NEW YORK (Reuters Health) – Patients undergoing percutaneous coronary intervention for acute coronary syndrome initially treated with the synthetic factor Xa inhibitor fondaparinux do not have significantly lower rates of bleeding if they receive a reduced dose of unfractionated heparin rather than the standard dose during the procedure.
These findings are to be published in the September 22 issue of the Journal of the American Medical Association and are being released early online to coincide with a presentation at the European Society of Cardiology meeting in Stockholm.
Dr. Sanjit S. Jolly at Hamilton General Hospital in Ontario, Canada, and colleagues note that the optimal dose of unfractionated heparin during PCI, whether or not fondaparinux has been used, has not been evaluated.
The researchers evaluated the safety of two heparin regimens in a randomized trial involving over 2000 high-risk patients with unstable angina or non-ST-segment elevation MI treated with subcutaneous fondaparinux and who were scheduled for PCI.
Approximately half the patients received a fixed low dose of 50 U/kg unfractionated heparin or a standard dose of 85 U/kg adjusted by activated clotting time (ACT).
The median amounts of unfractionated heparin administered were 3800 U and 6400 U in the low-dose and standard-dose groups, respectively, the team reports.
The primary composite outcome of peri-PCI major bleeding, minor bleeding, or major vascular access site complications occurred in 4.7% of the patients in the low-dose group and 5.8% in the standard-dose group, (odds ratio 0.80), Dr. Jolly and colleagues found. The difference was not significant at a p value of 0.27.
The investigators conclude that patients with acute coronary syndromes treated with fondaparinux and undergoing PCI “should receive the guideline-recommended ACT-guided standard dose of unfractionated heparin.”
Reference:
Low-Dose vs Standard-Dose Unfractionated Heparin for Percutaneous Coronary Intervention in Acute Coronary Syndromes Treated With Fondaparinux
JAMA 2010;304.
