P2899Stroke, thromboembolism and bleeding events in patients with atrial fibrillation according to the new EHRA valvular heart disease classification

Atrial fibrillation -Stroke prevention -General 611ponents among non-valvular atrial fibrillation (NVAF) patients prescribed NOACs or warfarin, stratified by index NOAC dosage.Methods: A retrospective observational study of NVAF patients newly initiating apixaban, dabigatran, rivaroxaban, or warfarin from 01JAN2013-30SEP2015 was conducted using CMS Medicare data and four other US commercial claims databases, covering >180 million beneficiaries annually (∼56% of US population).After propensity score matching in each database between each standard NOAC dose and warfarin (5mg BID apixaban-warfarin, 150mg BID dabigatranwarfarin, and 20mg QD rivaroxaban-warfarin), as well as each lower NOAC dose and warfarin (2.5mg BID apixaban-warfarin, 75mg BID dabigatran-warfarin, and 10 or 15mg QD rivaroxaban-warfarin), the resulting patient records were pooled.Cox models were used to estimate S/SE and MB hazard ratios (identified by inpatient claims).S/SE included ischemic stroke, hemorrhagic stroke, and SE; MB included gastrointestinal (GI) bleeding, intracranial hemorrhage (ICH), and other MB.Results: Patients initiating lower and standard NOAC doses had different baseline characteristics, such as age and renal disease.Patient data were assessed for a mean of 7-8 months.Standard-and lower-dose apixaban patients were each associated with lower rates of S/SE and MB versus warfarin.Standardand lower-dose dabigatran patients each had similar rates of S/SE compared to warfarin.Standard-dose dabigatran patients had a lower rate of MB and lowerdose dabigatran patients had a similar rate of MB versus warfarin.Standard-dose rivaroxaban patients were associated with a lower S/SE rate, and lower-dose rivaroxaban patients had a similar rate of S/SE compared to warfarin.Standardand lower-dose rivaroxaban patients were each associated with higher MB rates compared to warfarin.All doses of NOACs were associated with lower rates of ICH compared to warfarin.The hazard ratios for the S/SE, MB, and their components are shown in the figure .Conclusions: In this large observational study, apixaban was the only NOAC associated with lower rates of S/SE and MB for both doses compared to warfarin.Dose selection criteria cannot be ascertained from current data sources.Future studies of patients who were appropriately dosed should be warranted.