Replacement bileaflet mechanical heart valves – risk of inverted implantation

Specific manufacturers – measures to prevent inverted valve implantation resulting from incorrect mounting of the valve on its valve holder.


  • Do not attempt to reattach a valve to its holder if separated before or during valve surgery – it is contrary to the manufacturers’ instructions for use (IFU).
  • Ensure the whole surgical team is trained on the handling of each make of valve that they use, including awareness of warnings and precautions in the IFU and any design features influencing its use.

Action by

Cardiothoracic surgeons and theatre staff involved in replacement heart valve procedures.

Deadlines for actions

Actions underway: 14 September 2017

Actions complete: 12 October 2017

Problem / background

MHRA is aware of 5 incidents worldwide over the last 15 years where mechanical bi-leaflet prosthetic valves of different models are believed to have been implanted inverted because they were put on their holder upside-down. The actual figure is likely to be higher as there is under-reporting of these events.

Details of the 5 incidents:

  • 2 cases (one known to be fatal) in 2003 and 2004, resulting from a manufacturing quality control release mistake where valves were loaded inverted at the factory
  • 1 in 2006 resulting from separation of the valve from the holder (due to suture breakage) during transportation and subsequent remounting prior to surgery
  • 1 in 2006 where evidence indicates that the valve was remounted during the valve surgery
  • 1 UK incident (2015) involving inverted remounting of a valve in theatre leading to subsequent patient death.

The probability of this error remains very low relative to the millions of valves implanted during this time, but the harm that can result is extreme, sometimes fatal.

Despite warnings in the manufacturers’ IFU not to remount a valve on its holder, this has not entirely prevented this practice, with tragic consequences. Although the risk of inverted valve implantation cannot be completely eliminated, the holder itself can be designed to be unidirectional, preventing inverted mounting. One manufacturer’s (St. Jude Medical, now Abbott) holder design is currently unidirectional, thereby also eliminating the risk of inversion on the holder during valve assembly.

As a consequence of the recent UK incident (coupled with cases cited above), MHRA has acquired agreement from the other 3 manufacturers of mechanical heart valves (Liva Nova, Medtronic, On-X Life Technologies) to redesign their holders to be unidirectional.

These undertakings involve long-term design projects, including thorough risk/benefit assessment and regulatory approval. As a result, valves mounted on unidirectional holders are unlikely to become available in the UK for up to a year or more, depending on the manufacturer.

Until all manufacturers have made these changes, it is important that all clinical personnel handling mechanical heart valves are aware of the serious risk associated with inversion of the valve on its holder.


If you are responsible for cascading these alerts in your organisation, these are our suggested distribution lists.

Trusts (NHS boards in Scotland)

CAS and SABS (NI) liaison officers for onward distribution to all relevant staff including:

  • Cardiologists
  • Cardiology departments
  • Cardiology, directors of
  • Cardiothoracic departments
  • Cardiothoracic surgeons
  • Cardiothoracic surgery directors
  • Medical directors
  • Radiographer superintendents
  • Radiographers
  • Radiologists
  • Radiology departments
  • Radiology directors
  • Risk managers



Send enquiries about this notice to MHRA, quoting reference number MDA/2017/028 or 2015/003/027/401/002.

Technical aspects

Alexander McLaren or Hazel Randall, MHRA

Tel: 020 3080 7292 or 020 3080 7287

Email: or

Clinical aspects

Mark Grumbridge, MHRA

Tel: 020 3080 7274


Reporting adverse incidents in England

Through Yellow Card

Northern Ireland

Alerts in Northern Ireland are distributed via the NICAS system.

Enquiries and adverse incident reports in Northern Ireland should be addressed to:

Northern Ireland Adverse Incident Centre, CMO Group,
Department of Health, Social Services and Public Safety

Tel: 028 9052 3868


Northern Ireland Adverse Incident Centre (NIAIC)

Please report directly to NIAIC using the forms on our website.


Enquiries and adverse incident reports in Scotland should be addressed to:

Incident Reporting and Investigation Centre,
Health Facilities Scotland,
NHS National Services Scotland

Tel: 0131 275 7575

Fax: 0131 314 0722


Reporting adverse incidents in Scotland

NHS Boards and Local Authorities in Scotland – report to Health Facilities Scotland.

Contractors such as private hospitals carrying out NHS work and private care homes that accept social work funded clients – report to Health Facilities Scotland.

Private facilities providing care to private clients report to the Care Inspectorate and MHRA.


Enquiries in Wales should be addressed to:

Healthcare Quality Division,
Welsh Government

Tel: 02920 823 624 / 02920 825 510


Reporting adverse incidents in Wales

Report to MHRA through Yellow Card and follow specific advice for reporting in Wales in MDA/2004/054 (Wales).

Download document

MDA/2017/028R - Replacement bileaflet mechanical heart valves

Published 31 August 2017