Reduced Doses of Direct Oral Anticoagulants in Ischemic Stroke Patients with Nonvalvular Atrial Fibrillation.

BACKGROUND

The choice of standard or reduced doses of direct oral anticoagulants (DOACs) depends on patients' age, body weight, and renal function based on package instructions. Our aim was to conduct a simulation of DOAC dose using patients' data obtained on admission.

METHODS

This retrospective study included 314 ischemic stroke patients with nonvalvular atrial fibrillation admitted to our hospital between September 2014 and February 2018. Data on age, body weight, creatinine, and creatinine clearance were collected for each subject, and simulation was conducted for the dose of each DOAC.

RESULTS

The mean age of 314 subjects was 77.2 years; those aged 75 years or older accounted for 61.5% (193 patients). It was suggested that a standard dose of rivaroxaban could be used in 67.5% of patients and that of apixaban in 65.9%. By contrast, a standard dose of dabigatran could be used in only 16.9% of patients and that of edoxaban in only 32.5%. The simulation analysis for patients aged 75 years or older showed that a standard dose of rivaroxaban could be used in 54.9% of patients and that of apixaban in 44.6%, while that of edoxaban could be used in only 19.7% of patients.

CONCLUSIONS

When DOACs are prescribed for secondary prevention of cerebral infarction in patients with nonvalvular atrial fibrillation, the rate of standard or reduced dose varies depending on the kind of DOAC. Further analysis is required to clarify whether a standard dose of one DOAC or reduced dose of another DOAC yields the best result for each patient.