Effect of clopidogrel pretreatment before percutaneous coronary intervention in patients with ST-elevation myocardial infarction treated with fibrinolytics: the PCI-CLARITY study

Context  The benefit of clopidogrel pretreatment before percutaneous coronary intervention (PCI) remains debated and its use has not been universally adopted. Objective  To determine if clopidogrel pretreatment before PCI in patients with recent ST-segment elevation myocardial infarction (STEMI) is superior to clopidogrel treatment initiated at the time of PCI in preventing major adverse cardiovascular events. Design, Setting, and Participants  The PCI-Clopidogrel as Adjunctive Reperfusion Therapy (CLARITY) study was a prospectively planned analysis of the 1863 patients undergoing PCI after mandated angiography in CLARITY–Thrombolysis in Myocardial Infarction (TIMI) 28, a randomized, double-blind, placebo-controlled trial of clopidogrel in patients receiving fibrinolytics for STEMI. Patients were enrolled at 319 sites in 23 countries from February 2003 through October 2004. Interventions  Patients received aspirin and were randomized to receive either clopidogrel (300 mg loading dose, then 75 mg once daily) or placebo initiated with fibrinolysis and given until coronary angiography, which was performed 2 to 8 days after initiation of the study drug. For patients undergoing coronary artery stenting, it was recommended that open-label clopidogrel (including a loading dose) be administered after the diagnostic angiogram. Main Outcome Measures  The primary outcome was the incidence of the composite of cardiovascular death, recurrent MI, or stroke from PCI to 30 days after randomization. Secondary outcomes included MI or stroke before PCI and the aforementioned composite from randomization to 30 days. Results  Pretreatment with clopidogrel significantly reduced the incidence of cardiovascular death, MI, or stroke following PCI (34 [3.6%] vs 58 [6.2%]; adjusted odds ratio [OR], 0.54 [95% CI, 0.35-0.85]; P = .008). Pretreatment with clopidogrel also reduced the incidence of MI or stroke prior to PCI (37 [4.0%] vs 58 [6.2%]; OR, 0.62 [95% CI, 0.40-0.95]; P = .03). Overall, pretreatment with clopidogrel resulted in a highly significant reduction in cardiovascular death, MI, or stroke from randomization through 30 days (70 [7.5%] vs 112 [12.0%]; adjusted OR, 0.59 [95% CI, 0.43-0.81]; P = .001; number needed to treat = 23). There was no significant excess in the rates of TIMI major or minor bleeding (18 [2.0%] vs 17 [1.9%]; P>.99). Conclusions  Clopidogrel pretreatment significantly reduces the incidence of cardiovascular death or ischemic complications both before and after PCI and without a significant increase in major or minor bleeding. These data add further support to the early use of clopidogrel in STEMI and the strategy of routine clopidogrel pretreatment in patients undergoing PCI.      

Thrombolytic therapy vs primary percutaneous coronary intervention for myocardial infarction in patients presenting to hospitals without on-site cardiac surgery: a randomized controlled trial

Context  Trials comparing primary percutaneous coronary intervention (PCI) and thrombolytic therapy for treatment of acute myocardial infarction (MI) suggest primary PCI is the superior therapy, although they differ with respect to the durability of benefit. Because PCI is often limited to hospitals that have on-site cardiac surgery programs, most acute MI patients do not have access to this therapy. Objective  To determine whether treatment of acute MI with primary PCI is superior to thrombolytic therapy at hospitals without on-site cardiac surgery and, if so, whether superiority is durable. Design  The Atlantic Cardiovascular Patient Outcomes Research Team (C-PORT) trial, a prospective, randomized trial conducted from July 1996 through December 1999. Setting  Eleven community hospitals in Massachusetts and Maryland without on-site cardiac surgery or extant PCI programs. Patients  Four hundred fifty-one thrombolytic-eligible patients with acute MI of less than 12 hours' duration associated with ST-segment elevation on electrocardiogram. Interventions  After a formal primary PCI development program was completed at all sites, patients were randomly assigned to receive primary PCI (n = 225) or accelerated tissue plasminogen activator (bolus dose of 15 mg and an infusion of 0.75 mg/kg for 30 minutes followed by 0.5 mg/kg for 60 minutes; n = 226). After initiation of assigned treatment, all care was determined by treating physicians. Main Outcome Measures  Six-month composite incidence of death, recurrent MI, and stroke; median hospital length of stay. Results  The incidence of the composite end point was reduced in the primary PCI group at 6 weeks (10.7% vs 17.7%; P = .03) and 6 months (12.4% vs 19.9%; P = .03) after index MI. Six-month rates for individual outcomes were 6.2% vs 7.1% for death (P = .72), 5.3% vs 10.6% for recurrent MI (P = .04), and 2.2% vs 4.0% for stroke (P = .28) for primary PCI vs thrombolytic therapy, respectively. Median length of stay was also reduced in the primary PCI group (4.5 vs 6.0 days; P = .02). Conclusions  Compared with thrombolytic therapy, treatment of patients with primary PCI at hospitals without on-site cardiac surgery is associated with better clinical outcomes for 6 months after index MI and a shorter hospital stay.      

Clopidogrel use and long-term clinical outcomes after drug-eluting stent implantation

Context  Recent studies of drug-eluting intracoronary stents suggest that current antiplatelet regimens may not be sufficient to prevent late stent thrombosis. Objective  To assess the association between clopidogrel use and long-term clinical outcomes of patients receiving drug-eluting stents (DES) and bare-metal stents (BMS) for treatment of coronary artery disease. Design, Setting, and Patients  An observational study examining consecutive patients receiving intracoronary stents at Duke Heart Center, a tertiary care medical center in Durham, NC, between January 1, 2000, and July 31, 2005, with follow-up contact at 6, 12, and 24 months through September 7, 2006. Study population included 4666 patients undergoing initial percutaneous coronary intervention with BMS (n = 3165) or DES (n = 1501). Landmark analyses were performed among patients who were event-free (no death, myocardial infarction [MI], or revascularization) at 6- and 12-month follow-up. At these points, patients were divided into 4 groups based on stent type and self-reported clopidogrel use: DES with clopidogrel, DES without clopidogrel, BMS with clopidogrel, and BMS without clopidogrel. Main Outcome Measures  Death, nonfatal MI, and the composite of death or MI at 24-month follow-up. Results  Among patients with DES who were event-free at 6 months (637 with and 579 without clopidogrel), clopidogrel use was a significant predictor of lower adjusted rates of death (2.0% with vs 5.3% without; difference, –3.3%; 95% CI, –6.3% to –0.3%; P = .03) and death or MI (3.1% vs 7.2%; difference, –4.1%; 95% CI, –7.6% to –0.6%; P = .02) at 24 months. However, among patients with BMS (417 with and 1976 without clopidogrel), there were no differences in death (3.7% vs 4.5%; difference, –0.7%; 95% CI, –2.9% to 1.4%; P = .50) and death or MI (5.5% vs 6.0%; difference, –0.5%; 95% CI, –3.2% to 2.2%; P = .70). Among patients with DES who were event-free at 12 months (252 with and 276 without clopidogrel), clopidogrel use continued to predict lower rates of death (0% vs 3.5%; difference, –3.5%; 95% CI, –5.9% to –1.1%; P = .004) and death or MI (0% vs 4.5%; difference, –4.5%; 95% CI, –7.1% to –1.9%; P<.001) at 24 months. However, among patients with BMS (346 with and 1644 without clopidogrel), there continued to be no differences in death (3.3% vs 2.7%; difference, 0.6%; 95% CI, –1.5% to 2.8%; P = .57) and death or MI (4.7% vs 3.6%; difference, 1.0%; 95% CI, –1.6% to 3.6%; P = .44). Conclusions  The extended use of clopidogrel in patients with DES may be associated with a reduced risk for death and death or MI. However, the appropriate duration for clopidogrel administration can only be determined within the context of a large-scale randomized clinical trial.      

Effects of percutaneous coronary interventions in silent ischemia after myocardial infarction: the SWISSI II randomized controlled trial

Context  The effect of a percutaneous coronary intervention (PCI) on the long-term prognosis of patients with silent ischemia after a myocardial infarction (MI) is not known. Objective  To determine whether PCI compared with drug therapy improves long-term outcome of asymptomatic patients with silent ischemia after an MI. Design, Setting, and Participants  Randomized, unblinded, controlled trial (Swiss Interventional Study on Silent Ischemia Type II [SWISSI II]) conducted from May 2, 1991, to February 25, 1997, at 3 public hospitals in Switzerland of 201 patients with a recent MI, silent myocardial ischemia verified by stress imaging, and 1- or 2-vessel coronary artery disease. Follow-up ended on May 23, 2006. Interventions  Percutaneous coronary intervention aimed at full revascularization (n = 96) or intensive anti-ischemic drug therapy (n = 105). All patients received 100 mg/d of aspirin and a statin. Main Outcome Measures  Survival free of major adverse cardiac events defined as cardiac death, nonfatal MI, and/or symptom-driven revascularization. Secondary measures included exercise-induced ischemia and resting left ventricular ejection fraction during follow-up. Results  During a mean (SD) follow-up of 10.2 (2.6) years, 27 major adverse cardiac events occurred in the PCI group and 67 events occurred in the anti-ischemic drug therapy group (adjusted hazard ratio, 0.33; 95% confidence interval, 0.20-0.55; P<.001), which corresponds to an absolute event reduction of 6.3% per year (95% confidence interval, 3.7%-8.9%; P<.001). Patients in the PCI group had lower rates of ischemia (11.6% vs 28.9% in patients in the drug therapy group at final follow-up; P = .03) despite fewer drugs. Left ventricular ejection fraction remained preserved in PCI patients (mean [SD] of 53.9% [9.9%] at baseline to 55.6% [8.1%] at final follow-up) and decreased significantly (P<.001) in drug therapy patients (mean [SD] of 59.7% [11.8%] at baseline to 48.8% [7.9%] at final follow-up). Conclusion  Among patients with recent MI, silent myocardial ischemia verified by stress imaging, and 1- or 2-vessel coronary artery disease, PCI compared with anti-ischemic drug therapy reduced the long-term risk of major cardiac events. Trial Registration  clinicaltrials.gov Identifier: NCT00387231      

Aspirin for the primary prevention of cardiovascular events in women and men: a sex-specific meta-analysis of randomized controlled trials

Context  Aspirin therapy reduces the risk of cardiovascular disease in adults who are at increased risk. However, it is unclear if women derive the same benefit as men. Objective  To determine if the benefits and risks of aspirin treatment in the primary prevention of cardiovascular disease vary by sex. Data Sources and Study Selection  MEDLINE and the Cochrane Central Register of Controlled Trials databases (1966 to March 2005), bibliographies of retrieved trials, and reports presented at major scientific meetings. Eligible studies were prospective, randomized controlled trials of aspirin therapy in participants without cardiovascular disease that reported data on myocardial infarction (MI), stroke, and cardiovascular mortality. Six trials with a total of 95 456 individuals were identified; 3 trials included only men, 1 included only women, and 2 included both sexes. Data Extraction  Studies were reviewed to determine the number of patients randomized, mean duration of follow-up, and end points (a composite of cardiovascular events [nonfatal MI, nonfatal stroke, and cardiovascular mortality], each of these individual components separately, and major bleeding). Data Synthesis  Among 51 342 women, there were 1285 major cardiovascular events: 625 strokes, 469 MIs, and 364 cardiovascular deaths. Aspirin therapy was associated with a significant 12% reduction in cardiovascular events (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.79-0.99; P = .03) and a 17% reduction in stroke (OR, 0.83; 95% CI, 0.70-0.97; P = .02), which was a reflection of reduced rates of ischemic stroke (OR, 0.76; 95% CI, 0.63-0.93; P = .008). There was no significant effect on MI or cardiovascular mortality. Among 44 114 men, there were 2047 major cardiovascular events: 597 strokes, 1023 MIs, and 776 cardiovascular deaths. Aspirin therapy was associated with a significant 14% reduction in cardiovascular events (OR, 0.86; 95% CI, 0.78-0.94; P = .01) and a 32% reduction in MI (OR, 0.68; 95% CI, 0.54-0.86; P = .001). There was no significant effect on stroke or cardiovascular mortality. Aspirin treatment increased the risk of bleeding in women (OR, 1.68; 95% CI, 1.13-2.52; P = .01) and in men (OR, 1.72; 95% CI, 1.35-2.20; P<.001). Conclusions  For women and men, aspirin therapy reduced the risk of a composite of cardiovascular events due to its effect on reducing the risk of ischemic stroke in women and MI in men. Aspirin significantly increased the risk of bleeding to a similar degree among women and men.      

Early administration of reteplase plus abciximab vs abciximab alone in patients with acute myocardial infarction referred for percutaneous coronary intervention: a randomized controlled trial

Context  The optimal pharmacological strategy for bridging the delay between admission and performance of percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (MI) is not known. Objective  To assess whether early administration of reteplase plus abciximab produces better results compared with abciximab alone in patients with acute MI referred for PCI. Design, Setting, and Patients  Open-label, randomized controlled study conducted from May 3, 2001, through June 2, 2003, of 253 patients who were admitted to 13 community hospitals without catheterization facilities (n = 186) and to 5 hospitals with catheterization facilities (n = 67), with the diagnosis of an ST-segment elevation acute MI within 12 hours from onset of symptoms. Interventions  Patients received intravenously either the combination of a half-dose reteplase (two 5-U boluses, 30 minutes apart) with a standard dose of abciximab (0.25 mg/kg bolus, 0.125 µg/kg per minute infusion [maximum 10 µg/min for 12 hours]) or the standard dose of abciximab alone; all patients were then transferred for PCI. Main Outcome Measure  Final infarct size according to a single-photon emission computed tomography study with technetium Tc 99m sestamibi performed between 5 and 10 days after randomization in 228 patients (90.1% of entire sample). Results  Of the 253 patients enrolled, 125 were assigned to reteplase plus abciximab and 128 to abciximab alone. The median (interquartile range) of the final infarct size of the left ventricle was 13.0% (3.0%-28.0%) in the reteplase plus abciximab group and 11.5% (3.0%-26.3%) in the abciximab-alone group (P = .81). The mean difference in final infarct size of left ventricle between the reteplase plus abciximab group and the abciximab group was 1.3% (95% confidence interval [CI], –3.1% to 5.7%). Within 6 months after randomization, the composite secondary end point of death, recurrent MI, or stroke occurred in 8 patients (6.4%) in the reteplase plus abciximab group and 6 patients (4.7%) in the abciximab group (relative risk, 1.4; 95% CI, 0.5-3.9; log-rank P = .56). Major bleeding complications were observed in 7 patients (5.6%) in the reteplase plus abciximab group and 2 patients (1.6%) in the abciximab group (P = .16). Conclusion  Early administration of reteplase plus abciximab does not lead to a reduction of infarct size compared with abciximab alone in patients with acute MI referred for PCI.      

Oral antiplatelet therapy in cerebrovascular disease, coronary artery disease, and peripheral arterial disease

Context  Atherothrombosis is a pathophysiologic process that results in clinical ischemic events affecting the cerebral, coronary, and peripheral arterial circulation. Antiplatelet agents, used alone or in combination, are effective in preventing recurrent vascular events among individuals with established vascular disease. Objective  To summarize the current state of evidence regarding oral antiplatelet treatment in patients with cerebrovascular disease, coronary artery disease (CAD), and peripheral arterial disease. Evidence Acquisition  Using the key terms acute coronary syndrome, atherothrombosis, ischemic stroke, myocardial infarction, MI, peripheral arterial disease, TIA, transient ischemic attack, unstable angina,aspirin,ticlopidine,dipyridamole, and clopidogrel, we searched the MEDLINE database as well as the trial register of the Cochrane Groups to identify studies published from 1960 to August 2004. We manually searched journals and abstract booklets; scrutinized reference lists of trials and review articles; and reviewed meta-analyses, scientific statements, and guidelines from official societies. Evidence Synthesis  Appropriate oral first-line antiplatelet therapy is aspirin for individuals with ST-segment elevation myocardial infarction; aspirin or clopidogrel for those with TIA or stroke, chronic stable angina, or peripheral arterial disease; and aspirin combined with clopidogrel for those with non–ST-segment elevation acute coronary syndrome. Aspirin combined with dipyridamole is a possible alternative for patients who experience a first episode of TIA or stroke in the absence of clinically apparent CAD. Although ticlopidine has been shown to be of benefit in various vascular conditions, its adverse-effect profile has limited its use. Conclusions  Aspirin, ticlopidine, clopidogrel, aspirin combined with clopidogrel, and aspirin combined with dipyridamole are effective in preventing recurrent vascular events among various subgroups of patients with vascular disease. Current clinical trial evidence favors the use of aspirin or clopidogrel as first-line agents for the majority of patients with vascular disease. Clinical trials evaluating combination antiplatelet therapies will direct future practice.      

Abciximab in patients with acute coronary syndromes undergoing percutaneous coronary intervention after clopidogrel pretreatment: the ISAR-REACT 2 randomized trial

Context  No specifically designed studies have addressed the role of the glycoprotein IIb/IIIa inhibitor abciximab in patients with non–ST-segment elevation acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) after pretreatment with 600 mg of clopidogrel. Objective  To assess whether abciximab is associated with clinical benefit in high-risk patients with ACS undergoing PCI after pretreatment with 600 mg of clopidogrel. Design, Setting, and Patients  International, multicenter, randomized, double-blind, placebo-controlled study conducted from March 2003 through December 2005, enrolling 2022 patients (mean age, 66 years) with non–ST-segment elevation ACS undergoing PCI. Interventions  Patients were assigned to receive either abciximab (0.25 mg/kg of body weight bolus, followed by a 0.125-µg/kg per minute [maximum, 10 µg/min] infusion for 12 hours, plus heparin, 70 U/kg of body weight) or placebo (placebo bolus and infusion of 12 hours, plus heparin bolus, 140 U/kg). All patients received clopidogrel, 600 mg, at least 2 hours prior to the procedure, as well as 500 mg of oral or intravenous aspirin. Main Outcome Measures  The primary end point was a composite of death, myocardial infarction, or urgent target vessel revascularization occurring within 30 days after randomization; secondary end points were rates of in-hospital major and minor bleeding. Results  Of 2022 patients enrolled, 1012 were assigned to abciximab and 1010 to placebo. The primary end point was reached in 90 patients (8.9%) assigned to abciximab vs 120 patients (11.9%) assigned to placebo, a 25% reduction in risk with abciximab (relative risk [RR], 0.75; 95% CI, 0.58-0.97; P = .03). Among patients without an elevated troponin level, there was no difference in the incidence of primary end point events between the abciximab group (23/499 patients [4.6%]) and the placebo group (22/474 patients [4.6%]) (RR, 0.99; 95% CI, 0.56-1.76; P = .98), whereas among patients with an elevated troponin level, the incidence of events was significantly lower in the abciximab group (67/513 patients [13.1%]) compared with the placebo group (98/536 patients [18.3%]), which corresponds to an RR of 0.71 (95% CI, 0.54-0.95; P = .02) (P = .07 for interaction). There were no significant differences between the 2 groups regarding the risk of major and minor bleeding as well as need for transfusion. Conclusions  Abciximab reduces the risk of adverse events in patients with non–ST-segment elevation ACS undergoing PCI after pretreatment with 600 mg of clopidogrel. The benefits provided by abciximab appear to be confined to patients presenting with an elevated troponin level. Trial Registration  ClinicalTrials.gov Identifier: NCT00133003      

High-risk patients with acute coronary syndromes treated with low-molecular-weight or unfractionated heparin: outcomes at 6 months and 1 year in the SYNERGY trial

Context  The SYNERGY trial comparing enoxaparin and unfractionated heparin in high-risk patients with acute coronary syndromes (ACS) showed that enoxaparin was not inferior to unfractionated heparin in reducing death or nonfatal myocardial infarction (MI) at 30 days. Objective  To evaluate continued risk in this patient cohort through 6-month and 1-year follow-up. Design, Setting, and Patients  Overall, 9978 patients were randomized from August 2001 through December 2003 in 487 hospitals in 12 countries. Patients were followed up for 6 months and for 1 year. Main Outcome Measures  Six-month outcomes were death, nonfatal MI, revascularization procedures, stroke, and site-investigator–reported need for rehospitalization; 1-year outcome was all-cause death. Results  Six-month and 1-year follow-up data were available for 9957 (99.8%) and 9608 (96.3%) of 9978 patients, respectively; 541 patients (5.4%) had died at 6 months and 739 (7.4%) at 1 year. Death or nonfatal MI at 6 months occurred in 872 patients receiving enoxaparin (17.6%) vs 884 receiving unfractionated heparin (17.8%) (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.89-1.07; P = .65). In the subgroup of patients receiving consistent therapy, ie, only enoxaparin or unfractionated heparin during the index hospitalization (n = 6138), a reduction in death or nonfatal MI with enoxaparin was maintained at 180 days (HR, 0.85; 95% CI, 0.75-0.95; P = .006). Rehospitalization within 180 days occurred in 858 patients receiving enoxaparin (17.9%) and 911 receiving unfractionated heparin (19.0%) (HR, 0.94; 95% CI, 0.85-1.03; P = .17). One-year all-cause death rates were similar in the 2 treatment groups (380/4974 [7.6%] for enoxaparin vs 359/4948 [7.3%] for unfractionated heparin; HR, 1.06; 95% CI, 0.92-1.22; P = .44). One-year death rates in patients receiving consistent therapy were also similar (251/3386 [7.4%] for enoxaparin vs 213/2720 [7.8%] for unfractionated heparin; HR, 0.95; 95% CI, 0.79-1.14; P = .55). Conclusions  In the SYNERGY trial, patients continued to experience adverse cardiac events through long-term follow-up. The effect of enoxaparin on death or MI compared with that of unfractionated heparin at 6 months was similar to that observed at 30 days in the overall trial and in the consistent-therapy group. One-year death rates were also similar in both groups. High-risk patients with ACS remain susceptible to continued cardiac events despite aggressive therapies. ClinicalTrials.gov Identifier:  NCT00043784.      

Terminal complement blockade with pexelizumab during coronary artery bypass graft surgery requiring cardiopulmonary bypass: a randomized trial

Context  Inflammation and ischemia-reperfusion injury during coronary artery bypass graft (CABG) surgery requiring cardiopulmonary bypass are associated with postoperative myocardial infarction (MI) and mortality. Objective  To determine the efficacy and safety of pexelizumab, a C5 complement inhibitor, in reducing perioperative MI and mortality in CABG surgery. Design, Setting, and Participants  A randomized, double-blind, placebo-controlled trial, including 3099 patients (=" BORDER="0"> 18 years) undergoing CABG surgery with or without valve surgery at 205 hospitals in North America and Western Europe from January 2002 to February 2003. Interventions  Patients were randomly assigned to receive intravenous pexelizumab (2.0 mg/kg bolus plus 0.05 mg/kg per hour for 24 hours; n = 1553) or placebo (n = 1546) 10 minutes before undergoing the procedure. Main Outcome Measures  The primary composite end point was the incidence of death or MI within 30 days of randomization in those undergoing CABG surgery only (n = 2746). Secondary analyses included the intent-to-treat analyses of death or MI composite at days 4 and 30 in all 3099 study patients. Results  After 30 days, 134 (9.8%) of 1373 of patients receiving pexelizumab vs 161 (11.8%) of 1359 of patients receiving placebo (relative risk, 0.82; 95% confidence interval, 0.66-1.02; P = .07) died or experienced MI in the CABG surgery only population. In the intent-to-treat analyses, 178 (11.5%) of 1547 patients receiving pexelizumab vs 215 (14.0%) of 1535 receiving placebo died or experienced MI (relative risk, 0.82; 95% confidence interval, 0.68-0.99; P = .03). The trial was not powered to detect a reduction in mortality alone. Conclusions  Compared with placebo, pexelizumab was not associated with a significant reduction in the risk of the composite end point of death or MI in 2746 patients who had undergone CABG surgery only but was associated with a statistically significant risk reduction 30 days after the procedure among all 3099 patients undergoing CABG with or without valve surgery.