ORBIT Bleeding Risk Score for Anticoagulation in AF Patients
ORBIT (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) bleeding risk score for predicting major bleeding during anticoagulation for atrial fibrillation. Validated in over 7,400 AF patients.
Score interpretation
ORBIT 0-2 -- low bleeding risk; anticoagulate if CHA2DS2-VASc >= 2 (male) or >= 3 (female)
→ Anticoagulate: DOAC preferred over warfarin for non-valvular AF (lower intracranial bleeding with all DOACs vs warfarin); DOAC choice based on patient factors (renal function, adherence -- see doac_score); do not withhold anticoagulation for falls risk (NICE NG196: benefit usually outweighs risk unless high risk of serious head injury); PPI co-prescription if GI bleed history or NSAID use; annual ORBIT reassessment.
ORBIT 3 -- intermediate bleeding risk; anticoagulate but address modifiable factors
→ Address modifiable bleeding risk factors before or alongside anticoagulation: iron deficiency -- IV iron (NICE: Ferrinject/Monofer for non-dialysis CKD); anaemia investigation; BP control (target < 130/80 mmHg -- uncontrolled HTN is independent bleeding risk factor); avoid concomitant NSAIDs; minimise antiplatelet use (reassess indication -- aspirin for primary prevention NOT recommended with AF anticoagulation); DOAC preferred; ensure patient and family counselling on bleeding signs; OTC NSAID counselling; CrCl monitoring (3-monthly if CKD); increase monitoring frequency; haematology referral if complex anaemia.
ORBIT >= 4 -- high bleeding risk; carefully balance against stroke prevention benefit
→ Do not automatically withhold anticoagulation -- compare annual stroke risk (CHA2DS2-VASc) vs annual bleeding risk (ORBIT); if both high: anticoagulate but maximise bleeding risk reduction; haematology review for refractory anaemia or coagulation issues; GI specialist if GI bleed history; neurology if prior intracranial haemorrhage (special case: withhold for >= 4 weeks post-ICH, reassess mechanism with neurology, avoid DOACs if haemorrhagic transformation, consider warfarin with strict INR control for non-lobar ICH); LMWH bridging NOT recommended for AF; LAA occlusion (Watchman/Amulet device) consideration if high bleeding risk and anticoagulation genuinely contraindicated; interventional cardiology referral.
Interpretation bands for the ORBIT Score (Detailed). Apply clinical judgement and local guidance.
References
- O'Brien EC et al. The ORBIT bleeding score: a simple bedside score to assess bleeding risk in atrial fibrillation. Eur Heart J. 2015;36(46):3258-3264.
- NICE NG196. Atrial fibrillation: diagnosis and management. NICE. 2021.
Related
Curated clinical cross-links plus same-class fallbacks.
- Edoxaban (AF Stroke Prevention / VTE) · Direct Factor Xa Inhibitor (DOAC)
- Betrixaban (Extended VTE Prophylaxis — Medical Patients) · Oral Factor Xa Inhibitor (DOAC — Extended Duration)
- Bivalirudin (PCI Anticoagulation) · Direct Thrombin Inhibitor / PCI
- Vernakalant · Atrial-selective antiarrhythmic
- Aspirin (Loading Dose) · Antiplatelet — ACS / Ischaemic Stroke
- Alteplase (tPA) · Thrombolytic — Ischaemic Stroke / Massive PE
- Acute Heart Failure · ESC 2021 Heart Failure Guidelines; NICE NG106
- NSTEMI / Unstable Angina · ESC 2020 NSTEMI Guidelines; NICE NG185
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
- Ventricular Tachycardia / Fibrillation · Resuscitation Council UK ACLS; ESC 2022 Ventricular Arrhythmia Guidelines
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.