Dosing of Direct Oral Anticoagulants in Patients with Moderate Chronic Kidney Disease in US Clinical Practice: Results from the Outcomes Registry for Better Informed Treatment of AF (ORBIT-AF II).

Introduction: Direct oral anticoagulants (DOACs) have partial renal clearance and generally require dosage adjustments based on renal function. While current US and European guidance recommends dose adjustments in patients with moderate chronic kidney disease (CKD), it is unclear how often this is done appropriately in routine clinical practice.

Methods: We examined rates of appropriate and inappropriate dosing in patients with atrial fibrillation (AF) and moderate CKD, as determined by creatinine clearance (CrCl) of 30-50 mL/min calculated with the Cockcroft-Gault formula. Descriptive statistics were used to describe the rate of appropriate and inappropriate dosing as well as event rates.

Results: Among 1134 patients (8.5% of the overall ORBIT-AF II registry) with AF and CrCl 30-50 mL/min, the median age was 82 (25th, 75th percentile: 78, 86), 38% were male, and the median CHADSVASC score was 4 (25th, 75th percentile: 4, 5). At baseline, more than one-third (34%) of patients with moderate CKD were inappropriately dosed with DOACs. When evaluating the specific prescribed doses in those with moderate CKD, 15% (N = 170/1134) were underdosed, 66% (743/1134) were appropriately dosed, and 20% (N = 221/1134) were overdosed. There were no significant differences in comorbid medical conditions between patients with moderate CKD who were appropriately and inappropriately dosed with a DOAC.

Conclusion: In routine clinical practice, prescribing of DOACs in patients with AF with moderate CKD is often inconsistent with drug labeling, with up to one-third of patients being inappropriately dosed.