A55(Th)
APPROPRIATE HEPARIN USE IN THROMBOPROPHYLAXIS AND THE
TREATMENT OF ACUTE CORONARY SYNDROME IN PATIENTS WITH RENAL
FAILURE
Yiu, V1, Namagondlu, G2, Camilleri, B2
Addenbrookes Hospital, 2Ipswich Hospital
1
INTRODUCTION: Evidence based guidelines recommend the use of thromboprophylaxis in
hospitalised patients at risk of venous thromboembolism (VTE). The most commonly used
agent is heparin, usually low molecular weight heparin (LMWH). This is also commonly used
in the treatment of acute coronary syndrome (ACS). Unfractionated heparin (UFH) has a narrow
therapeutic window, requires monitoring and can rarely be associated with thrombocytopenia.
LMWH has similar efficacy but has the advantage of fixed dosing. It is renally excreted and
hence dose adjustment is needed for patients with renal impairment.
Ipswich Hospital recently published guidelines on screening all patients admitted for VTE risk
factors and appropriate dosing of LMWH (if eGFR <30ml/min, half dose Clexane should be
used). Guidelines on ACS treatment recommended 1mg/kg once daily if eGFR<30ml/min, or
the use of UFH if eGFR <15ml/min.
METHODS: We audited compliance with these guidelines in 30 medical patients and 15
patients with ACS admitted over a 3 month period who also had renal impairment. Consecutive
patients’ notes were reviewed and a proforma used to collect data.
RESULTS: The mean age of patients was 80.4years, and two thirds were male. The mean
eGFR was 20.5ml/min. The majority of patients admitted were screened for VTE risk (86%)
and had Clexane prescribed (70%). However, over half the patients did not have a dose
appropriate for reduced eGFR. 1 patient whose eGFR improved did not have the Clexane dose
adjusted; another had their dose adjusted only after 4 days. 60% patients admitted for ACS
were male, with a mean age of 77.8years. Patients who were already on warfarin with a
therapeutic INR did not have clexane for ACS treatment. There were several patients who were
deemed too frail for further treatment, hence 80% were prescribed LMWH/UFH. Around half
had inappropriate dosing and one third had longer duration of treatment than the recommended
48 hours. Over half did not have an eGFR appropriate prophylactic dose of Clexane prescribed
after treatment.
CONCLUSIONS: VTE prophylaxis is now commonly prescribed and is vital to reduce
morbidity and mortality in hospital patients. However, patients frequently have renal
impairment on admission and they are at increased risk of bleeding from inappropriately high
doses of Clexane. If their GFR improves during admission and the Clexane dose is not revised,
they do not derive the benefits of this treatment. Bleeding risk is especially important in
patients with ACS who also receive antiplatelet therapy and may undergo invasive procedures
such as angiograms. We proposed measures such as mandatory documentation of eGFR on the
admission clerking, VTE/ACS treatment guidelines to be placed on all wards, improving
awareness through Trust induction and collaborating with other health professionals (nurses,
pharmacists) to help ensure all patients with renal impairment receive appropriate VTE
prophylaxis and ACS treatment. This study was a snapshot of practice at Ipswich Hospital, and
more studies are needed to address optimum dosing regimens and practice on a national scale.