Almost half of patients who need potentially life-saving stroke surgery do not get it quick enough despite guidelines being in place since 2008.
A report from the Royal College of Surgeons and the Vascular Society of Great Britain and Ireland found 44% of people who need surgery of the neck arteries in order to prevent a stroke are not receiving it within the two week timeframe set by the National Institute for Health and Care Excellence.
Millions of lives could be saved every year if people ate more potassium-rich foods such as bananas and cut down on their salt intake, health experts have said.
People who have a high potassium intake have a 24% reduced risk of stroke, according to a new study.
And increasing levels of potassium - which can be found in many foods including fruit, vegetables, nuts, seeds, milk, fish, beef, chicken, turkey and bread - can help to reduce high blood pressure, the results indicate.
Researchers also said that increased levels of the chemical do not have an adverse effect on kidney function in adults.
Previous studies have suggested that older people are at an increased risk of harm from potassium because as people get older, their kidneys may become less able to remove potassium from their blood.
The Department of Health advises that older people should not have potassium supplements unless advised to take them by a doctor.
It says that adults need 3,500mg of potassium a day - which people should be able to get from eating a balanced diet.
The research, published on bmj.com, analysed data on potassium intake and health concerning 128,000 participants, who took part in 33 trials.
Care of stroke patientsin hospital has improved dramatically over recent years with the majority ofpatients now treated in specialist stroke units, but we know there is still more to do.
That is why we have established a programme which focuses on driving up standards for stroke patients, by ensuring, among other things, that patients have a joint care plan prepared for them before they leave hospital.
Modernisation of the NHS will help to integrate health and social care services.
The new Health and Wellbeing Boards will bring together representatives of different health and care services to agree a joint health and wellbeing strategy for their area.
Making sure that different services work together around patient needs will be key to that strategy.
Jon Barrick, chief executive at the Stroke Association, said:
More people than ever are surviving a stroke and that's a welcome improvement.
But many stroke survivors tell us that after all the effort to save their lives they then feel abandoned when they return home.
The NHS and local authorities are failing in their responsibilities to provide appropriate and timely support to stroke survivors and their families; and the growing evidence of cuts for people currently getting services is very worrying.
The Stroke Association is calling for the NHS to ensure all stroke survivors have their health and social care needs assessed and regularly reviewed.