Joint Statement: Anticoagulation of Patients with Mechanical Heart Valves
The British Cardiovascular Society (BCS) has today released a Joint Statement together with the British Heart Valve Society (BHVS), the Society for Cardiothoracic Surgeons (SCTS), the British Society of Echocardiography (BSE), the Primary Care Cardiovascular Society (PCCS) and the British Congenital Cardiac Association (BCCA) on Anticoagulation of Patients with Mechanical Heart Valves.
On 14 July 2021, a National Patient Safety Alert was issued by NHS England relating to choice of anticoagulant drugs prescribed to patients with mechanical heart valves. This was triggered by cases presenting to hospital of patients who 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 normalised ratio (INR). Thus, guidance was provided for patients who could be safely switched from warfarin to newer oral anticoagulant drugs – this did not include patients with mechanical heart valves.
The NPSA stated that fourteen patients with mechanical heart valves have been identified who had been switched from warfarin to alternative anticoagulant drugs – one patient was switched to a low molecular weight heparin (LMWH) and thirteen patients to a NOAC. On subsequent analysis of patient records in primary care, a further 750 patients have been identified who are coded as having a mechanical heart valve and prescribed a NOAC.
We wish to confirm and reiterate 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 contraindicated in patients with mechanical valves as per both European and North American clinical practice guidelines because of a higher incidence of thromboembolic complications when compared to warfarin.
LMWH injections can be used as an alternative to warfarin in certain clinical settings, under direct supervision of a responsible physician. As an example, patients with a mechanical valve who are pregnant or who have scheduled surgery may receive LMWH injections during a defined time period, after which warfarin therapy would be recommenced.
Any patients with mechanical heart valves who are receiving novel oral anticoagulants instead of warfarin should be reviewed urgently. Any who were 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. Any patients who were switched to LMWH injections due to the pandemic should also be seen to consider resumption of anticoagulation with warfarin.
1. Inappropriate anticoagulation of patients with a mechanical heart valve. National Patient Safety Alert. NHS England Ref NatPSA/2021/006/NHSPS. Date of Issue: 14 July 2021
2. 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
3. Baumgartner H et al. 2017 ESC/EACTS Guidelines for the management of valvular heart disease. Eur Heart J 2017; 00: 1-53
4. Otto CM et al. 2020 ACC/AHA Guideline for the management of patients with valvular heart disease. Circulation 2021; 143:e72-e2