Relationship between time in therapeutic range and comparative treatment effect of rivaroxaban and warfarin: Results from the ROCKET AF trial

J.P. Piccini, A.S. Hellkamp, Y. Lokhnygina, M. Patel, F.E. Harrell, D.E. Singer, R.C. Becker, G.U. Breithardt, J.L. Halperin, Graeme J. Hankey, S.D. Berkowitz, C.C. Nessel, K.W. Mahaffey, K.A.A. Fox, R.M. Califf

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    Background: Time in therapeutic range (TTR) is a standard quality measure of the use of warfarin. We assessed the relative effects of rivaroxaban versus warfarin at the level of trial center TTR (cTTR) since such analysis preserves randomized comparisons. Methods and Results: TTR was calculated using the Rosendaal method, without exclusion of international normalized ratio (INR) values performed during warfarin initiation. Measurements during warfarin interruptions >7 days were excluded. INRs were performed via standardized finger-stick point-of-care devices at least every 4 weeks. The primary efficacy endpoint (stroke or noncentral nervous system embolism) was examined by quartiles of cTTR and by cTTR as a continuous function. Centers with the highest cTTRs by quartile had lower-risk patients as reflected by lower CHADS2 scores (P
    Original languageEnglish
    Article numbere000521
    JournalJournal of the American Heart Association
    Issue number2
    Publication statusPublished - Apr 2014


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