Persistence with VKA treatment in newly treated atrial fibrillation patients: an analysis based on a large sample of 38,076 German patients

Abstract

Purpose The aim of this study was to describe persistence with vitamin K antagonist (VKA) treatment in German atrial fibrillation (AF) patients and to identify factors which may be associated with early discontinuation of VKA therapy. Methods We did a retrospective cohort study based on an anonymized German claims dataset with VKA treatment-naïve AF patients, who received at least one VKA prescription. VKA therapy discontinuation was defined as a gap >180 days. Results We identified 38,076 VKA patients who started a VKA therapy (mean age 76.13 years; 56.08% female; mean CHA₂DS₂-VASc-Score 4.49; mean Charlson Comorbidity Index (CCI) 3.91). After four quarters since start of VKA treatment, 14,889 (39.10%) of observed patients had discontinued their VKA treatment (after eight quarters: 54.61%). Mean time until treatment discontinuation was 390.55 days. Risk of VKA discontinuation increased with the diagnosis of dementia within the first two quarters of VKA treatment [HR 1.35 (95% CI 1.29–1.40)], diagnosed alcohol or drug abuse in the baseline period [HR 1.25; 95% CI 1.18–1.33)], female gender [HR 1.08; 95% CI 1.05–1.10)], higher age (HR 1.03; 95% CI 1.03–1.03), higher CCI (HR 1.05; 95% CI 1.04–1.05), any prescription of NSAID (HR 1.07; 95% CI 1.04–1.10), and number of surgeries in the first two quarters of VKA treatment (HR 1.05; 95% CI 1.04–1.05). At least one yearly visit to a cardiologist since start of VKA treatment decreased the risk of non-persistence [HR 0.90; 95% CI 0.88–0.93] and a cancer diagnosis in the baseline period (HR 0.92; 95% CI 0.89–0.96). Conclusion Non-persistence related to VKA therapy is common in AF patients. Older more comorbid female patients as well as patients who face surgeries and who do not visit a cardiologist regularly face a higher therapy discontinuation risk.