National Patient Safety Alert: Inappropriate anticoagulation of patients with a mechanical heart valve (14 July 2021)

Summary

All patients with prosthetic mechanical heart valves require life-long oral anticoagulation with a vitamin K antagonist (VKA), usually warfarin, as these valves predispose the patient to systemic embolism. Thrombosis of a prosthetic valve is potentially life-threatening as it can result in haemodynamically severe stenosis or regurgitation and acute heart failure. The risk depends on the type of valve, its position, and other factors. 

Since 1 March 2020, 14 incidents have been reported of patients with a mechanical heart valve being switched to a a low molecular weight heparin (LMWH) or a direct oral anticoagulant (DOAC); two patients were hospitalised due to valve thrombosis and/or required emergency surgery and one was admitted due to severe anaemia. The reports included cases where patients’ anticoagulation was switched from warfarin in primary and in secondary care.

Content

Actions

General practices:

• Practices using EMIS: If you have received a ‘task’ from EMIS identifying specific patients who have a record of a mechanical heart valve and are receiving a DOAC, and you have not already actioned this request, urgently review these patients to ensure they are on the most appropriate anticoagulation therapy and monitoring.
• Practices using TPP: If you have received a ‘task’ from TPP identifying specific patients who have a record of a mechanical heart valve and are receiving a DOAC, and you have not already actioned this request, urgently review these patients to ensure they are on the most appropriate anticoagulation therapy and monitoring.
• Practices using other GP system software: If your practice does not use EMIS or TPP software, urgently review all patients with a mechanical heart valve to ensure they are on the appropriate anticoagulant therapy and monitoring.

Providers of anticoagulation services:

• Urgently check patient records from January 2020 to identify any patient with a mechanical heart valve who has been switched from a VKA to an alternative anticoagulant.
• For identified patients you should either: (i) Urgently review these patients if still under the care of the service to ensure they are on the appropriate anticoagulant therapy and monitoring or (ii) Work with the patient’s GP to ensure the patient receives an urgent review.