New Anticoagulants May Be More Effective Than Warfarin

Warfarin may increase bleeding risk more than non-vitamin K antagonist oral anticoagulants.

New anticoagulants may cause less intracranial bleeding than the standard treatment, while providing the same amount of stroke prevention.

Stroke prevention is especially important for patients with atrial fibrillation, because it can cause adverse effects for the patient, and are quite costly. A recent study found that the annual stroke-related costs for health plans among these patients is approximately $4,930,787.

Preventing these costs are beneficial for both the patient and the payer.

In a study presented at the European Society of Cardiology, investigators compared the risk of stroke and intracranial bleeding among 43,299 patients with atrial fibrillation.

"Atrial fibrillation is the most common cardiac rhythm disorder and currently affects more than 10 million Europeans," said researcher Laila Staerk, MD. “Atrial fibrillation is associated with a 5-fold risk of stroke, potentially leading to disability and death. In the next 4 decades, the number of patients with atrial fibrillation is expected to triple so the number of Europeans diagnosed could rise to a staggering 25 to 30 million."

Patients with atrial fibrillation are treated with oral anticoagulants to reduce stroke risk, but treatment options increase bleeding, specifically intracranial bleeding. The current study examined the risks associated with the 2 treatments: non-vitamin K antagonist oral anticoagulants (NOACs) and vitamin K antagonists (warfarin).

Patients included in the study were treated with NOACs (dabigatran, rivaroxaban, or apixaban) or warfarin. Approximately 42% of the patients were taking warfarin and 29% were taking dabigatran. Another 16% and 13% were taking apixaban and rivaroxaban, respectively.

Investigators discovered that 1054 patients had a stroke, and there were 261 intracranial bleeds during the study.

They also found that the stroke risk within a year was similar among all treatment groups. However, the intracranial bleeding risk was significantly lower in patients treated with dabigatran (0.3%) and apixaban (0.4%), compared with patients treated with warfarin (0.6%), according to the study.

These findings suggest that both drugs provide a similar reduction in stroke risk, but NOACs may provide more beneficial outcomes regarding bleeding.

“Our results complement the large randomized phase III trials by providing 'real world' data on stroke and intracranial bleeding with NOACs versus warfarin since fragile patients were not excluded from our nationwide cohort. For example, patients with increased risk of bleeding, liver disease, and chronic kidney disease are less represented in trials,” Dr Staerk concluded. “In the future it would be exciting to see a head-to-head randomized trial performed to compare the different NOAC treatments in patients with atrial fibrillation.”