Researchers from the University of Birmingham analysed data from The Health Improvement Network (THIN) database which includes patient records from 640 general practices in the UK. They compared the frequency of stroke in patients with resolved AF, those with ongoing AF and those who never had AF.
The researchers found that between 2013 and 2016, patients with a diagnosis of resolved AF were at similar risk of stroke or TIA to patients with ongoing AF but at 60% greater risk than those without AF.
However, patients with resolved AF were only one fifth as likely as those with ongoing AF to receive anticoagulant treatment. Only 9.6% of patients were prescribed anticoagulants up to 90 days after being coded as ‘AF resolved’ and only 8.2% continued with anticoagulants 91 to 180 days after the ‘AF resolved’ date.
The clinical code ‘AF resolved’ is widely used in general practice in the UK. In 2016, 10.5% of people with AF in the UK were classed 'AF resolved', compared with less than 1% in 2000.
"One possibility as to why people whose AF has resolved continue to be at high risk of stroke is that it had not really resolved in the first instance," said Professor Tom Marshall, from the University of Birmingham’s Institute of Applied Health Research.
"AF can be present one day and absent the next, so giving someone the all-clear may be a mistake. Another possibility is that it can come back. Many people don’t know when they have this condition and it can come back without them or their doctor realising," he added.
"GPs keep a register of people with AF, this means they are reviewed regularly and are prescribed clot-preventing drugs. But if the AF seems to have resolved they are taken off the register and rarely continue their treatment. It is as if they fall off the radar," he went on to say. "We have shown they are still at high risk of stroke and should still be treated. We cannot ever safely consider atrial fibrillation to have resolved."