Impaired kidney function (OR 2.22; 95% CI 1.30-3.78) and concomitant amiodarone intake (OR 1.97) were significantly associated with residual rivaroxaban plasma concentrations >50 mcg/L at 24-48 hours.
Observational (n=368)
No
What factors are associated with higher-than-expected residual rivaroxaban plasma concentrations in real-life patients?
Impaired kidney function and concomitant amiodarone use are independently associated with higher-than-expected residual rivaroxaban plasma concentrations, suggesting standard discontinuation intervals may be insufficient before elective surgery.
Effect estimate: OR 2.22 (95% CI 1.30-3.78)
p-value: p=0.003
Introduction Rivaroxaban (RXA) is a direct oral factor Xa (Xa) antagonist with a short half-life and a fast onset and offset of effect. Before elective surgery, discontinuation is recommended with an interval of at least > 24 hours. In clinical practice, this is, however, not always sufficient to achieve a residual RXA plasma concentration deemed appropriate for surgery, defined as ≤ 50 mcg/L. Our study aimed at identifying factors associated with a higher-than-expected residual RXA plasma concentration in a large group of real-life patients. Materials and Methods This retrospective single-centre study included all patients taking RXA between 2012 and 2016 where RXA plasma concentration was determined by pharmacodynamic anti-Xa assay (518 measurements in 368 patients). Medical records were reviewed. Residual RXA plasma concentrations were then compared with expected values according to a pharmacokinetic model. Results Residual RXA plasma concentration was significantly higher-than-expected in patients with atrial fibrillation, impaired kidney function (glomerular filtration rate GFR 50 mcg/L at 24 to 48 hours after the last RXA intake. Conclusion In our group of real-life patients, impaired kidney function (GFR < 60 mL/min) and co-medication with amiodarone were independently associated with higher-than-expected residual RXA plasma concentrations. In these patients, standard intervals of RXA discontinuation may not always be sufficient before elective surgery and routine pre-operative determination of the residual RXA concentration could be advisable.
Schedler et al. (Tue,) conducted a observational in Patients taking rivaroxaban (n=368). Rivaroxaban was evaluated on Rivaroxaban plasma concentrations > 50 mcg/L at 24 to 48 hours after the last intake (associated with impaired kidney function) (OR 2.22, 95% CI 1.30-3.78, p=0.003). Impaired kidney function (OR 2.22; 95% CI 1.30-3.78) and concomitant amiodarone intake (OR 1.97) were significantly associated with residual rivaroxaban plasma concentrations >50 mcg/L at 24-48 hours.