Women being treated for AF are less likely to be prescribed appropriate antithrombotic therapy than male patients, a Tasmanian study shows.
A retrospective study of 2090 patients (44.7% female) treated for AF at the Royal Hobart Hospital between 2011-2015 found that female patients with a high stroke risk were significantly less likely to receive guideline-recommended treatment than male patients.
In the study, 56.7% of women with a CHA2 DS2 -VA score ≥ 2 were prescribed an oral anticoaguant compared with 62.2% of men (difference P = 0.023).
Female sex was an independent negative predictor of oral anticoagulant prescribing (adjusted odds ratio = 0.83; P = 0.041).
There was no significant sex difference in oral anticoagulant use for patients with a CHA2 DS2 -VA score of 1 or 0.
However the study did find high rates of anticoagulant use in patients with low CHA2 DS2 –VA score (39.3% and 33.3% of male and female patients, respectively). It also found that antiplatelet agents were being widely used as monotherapy (34.3% of women, 33% of men) for stroke prevention despite this being contrary to the most recent stroke prevention guidelines.
Rates for thromboembolism, bleeding, and all cause mortality rates were not significantly different between male and female patients newly initiated on antithrombotic therapy.
The study investigators said the lack of specific Australian AF guidelines in the period covered by the study meant that prescribers were likely to have been following international recommendations such as the European Society of Cardiology (ESC) guidelines.
“Our research suggests that female patients with AF in the Australian health care setting may be less likely to be prescribed adequate stroke prevention,” they concluded.
They also noted that the 2018 Australian Heart Foundation AF treatment guidelines had become ‘sexless’ by removing female gender from risk stratification scores
“The introduction of CHA2 DS2 -VA stroke risk stratification by the Australian AF guidelines could potentially lead to underrecognition of the female sex as a factor that may affect stroke risk. This could further increase the sex difference in OAC prescribing,” they wrote
“Given the previous lack of Australian data assessing sex differences in the prescribing of antithrombotic therapy according to stroke risk scores, our study highlights opportunities to improve practice, particularly in female patients who may be less likely to receive OACs when they are indicated.
The findings are published in the Annals of Pharmacotherapy.