• Cardiology Clinical Trials
• Interventional Techniques & Devices
• Thrombotic Disorders

Unfractionated heparin (UFH), at a dose of 100 U/kg, is preferable to standard higher-dose treatment in patients who are undergoing elective percutaneous coronary intervention (PCI), according to new findings from the Intracoronary Stenting and Antithrombotic Regimen-Rapid Early Action for Coronary Treatment 3A (ISAR-REACT 3A; NCT00735280) trial.

Although 140 U/kg has been the standard dose for UFH in interventional cardiology for decades, physicians have started to use lower doses of UFH to decrease the risk of bleeding, said Stefanie Schulz, MD, Deutsches Herzzentrum, Munich, Germany. Dr. Schulz presented results of the ISAR-REACT 3A trial, which confirmed the benefits of lower-dose UFH in patients who are undergoing elective PCI.

In the ISAR-REACT 3A trial, 2505 biomarker-negative patients who were undergoing elective PCI were treated with a bolus dose of UFH 100 U/kg without activated clotting time (ACT) monitoring. This treatment group was compared with two historical control groups from the main ISAR-REACT 3 trial, including patients who were treated with a bolus dose of UFH 140 U/kg (n=2281) or with bivalirudin (n=2289) [Kastrati A et al. N Eng J Med 2008].

In the ISAR-REACT 3 trial, treatment with bivalirudin significantly reduced the risk of minor bleeding (6.8% vs 9.9%; p=0.0001) and major bleeding (3.1% vs 4.6%; p=0.008) compared with UFH 140 U/kg in patients who were undergoing elective PCI. However, the net clinical benefit, which accounted for death, myocardial infarction (MI), urgent target vessel revascularization (TVR), and major bleeding, was similar in the bivalirudin and UFH 140 U/kg groups at 30 days (8.3% vs 8.7%; p=0.57) [Kastrati A et al. N Eng J Med 2008].

In the current ISAR-REACT 3A study, the net clinical benefit at 30 days favored treatment with UFH 100 U/kg compared with UFH 140 U/kg (7.3% vs 8.7%; p=0.007). Although the 100-U/kg and 140-U/kg dosing groups were associated with similar rates of death, MI, or urgent TVR (4.4% vs 5.0%; p=0.15), the risk of major bleeding was 29% lower in the 100-U/kg dosing group (3.6% vs 4.6%; p=0.03).

In the second comparison, treatment with UFH 100 U/kg met the criteria for noninferiority compared with bivalirudin. Low-dose UFH and bivalirudin had similar rates of death, MI, or urgent TVR (4.4% vs 5.9%), as well as similar rates of major (3.6% vs 3.1%) and minor bleeding (6.2% vs 6.8%).

Findings from the ISAR-REACT 3A trial support a shift in practice for biomarker-negative patients who receive elective PCI. Reducing the UFH dose from 140 U/kg to 100 U/kg provides a superior net clinical benefit for PCI patients and is noninferior to treatment with bivalirudin, Dr. Schulz concluded.

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