Anticoagulants may increase stroke risk in over-65s with chronic kidney disease

Research from various academic institutions around London has revealed that anticoagulants may increase the risk of stroke in over-65s if they have chronic kidney disease.

This latest research, published in the British Medical Journal, assessed the association of anticoagulant use and irregular heartbeat in patients aged 65 years and older. Analysing data from the Royal College of General Practitioners database collected between January 2006 and December 2016, the team found 6977 patients who had been newly diagnosed with atrial fibrillation who also had chronic kidney disease. Out of these, 2434 were taking anticoagulants within 60 days of diagnosis.

It was found that there was an increased rate of ischaemic stroke and haemorrhage in patients with chronic kidney disease who were taking anticoagulants to treat atrial fibrillation. However, this group also demonstrated a lower rate of all-cause mortality.

“Chronic kidney disease is common among older people, and one in three people affected also have atrial fibrillation, commonly called an irregular heartbeat — and for that, they typically get prescribed blood thinners to reduce their risk of stroke. We found that in this particular group, their medication seems to do the opposite of its intended effect,” said the study’s first author, Dr Shankar Kumar (UCL Centre for Medical Imaging).

“People with chronic kidney disease tend to have numerous severe complications, including cardiovascular illnesses. As their blood clots more but they also bleed more easily, it is extremely difficult to strike a balance between different treatments,” explained senior author Professor John Camm, professor of clinical cardiology at St George’s, University of London.

“As we found a paradoxical reduced mortality rate alongside increased rates of stroke and major bleeding, this is clearly a very complex area. We strongly call for randomised controlled studies to test the clinical value and safety of anticoagulant drug therapy for people with both atrial fibrillation and chronic kidney disease,” added Kumar.

“Our work shows the power of big data in providing real world evidence to study important clinical scenarios. Until more data is available, general practitioners, nephrologists and cardiologists need to weigh up the risks and benefits of giving an anticoagulant and make a decision together with their patient,” commented co-author Professor David Goldsmith (Guy’s and St Thomas’ NHS Foundation Trust and St George’s, University of London).