Safety and Efficacy of Direct Oral Anticoagulants for Atrial Fibrillation in Patients with Renal Impairment

Direct oral anticoagulant use in special populations

PURPOSE OF REVIEW

The pivotal phase III trials demonstrating efficacy and safety of direct oral anticoagulants (DOACs) in the treatment of venous thromboembolism (VTE) or nonvalvular atrial fibrillation (NVAF) excluded patients with important and common comorbidities, including obesity, advanced chronic kidney disease, cirrhosis, cancer and antiphospholipid antibody syndrome. Despite the lack of large prospective randomized control trials in these patient populations, the use of DOACs has led to a wealth of efficacy and safety data within these groups.

RECENT FINDINGS

Retrospective studies, meta-analyses, national databases and pharmacokinetic data have shed light on the efficacy and safety of DOACs in these patient populations. Although DOACs should be avoided in those with high-risk triple positive antiphospholipid antibody syndrome, advanced cirrhosis, advanced kidney disease and intact gastrointestinal cancers, and used with caution in genitourinary cancers, their use extends beyond the inclusion criteria of the initial randomized control trials.

SUMMARY

DOACs have revolutionized anticoagulant management and have become the cornerstone for VTE treatment and stroke prevention in NVAF. The decision to use DOACs must be individualized. Patient preference, underlying comorbidities and informed consent must always be considered when selecting the most appropriate anticoagulant.

Oral Anticoagulant Agents in Patients With Atrial Fibrillation and CKD: A Systematic Review and Pairwise Network Meta-analysis

OBJECTIVE

To evaluate the relative efficacy and safety of different oral anticoagulant agents (OACs) for patients with atrial fibrillation (AF) and chronic kidney disease (CKD).

STUDY DESIGN

Systematic review and pairwise and Bayesian network meta-analysis.

SETTING & STUDY POPULATIONS

Adult patients with AF and CKD stages 3-5D who received OACs.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials (RCTs) and observational studies that reported the efficacy and safety outcomes of subgroups with a glomerular filtration rate (GFR)<60mL/min.

DATA EXTRACTION

Two reviewers independently abstracted data, assessed study quality, and rated the strength of evidence (SOE).

ANALYTICAL APPROACH

Random-effects models using restricted maximum-likelihood methods were fit for the pairwise meta-analyses as well as a network meta-analysis within a Bayesian framework.

RESULTS

Pairwise meta-analysis including 8 RCTs and 46 observational studies showed that direct OACs (DOACs) were superior to warfarin in preventing thromboembolic events (hazard ratio [HR], 0.86 [95% CI, 0.78-0.95]), without heterogeneity (I²=10.5%), and in reducing the risk of bleeding events (HR, 0.81 [95% CI, 0.66-0.99]), with substantial heterogeneity (I²=69.8%), in patients with AF and a GFR of 15-60mL/min. Bayesian network meta-analysis including 8 RCTs showed that dose-adjusted apixaban and a 15-mg dose of edoxaban were superior to the other OAC regimens in reducing bleeding events. Dose-adjusted apixaban was more effective than edoxaban in preventing thromboembolic events for patients with AF and GFR in the range of 25-50 or 30-50mL/min. In dialysis recipients with AF, the use of OACs increased the risk of bleeding events by 28% (HR, 1.28 [95% CI, 1.03-1.60]) without significant beneficial effects versus not using anticoagulants.

LIMITATIONS

Low SOE and heterogeneity in most comparisons.

CONCLUSIONS

This study suggests that DOACs are superior to warfarin for the prevention of thromboembolic events and reduction in bleeding risk in patients with AF and mild to moderate kidney disease. However, the low SOE limits the conclusions that can be drawn about the preferred DOAC. Notably, the use of OACs may increase bleeding risk without significant benefits in dialysis recipients with AF.

REGISTRATION

Registered at PROSPERO with identification number CRD42018090896.

Direct Oral Anticoagulant Use in Special Populations: Elderly, Obesity, and Renal Failure

PURPOSE OF REVIEW

The purpose of this review is to examine the safety and effectiveness of direct oral anticoagulants and provide recommendations for the treatment of venous thromboembolism and atrial fibrillation in obese patients, elderly patients, and patients with chronic kidney disease.

RECENT FINDINGS

Multiple retrospective cohort studies have shown no difference in bleeding, stroke, or venous thromboembolism outcomes between DOACs and warfarin in patients who are obese, elderly, or those with chronic kidney disease or on dialysis. Some studies have shown that DOACs have a lower bleeding risk than warfarin in these populations. DOACs may be a safe and effective alternative to warfarin for the prevention of stroke in atrial fibrillation patients who are obese, elderly, or those with chronic kidney disease or on dialysis. Apixaban may improve clinical outcomes by lowering the risk of bleeding versus warfarin. DOACs may also be an effective and safe alternative to warfarin for the treatment of venous thromboembolism in obese patients; however, additional studies are needed to assess their use in elderly patients and those with CKD.