Warfarin not linked to higher brain bleed risk
Older adults on warfarin are not at greater risk of brain bleeds after falls, even with high blood-thinning levels, according to new research.
The study challenges current emergency protocols that call for repeat scans and close monitoring of patients on warfarin after head injuries.
The researchers reviewed each patient’s medical history, physical exam results, blood tests and CT scans, and followed up two weeks after the injury with phone calls and chart reviews to identify any delayed brain bleeds.
They also looked at the type and severity of haemorrhages, hospital stays and survival rates.
Surprisingly, those with lower-than-recommended blood-thinning levels had the highest risk of bleeding.
Richard Shih is senior author and professor of emergency medicine at FAU Schmidt College of Medicine.
He said: “Data from our study suggest supratherapeutic INR [International Normalised Ratio] levels may not increase intracranial haemorrhage risk as much as we previously believed.
“This raises important questions about current emergency care protocols and how we monitor these patients.
Researchers at Florida Atlantic University’s Charles E. Schmidt College of Medicine analysed data from 2,686 patients aged 65 and over who were admitted to emergency departments at two Level I trauma centres in South Florida over one year.
The study compared patients who were on warfarin before their injury with those not taking any blood thinners.
Warfarin’s blood-thinning effect is measured by the International Normalised Ratio (INR). Typically, a higher INR is associated with a greater risk of bleeding.
Researchers found that around 11 per cent of all patients developed brain bleeding after a fall.
Of those not on warfarin, 6 per cent had brain bleeds, compared to about 7 per cent of patients who were taking the drug. Bleeding rates were similar between those with INR levels above and below 3.0.
However, patients with INR levels lower than the therapeutic range had the highest bleeding rates – close to 20 per cent.
Those within or slightly above the recommended range had fewer bleeds, and no brain haemorrhages occurred in patients with critically high INR levels above 5.
Shih said: “It’s critical to re-examine our approach to managing anticoagulation in older adults after head trauma to provide the safest, most effective care without unnecessary tests or hospital stays.
“It’s our hope that findings from our research will help improve patient outcomes while reducing health care costs.”
Falls are the leading cause of injury and death among older US adults, causing 38,000 deaths and 3 million emergency visits in the US in 2021.
Non-fatal falls in this age group cost the healthcare system US$80bn in 2020.
