Long term anticoagulation reduces recurrence of venous thromboembolism

Patients who survive an episode of venous thromboembolism are at risk of a recurrence, which is why they are usually treated with warfarin. But how long should this treatment continue? Randomised controlled trials investigating the impact of different durations of anticoagulation have reported conflicting results. A meta-analysis helps to resolve the discrepancies, but there is probably no straightforward answer.

Fifteen randomised controlled trials evaluating different durations of anticoagulation in terms of risk of recurrence were included in the meta-analysis. The investigators found that the discordance between trials that reported large benefits and others that reported only small or no benefit was largely explained by differences in the periods used for defining recurrence rates. Differences in the baseline prevalence of risk factors accounted for much of the variation in event rates between studies.

The investigators conclude that long term anticoagulation in patients with venous thromboembolism does reduce the risk of recurrence. The magnitude of this risk reduction is greatest while the patient is receiving treatment, but even after treatment is stopped there is benefit. The incremental benefit of prolonging anticoagulation decreases as the duration of anticoagulation increases but lasts for at least six months.

Pulmonary artery catheters do not reduce mortality in intensive care patients

Pulmonary artery catheters have been used for 30 years to monitor cardiac output and other haemodynamic variables in severely ill patients. Although they are ingenious pieces of technology, argument continues over whether the quality of the information they provide outweighs the complications associated with their insertion. A randomised trial involving over 1000 patients from 65 intensive care units in the UK reports no difference in mortality or length of stay in hospital between patients managed with or without a catheter.

The trial was pragmatic in its approach. Clinicians enrolled patients who they thought should be managed with a pulmonary artery catheter but, after randomisation, other …