On July 14th 2021, a National Patient Safety Alert was issued by NHS England relating to choice of anticoagulant drugs prescribed to patients with mechanical heart valves.1 This was triggered by cases presenting to hospital of patients that had been switched from anticoagulation with warfarin to a novel oral anticoagulant (NOAC).
As a result of the Coronavirus pandemic and the national lockdown in 2020, some patients experienced significant difficulty in continuing blood monitoring of the international normalized ratio (INR). As a result, guidance was provided for patients that could be safely switched from warfarin to newer oral anticoagulant drugs – this did not include patients with mechanical heart valves.2
The NPSA states that fourteen patients with mechanical heart valves have been identified that had been switched from warfarin to alternative anticoagulant drugs – one patient was switched to low molecular weight heparin and thirteen patients to a NOAC. On subsequent analysis of patient records in primary care, a further 750 patients have been found who are coded as having a mechanical heart valve and prescribed a NOAC.
We wish to confirm and re-iterate to managers, commissioners, healthcare professionals and patients that, at present, none of the novel oral anticoagulant drugs (dabigatran, edoxaban, apixaban & rivaroxaban) are licensed for use in patients with mechanical heart valves and, in fact, they are contra-indicated in patients with mechanical valves as per both European3 and North American4 clinical practice guidelines (because of higher incidence of thromboembolic complications when compared to Warfarin).
We are liaising with other professional Societies and will issue a formal Joint Statement shortly. In the interim any patients with mechanical heart valves who are receiving novel oral anticoagulants instead of warfarin should be reviewed urgently. Any that have been switched to a NOAC without explicitly documented prior discussions involving their responsible valve specialist should be converted to warfarin therapy as a priority. In case of uncertainty, urgent discussion with a valve specialist is needed.
- Inappropriate anticoagulation of patients with a mechanical heart valve. National Patient Safety Alert. NHS England Ref NatPSA/2021/006/NHSPS. Date of Issue July 14th 2021
- NICE Clinical Guide for the management of anticoagulant services during the Coronavirus pandemic. Updated Feb 2021. Htttps://www.nice.org.uk/Media/Default/About/COVID-19/Specialty-guides/specialty-guide-anticoagulant-services-and-coronavirus.pdf
- Baumgartner H et al. 2017 ESC/EACTS Guidelines for the management of valvular heart disease. Eur Heart J 2017; 00: 1-53
- Otto CM et al. 2020 ACC/AHA Guideline for the management of patients with valvular heart disease. Circulation 2021; 143:e72-e227