Abstract
Rivaroxaban has no specific monitoring index, such as the PT-INR for warfarin. Thus, we investigated whether PT and renal function were useful monitoring indices for rivaroxaban.
Patients taking rivaroxaban (10 mg) when they were admitted to the Sapporo Medical University Hospital from November 1, 2013 to April 30, 2018 were included in this study. The primary outcomes were the presence or absence of bleeding, PT, creatinine clearance (CCr), and estimated glomerular filtration rate cystatin C (eGFRcys). Forty patients were included (mean age 71.5 ± 8.1 years) and 14 were women. A positive result for fecal occult blood test was indicative of bleeding. Nine patients exhibited bleeding and were placed in the bleeding group, in which the PT was significantly longer (17.0 ± 2.1 s vs 15.3 ± 1.9 s; p = 0.031) and renal function was lower (CCr: 44.6 ± 15.7 mL/min vs 59.5 ± 20.1 mL/min, p = 0.047; eGFRcys: 39.4 ± 12.6 mL/min vs 57.6 ± 18.5 mL/min, p = 0.009) than those in the non-bleeding group. We investigated cut-off values of bleeding using a receiver operating characteristic analysis. The values were as follows: PT 16.1 s (sensitivity: 77.8%, specificity: 61.3%), CCr 42.1 mL/min (sensitivity: 66.7%, specificity: 77.4%), and eGFRcys 46.1 mL/min (sensitivity: 77.8%, specificity: 74.2%). These results suggested that not only CCr, but also PT and eGFRcys could be used as monitoring indices in patients administered rivaroxaban.
