What is the clinical evidence from this study?

Study design: Cohort. Population: End-Stage Kidney Disease and Atrial Fibrillation (n=2198). Intervention: Oral anticoagulants vs. No oral anticoagulants. Primary outcome: All-cause death (HR 0.71, 95% CI 0.58-0.86, p=<0.001).

February 14, 2023Open Access

Survival Benefit of Anticoagulation in Patients with End-Stage Kidney Disease and Atrial Fibrillation: A National Population-Based Study

Key Result

In patients with end-stage kidney disease and atrial fibrillation, oral anticoagulant use was associated with a 29% lower risk of all-cause death (HR 0.71) compared to no anticoagulation.

Study Design

Type

Cohort (n=2,198)

Structured PICO

Does oral anticoagulant therapy reduce all-cause death and cardiovascular events in patients with end-stage kidney disease and atrial fibrillation?

Population

2,248 matched patients with end-stage kidney disease (ESKD) and atrial fibrillation (AF) with a CHA2DS2-VASc score of ≥ 1 (men) or ≥ 2 (women), mean age 69.3, 58% male, South Korean national cohort.

Intervention

Oral anticoagulants (OACs, including direct oral anticoagulants and warfarin) initiated within 6 months of AF diagnosis with a medication possession ratio >80%.

Comparator

No oral anticoagulant therapy (matched 1:3 using propensity scores for age, sex, CHA2DS2-VASc score, Charlson Comorbidity Index, time from ESKD to AF, and medications).

Outcome

All-cause deathhard clinical

In patients with end-stage kidney disease and atrial fibrillation, direct oral anticoagulants are associated with reduced risks of all-cause death, ischemic stroke, and MACE without increasing severe bleeding, whereas warfarin increases bleeding risk without these benefits.

Main Result

Effect estimate: HR 0.71 (95% CI 0.58-0.86)

Absolute Event Rate: 24.4% vs 32.5%

p-value: p=<0.001

Limitations

Limited information in the claims database, such as lack of laboratory results or OAC dose
Inability to completely eliminate selection bias due to the retrospective observational design
Diagnoses of cardiovascular and cerebrovascular disease were established through operational definitions, which may have led to misdiagnosis

Abstract

Abstract Background The prevalence of atrial fibrillation (AF) in patients with end-stage kidney disease (ESKD) is high and increasing; however, current evidence is insufficient and conflicting regarding oral anticoagulant (OAC) use in patients with ESKD and AF. Methods A retrospective cohort study of patients diagnosed with AF after ESKD from January 2007 to December 2017 was conducted using the Korea National Health Insurance System Database. The primary outcome was all-cause death. Secondary outcomes were ischemic stroke, severe bleeding, and major adverse cardiovascular event (MACE). Outcomes were compared between OAC user and nonuser groups using landmark analysis (6 months after AF diagnosis) and 1:3 propensity score matching. Results Among patients diagnosed with AF after ESKD, the number of patients prescribed any OAC increased 2.3-fold from 2012 (n=3,579) to 2018 (n=8,341), and the proportion prescribed direct OACs (among those prescribed any OAC) increased steadily from 0% in 2012 to 51.4% in 2018. Matched cohort analysis showed that compared with OAC nonusers, OAC users had a lower risk of all-cause death (hazard ratio HR 0.71; 95% confidence interval CI 0.58–86), ischemic stroke (HR 0.63; 95% CI 0.43–92), and MACE (HR 0.76; 95% CI 0.59–0.98) but no increased risk of severe bleeding (HR 1.58; 95% CI 0.99–2.52). Subgroup analysis according to type of OAC revealed that patients receiving direct OACs had a significantly lower risk of all-cause death (HR 0.44; 95% CI 0.28–0.69), ischemic stroke (HR 0.36; 95% CI 0.13–0.99), and MACE (HR 0.42; 95% CI 0.22–0.79) than OAC nonusers but no increased risk of severe bleeding (HR 0.26; 95% CI 0.04–1.90). Conversely, warfarin use was not associated with all-cause death (HR 0.98; 95% CI 0.79–1.21), ischemic stroke (HR 0.78; 95% CI 0.51–1.19), or MACE (HR 1.03; 95% CI 0.79–1.36) but was associated with a higher risk of severe bleeding (HR 2.43; 95% CI 1.50–3.93). Conclusions In patients with ESKD and AF, OACs were associated with reduced all-cause death, ischemic stroke, and MACE risks but no increased risk of severe bleeding. Direct OACs were preferable to warfarin with regard to efficacy and safety. Clinical Perspective What is new? Outcomes of oral anticoagulation in patients with end-stage kidney disease and atrial fibrillation are currently unknown. In this nationwide cohort study of patients with end-stage kidney disease and atrial fibrillation who had a CHA 2 DS 2 -VASc score of ≥ 1 (men) or ≥ 2 (women), oral anticoagulant therapy was associated with lower risks of all-cause death, stroke, and major adverse cardiovascular event but was no difference in severe bleeding, compared with no anticoagulation. When analyzing types of anticoagulants, these reduced risks were found in patients receiving direct oral anticoagulants but not warfarin. What are the clinical implications? Anticoagulation therapy may be superior to no anticoagulation in patients with end-stage kidney disease and atrial fibrillation. These findings require confirmation in randomized trials.

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