The number of hospitals in England allowed to perform children's heart surgery is to be cut in a controversial move.
NHS England has published what it hopes will be the final decision on the matter after previous reviews led to some NHS trusts launching legal action.
The plans cover units performing both adult and children's congenital heart surgery (CHD), and those providing cardiac specialist care for CHD.
Around 80% of the CHD work undertaken at these units relates to children.
Under the plans, 13 level 1 centres that perform surgery will be cut to 10, and nine level 2 specialist cardiac centres will be cut to four.
Some NHS trusts said they would fight the decision, with Leicester saying it would not sit by while officials at NHS England "destroy our fabulous service".
It said its results were among the best in the country and that closing its service would threaten other key children's services in the region, including intensive care.
Royal Brompton and Harefield NHS Foundation Trust in London, which lost a legal challenge over plans to close its unit in 2012, described the decision as "extraordinary" and "ill-conceived".
It also criticised NHS England's handling of the announcement, saying it asked the trust to submit extra detail but then took no notice of it.
Level 1 units set to lose services are those at Central Manchester University Hospitals NHS Foundation Trust, University Hospitals of Leicester NHS Trust and Royal Brompton and Harefield NHS Foundation Trust in London.
Those level 2 units that will lose services - none of which perform surgery - are Blackpool Teaching Hospitals NHS Foundation Trust, University Hospital of South Manchester NHS Foundation Trust, Papworth Hospital NHS Foundation Trust, Nottingham University Hospitals NHS Trust and Imperial College Healthcare NHS Trust.
All units providing adult and children's congenital heart surgery in England were assessed against new standards to work out if they were providing good care.
They were all found to be providing safe care - with death rates within acceptable limits - but NHS England said some saw too few cases to maintain standards.
Some evidence suggests surgeons should see 125 patients per surgeon per year to ensure surgeons remain competent and highly skilled.
Officials at NHS England believe that while units in England are safe, not all are providing excellent care.
They hope that by centralising services, outcomes for patients will continue to improve, with more patients surviving and those children born with congenital heart defects living longer into adulthood.
The changes are due to be brought in from April next year.
Congenital heart disease services have been the subject of a number of reviews since the public inquiry at Bristol Royal Infirmary in 2001.
In 2015, NHS England published new standards that units must meet for the organisation to continue commissioning their services.
Dr Jonathan Fielden, NHS England director of specialised commissioning, said: "Patients, families and staff need to be assured of sustainable, high quality services now, and into the future.
"There has been a great deal of uncertainty over the future of congenital heart disease services over the past 15 years.
"We owe it to patients, families and staff to end that uncertainty, and to provide clear direction for the safety and quality of this specialist area of medicine going forward.
"A great deal of work has gone into achieving consensus across the board on the standards that providers should meet.
"We are determined to take all actions necessary to ensure that those standards are met, so that patients get the high quality and safe services that they expect and deserve."
Professor Sir Ian Kennedy, who was chairman of the public inquiry at Bristol Royal Infirmary, said: "These are vital services and we have waited 15 years to arrive at a solution which delivers quality and consistency for current and future generations.
"It is good news for patients that there is finally a clear consensus on the standards that need to be met, and that we are now seeing decisive action to make those standards a reality for every patient in every part of the country."