DOAC plasma levels in NVAF patients were linked to acute events: low levels (Q1) doubled thromboembolic risk (OR 2.11), high levels (Q4) increased bleeding risk (OR 2.64).
Are DOAC plasma levels associated with the risk of acute thromboembolic and bleeding events in patients with non-valvular atrial fibrillation?
In DOAC-treated NVAF patients, low plasma levels are strongly associated with thromboembolic events and high levels with bleeding events, suggesting a potential clinical utility for routine monitoring.
Absolute Event Rate: 0% vs 0%
Abstract Background Direct oral anticoagulants (DOACs) are the standard treatment for preventing thromboembolic events in patients with non-valvular atrial fibrillation (NVAF). DOACs are regularly administered without the need for anti-Xa or anti-IIa plasma level monitoring. Objectives This prospective cohort study aimed to assess the association between anti-Xa or anti-IIa plasma level measurements and the occurrence of acute thromboembolic and bleeding events in DOAC-treated NVAF patients at the time of the acute events. Methods Consecutive long-term DOAC-treated NVAF patients who presented at a single European Emergency Department either for an acute thromboembolic or bleeding event (cases) or for other medical reasons (controls) were included. DOAC levels were assessed with drug-specific anti-Xa chromogenic analysis and diluted thrombin time assay, categorized into quartiles, and analyzed in relation to the type of the acute event. Results A total of 1794 NVAF patients (mean age 82 years, 49% female) who had plasma levels tested for an acute thromboembolic event (8%), bleeding event (15%), or other reasons (77%) were enrolled. NVAF patients with acute thromboembolic events had significantly lower plasma levels of DOACs compared to controls (Q1: 50% vs 26%, p0.001), while those with bleeding events had higher levels (Q4: 46% vs 23%, p0.001). Specifically, plasma levels of DOACs in the first quartile were associated with a significantly higher risk of acute thromboembolic events OR 2.11 (95% CI: 1.42-3.11; p0.001), whereas plasma levels in the fourth quartile were associated with a significantly higher risk of acute bleeding events OR 2.64 (95% CI: 1.89-3.69; p0.001). Conclusion This study highlights the significant interindividual variability in anti-IIa and anti-Xa plasma levels and their strong relationship with acute thromboembolic and bleeding events. These findings suggest that monitoring DOAC plasma levels in clinical practice could help in estimating the risk of thromboembolic and bleeding events.
Mazza et al. (Sat,) reported a other. DOAC plasma levels in NVAF patients were linked to acute events: low levels (Q1) doubled thromboembolic risk (OR 2.11), high levels (Q4) increased bleeding risk (OR 2.64).