For most warfarin indications, the target maintenance international normalised ratio (INR) is 2–3. Risk factors for bleeding complications with warfarin use include age, history of past bleeding and specific comorbid conditions. To reverse the effects of warfarin, vitamin K1 can be given. Immediate reversal is achieved with a prothrombin complex concentrate (PCC) and fresh frozen plasma (FFP). Vitamin K1 is essential for sustaining the reversal achieved by PCC and FFP. When oral vitamin K1 is used for warfarin reversal, the injectable formulation of vitamin K1 is preferable to tablets because of its flexible dosing; this formulation can be given orally or injected. To temporarily reverse the effect of warfarin when there is a need to continue warfarin therapy, vitamin K1 should be given in a dose that will quickly lower the INR to a safe, but not subtherapeutic, range and will not cause resistance once warfarin is reinstated. Prothrombinex‐HT is the only PCC approved in Australia and New Zealand for warfarin reversal. It contains factors II, IX and X, and low levels of factor VII. FFP should be added to Prothrombinex‐HT as a source of factor VII when used for warfarin reversal. Simple dental or dermatological procedures may not require interruption to warfarin therapy. If necessary, warfarin therapy can be withheld 5 days before elective surgery, when the INR usually falls to below 1.5 and surgery can be conducted safely. Bridging anticoagulation therapy for patients at high risk for thromboembolism should be undertaken in consultation with the relevant experts.

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The vidas D-dimer assay with a threshold value of 500 ng/mL has little clinical value as an exclusion test in patients more than 80 years old. The assay specificity is poor (26%) in patients aged 60-80 years but could be improved by increasing the threshold value to 1000 ng/mL. We believe that this should be tested in a prospective trial.

Summary. Background: Recurrent thromboembolic events after an initial deep vein thrombosis (DVT) are relatively frequent. Residual thrombus in the affected veins on ultrasound scan at the completion of anticoagulant therapy has been described as a recurrence risk factor, and may have utility in stratifying those patients at risk. Objectives: The aims of the study were to correlate the risk of recurrence of DVT with the results of ultrasound at completion of oral anticoagulant therapy. A secondary aim was to review the mortality in this population. Patients: A cohort of 316 DVT patients was included. The patients were divided into those with completely clear vessels on follow-up scan (45%) and those with residual thrombus identified (55%). Results: The cumulative incidence of recurrence was 10% by 2 years and 23% by 5 years. Patients with residual thrombus on follow-up ultrasound were at higher risk of recurrence (hazard ratio [HR] 2.2, 1.19-4.21; P ¼ 0.012) which remained significant after multivariate adjustment for age, gender and malignancy (HR 2.2, 1.15-4.17; P ¼ 0.018). During follow-up, the cumulative mortality was 12% at 2 years and 27% by 5 years. The risk of death was increased in patients with residual thrombus on follow-up scan (HR 3.9, 1.93-7.71; P < 0.001) and this risk persisted after multivariate analysis of age, gender and malignancy (2.8, 1.37-5.72; P ¼ 0.005). The majority of deaths were due to malignancy (68%) however 10 (18%) died from vascular causes. There was a trend towards increased vascular death in the patients with residual thrombus on follow-up ultrasound scan, which did not reach significance (HR 4.1,; P ¼ 0.13). Conclusions: Consistent with previous cohort studies, recurrence risk is increased in patients with residual thrombus on ultrasound. The increased risk of death in patients with residual thrombus, with a trend towards increased vascular death, may suggest that failure of thrombus resolution is a marker of more global vascular dysfunction.