Abstract Number: PB2086
Meeting: ISTH 2020 Congress
Background: The ESC AF guidelines recommend patients treated with vitamin-K antagonists (e.g. warfarin), have their time in therapeutic range (TTR) kept as “high as possible” e.g. ≥ 70%. The CHADS2D2Vasc risk assessment tool has replaced CHADS2 score for identifying patients with NVAF who should receive oral anticoagulation (OAC). Female sex was identified as an additional stroke risk factor. HASBLED bleeding risk score does not discriminate between sexes.
Aims: High TTR is associated with reduced stroke risk. We aimed to determine whether poor TTR (i.e. ≤ 70%) was associated with bleeding outcomes and explore potential relationships with important covariates including sex.
Methods: Patient-level, population-scale, linked, anonymised data for warfarin-treated AF patients in Wales (UK). Descriptive statistics and Cox multiple regression estimates of hazard ratio for bleeding with TTR 70% ≤ and association with sex.
Results: Total 35,036 AF patients met inclusion criteria; mean age 74 years, 43% female sex, mean CHA2DS2Vasc 3.5 (SD1.7), of whom 15,074 (43%) had TTR ≤ 70%. A total of 5,809 bleeds occurred in 5,302 patients (table 1).
Multivariate models adjusted for relevant covariates (age, sex, prior bleeding, hypertension, diabetes, heart failure, ischaemic heart disease, stroke, peripheral vascular disease (PVD), thromboembolism, liver disease, chronic kidney disease, and alcohol), showed TTR < 70% was associated with an overall increased hazard ratio of bleeding (1.45 [95%CI 1.37-1.53]) p< 0.001 with female sex associated with fewer bleeds (HR 0.84 [95%CI 0.80-0.89]) p< 0.001. These relationships were similar when considering other guideline criteria for poor INR control (e.g. UK NICE).
Conclusions: Periods of poor INR control are associated with increased bleeding event rates, independently of commonly recognised stroke and bleeding risk factors. Of note, bleeding risk is independently lower in females, emphasising the importance of exploring further the relationships between sex and site-specific bleeding risk.
|Total||2224 (38.3%)||1492 (25.7%)||601 (10.3%)||581 (10.0%)||334 (5.7%)||138 (2.4%)||439 (7.6%)|
|Male||1313 (59%)||1121 (75.1%)||332 (55.2%)||375 (64.5%)||N/A||76 (55.1%)||271 (61.7%)|
|Female||911 (41%)||371 (24.9%)||269 (44.8%)||206 (35.5%)||334 (100%)||62 (44.9%)||168 (38.3%)|
[Table 1 Bleeding events by site and sex]
To cite this abstract in AMA style:Harris D, Torabi F, Alikan R, Akbari A, Mallory D, Thayer D, Wang T, Grundy S, Lister S, Gravenor M, Halcox J. An observational Study of INR Control and Bleeding Events, According to European Society of Cardiology (ESC) Guidelines, in Non-valvular Atrial Fibrillation (NVAF) Stratified by Male and Female Sex [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/an-observational-study-of-inr-control-and-bleeding-events-according-to-european-society-of-cardiology-esc-guidelines-in-non-valvular-atrial-fibrillation-nvaf-stratified-by-male-and-female-sex/. Accessed January 28, 2022.
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