Late Detection of Atrial Fibrillation after Stroke: Implications for the Secondary Prevention

Background: This study is aimed at investigating the incidence of atrial fibrillation (AF) within 5 years after an acute cerebrovascular event in AF-naive patients and its relevance for secondary prevention. Methods: The current case-control study sample included patients who had received an initial ischemic stroke diagnosis documented in the Disease Analyzer database (IQVIA), which compiles data such as risk factors, drug prescriptions, and diagnoses obtained from 1,262 general practices in Germany. Results: After the selection procedure, the stroke and non-stroke groups each included 22,774 patients. In both groups, the mean age of the population was 68.0 years (SD +/- 12 years), and the proportion of male participants was 51.1%. Within 5 years of follow-up, we calculated a higher probability for detecting AF in stroke patients than in controls (hazard ratio 4.95; 95% CI 1.93-2.09, p < 0.001). In the stroke group, AF was detected in 2,369 individuals (10.4%), whereas AF was only evident in 1,101 patients (4.8%) in the non-stroke group. In 1,741 (73.5%) patients (out of 2,369), oral anticoagulants had been prescribed after the AF diagnosis. In stroke patients, factors like diabetes mellitus and ischemic heart disease were associated with restraint in prescribing oral anticoagulants; age did not influence the decision for or against oral anticoagulants (mean age 72.9 vs. 72.7 years). Conclusion: A recent stroke is a strong preconditioning factor for detecting AF within 5 years after an acute event. The majority of these patients are treated with oral anticoagulants, regardless of their age.