The benefit of anticoagulants (AC) to prevent thrombotic complications during percutaneous coronary intervention (PCI) is well established. In acute coronary syndrome (ACS) patients previously treated with enoxaparin, an additional bolus of AC is not recommended if the last injection was realized within 8 h. In this setting, many interventional cardiologists use unfractionated heparin (UFH) at the time of sheath insertion.

The aim of our study was to describe local current practices for AC use during PCI in patients already treated with enoxaparin and admitted for ACS and to assess the biological impact of UFH addition at the beginning of the procedure.

A standardized survey was sent to the interventional cardiologists of the southwest of France to investigate their practice in terms of periprocedural AC use. In 2 centers, ACS patients previously treated with subcutaneous injection of enoxaparin within 8 h and who received intravenous UFH at the time of sheath insertion were prospectively included and their plasma anti-Xa activity was assessed at the sheath insertion and 30 min after UFH bolus. In-hospital bleeding and ischemic events were collected. The adequate therapeutic window was defined by anti Xa activity (range 0.5 to 0.9 IU/mL). Results: Among the 41 interventional cardiologists who replied, a large majority (75,6%) considered the addition of UFH in patients who received enoxaparin within 8 h as a valid option. 47 ACS patients were enrolled. The dose of the bolus of UFH was highly variable from 20 to 90 UI / kg. Anti-Xa activities were above 0.9 IU/mL in 14,9% of patients at the sheath insertion and in 72,3% of patients 30 min after UFH injection. 2 bleeding complications occurred, both in over-coagulated patients. No ischemic events were reported.

The use of UFH in patients who already received enoxaparin may result in over-anticoagulation and lead to bleeding complications.