Information about Rivaroxaban plasma levels (RivLev) may guide treatment decisions in patients with acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH) taking rivaroxaban.
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.
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<.05). INR≤1.0 had a specificity of 98.9% and a sensitivity of 25.7% to predict RivLev≤100ng/ml. INR≥1.4 had a sensitivity of 59.3% and specificity of 90.1% to predict RivLev≥75ng/ml.
RivLev did not differ between patients with AIS and ICH. Half of the patients with AIS under Rivaroxaban had RivLev low enough to consider thrombolysis. In ICH-patients, 2/3 had RivLev high enough to meet the eligibility for the use of a specific reversal agent. INR-thresholds perform poor to inform treatment decisions in individual patients. This article is protected by copyright. All rights reserved.