Clot risk could be halved for patients with heart disease and arrhythmia by using a certain type of blood thinner.
This is according to a new study.
Researchers at the Perelman School of Medicine discovered that “A difference in the effectiveness against strokes and other blood clots was easily visible.”
This was in the first year among patients who were prescribed the anticoagulant apixaban rather than its rival, rivaroxaban.
In this “emulated’ clinical trial, researchers analysed comparisons between matched patients in a large health insurance database.
All patients analysed were individuals who were known to have atrial fibrillation (AF) and associated valvular heart disease (VHD).
They also took one for of an anticoagulant, more commonly known as blood thinners, in order to slow down the formation of new blood clots and help avoid existing clot from growing larger and potentially more dangerous.
The study found that patients taking apixaban had their dangerous clot risk almost halved in comparison to those taking rivaroxaban.
Statistics show that at least several million Americans are diagnosed with AF, which is a type of irregular heartbeat that leads to blood clots in the heart, it is also thought that more than 60 per cent of these patients have associated VHD, which also means they essentially have significant heart valve damage.
Stroke risk is heavily increased in those with AF compared to those without, furthermore, VHD is suspected of adding to the risk of stroke or death.
To this date, apixaban and rivaroxaban are the most prescribed anticoagulants for reducing stroke risk in AF/VHD patients. Some traditional blood thinners can be affected by a patient’s diet, however, apixaban and rivaroxaban do not, thus making them easier to manage.
However, until this study there was no clinical trials which compared the two directly in patient population.
First author of the study, Ghadeer Dawwas says: “The lack of clinical trial evidence and wide use of both drugs in patients with AF and VHD calls for real-world evidence that can guide treatment selection in clinical practice.”
Close to 10,000 patients who had recently began their course of apixaban were compared with 10,000 patients who just had begun taking rivaroxaban.
This study was not of the clinical trial type, where patients are randomly assigned to different groups to minimise differences between them.
Instead, the researchers emulated a clinical trial by assigning each patient in the apixaban group to one in the rivaroxaban group, who was of similar age and other outcome affecting characteristics.
The patient records used in this study came from a large commercial health insurance database with de-identified data from 2013 to 2020.
The number of strokes, as well as blood clots in the body other than the brain in the patients seen over the span of several years after they began taking the medication suggests that patients in the apixaban group had a 43 per cent lower clot risk.
They also had a 49 per cent lower risk of a gastrointestinal or intracranial bleeding event.
Study senior author, Sean Hennessy, says: “Until evidence from randomised controlled trials becomes available, we believe clinicians should consider our findings when selecting anticoagulants in patients with AF and VHD.”
The analysis of this study shows that the numbers of patients who had strokes or systemic emboli in each group diverged almost immediately.
Patients in the rivaroxaban group had markedly more of these events at six months and twelve months of follow up.
The researchers calculated that the rate of stroke per patient per year of follow-up was about one per cent for rivaroxaban users and roughly half of that for apixaban users.
Likewise, the rate of bleeding events in the rivaroxaban group was about double that in the apixaban group.
The results suggest overall that in comparison to the rivaroxaban group, the apixaban group had 43 per cent lower risk of stroke and 49 per cent the risk of a bleeding event compared to rivaroxaban.
