variable recovery from platelet inhibition and in 72% of patients CT returned to normal (< or =130 seconds). CONCLUSIONS: Findings with the PFA-100 were similar to results observed with platelet aggregometry and receptor occupancy measurements. Most patients treated with abciximab exhibit normalized platelet function at 24 hours despite moderate levels of receptor occupancy, suggesting dissociation between occupancy and function.

Abciximab↗

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Angioplasty, Balloon, Coronary↗

Economic assessment of platelet glycoprotein IIb/IIIa receptor blockade with abciximab and low-dose heparin during percutaneous coronary revascularization: results from the EPILOG randomized trial. Evaluation in PTCA to Improve Long-term Outcome with abciximab GP IIb/IIIa blockade.

BACKGROUND: In the EPILOG trial (Evaluation in PTCA to Improve Long-term Outcome with abciximab GP IIb/IIIa blockade), abciximab administered with weight-adjusted heparin diminished the risk of ischemic complications within 30 days by 56% among patients undergoing percutaneous coronary revascularization, without increased bleeding complications. METHODS AND RESULTS: A prospective economic assessment was performed in the 2792 patients enrolled in EPILOG. Patients were randomized to receive placebo with standard-dose weight-adjusted heparin, abciximab with low-dose weight-adjusted heparin, or abciximab with standard-dose weight-adjusted heparin during percutaneous coronary intervention. Hospital billing data for the baseline hospitalization were collected for 2581 patients (92.4% of total) and imputed for the remainder, with physician fees estimated from the Medicare Fee Schedule. For the baseline hospitalization, medical costs (hospitalization and physician fees) averaged $9632 for the placebo arm compared with $8758 (P:=0.005) and $9092 (P:=0.176) for the abciximab with low-dose and standard-dose heparin arms, respectively. Inclusive of average drug cost ($1454 to $1457), the net incremental baseline cost of these 2 abciximab strategies was $583 with low-dose weight-adjusted heparin and $914 with standard-dose weight-adjusted heparin. During 6-month follow-up, average hospital costs were not significantly different in the 3 treatment groups; cumulative net incremental costs were $1236 and $1268 in the abciximab with low-dose and standard-dose heparin groups, respectively. CONCLUSIONS: Treatment with abciximab and low-dose, weight-adjusted heparin during percutaneous coronary revascularization reduces ischemic events and associated costs, thereby offsetting some of the cost of the drug. The suppression of bleeding complications associated with this agent by heparin dose reduction optimizes the economic attractiveness of this treatment strategy.

Abciximab↗

The benefit of abciximab in percutaneous coronary revascularization is not device-specific.

Abciximab has been shown to decrease adverse outcomes after percutaneous coronary interventions, but it is unclear whether this beneficial effect is more or less pronounced with specific devices. This study sought to determine the relative magnitude of the benefit of abciximab among different interventional devices. Data from the 5 placebo-controlled trials of abciximab during coronary intervention were pooled. Patients were divided into groups based on whether they received balloon angioplasty alone, elective stenting, bailout stenting, or directional coronary atherectomy. In the patients undergoing balloon angioplasty, the 30-day hazard ratio for death or myocardial infarction (MI) in the group randomized to abciximab versus the placebo-treated group was 0.52 (p <0.001), for elective stenting the hazard ratio was 0.51 (p <0.001), for bailout stenting the hazard ratio was 0.38 (p <0.001), and for directional coronary atherectomy the hazard ratio was 0.38 (p = 0.007). A Cox proportional-hazards model revealed that overall, the use of abciximab decreased the composite end point of 30-day death or MI rates (hazard ratio 0.55, 95% confidence interval 0.43 to 0.69, p <0. 001). However, bailout stenting and directional coronary atherectomy were associated with increased rates of death or MI compared with balloon angioplasty, as was elective stenting in women compared with men. There was no significant increase in major bleeding episodes associated with abciximab in any of the device categories. These findings from all the controlled coronary revascularization trials using abciximab demonstrate that a decrease in death and MI is achieved with abciximab regardless of the type of device used, without an increase in significant bleeding complications.

Abciximab↗

Timing of and risk factors for myocardial ischemic events after percutaneous coronary intervention (IMPACT-II). Integrilin to Minimize Platelet Aggregation and Coronary Thrombosis.

We studied both the time course and risk factors for adverse clinical events after percutaneous coronary intervention (PCI). Such information is critical to clinical decision-making, but scant quantitative data exist to describe the time course of these adverse outcomes. Patients enrolled in the Integrilin to Minimize Platelet Aggregation and Coronary Thrombosis-II (IMPACT-II) trial were analyzed. Patients undergoing elective, urgent, or emergency PCI (n = 4,010) were randomized to receive either placebo or 1 of 2 eptifibatide regimens during intervention. We evaluated the time to the primary end point of the trial, the 30-day composite of death, myocardial infarction, repeat nonelective PCI, nonelective bypass surgery, or stenting for abrupt closure. Adverse events occurred in 407 patients (10.1%). Because the risk of events declined substantially between 6 and 9 hours (66% occurred within 6 hours), events were classified as occurring before or after 6 hours. Independent predictors of "early" events included dissection, pre- and postprocedural coronary blood flow, side-branch occlusion, procedural thrombolytic use, previous bypass, presentation with unstable angina, absence of diabetes, and hyperlipidemia. The predictors of "late" events included lower weight, increased baseline heart rate, coronary dissection, and procedural thrombolytic use. The risk of ischemic events were greatest immediately after PCI and rapidly declined, so that by 9 hours the hazard function plot was flat; 66% of events occurred within 6 hours of PCI. Knowledge of the risk factors for early and late events help risk-stratify patients before and after intervention for myocardial ischemic events.

Aged↗

Efficacy of abciximab readministration in coronary intervention.

Abciximab, an Fab monoclonal antibody fragment that blocks the platelet glycoprotein IIb/IIIa receptor, is increasingly used as an adjunct to coronary intervention. Little is known, however, about the efficacy and safety of readministration of abciximab. This study examined and characterized outcomes of patients receiving abciximab for a second time. From April 1995 to June 1997, 164 consecutive patients were readministered abciximab at our 3 institutions. We retrospectively examined and analyzed in-hospital outcomes in this cohort. The median time to readministration was 95 days. The angiographic success rate of percutaneous intervention was 99.5%. Rates and 95% confidence intervals of in-hospital events were death 2% (0.7% to 6.1%), myocardial infarction 3% (1% to 7%), coronary bypass surgery 0% (0% to 2.2%), and intracranial hemorrhage 2% (0.4% to 5.3%). Severe thrombocytopenia was observed in 4% of patients (1.4% to 7.8%) after readministration. Allergic or anaphylactic reactions were not observed. Major bleeding was associated with excessive concomitant antithrombotic therapy. Patients undergoing readministration of abciximab within 2 weeks of first administration experienced a higher incidence of severe thrombocytopenia (12% vs. 2%, p = 0.046). Thus, abciximab remains clinically efficacious when readministered as an adjunct to percutaneous coronary intervention. However, concomitant heparin administration must be carefully monitored and warfarin therapy should be avoided. Vigilant surveillance for thrombocytopenia should be employed. Reduced dosing may be necessary when abciximab is readministered within days of the initial administration.

Abciximab↗