Germany: In a new study published in the Journal of Thrombosis and Haemostasis it has been revealed that monitoring direct oral anticoagulant (DOAC) plasma levels may aid in identifying individuals at high risk of stroke recurrence and should be explored for select subgroups, including those with a high glomerular filtration rate (GFR).
Despite the recommended use of direct oral anticoagulants, patients with atrial fibrillation have a significant risk of ischemic stroke. In clinical studies, the risk corresponds with functional DOAC plasma levels, but the usefulness of measuring them in community usage is unknown. As a result, Gabriela Siedler and colleagues carried out this investigation to evaluate the clinical consequences and prognostic usefulness of DOAC plasma level monitoring during a steady state.

Between 2016 and 2020, 397 people taking oral anticoagulants for secondary stroke prevention were enrolled in this observational clinical cohort research of patients with ischemic stroke and atrial fibrillation. During steady-state, the functional DOAC plasma levels were assessed. The key outcome indicator was early stroke recurrence within 3 months.
The key findings of this study were as follows:
1. Three hundred ninety-seven patients were included (201 females, mean age 78 [9] years, median CHA2DS2VASc-Score 6).
2. DOAC plasma trough level was 95.9 (66.9) ng/ml on average.
3. In a multivariate model, a high glomerular filtration rate was an independent predictor of lower levels (R coefficient: 0.174).
4. Despite the use of DOAC, 10 patients (3%) experienced early ischemic stroke recurrence during follow-up, and 10 clinically meaningful bleeding problems occurred (3% ).
5. After propensity score matching, ischemic stroke recurrence was linked with numerically reduced plasma levels in individuals on apixaban and dabigatran.
In conclusion, this investigation lacked the capacity to detect statistically significant differences between the single drugs. Larger, multi-center investigations should be launched to confirm the findings and study the substance-specific relationship. Furthermore, because no cerebral follow-up imaging was performed in this investigation, subclinical infarction was not observed.
Reference:
Siedler, G., Macha, K., Stoll, S., Plechschmidt, J., Wang, R., Gerner, S. T., Strasser, E., Schwab, S., & Kallmünzer, B. (2022). Monitoring of direct oral anticoagulants plasma levels for secondary stroke prevention. In Journal of Thrombosis and Haemostasis. Wiley. https://doi.org/10.1111/jth.15677