What is the target International Normalized Ratio (INR) range for a patient with atrial fibrillation (A-fib) and end-stage renal disease (dialysis) on warfarin?

Target INR Range for Patients with Atrial Fibrillation on Dialysis

For patients with nonvalvular atrial fibrillation who have end-stage chronic kidney disease (CKD) or are on hemodialysis with a CHA₂DS₂-VASc score of 2 or greater, warfarin with a target INR of 2.0 to 3.0 is the recommended anticoagulation strategy. 1

Anticoagulation Recommendations for A-fib Patients on Dialysis

Warfarin as First-Line Therapy

• Warfarin remains the anticoagulant of choice for patients with atrial fibrillation who are on dialysis, with a target INR of 2.0 to 3.0 1
• This recommendation is supported by Class IIa, Level of Evidence B guidance from the American College of Cardiology/American Heart Association/Heart Rhythm Society (ACC/AHA/HRS) 1
• Direct oral anticoagulants (DOACs) such as dabigatran and rivaroxaban are not recommended in patients with AF and end-stage CKD or on dialysis due to lack of evidence regarding the balance of risks and benefits (Class III: No Benefit) 1

Monitoring Requirements

• INR should be determined at least weekly during initiation of warfarin therapy 1
• Once anticoagulation is stable (INR in therapeutic range), monitoring should occur at least monthly 1
• Extended interval follow-up (beyond 4 weeks) may not be feasible for many patients on dialysis, as studies show that even previously stable patients often cannot maintain stable INRs with extended intervals 2

Special Considerations for Dialysis Patients

Stroke vs. Bleeding Risk Assessment

• Patients with end-stage renal disease on dialysis have both increased risk of thromboembolism and increased risk of bleeding 1
• The CHA₂DS₂-VASc score should still be used to assess stroke risk in these patients 1
• For patients with a CHA₂DS₂-VASc score of 2 or greater in men or 3 or greater in women who are on dialysis, warfarin anticoagulation is reasonable 1

Medication Choice Limitations

• Apixaban might be considered in some dialysis patients according to more recent guidelines (2019 update), but warfarin remains the primary recommendation with the most evidence 1
• Dabigatran, rivaroxaban, and edoxaban are specifically not recommended in dialysis patients 1

Common Pitfalls and Caveats

• Maintaining therapeutic range is challenging: Patients with AF in the US typically spend only about 55% of their time within therapeutic INR range 3
• Higher bleeding risk: Dialysis patients have an inherently higher risk of bleeding complications, making tight INR control particularly important 1
• Avoid subtherapeutic INR targets: Lower INR targets (1.5-2.0) have been associated with higher rates of thromboembolism without mortality benefit compared to standard targets (2.0-3.0) 4
• Regular reassessment: Periodic reevaluation of the need for and choice of anticoagulant therapy is recommended to reassess stroke and bleeding risks 1

Warfarin Dosing and Management

• Warfarin dosing must be individualized for each patient according to their PT/INR response 5
• For patients with mechanical heart valves, the target INR may differ (2.5-3.5), but for nonvalvular AF, the target remains 2.0-3.0 5
• Anticoagulation clinic services are associated with better INR control compared to standard community care and should be considered for dialysis patients when available 3

Remember that maintaining patients within the therapeutic INR range of 2.0-3.0 is associated with longer survival and reduced morbidity in patients with nonvalvular AF 6, making this target range particularly important despite the challenges of managing anticoagulation in dialysis patients.