Rivaroxaban plasma levels in acute ischemic stroke and intracerebral hemorrhage

OBJECTIVE: Information about Rivaroxaban plasma levels (RivLev) may guide treatment decisions in patients with acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH) taking rivaroxaban. METHODS: In a multicenter registry-based study (Novel-Oral-Anticoagulants-In-Stroke-Patients collaboration;NOACISP;ClinicalTrials.gov:NCT02353585) of patients with stroke while taking rivaroxaban, we compared RivLev in patients with AIS and ICH. We determined how many AIS-patients had RivLev≤100ng/ml, indicating possible eligibility for thrombolysis and how many ICH-patients had RivLev≥75ng/ml, possibly eligible for the use of specific reversal agents. We explored factors associated with RivLev (Spearman correlation; regression models) and studied the sensitivity and specificity of INR-thresholds to substitute RivLevs using cross tables and ROC curves. RESULTS: Among 241 patients (median age 80 years[IQR73-84], median time-from-onset-to-admission 2 hours[IQR1-4.5hours], median RivLev 89ng/ml[31-194]), 190 had AIS and 51 had ICH. RivLev were similar in AIS-patients (82ng/ml[IQR30-202] and ICH-patients (102ng/ml[IQR 51-165]; p=0.24). Trough RivLev(≤137ng/ml) occurred in 126/190 (66.3%) AIS- and 34/51 (66.7%) ICH-patients. Among AIS-patients, 108/190 (56.8%) had RivLev≤100ng/ml. In ICH-patients 33/51(64.7%) had RivLev≥75ng/ml. RivLev were associated with rivaroxaban dosage, inversely with renal function and time-since-last-intake (each p