The NHS is failing to act quickly enough when people suffer symptoms of a transient ischemic attack, also known as a mini stroke, costing an estimated 500 lives a year, according to a report.
People who experience classic signs of a mini stroke are treated as a low priority, according to a UK audit of services from leading doctors.
Those with facial or arm weakness, speech problems or blurred vision, or a combination, are at risk of having a severe stroke if they do not receive surgery as soon as possible.
The operation, called a carotid endarterectomy, should be carried out within 48 hours but no longer than 14 days after symptoms appear.
The audit found low public awareness of symptoms combined with poor knowledge among health staff about treatments meant patients were not treated as emergencies.
As a result, thousands wait weeks or sometimes months for an operation that may be of no benefit to them by the time they receive it.
If patients had surgery within two weeks, around 200 strokes could be prevented for every 1,000 operations, the experts said.
Some 10,000 operations should be carried out by the NHS each year and, if every one of these patients got surgery within 14 days, 2,000 strokes could be prevented, they continued.
This means some 500 lives could therefore be saved each year, the report concluded.
The Vascular Surgical Society audit, carried out at the Royal College of Physicians, said NICE guidance set a timeframe of two weeks from symptoms to surgery.
Professor Ross Naylor, consultant vascular surgeon at Leicester Royal Infirmary and a member of the UK Audit Steering Group, said patients should be treated within 48 hours.
“Healthcare purchasers and providers must stop tolerating delays in the system and address the problems. Strokes and TIAs are emergencies and must be treated as such.”
Regions doing well in this area include Leicester, Derby, Southend, West Hertfordshire, County Durham, London, Aintree, Blackpool, Chester, Lancashire, Bolton, Tameside, Morecombe, Berkshire, East and South Kent.
Areas doing poorly include Norfolk and Norwich, Peterborough, Northampton, Nottingham, Bedfordshire, East and South Hertfordshire, Sunderland, Cumbria, Brighton, Sussex and the West Midlands.