Early in the Covid-19 pandemic, published guidance supported clinical teams to review patients treated with a vitamin K antagonist (VKA) and where appropriate change their medication to an alternative anticoagulant (eg a low molecular weight heparin (LMWH) or a direct oral anticoagulant (DOAC)). This was partly to reduce the frequency of clinic attendance for monitoring, and thus reduce the risk to patients. The guidance listed exceptions where specific patients should not be switched from a VKA, including patients with a mechanical heart valve.

However, incidents have been reported of patients with a mechanical heart valve being switched to a LMWH or a DOAC. This alert asks GPs and other NHS providers of anticoagulation services to identify any patients who have a record of a mechanical heart valve and are receiving a DOAC, and to urgently review these patients to ensure they are on the most appropriate anticoagulation therapy and monitoring.