Safety Signal Evaluation of a Risk of Syncope and Dizziness Not Related to Bleeding or Stroke in Direct Oral Anticoagulant-treated Patients.

Purpose: In clinical studies, rivaroxaban treatment has been associated with increased incidence of syncope not related to bleeding, anemia, or stroke. The study objective was to evaluate the occurrence of dizziness and/or syncope not related to bleeding, anemia, or stroke in patients treated with direct oral anticoagulants (DOACs).

Methods: A retrospective, observational, comparative study of adult patients diagnosed with atrial fibrillation and treated with DOACs was conducted using digital retrieval of medical records. Primary outcomes were an emergency department (ED) visit or hospitalization due to syncope, fall, or dizziness. Cases related to bleeding, anemia, or stroke were excluded. Separate examination of a sample of records validated the data.

Findings: Of 6467 eligible patients, 256 (4%) were hospitalized or referred to the ED due to fall, syncope, or dizziness during a mean observation period of 20.1 months. After multivariate regression analysis, statistically independent risk factors were found to be age (hazard ratio [HR] = 1.04, P < 0.0001) and benzodiazepine use (HR = 1.33, P = 0.03). No statistically significant difference was found among the different DOAC types regarding the primary outcome (apixaban and rivaroxaban HR = 0.97, P = 0.85; dabigatran and rivaroxaban HR = 1.2, P = 0.386).

Implications: The study results failed to confirm the claimed association between the use of a DOAC and syncopal symptoms unrelated to bleeding, anemia, or stroke in this relatively large Israeli patient population. Age and benzodiazepine treatment were significant independent risk factors of these events.