P4742Evaluation of the HAS-BLED, ATRIA and ORBIT bleeding risk scores in newly diagnosed non-valvular atrial fibrillation
Authors: Bergamaschi L , Stefanizzi A , Coriano M , Paolisso P , Magnani I , Rinaldi A , Saturi G , Foa A , Pomata D , Cavazza M , Caldarera I , Pizzi C , Galie N 
Published: October 2019

Abstract

Background
Several risk scores have been proposed to assess the bleeding risk in patients with Atrial Fibrillation.

Purpose
To compare the efficacy of HAS-BLED, ATRIA and ORBIT scores to predict major bleedings in newly diagnosed non-valvular AF (NV-AF) treated with vitamin K antagonists (VKAs) or new oral anticoagulants (NOACs).

Methods
We analyzed all consecutive patients with AF at our outpatient clinic from January to December 2017. Only those with new diagnosed NV-AF starting new anticoagulant therapy were enrolled. Major hemorrhagic events were defined according to the ISTH definition in non-surgical patients.

Results
Out of the 820 patients admitted with AF, 305 were newly diagnosed with NV-AF starting oral anticoagulation. Overall, 51.3% were male with a mean age of 72.6±13.7 years. Thirty-six patients (11.8%) started VKAs whereas 269 (88.2%) patients were treated with NOACs. The median follow-up time was 10.4±3.4 months. During follow-up, 123 (32.2%) bleeding events were recorded, 21 (17,1%) in the VKA group and 102 (82,9%) in the NOAC group. Eleven (2.9%) major bleeding events occurred: 5 (45.5%) in the VKA group and 6 (54.5%) in the NOAC group.
Overall, patients with major hemorrhagic events showed a mean value of the scores significantly higher when compared to patients without such bleeding complications (HASBLED 3.4 vs 2.4 p=0.007; ATRIA 5.6 vs 2.4 p<0.001; ORBIT 3.6 vs 1.8 p<0,001). Conversely, when analyzing the VKA subgroup, only the ATRIA score was significantly higher in patients with major adverse events (7.4 vs 3.5 p<0.001; HAS-BLED: 4.4 vs 3.6 p=0.27; ORBIT 4.4 vs 2.9 p=0.13). An ATRIA score ≥4 identified patients at high risk of bleeding (29.4% vs. 0% events. respectively, p=0.04). In the NOAC group, patients with major bleeding events had higher mean values of ATRIA (4.0 vs 2.3 p=0.02) and ORBIT (2.8 vs 1.6 p=0,04) but not the HAS-BLED (2.5 vs 2.3 p=0.57) scores. Similarly, patients on NOACs with an ATRIA score ≥4 had higher rates of major bleedings (8.1% vs. 1.6% p=0,02).
Comparing the single elements of the ATRIA score, only glomerular filtration rate <30 ml/min/1.73 mq was associated with major bleedings in the VKA group (p<0.001) whereas, in the NOAC group, anemia was strongly associated with bleeding events (p=0,02). In fact, multivariate analysis in the NOAC group showed that hemoglobin level at admission was an independent predictor for major bleeding events (OR 0.41, 95% CI 0.23–0.75, P=0.003). Conversely, in the VKA group, baseline creatinine level was an independent predictor for these events (OR 12.76, 95% CI 1.6–101.7, P=0.016).

Conclusions
The ATRIA score showed the best efficacy in predicting major bleeding events. Hemoglobin and creatinine levels at admission were independent predictors for major hemorrhagic events in the NOAC and in the VKA groups, respectively. The latter finding might be helpful in stratifying the hemorrhagic risk at the beginning of treatment.