Patients with certain blood groups wait much longer for heart transplants

28 September 2018

People with Group O blood wait longer for a heart transplant than those with other blood groups.

Data published this month in NHS Blood and Transplant’s annual report into Cardiothoracic Organ Donation and Transplantation demonstrate the difference.

The figures are being highlighted by NHSBT for World Heart Day (Saturday, September 29th) to highlight how the shortage of organ donors affects some patients more than others.

Transplant waiting times vary considerably depending on several factors including patient size, urgency of need, the patient’s antibody levels, and blood group, and each individual’s waiting time will vary. However, the overall median adult waiting times to heart transplant are1

  • Group O – 479 days
  • Group B – 150 days
  • Group A – 87 days
  • Group AB – 24 days

The longer waiting times arise because people with Group O blood can donate to every other group but they can only receive organs from people who are also Group O. In contrast, patients with AB group blood can receive organs from every other group.2

Transplanting an organ from an incompatible blood group will normally trigger the recipient’s antibodies to interact with and damage the transplanted organ immediately. The organ usually ceases to function.

Outcomes vary for individuals, but longer waiting times to heart transplant can increase the risk for patients and may lead to them needing urgent transplantation or support with a Left Ventricular Assist Device.3 

Patrick McCann is blood group O and been on the waiting list since August 2015 – more than three years, or more than 1,100 days. He turned 36 this week.4 

Patrick sits on a hospital bed wearing an organs t-shirtPatrick, from Padiham in Lancashire, was born with tricuspid atresia, a congenital heart disease that means he is missing a heart valve. The defect means the right side of his heart is too small and it cannot pump strongly enough to supply blood to the rest of his body. He can only walk about 50 yards before he is out of breath.

Patrick had a Fontan procedure when he was six, to divert the flow of blood around his right ventricle. This means the left side of his heart does all the work for his whole body.

Patrick, who works for Tesco on the checkout, has had two ‘false alarms’ and lives with the constant anxiety of not knowing when, or if, he will receive a transplant.

“I feel worried about the phone ringing while I am too far from home and sometimes I worry about not getting a transplant in time. I am trying to live life as best I can,” he said.

Patrick, is listed for transplant at the Freeman Hospital in Newcastle. At different points in his life his heart rate has been as low as 28 beats per minute and as high as 300 beats per minute.

He said: “It's a struggle at times, waiting so long.

“I do spend a lot of time thinking and wondering, if I'll get my transplant in time, when it will be, what life will be like afterwards and also how long I can remain stable for, while waiting.

“I do try to keep myself occupied, to stop my mind from wandering at times, as overthinking, and then worrying more, doesn't help the situation.”

Patrick supports the introduction of an opt out organ donation system and encourages all those wishing to donate their organ to share their decision with their family.

Dr Jayan Parameshwar, Consultant Cardiologist at Royal Papworth Hospital, and Chair of the Cardiothoracic Advisory Group for NHS Blood and Transplant said: “The problem faced by patients with Blood Group O is something we are acutely aware off and monitor constantly.

“The organ allocation system has been altered to minimise this problem on more than one occasion but it is not possible to overcome it.5 

“This is because in critically ill patients with Blood Group A or AB, it is not possible to wait for an identical blood group donor. O is the most common blood group in the UK and inevitable more donors will carry Blood Group O. Some of these donor organs will therefore be transplanted into patients with other blood groups.

“Increasing the number of organs donors is the best way to help patients with all blood groups. We need more families to say yes to organ donation so that more lives are saved. Please tell your family you want to donate.”

Mr Asif Hasan, Consultant Paediatric Cardiothoracic Surgeon at Newcastle Hospitals, said: “O blood group patients awaiting heart transplantation are particularly disadvantaged, as they cannot receive hearts from other blood groups due to ABO incompatibility. Blood group incompatible heart transplants can result in hyperacute rejection, which is invariably fatal.

“We desperately need more donors to reduce the unacceptably high risk of deaths of patients waiting for heart transplants.”

  • More than 25 million people are already on the NHS Organ Donor Register. Join them today and tell your family you want to save lives. Register at



Press release notes

  1. Median active waiting time to heart transplant for adult patients registered on the transplant list, by urgency at registration and blood group, 1 April 2012 to 31 March 2015. Taken from table 3.3 of the 2017/18 NHS Blood and Transplant Annual Report on Cardiothoracic Organ Transplantation 
  2. Young children can receive transplants from other blood groups due to their weaker immune systems.
  3. One year after listing for non-urgent heart transplant, 11% of all patients had died, 5% had been removed from the list, 27% had become urgent, 39% were still waiting, and 18% had been transplanted. Post-registration outcome for 132 non-urgent heart only registrations made in the UK, 1 April 2014 to 31 March 2015. Taken from figure 3.4 of the 2017/18 NHS Blood and Transplant Annual Report on Cardiothoracic Organ Transplantation 
  4. Median waiting time to heart transplant is 180 days overall. For patients entering the list as non-urgent it is 502 days and for patients entering the list as urgent it is 26 days. Taken from table 3.2 of the 2017/18 NHS Blood and Transplant Annual Report on Cardiothoracic Organ Transplantation
  5. NHS Blood and Transplant has adjusted the allocation system to reduce waiting times although the problem persists. A blood Group O heart should now be offered to a Group O or Group B patients before considered for Group A and AB patients (except for patients on the Super-Urgent Waiting list).

Notes to editors

  • NHS Blood and Transplant is a joint England and Wales Special Health Authority. We provide the blood donation service for England and the organ donation service for the UK. We also provide donated tissues, stem cells and cord blood. We are an essential part of the NHS, saving and improving lives through public donation.
  • It is quick and easy to join the NHS Organ Donor Register. Call 0300 123 23 23 or visit
  • Families are always involved in organ donation discussions. You can make things easier for your family by telling them you want to donate.
  • Every day across the UK around three people who could have benefited from a transplant die because there aren’t enough organ donors.
  • Anyone can join the NHS Organ Donor Register, age and medical conditions are not necessarily a barrier to donation.
  • One donor can save or transform up to nine lives through organ donation and save and transforms even more by donating tissue.
  • The Government has announced plans for a presumed consent system of organ donation to take effect from spring 2020. Under the system, you would be a donor unless you register a decision not to donate. Families will still be able to object to donation so it’s important that you make their decision easier at a difficult time by also telling them that you want to donate.