Bivalirudin versus unfractionated heparin during percutaneous coronary intervention.

BACKGROUND: Whether bivalirudin is superior to unfractionated heparin in patients with stable or unstable angina who undergo percutaneous coronary intervention (PCI) after pretreatment with clopidogrel is unknown. METHODS: We enrolled 4570 patients with stable or unstable angina (with normal levels of troponin T and creatine kinase MB) who were undergoing PCI after pretreatment with a 600-mg dose of clopidogrel at least 2 hours before the procedure; 2289 patients were randomly assigned in a double-blind manner to receive bivalirudin, and 2281 to receive unfractionated heparin. The primary end point was the composite of death, myocardial infarction, urgent target-vessel revascularization due to myocardial ischemia within 30 days after randomization, or major bleeding during the index hospitalization (with a net clinical benefit defined as a reduction in the incidence of the end point). The secondary end point was the composite of death, myocardial infarction, or urgent target-vessel revascularization. RESULTS: The incidence of the primary end point was 8.3% (190 patients) in the bivalirudin group as compared with 8.7% (199 patients) in the unfractionated-heparin group (relative risk, 0.94; 95% confidence interval [CI], 0.77 to 1.15; P=0.57). The secondary end point occurred in 134 patients (5.9%) in the bivalirudin group and 115 patients (5.0%) in the unfractionated-heparin group (relative risk, 1.16; 95% CI, 0.91 to 1.49; P=0.23). The incidence of major bleeding was 3.1% (70 patients) in the bivalirudin group and 4.6% (104 patients) in the unfractionated-heparin group (relative risk, 0.66; 95% CI, 0.49 to 0.90; P=0.008). CONCLUSIONS: In patients with stable and unstable angina who underwent PCI after pretreatment with clopidogrel, bivalirudin did not provide a net clinical benefit (i.e., it did not reduce the incidence of the composite end point of death, myocardial infarction, urgent target-vessel revascularization, or major bleeding) as compared with unfractionated heparin, but it did significantly reduce the incidence of major bleeding. (ClinicalTrials.gov number, NCT00262054.)

Abciximab in patients with acute ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention after clopidogrel loading: a randomized double-blind trial.

BACKGROUND: The glycoprotein IIb/IIIa receptor inhibitor abciximab has improved the efficacy of primary percutaneous coronary interventions in patients with acute myocardial infarction. However, it is not known whether abciximab remains beneficial after adequate clopidogrel loading in patients with acute ST-segment-elevation myocardial infarction. METHODS AND RESULTS: A total of 800 patients with acute ST-segment-elevation myocardial infarction within 24 hours from symptom onset, all treated with 600 mg clopidogrel, were randomly assigned in a double-blind fashion to receive either abciximab (n=401) or placebo (n=399) in the intensive care unit before being sent to the catheterization laboratory. The primary end point, infarct size measured by single-photon emission computed tomography with technetium-99m sestamibi before hospital discharge, was 15.7+/-17.2% (mean+/-SD) of the left ventricle in the abciximab group and 16.6+/-18.6% of the left ventricle in the placebo group (P=0.47). At 30 days, the composite of death, recurrent myocardial infarction, stroke, or urgent revascularization of the infarct-related artery was observed in 20 patients in the abciximab group (5.0%) and 15 patients in the placebo group (3.8%) (relative risk, 1.3; 95% CI, 0.7 to 2.6; P=0.40). Major bleeding complications were observed in 7 patients in each group (1.8%). CONCLUSIONS: Upstream administration of abciximab is not associated with a reduction in infarct size in patients presenting with acute myocardial infarction within 24 hours of symptom onset and receiving 600 mg clopidogrel.

Paclitaxel-eluting or sirolimus-eluting stents to prevent restenosis in diabetic patients.

BACKGROUND: Drug-eluting stents are highly effective in reducing the rate of in-stent restenosis. It is not known whether there are differences in the effectiveness of currently approved drug-eluting stents in the high-risk subgroup of patients with diabetes mellitus. METHODS: We enrolled 250 patients with diabetes and coronary artery disease: 125 were randomly assigned to receive paclitaxel-eluting stents, and 125 to receive sirolimus-eluting stents. The primary end point was in-segment late luminal loss. Secondary end points were angiographic restenosis (defined as in-segment stenosis of at least 50 percent at follow-up angiography) and the need for revascularization of the target lesion during a nine-month follow-up period. The study was designed to show noninferiority of the paclitaxel stent as compared with the sirolimus stent, defined as a difference in the extent of in-segment late luminal loss of no more than 0.16 mm. RESULTS: The extent of in-segment late luminal loss was 0.24 mm (95 percent confidence interval, 0.09 to 0.39) greater in the paclitaxel-stent group than in the sirolimus-stent group (P=0.002). In-segment restenosis was identified on follow-up angiography in 16.5 percent of the patients in the paclitaxel-stent group and 6.9 percent of the patients in the sirolimus-stent group (P=0.03). Target-lesion revascularization was performed in 12.0 percent of the patients in the paclitaxel-stent group and 6.4 percent of the patients in the sirolimus-stent group (P=0.13). CONCLUSIONS: In patients with diabetes mellitus and coronary artery disease, use of the sirolimus-eluting stent is associated with a decrease in the extent of late luminal loss, as compared with use of the paclitaxel-eluting stent, suggesting a reduced risk of restenosis.

Effect of abciximab on clinical and angiographic restenosis in patients with non-ST-segment elevation acute coronary syndromes.

The ISAR-REACT 2 trial was designed to assess the effect of abciximab in patients with acute coronary syndromes undergoing percutaneous coronary intervention after a 600-mg loading dose of clopidogrel. The aim of the present study was to investigate the impact of abciximab on clinical and angiographic restenosis after coronary stenting in patients with acute coronary syndromes. The angiographic substudy included 1,544 patients from the ISAR-REACT 2 trial randomly assigned to abciximab (771 patients) or placebo (773 patients). All patients were scheduled for routine angiographic follow-up at 6 to 8 months after intervention. The primary end point was incidence of angiographic in-segment binary restenosis. The secondary end point was 1-year incidence of target-lesion revascularization. Binary restenosis was observed in 21.9% of patients in the abciximab group and 24.5% of patients in the placebo group (p=0.29). Percentages of in-stent (29+/-22% vs 33+/-24%; p=0.02) and in-segment (35+/-20% vs 38+/-21%; p=0.04) diameter stenoses were significantly lower in the abciximab group than the placebo group. There was a strong trend toward lower 1-year incidence of target-lesion revascularization in patients treated with abciximab than in patients treated with placebo (13.6% vs 16.8%; p=0.08). In conclusion, in patients with non-ST-segment elevation acute coronary syndromes undergoing early percutaneous coronary intervention with stenting after a 600-mg loading dose of clopidogrel, abciximab therapy may have a slight positive impact on the prevention of restenosis.

Predictive factors of restenosis after coronary implantation of sirolimus- or paclitaxel-eluting stents.

BACKGROUND: The efficacy of drug-eluting stents in reducing restenosis risk has not been uniform across patient subsets. Identifying predictive factors of restenosis may help improve outcomes after percutaneous coronary interventions. METHODS AND RESULTS: All patients who underwent successful implantation of sirolimus- or paclitaxel-eluting stents in native vessels for de novo lesions between August 2002 and December 2004 were eligible for this study. All data were prospectively collected. Angiographic restenosis was defined as diameter stenosis > or =50% at follow-up in the in-segment area. Target lesion revascularization was defined as any revascularization procedure involving the target lesion. Included in this study were 1845 patients with 2093 target lesions. Multivariable analysis showed that vessel size, final diameter stenosis, and drug-eluting stent type were the strongest predictors of restenosis. A 0.5-mm decrease in vessel size was associated with adjusted odds ratios (ORs) of 1.74 (95% CI, 1.31 to 2.32) for angiographic restenosis and 1.65 (95% CI, 1.22 to 2.23) for target lesion revascularization. A 5% increase in final diameter stenosis was associated with adjusted ORs of 1.30 (95% CI, 1.15 to 1.47) for angiographic restenosis and 1.18 (95% CI, 1.03 to 1.35) for target lesion revascularization. Compared with paclitaxel-eluting stent, sirolimus-eluting stent was associated with adjusted ORs of 0.60 (95% CI, 0.44 to 0.81) for angiographic restenosis and 0.67 (95% CI, 0.49 to 0.91) for target lesion revascularization. CONCLUSIONS: Vessel size and drug-eluting stent type are the most important predictors of angiographic and clinical restenosis, with drug-eluting stent type having a particular impact on restenosis of small coronary vessels.

Randomized trial of a nonpolymer-based rapamycin-eluting stent versus a polymer-based paclitaxel-eluting stent for the reduction of late lumen loss.

BACKGROUND: Although drug-eluting stents (DESs) constitute a major achievement in preventing restenosis, concerns remain regarding the increased inflammatory and thrombogenic responses associated with the polymers used. Recently, we showed that a nonpolymer on-site coating with rapamycin not only is feasible and safe but also leads to a dose-dependent reduction in restenosis. METHODS AND RESULTS: To assess whether polymer-free stents coated on-site with 2% rapamycin solution are inferior to polymer-based paclitaxel-eluting stents for the prevention of restenosis, we randomly assigned a total of 450 patients with de novo lesions in native coronary vessels, excluding the left main trunk, to either the polymer-free, rapamycin-coated Yukon DES (rapamycin stent) or the polymer-based, paclitaxel-eluting Taxus stent (paclitaxel stent). The primary end point was in-stent late lumen loss. Secondary end points were angiographic restenosis and target lesion revascularization. The study was designed to test the noninferiority of the rapamycin stent compared with the paclitaxel stent with respect to late lumen loss according to a noninferiority margin of 0.13 mm. Follow-up angiography was completed in 81% of the patients. The mean difference in in-stent late lumen loss between the rapamycin-stent group and the paclitaxel-stent group was 0.002 mm, and the upper limit of the 1-sided 95% confidence interval was 0.10 mm (P=0.02 from test for noninferiority). No significant differences were observed regarding angiographic restenosis rates (14.2% with the rapamycin stent and 15.5% with the paclitaxel stent) and target lesion revascularization rates due to restenosis (9.3% in both groups). CONCLUSIONS: The polymer-free, rapamycin-coated stent has an antirestenotic effect that is not inferior to that observed with the polymer-based paclitaxel-eluting stent.

Age-dependent effect of abciximab in patients with acute coronary syndromes treated with percutaneous coronary interventions.

BACKGROUND: No studies have specifically performed an age-based analysis of the efficacy of abciximab in patients with non-ST-segment elevation acute coronary syndromes undergoing percutaneous coronary intervention (PCI). The aim of the study was to assess whether there are age-dependent differences in the clinical benefit of abciximab in patients with acute coronary syndrome treated with PCI. METHODS AND RESULTS: We performed this retrospective analysis of 2022 patients with acute coronary syndrome enrolled in the Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment (ISAR-REACT 2) study and randomized to receive abciximab or placebo during a PCI procedure. The incidence of major adverse cardiac events (MACE) during the 30 days after PCI was the primary end point of the study. On the basis of the cutoff age value provided by logistic regression in connection with bootstrap resampling, patients were divided into those younger (n=1220) and older (n=802) than 70 years. Among younger patients, the incidence of MACE was 7.7% in the abciximab group versus 13.3% in the placebo group (relative risk 0.57, 95% confidence interval 0.40 to 0.80, P=0.001). In contrast, no difference was observed among older patients: The incidence of MACE was 10.9% in the abciximab group versus 9.9% in the placebo group (relative risk 1.10, 95% confidence interval 0.72 to 1.69, P=0.65). After adjustment for other variables, including cardiac troponin, there was a significant interaction between age and abciximab (P=0.04) with respect to MACE reduction, with abciximab being more effective in younger patients. CONCLUSIONS: In patients with non-ST-elevation acute coronary syndromes undergoing PCI, the efficacy of abciximab appears to be age-dependent, with greater benefit among younger patients.

A clinical trial of abciximab in elective percutaneous coronary intervention after pretreatment with clopidogrel.

BACKGROUND: Whether the glycoprotein IIb/IIIa inhibitor abciximab is beneficial in patients undergoing elective percutaneous coronary intervention after pretreatment with clopidogrel is unknown. METHODS: We enrolled 2159 patients with coronary artery disease who underwent a percutaneous coronary intervention: 1079 patients were randomly assigned in a double-blind manner to receive abciximab and 1080 patients to receive placebo. All patients were pretreated with a 600-mg dose of clopidogrel at least two hours before the procedure. The primary end point of the trial was the composite of death, myocardial infarction, and urgent target-vessel revascularization within 30 days after randomization. RESULTS: The incidence of the primary end point was 4 percent (45 patients) in the abciximab group, as compared with 4 percent (43 patients) in the placebo group (relative risk, 1.05; 95 percent confidence interval, 0.69 to 1.59; P=0.82). Most adverse events were myocardial infarctions: the incidence was 4 percent (40 patients) in the abciximab group and 4 percent (41 patients) in the placebo group (P=0.91). Twelve patients (1 percent) in the abciximab group and eight patients (1 percent) in the placebo group had major bleeding complications (P=0.37). Profound thrombocytopenia occurred in 10 patients (1 percent) in the abciximab group but in none in the placebo group (P=0.002). CONCLUSIONS: Our data suggest that in patients at low-to-intermediate risk who undergo elective percutaneous coronary intervention after pretreatment with a high loading dose of clopidogrel, abciximab is associated with no clinically measurable benefit within the first 30 days.

Sex and effect of abciximab in patients with acute coronary syndromes treated with percutaneous coronary interventions: results from Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment 2 trial.

BACKGROUND: It is not known whether there exists a sex-dependent difference in the clinical benefit of abciximab in patients with acute coronary syndromes (ACS) undergoing a percutaneous coronary intervention (PCI). METHODS: We performed this retrospective analysis of 2022 patients (498 women) with ACS enrolled in the Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment 2 trial and randomized to receive abciximab or placebo during a PCI procedure. The incidence of major adverse cardiac events (MACE) during the 30 days after PCI was the primary end point of the study. RESULTS: Among men, the 30-day incidence of MACE was 8.6% in the abciximab group compared with 12.6% in the placebo group, relative risk (RR) 0.69 (95% confidence interval [CI] 0.50-0.94), P = .01. The 30-day incidence of MACE in women was 9.7% in the abciximab group compared with 9.9% in the placebo group, RR 0.98 (95% CI, 0.56-1.72), P = .97. After adjustment for baseline clinical and angiographic characteristics, there was no significant interaction between sex and abciximab (P = .71); adjusted RR was 0.70 (95% CI, 0.34-1.34) in women and 0.60 (95% CI, 0.40-0.90) in men. The incidence of major bleeding was significantly greater in women (3.6%) than in men (0.7%), RR 5.5 (95% CI, 2.54-11.9), P < .001, without any dependence on the form of therapy received. CONCLUSIONS: In patients with non-ST elevation ACS undergoing a PCI, the benefit with abciximab is greater in men than in women. This is apparently the result of sex-based differences in risk profile.

Quantitative measurement of infarct size by contrast-enhanced magnetic resonance imaging early after acute myocardial infarction: comparison with single-photon emission tomography using Tc99m-sestamibi.

OBJECTIVES: The aim of this research was to evaluate kinetics and extent of myocardial contrast enhancement (CE) in comparison with single-photon emission computed tomography (SPECT) early after acute myocardial infarction (AMI). BACKGROUND: Quantification of infarct size serves as a surrogate end point in evaluating new therapies of AMI. Contrast-enhanced magnetic resonance imaging (CeMRI) of the myocardium is a promising new method for identification of irreversible tissue injury. METHODS: A total of 33 patients were examined by CeMRI and SPECT 7 +/- 2 days after AMI and successful coronary intervention. After gadolinium-diethylenetraimine pentaacetic acid injection (0.2 mmol/kg), continuous short-axis slices of the left ventricle (LV) were acquired every 7 min up to 42 min using different inversion times (TI). Myocardial CE at each imaging time point was quantified and compared with corresponding SPECT perfusion defect. RESULTS: All patients showed myocardial CE in the infarct region. A constant TI for CeMRI resulted in a decrease of signal intensity and extent of CE on late acquisitions. With TI adjustment, infarct image intensity peaked at 21 min with a contrast of 478% of remote myocardium and remained at this level up to 42 min after contrast injection (437%); CE extent was stable over time and agreed well with SPECT within an average difference of 3% of the LV myocardium, yielding the best correlation at 28 min (r = 0.86). CONCLUSIONS: In patients after AMI and successful reperfusion, CE is stable over time and matches well with SPECT perfusion defect; CeMRI under standardized conditions can accurately assess myocardial infarct size in vivo and may be attractive for serving as a surrogate end point early after AMI.