ISAR-REACT 3A: Reduced UFH dose in PCI patients lowers bleeding risk
MedWire News: Lowering the dose of unfractionated heparin (UFH) in patients undergoing percutaneous coronary intervention (PCI) offers a clinical benefit driven by reductions in bleeding risk, as shown by results from the ISAR-REACT 3A study.
Over 2500 patients were given a reduced bolus dose of 100 U/kg UFH during PCI and the results were compared with historical data from the ISAR-REACT 3 study of over 2200 patients given a bolus dose of 140 U/kg UFH and a similar number treated with bivalirudin.
As reported at the European Society of Cardiology Annual Congress, in Stockholm, Sweden, the lower dose of UFH was associated with a significantly reduced likelihood of reaching the primary composite endpoint of death, myocardial infarction (MI), urgent target vessel revascularization (uTVR), and bleeding, primarily through a significant reduction in bleeding risk. Reduced-dose UFH was also non-inferior to bivalirudin.
Lead researcher Stefanie Schulz (Deutsche Herzzentrum, Munich, Germany) commented that, in biomarker-negative patients, "a reduced dose of heparin represented a simple and safe method of lowering the bleeding risk after PCI without increasing the risk of ischemic complications."
In total, 2505 biomarker-negative patients were recruited to the prospective, multicenter, single-arm, open-label, historical control Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment (ISAR-REACT) 3A trial and given a bolus dose of 100 U/kg UHF during PCI. Results were compared with 4570 patients from the previous ISAR-REACT 3 trial, consisting of 2281 patients given a bolus of 140 U/kg UFH and 2289 given bivalirudin.
Although the three patient groups were comparable in terms of average age and the proportion of women, there were significant differences in baseline characteristics, with ISAR-REACT-3A patients, in general, more likely to have cardiovascular risk factors than their historical counterparts.
On a superiority analysis, patients given a lower-dose UFH bolus were significantly less likely to reach the primary composite endpoint at 30 days than those given a larger bolus, at 7.3% versus 8.7% and an adjusted hazard ratio of 0.75 (p=0.007).
Examination of the secondary composite endpoints of death, MI, and uTVR, with bleeding as a separate endpoint, revealed that a reduction in bleeding rates was largely responsible for the difference in achieving the primary endpoint, at 3.6% versus 4.6% for low-dose and high-dose UFH, respectively, and an adjusted hazard ratio of 0.71 (p=0.03).
When comparing 100 U/kg UFH with bivalirudin on a non-inferiority analysis, it was found that 7.3% of lower-dose UFH patients achieved the primary composite endpoint, versus 8.3% of bivalirudin patients (p for noninferiority=0.001).
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By Liam Davenport