Researchers encourage removal of gender from clinical risk scores in atrial fibrillation

19th September 2024

Gender should not play a role in decision-making for oral anticoagulation in patients with atrial fibrillation, a new study concludes.

The research, published in the European Heart Journal, indicates that removing gender from clinical risk scores could simplify the process of deciding which patients should be given blood thinning medication without compromising on accuracy.

Streamlining the risk stratification process would also contribute to equality in care, according to the study’s authors.

The researchers say the findings contribute to growing evidence to avoid consideration of the patient’s gender when offering this type of medication in atrial fibrillation management.

The findings are in line with the new 2024 European Society of Cardiology (ESC) guidelines, which were presented this month at the ESC Congress in London.

Historical data has reported higher rates of strokes in women with atrial fibrillation, but this is likely associated with other risk factors, such as older age at the time of the stroke and lower anticoagulation rates in women, and higher mortality rates in men.

More recently, gender has been considered a risk modifier. However, international guidelines vary considerably.

To understand whether female gender should play a role in the decision-making process for the prescription of anticoagulants, researchers from the University of Birmingham conducted a large observational study.

The analysis involved 78,852 patients with atrial fibrillation, 28,590 of whom were female.

All patients over the age of 75 and those with a history of a prior stroke were excluded since the use of anticoagulants is standard clinical practice in these groups, regardless of gender.

The research cohort focused on a group of patients where the need for anticoagulation medication was less clear.

Differences between men and women, including age and other health conditions were accounted for.

Using UK primary care electronic health records, the analysis showed women with atrial fibrillation had a lower a rate of death from any cause, stroke or major blood clot, combined, than men. This was mainly due to lower mortality among the women. Rates of stroke, arterial blood clots and vascular dementia did not differ between women and men during the average of five years of follow-up.

The team then examined the effectiveness of the most commonly used global stroke risk assessment tool, the CHA₂DS₂-VASc score, which is recommended by NICE.

The findings showed that the tool only modestly predicted which patients would go on to have an adverse outcome, like stroke, and when used without gender input (CHA₂DS₂-VA) the tool had slightly better precision.

Dr Asgher Champsi, clinical research fellow at the University of Birmingham and co-first author of the paper, said: ‘This research questions whether gender should be used to make decisions on the prevention of stroke, blood clots and death in patients with atrial fibrillation.

‘Removing gender from clinical risk scores could streamline risk stratification without compromising accuracy, and contribute to equality in care.’

Dipak Kotecha, Professor of cardiology at the University of Birmingham, added: ‘Healthcare professionals and patients need to be aware of the poor performance of available risk scores.

‘A personalised approach to decision-making on oral anticoagulation is critical to improve outcomes for patients with atrial fibrillation and reduce the huge burden of health and social care costs.

‘Rather than gender, this includes a broader range of factors that can lead to blood clots beyond conventional risk scores.’

A version of this article was originally published by our sister publication Nursing in Practice.

Less frequent intracranial bleeds with DOACs compared with vitamin K antagonists among renally impaired ED patients

7th October 2021

Intracranial bleeds occurred less frequently among renally impaired ED admitted patients prescribed DOACs compared with vitamin K antagonists.

Anticoagulant-associated bleeding is a common and potentially serious problem for patients. Direct oral anticoagulants (DOACs) such as apixaban, dabigatran and rivaroxaban are now being increasingly used instead of vitamin K antagonists (VKA) such as warfarin. This change is largely due to the emerging evidence indicating beneficial effects from DOACs such as a lower incidence of bleeding. For example, a 2014 meta-analysis concluded that in comparison with warfarin, DOACs were associated with significant reduction in all-cause mortality and intracranial bleeds but there was an increased incidence of gastrointestinal bleeding. An additional problem for DOACs comes from a study in elderly patients that highlighted how major bleeding episodes in those prescribed DOACs were associated with a decline in renal function based on a reduction in glomerular filtration rate (GFR).

But are there important differences in the bleeding characteristics of patients with impaired kidney function, admitted to an emergency department (ED) due to an acute haemorrhage? This was the question addressed by a team from the Department of Emergency Medicine, University Hospital, Bern, Switzerland. They performed a retrospective study over a four year period, of patients treated at the ED for an acute haemorrhage prescribed either a DOAC or VKA and with impaired kidney function, defined as a GFR < 60 ml/min. The team compared the areas affected by bleeding e.g., intracranial or gastrointestinal etc, by drug class (i.e., DOAC or VKA) and several other relevant outcomes such as the length of hospital stay and the need for intensive care unit admission.

Findings

The initial database search identified 14,684 patients though after exclusions, mainly due to no GFR data, evidence of no bleeding or irregular consultation documentation, 158 patients prescribed a DOAC and 419 VKA were included in the analysis. The overall median age of patients was 79 years (56.7% male) and the renal function of VKA patients was significantly worse compared to those prescribed DOACs (creatinine levels, 132 vs 141 DOAC vs VKA, p = 0.002). Moreover, there was a higher number of intracranial bleeds in the VKA group (22.4% vs 14.6%, VKA vs DOACs, p = 0.036), but there were no differences for other sites. The most common site for a bleed was the gastrointestinal tract (34.8% vs 28.6%, DOAC vs VKA). Although DOAC patients required a higher number of emergency endoscopies (15.8% vs 9.1%, DOAC vs VKA, p = 0.020), VKA patients required a higher number of interventions to stop the bleeding compared to DOAC (22.2% vs. 13.9%, p = 0.027).

Most patients were treated in hospital (92.4% DOAC vs 90.2% VKA, p = 0.431) and a higher proportion of VKA patients were admitted to intensive care (38.2% vs 43.4%, DOAC vs VKA). However, overall, there were no differences in the length of hospital stay.

The authors concluded that among ED admissions due to an acute haemorrhage in patients prescribed anticoagulants and with impaired renal function, those taking DOACs had a lower incidence of intracranial bleeds.

Citation

Muller M et al. Impaired kidney function at ED admission: a comparison of bleeding complications of patients with different oral anticoagulants. BMC Emerg Med 2021