Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0002962 (angina)
 21,142 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several new anticoagulants and antiplatelet agents have been developed for use in coronary angioplasty, but almost all have been associated with an increased incidence of bleeding complications. Hirulog, a direct thrombin inhibitor, has several theoretical advantages over heparin. It is unclear, however, whether the use of hirulog as a substitute for heparin in angioplasty would result in a higher incidence of bleeding or other side effects. The safety profile of hirulog was compared with that of heparin in a randomized, double-blind trial in 4312 patients who were scheduled to undergo angioplasty for unstable or postinfarction angina. The goal of anticoagulation was to achieve an activated clotting time of approximately 350 seconds with hirulog (bolus dose of 1.0 mg/kg body weight followed by a 4-hour infusion of 2.5 mg/kg per hour and a 14- to 20-hour infusion of 0.2 mg/kg per hour) or heparin (bolus dose of 175 units/kg followed by an 18- to 24-hour infusion of 15 units/kg per hour). Adverse events were recorded prospectively by study personnel and confirmed independently by clinical monitors blinded to treatment assignment. Compared with heparin in an intention-to-treat analysis, hirulog therapy was associated with either equivalent or lower rates of side effects. Most of the side effects of hirulog and heparin were related to hemorrhagic complications such as intravascular puncture site hemorrhage (29.1% vs 61.6%; p < 0.001), hematuria (16.6% vs 20.6%; p = 0.001), bleeding requiring red cell transfusion (3.7% vs 8.6%; p < 0.001), or hematemesis (0.8% vs 1.9%; p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Comparative safety profiles of hirulog and heparin in patients undergoing coronary angioplasty. The Hirulog Angioplasty Study Investigators. 766 14

In an open-label pilot study of 20 patients with unstable angina (Braunwald class I-IIIB), hirulog was administered as a continuous intravenous infusion for 5 days in a dose of 0.2 mg/kg/hour to produce an activated partial thromboplastin time of approximately 200% of control. The primary end points of the study were: death, development of a transmural myocardial infarction, and intractable angina needing interventions such as an intraaortic balloon pump insertion, angioplasty and surgery. The secondary end points were the presence of an intracoronary thrombus detected on angiography and hemorrhagic complications during therapy. There was no death or transmural infarction in this study cohort; however, 1 patient developed intractable angina. Intracoronary thrombus was documented in 2 patients. Infusion of hirulog resulted in a steady prolongation of the activated partial thromboplastin time without any hemorrhagic or other adverse effect. Hirulog appears to be an effective antithrombotic agent that is tolerated well and may have advantages over heparin in the management of patients with unstable angina.
 ...
PMID:Usefulness and tolerability of hirulog, a direct thrombin-inhibitor, in unstable angina pectoris. 825 26

The outcome of coronary angioplasty performed for unstable angina is determined, in part, by the acuteness and severity of the clinical presentation. The risk of abrupt vessel closure is increased in patients with postinfarction angina. The Hirulog Angioplasty Study compared the efficacy and safety of bivalirudin with weight-adjusted heparin in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) for unstable or postinfarction angina. We report the results of the intent-to-treat analysis using adjudicated data for the prespecified group of 741 patients who underwent angioplasty within 2 weeks of documented myocardial infarction. Patients received either bivalirudin or heparin immediately before angioplasty. The primary efficacy endpoint was procedural failure defined as abrupt vessel closure, death, myocardial infarction, or revascularization during hospitalization. Bivalirudin significantly (p = 0.004) decreased the incidence of procedural failure compared with heparin (5.1% vs 10.8%, odds ratio 0.45; 95% CI 0.25-0.79). The improved efficacy of bivalirudin was replicated for each individual clinical endpoint. The incidence of major bleeding was significantly (p = 0.001) lower in bivalirudin-treated patients compared with heparin-treated patients (2.4% vs 11.8%, respectively). The benefits observed with bivalirudin are of similar magnitude as those reported for platelet glycoprotein (GP) IIb/IIIa inhibitors, such as abciximab. Bivalirudin may be a more effective foundation anticoagulant than heparin in patients undergoing coronary angioplasty for postinfarction angina.
 ...
PMID:A randomized comparison of bivalirudin and heparin in patients undergoing coronary angioplasty for postinfarction angina. Hirulog Angioplasty Study Investigators. 980 91

The dosing of anticoagulants during coronary angioplasty is commonly guided by measurements of activated clotting time (ACT), but the usefulness of these measurements remains uncertain. The Hirulog Angioplasty Study was a randomized, double-blind comparison of heparin versus bivalirudin in 4,312 patients undergoing angioplasty for unstable or postinfarction angina. In 4,098 of the patients randomized, the balloon was inflated. All patients had ACT measurements 5 minutes after a weight-adjusted bolus of heparin or bivalirudin, and patients undergoing complicated or prolonged angioplasty procedures lasting >45 minutes had additional ACT measurements to guide further anticoagulant therapy. The analysis presented in this article evaluated the relation between the initial or maximum ACT measurements and the risk of abrupt vessel closure during heparin or bivalirudin therapy. Abrupt vessel closure occurred in 189 of 2,039 patients (9.3%) treated with heparin, and in 189 of 2,059 patients (9.2%) treated with bivalirudin (p = not significant). An inverse relation between the risk of abrupt closure and initial ACT measurements was observed in heparin-treated patients: the probability of abrupt vessel closure decreased by 1.3% for every 10-second increase in the initial ACT response to heparin therapy (p = 0.02). Among 903 of 2,039 heparin-treated patients (44%) who received additional heparin for prolonged or complicated procedures, the likelihood of abrupt vessel closure also decreased by 1.1% for every 10-second increase in ACT (p = 0.04). In 2,059 patients treated with bivalirudin, however, no relation between the probability of abrupt vessel closure and the initial ACT measurement was observed (p = 0.88). From the results it was concluded that when heparin is used during coronary angioplasty, the risk of abrupt vessel closure is related to patient responsiveness to anticoagulation therapy. Heparin-resistant patients are more likely to experience abrupt vessel closure than patients who have high ACT values in response to initial therapy. In contrast, when bivalirudin is used during coronary angioplasty, a flat relation between the risk of abrupt vessel closure and ACT values is seen. This suggests that the direct thrombin inhibitor, bivalirudin, provides more even levels of anticoagulation and more predictable levels of risk of abrupt closure than heparin. Measurements of ACT may not be necessary when bivalirudin is used during coronary angioplasty.
 ...
PMID:Relation between abrupt vessel closure and the anticoagulant response to heparin or bivalirudin during coronary angioplasty. 980 92