An increased use of clot-busting medicines prevented 4,000 strokes in England between 2015 and 2016, according to new research.
The drugs were given to patients who were suffering from an irregular heartbeat called atrial fibrillation (AF) which can result in a five-fold increased risk of a stroke, compared to people who do not have the condition.
But the study, conducted by researchers at the University of Leeds, estimated there are half a million people living with undiagnosed AF.
"Our ageing population makes it clear that without intervention, cases of AF and associated strokes are only going to increase. Its a truly preventable public health crisis."
Chris Gale, Professor of Cardiovascular Medicine and Consultant Cardiologist who supervised the study, said: Sudden strokes in people who have AF are unnecessarily common. Treatments which prevent AF-related strokes are saving lives, but there are still many thousands of people in the UK living with undiagnosed AF who are missing out.
"The risk of AF rises dramatically with age. Our ageing population makes it clear that without intervention, cases of AF and associated strokes are only going to increase.
Its a truly preventable public health crisis.
The British Heart Foundation, which part funded the research, said the findings highlight the urgent need for better screening.
The findings of the study have been published in the European Heart Journal.
AF is the most common type of irregular heartbeat. It causes the hearts chambers to beat in an uncoordinated, irregular manner.
The irregular rhythm can cause blood to pool in the heart, which can form into a blood clot. It this clot travels to the brain it can block the blood supply, leading to a stroke.
The researchers used national data collected between 2006 and 2016 to look at the numbers of patients who had been diagnosed with AF, whether patients at high-risk of a stroke had been given anticoagulants or clot-busting drugs, and the number of strokes that occurred.
They found that, since 2009, the number of people with AF who were being treated with anticoagulants had more than doubled.
The researchers estimate that, had the uptake of anticoagulants stayed at 2009 levels, there would have been around 4,000 more strokes in patients with AF in England in the 2015/16 financial year.
Stroke is the fourth biggest killer in the UK and the leading cause of disability and in 2016, killed almost twice as many women as breast cancer.
AF contributes to between 20 to 30 per cent of all strokes, and treating these patients with anticoagulants can cut patients risk of stroke by two thirds.
The researchers say the increase in the use of clot-busting medicine is likely thanks to efforts across the health service to educate patients and doctors about the benefits of anticoagulation, changes to guidelines in the UK and Europe, and new types of anticoagulants which provide a safer and more convenient alternative to warfarin, which requires consistent monitoring and an added risk of major bleeds.
Worryingly, one in five AF diagnosed patients at a high-risk of a stroke are not currently taking anticoagulants.
The researchers warn that the study is based on data analysis with figures coming from a number of sources. They were unable to track individual patients. They also point out that the study shows an association, and cannot prove causation.
Professor Sir Nilesh Samani, Medical Director at the British Heart Foundation said: "This study demonstrates the real benefits to patients when research evidence is put into practice.
The increased use of anticoagulants in patients with AF and the fall in the expected number of strokes is a major success story but much more needs to be done.
There are still half a million people in the UK with silent AF, who have no idea theyre at risk of having a stroke.
Spotting AF can be surprisingly easy; often all it takes is a simple pulse check. A normal heart beat will feel regular, but if you find yours is irregular or random, go and see your GP. It could save your life.
The study was funded by the British heart Foundation and the Wellcome Trust.
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