CardioBoyo Warfarin
INR Monitoring & Anticoagulation Protocol
v1.1
Clinical modules
Select a pathway to begin your assessment
Clinical pathways
INR Management
Dose adjust · Trend · Follow-up
New Patient
Initiation · Starting dose
Risk Assessment
HAS-BLED · CHA₂DS₂-VASc · ORBIT
Drug Interactions
Major · Moderate · Food
Score Library
Validated clinical scores
Documentation
Clinical note · PDF export
Phase 2
Peri-procedural
Bridge · Hold · Restart
Phase 2
Resumption
Post-bleed restart
PlatformCardioBoyo Warfarin v1.1 · 2025
EcosystemCardioBoyo Platform
Session modeExpert
Clinical decision support only. All INR-based dose adjustment recommendations must be interpreted in context of the full clinical picture. This tool does not replace physician judgement or specialist consultation. Final prescribing decisions remain with the responsible clinician.
Evidence base & references
Guidelines · Studies · Consensus documents
Atrial fibrillation
■ACC/AHA/ACCP/HRS Guideline for Diagnosis and Management of Atrial Fibrillation 2023
■ESC Guidelines for Management of Atrial Fibrillation (Van Gelder et al.) 2024
■APHRS Consensus Statement on AF Management in Asian Populations 2021
Valvular heart disease
■ACC/AHA Guideline for Management of Valvular Heart Disease 2021
■ESC/EACTS Guidelines for Management of Valvular Heart Disease 2021
Antithrombotic therapy & VTE
■ACCP — Antithrombotic Therapy for VTE Disease (CHEST Guideline) 2022
■ASH Guidelines for Management of Venous Thromboembolism 2020
Warfarin initiation & dosing
■Fennerty A, et al. Flexible induction dose regimen for warfarin. BMJ 1984
■Kovacs MJ, et al. 10mg vs 5mg warfarin initiation nomogram. Ann Intern Med 2003
■Holbrook A, et al. Evidence-based management of anticoagulant therapy. Chest 2012
Asian population & pharmacogenomics
■VKORC1 -1639G>A allele prevalence in East and Southeast Asian populations — cohort studies
■AsiaAF Registry — TTR and anticoagulation outcomes in Asian AF patients
■J-RHYTHM Registry — Warfarin management in Japanese AF patients
■Lip GYH, et al. ICH risk with warfarin in Asian vs. non-Asian populations. Stroke 2017
Bleeding management
■Galli M, et al. Managing bleeds on anticoagulant therapy. EHJ Acute Cardiovascular Care 2026
■Tomaselli GF, et al. ACC Expert Consensus — Bleeding on Oral Anticoagulants. JACC 2020
■AHA/ASA Guideline for Management of Spontaneous Intracerebral Hemorrhage 2022
Risk scores
■Pisters R, et al. HAS-BLED score. Chest 2010
■Lip GYH, et al. CHA₂DS₂-VASc score. Chest 2010
■O'Brien EC, et al. ORBIT bleeding score. Eur Heart J 2015
■Lip GYH, et al. SAMe-TT₂R₂ score. Am J Med 2014
■Mehran R, et al. BARC bleeding classification. Circulation 2011
Warfarin initiation — updated evidence
■Chai-Adisaksopha C, et al. Warfarin dosing in Asian populations: systematic review and meta-analysis. Thrombosis Research 2024
■Suwanwela NC, et al. Initial warfarin dosing and INR response in Thai AF patients. Journal of Clinical Medicine 2024
■Limdi NA, Wadelius M. Pharmacogenetics of warfarin: global and Asian perspectives. Clinical Pharmacology & Therapeutics Updated
■Dager WE, et al. Warfarin initiation and dose adjustment strategies: updated review. Pharmacotherapy 2023–2024
■Zhang Y, et al. Warfarin dose requirements in chronic kidney disease. Clinical and Applied Thrombosis/Hemostasis 2024
■Witt DM, et al. Warfarin management in complex patients (elderly, HF, comorbidities). Journal of Thrombosis and Thrombolysis Updated
■Queensland Health. Warfarin Management Guideline Updated
■Garcia DA, et al. Practical management of warfarin therapy. Circulation Updated
■Fixed-dose vs loading-dose warfarin initiation and outcomes. European Journal of Clinical Pharmacology 2025
Drug interactions & quality
■Holbrook AM, et al. Systematic overview of warfarin interactions. Arch Intern Med 2005
■Steffel J, et al. EHRA Practical Guide on NOACs. Europace 2021
■Rosendaal FR, et al. TTR methodology. Thromb Haemost 1993
INR Management
Dose adjustment · Trend · Follow-up
Patient parameters
IndicationPrimary diagnosis
Asian ethnicitySensitivity modifier
Asian sensitivity flag active VKORC1 risk
Current INR
Today's INRRequired
1.02.03.05.0+
Sub-therapeuticSupra-therapeutic
Previous INROptional — trend
INR before thatOptional
Current weekly dose
Enter total weekly dose — or expand for daily breakdown
mg / week
Expand daily breakdown →
Bleeding status
Any active bleeding present?
Recommendation
INR status
Sub-therapeutic
Target: 2.0–3.0 · Current: 1.7
[ACC/AHA 2023]
New prescribed schedule
Weekly dose—
Monthly tablets (2mg)—
New Patient Initiation
Warfarin-naïve · Starting dose protocol
Patient profile
Indication
Asian / Southeast Asian ethnicityApplies Indonesian population adaptation
Age ≥70 years
Heart failure (any NYHA class)
Body weight <50kg
Hepatic impairmentCirrhosis or elevated LFTs
CKD / Renal impairmenteGFR <30 or on dialysis
Active drug potentiatore.g. amiodarone, fluconazole
Starting dose selection
Initiation protocol
Risk Assessment
HAS-BLED · CHA₂DS₂-VASc · ORBIT
Thromboembolic risk — CHA₂DS₂-VASc
Stroke risk stratification in non-valvular atrial fibrillation. Score ≥2 (male) or ≥3 (female) indicates anticoagulation is recommended. [Lip et al. Chest 2010]
Congestive heart failure / LVEF <40%+1
Hypertension (BP >140/90 or on treatment)+1
Age ≥75 years+2
Diabetes mellitus+1
Stroke / TIA / thromboembolism history+2
Vascular disease (MI, PAD, aortic plaque)+1
Age 65–74 years+1
Sex category female+1 (risk modifier)
CHA₂DS₂-VASc
0
Low risk — anticoagulation not recommended
Low risk
Bleeding risk — HAS-BLED
Annual major bleeding risk in anticoagulated patients. Score ≥3 = high risk. High HAS-BLED should prompt correction of modifiable factors — not automatic withdrawal. [Pisters et al. Chest 2010]
Hypertension (uncontrolled, SBP >160)+1
Renal dysfunctionDialysis, transplant, Cr >200 µmol/L · +1
Hepatic dysfunctionCirrhosis, elevated LFTs · +1
Stroke history+1
Bleeding history or predispositionPrior major bleed, anaemia · +1
Labile INRTTR <60% or wide fluctuation · +1
Elderly (>65 years)+1
Drugs — antiplatelets or NSAIDs+1
Alcohol use ≥8 drinks/week+1
HAS-BLED
0
Low risk — standard monitoring
Low risk
Integrated summary
Clinical risk summary
Thromboembolic riskLow (score 0)
Bleeding riskLow (score 0)
Complete both scores above to generate a clinical recommendation.
Asian population note: ICH risk on warfarin is significantly higher in Asian patients at equivalent INR levels. HAS-BLED ≥3 should prompt correction of modifiable factors — not automatic anticoagulation withdrawal. [Lip et al. Stroke 2017 · Galli et al. EHJ ACC 2026]
Drug Interactions
Warfarin · Cardiology-focused database
Check a medication
Full interaction summary
Score Library
Validated warfarin-relevant clinical scores
Documentation
Clinical note · Copy-paste · PDF export
Generated clinical note
Review and copy the clinical note below. Edit in your local EMR as needed before inclusion in the patient record.
Complete a clinical module first, then return here to generate documentation.
Documentation note: Generated by CardioBoyo Warfarin v1.1 — a clinical decision support tool. All recommendations must be verified by the responsible clinician before inclusion in the medical record.
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