First experience with direct factor Xa inhibition in patients with stable coronary disease: a pharmacokinetic and pharmacodynamic evaluation.

BACKGROUND: Thrombin generation is critical to the formation of an arterial thrombus after rupture of an atherosclerotic plaque. In patients with stable coronary disease receiving standard medical therapy, we evaluated the pharmacokinetics, pharmacodynamics, and safety profile of DX-9065a, a novel small-molecule anticoagulant that directly, selectively, and reversibly inhibits factor Xa. METHODS AND RESULTS: In a double-blind trial, 73 patients (median age, 63 years; 29% women) were randomly assigned to receive a fixed-dose intravenous bolus, followed by a 72-hour infusion of placebo or 1 of 4 weight-adjusted regimens of DX-9065a. Plasma samples were collected during infusion and a 24-hour elimination period. Only minor bleeding occurred, predominantly ecchymoses at infusion sites, and its incidence did not differ significantly among the groups, including placebo. Median hemoglobin, platelet count, serum creatinine level, and liver function tests did not change significantly from baseline during infusion or elimination. Significant predictors of pharmacokinetic response included infusion dose and weight. At 60 hours into the DX-9065a infusion, plasma drug levels correlated strongly with anti-factor Xa activity (r=0.97), prothrombin time (r=0.77), and international normalized ratio (r=0.72) but less so with activated partial thromboplastin time (r=0.56; all P<0.001). CONCLUSIONS: This is the first study of a selective, reversible, and direct small-molecule factor Xa inhibitor in patients with stable coronary disease. These data lay the foundation for further investigation of factor Xa inhibitors in the treatment of patients with coronary atherothrombosis.

Comparison of coronary artery bypass grafting versus medical therapy on long-term outcome in patients with ischemic cardiomyopathy (a 25-year experience from the Duke Cardiovascular Disease Databank).

In this observational treatment comparison in a single center over 25 years, we sought to assess long-term outcomes of coronary artery bypass surgery (CABG) or medical therapy in patients with heart failure, coronary artery disease, and left ventricular systolic dysfunction. The benefit of CABG compared with medical therapy alone in these patients is a source of continuing clinical debate. This analysis considered all patients with New York Heart Association class II or greater symptoms, 1 or more epicardial coronary vessels with a > or = 75% stenosis, and a left ventricular ejection fraction <40% who underwent an initial cardiac catheterization at Duke University Medical Center from 1969 to 1994. Patients were classified into the medical therapy group (n = 1,052) or CABG group (n = 339) depending on which therapy they received within 30 days of catheterization. Cardiovascular event and mortality follow-up commenced on the day of CABG, or at catheterization plus 8 days (the mean time to CABG) for the medical therapy arm. A Cox proportional-hazards model was employed to adjust for differences in baseline characteristics. In the first 30 days from baseline, there was an interaction between treatment strategy and number of diseased vessels. Unadjusted, event-free, and adjusted survival strongly favored CABG over medical therapy after 30 days to >10 years regardless of the extent of coronary disease (p <0.001). Thus, regardless of the severity of coronary disease, heart failure symptoms, or ventricular dysfunction, CABG provides extended event-free and survival advantage over medical therapy alone in patients with an ischemic cardiomyopathy.

Early intensive vs a delayed conservative simvastatin strategy in patients with acute coronary syndromes: phase Z of the A to Z trial.

CONTEXT: Limited data are available evaluating how the timing and intensity of statin therapy following an acute coronary syndrome (ACS) event affect clinical outcome. OBJECTIVE: To compare early initiation of an intensive statin regimen with delayed initiation of a less intensive regimen in patients with ACS. DESIGN, SETTING, AND PARTICIPANTS: International, randomized, double-blind trial of patients with ACS receiving 40 mg/d of simvastatin for 1 month followed by 80 mg/d thereafter (n = 2265) compared with ACS patients receiving placebo for 4 months followed by 20 mg/d of simvastatin (n = 2232), who were enrolled in phase Z of the A to Z trial between December 29, 1999, and January 6, 2003. MAIN OUTCOME MEASURE: The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, readmission for ACS, and stroke. Follow-up was for at least 6 months and up to 24 months. RESULTS: Among the patients in the placebo plus simvastatin group, the median low-density lipoprotein (LDL) cholesterol level achieved while taking placebo was 122 mg/dL (3.16 mmol/L) at 1 month and was 77 mg/dL (1.99 mmol/L) at 8 months while taking 20 mg/d of simvastatin. Among the patients in the simvastatin only group, the median LDL cholesterol level achieved at 1 month while taking 40 mg/d of simvastatin was 68 mg/dL (1.76 mmol/L) and was 63 mg/dL (1.63 mmol/L) at 8 months while taking 80 mg/d of simvastatin. A total of 343 patients (16.7%) in the placebo plus simvastatin group experienced the primary end point compared with 309 (14.4%) in the simvastatin only group (40 mg/80 mg) (hazard ratio [HR], 0.89; 95% confidence interval [CI] 0.76-1.04; P =.14). Cardiovascular death occurred in 109 (5.4%) and 83 (4.1%) patients in the 2 groups (HR, 0.75; 95% CI, 0.57-1.00; P =.05) but no differences were observed in other individual components of the primary end point. No difference was evident during the first 4 months between the groups for the primary end point (HR, 1.01; 95% CI, 0.83-1.25; P =.89), but from 4 months through the end of the study the primary end point was significantly reduced in the simvastatin only group (HR, 0.75; 95% CI, 0.60-0.95; P =.02). Myopathy (creatine kinase >10 times the upper limit of normal associated with muscle symptoms) occurred in 9 patients (0.4%) receiving simvastatin 80 mg/d, in no patients receiving lower doses of simvastatin, and in 1 patient receiving placebo (P =.02). CONCLUSIONS: The trial did not achieve the prespecified end point. However, among patients with ACS, the early initiation of an aggressive simvastatin regimen resulted in a favorable trend toward reduction of major cardiovascular events.

Safety and efficacy of enoxaparin vs unfractionated heparin in patients with non-ST-segment elevation acute coronary syndromes who receive tirofiban and aspirin: a randomized controlled trial.

CONTEXT: Enoxaparin or the combination of glycoprotein IIb/IIIa inhibitor tirofiban with unfractionated heparin independently have shown superior efficacy over unfractionated heparin alone in patients with non-ST-elevation acute coronary syndromes (ACS). It is not clear if combining enoxaparin with glycoprotein IIb/IIIa inhibitors is as safe or as effective as the current standard combination of unfractionated heparin with glycoprotein IIb/IIIa inhibitors. OBJECTIVE: To assess efficacy and safety of the combination of enoxaparin and tirofiban compared with unfractionated heparin and tirofiban in patients with non-ST-elevation ACS. DESIGN, SETTING, AND PARTICIPANTS: A prospective, international, open-label, randomized, noninferiority trial of 1 mg/kg of enoxaparin every 12 hours (n = 2026) compared with weight-adjusted intravenous unfractionated heparin (n = 1961) in patients with non-ST-elevation ACS receiving tirofiban and aspirin. Phase A of the A to Z trial was conducted between December 1999 and May 2002. MAIN OUTCOME MEASURES: Death, recurrent myocardial infarction, or refractory ischemia at 7 days in the intent-to-treat population with boundaries set for superiority and noninferiority. Safety based on measures of bleeding using the Thrombolysis in Myocardial Infarction (TIMI) classification system. RESULTS: A total of 169 (8.4%) of 2018 patients randomized to enoxaparin experienced death, myocardial infarction, or refractory ischemia at 7 days compared with 184 (9.4%) of 1952 patients randomized to unfractionated heparin (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.71-1.08). This met the prespecified criterion for noninferiority. All components of the composite primary and secondary end points favored enoxaparin except death, which occurred in only 1% of patients (23 for enoxaparin and 17 for unfractionated heparin). Rates for any TIMI grade bleeding were low (3.0% for enoxaparin and 2.2% for unfractionated heparin; P =.13). Using a worst-case approach that combined 2 independent bleeding evaluations, use of enoxaparin was associated with 1 additional TIMI major bleeding episode for each 200 patients treated. CONCLUSIONS: In patients receiving tirofiban and aspirin, enoxaparin is a suitable alternative to unfractionated heparin for treatment of non-ST-elevation ACS. The 12% relative and 1% absolute reductions in the primary end point in favor of enoxaparin met criterion for noninferiority and are consistent with prior trials performed without the use of glycoprotein IIb/IIIa inhibitors.