Efficacy and safety of direct oral anticoagulants in patients with atrial fibrillation and chronic kidney disease

Meta-analysis evaluating apixaban in patients with atrial fibrillation and end-stage renal disease requiring dialysis

BACKGROUND

Warfarin is considered the primary oral anticoagulant for patients with atrial fibrillation and end-stage renal disease (ESRD) requiring dialysis. Although warfarin can offer significant stroke prevention in this population, the accompanying major bleeding risks make warfarin nearly prohibitive. Apixaban was shown to be superior to warfarin in preventing stroke or systemic embolism, with a lower risk of bleeding and mortality in a large, randomized trial of individuals with mostly normal renal function but none with ESRD.

METHODS

We systematically reviewed evidence comparing apixaban versus warfarin for atrial fibrillation in this population, and evaluated outcomes of stroke or systemic embolism, and major bleeding using random-effects models. The main safety outcome was major bleeding, and the main effectiveness outcome was stroke or systemic embolism.

RESULTS

We found five observational studies of 10 036 patients (2638 receiving apixaban, and 7398 receiving warfarin) meeting inclusion criteria. Pooled analysis demonstrated a significant reduction in major bleeding with apixaban as compared to warfarin (odds ratio [OR] 0.51, 95% confidence interval [CI] 0.42-0.61; p < .0001). Apixaban was also associated with a reduction in intracranial bleeding (OR 0.58, 95% CI 0.37-0.92; p = .02) and in gastrointestinal bleeding (OR 0.61, 95% CI 0.51-0.73; p < .0001). Furthermore, apixaban was associated with a reduction in stroke/systemic embolism (OR 0.64, 95% CI 0.50-0.82; p < .0001).

CONCLUSION

Apixaban was associated with superior outcomes and reduced adverse events compared to warfarin in observational studies of patients with atrial fibrillation on dialysis. Randomized controlled studies are needed to confirm these findings.

Atrial fibrillation and Alzheimer's disease: A conundrum

During ageing, the prevalence of Alzheimer's disease (AD) and of cardiovascular disease CVD) increases. Our aim is to investigate the relationship between AD and CVD and its risk factors, with a view to explaining the underlying mechanisms of this association. This review is based on the material obtained via MEDLINE (PubMed), Embase and Clinical Trials databases, from January 1980 until May 2019. The search term used was "Alzheimer's disease", combined with "cardiovascular disease", "hypertension", "dyslipidaemia", "diabetes mellitus", "atrial fibrillation", "coronary artery disease", "heart valve disease", "heart failure". Out of the 1328 papers initially retrieved, 431 duplicates and 216 records in languages other than English were removed; thus, only 98 papers were included in our research material. We have found that AD and CVD are frequently associated, while both of them, alone may be considered deleterious to health, the study of their combination constitutes a clinical challenge. Further research will help to clarify the real impact of CVD and its risk factors on AD, in order to better comprehend the effects of subclinical and clinical cardiovascular diseases on the brain. It may be hypothesized that there are various mechanisms underlying the association between AD and CVD, the main ones being: hypoperfusion and emboli, atherosclerosis, furthermore in both the heart and brain of AD patients, amyloid deposits may be present, thus causing damage to these organs. We need to clarify the real impact of these underlying hypothesized mechanisms and to investigate gender issues.

Effect of Rivaroxaban or Apixaban in Atrial Fibrillation Patients with Stage 4-5 Chronic Kidney Disease or on Dialysis

BACKGROUND

Anticoagulant treatment in non-valvular atrial fibrillation (AF) patients with severe chronic kidney disease (CKD) or on dialysis remains a matter of debate. The object of this study was to quantify the benefit-risk profiles of rivaroxaban or apixaban versus warfarin in AF patients with stage 4-5 CKD or on dialysis.

METHOD

A comprehensive search of the Cochrane Library, PubMed, Ovid, and Google Scholar databases was performed for eligible studies that comparing the effect and safety of rivaroxaban or apixaban versus warfarin in AF patients with stage 4-5 CKD or on dialysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were abstracted, and then pooled using a random-effects model.

RESULTS

A total of seven studies, one post hoc analysis of RCT and six observational cohorts, were included in this meta-analysis. Compared with warfarin use, the use of rivaroxaban or apixaban was significantly associated with reduced risks of all-cause death (HR = 0.82, 95% CI 0.72-0.93) and gastrointestinal bleeding (HR = 0.87, 95% CI 0.80-0.95). There were no significant differences in the risks of stroke or systemic embolism (rivaroxaban, HR = 0.71, 95% CI 0.43-1.19; apixaban, HR = 0.86, 95%CI 0.68-1.09) and major bleeding (rivaroxaban, HR = 0.96, 95% CI 0.64-1.45; apixaban, HR = 0.56, 95%CI 0.28-1.12).

CONCLUSIONS

Current evidence suggests that rivaroxaban or apixaban are safe and at least as effective as warfarin in patients with AF and stage 4-5 CKD or on dialysis.

Clinical factors associated with safety and efficacy in patients receiving direct oral anticoagulants for non-valvular atrial fibrillation

Although patients suffering from atrial fibrillation have increased worldwide, detailed information about factors associated with bleeding during direct oral anticoagulant therapy remains insufficient. We studied 1086 patients for whom direct oral anticoagulants were initiated for non-valvular atrial fibrillation between April 2011 and June 2017. Endpoints were clinically relevant bleeding or major adverse cardiac and cerebrovascular events until the end of December 2018. Incidences of bleeding and thrombosis were 4.5 per 100 person-years and 4.7 per 100 person-years, respectively. Most bleeding events represented gastrointestinal bleeding. Multivariate analysis revealed initiation of anticoagulants at ≥ 85 years old as significantly associated with bleeding, particularly gastrointestinal bleeding, but not major cardiac and cerebrovascular events. Other significant factors included chronic kidney disease, low-dose aspirin and nonsteroidal anti-inflammatory drugs. For gastrointestinal bleeding alone, histories of gastrointestinal bleeding and malignancy also showed positive correlations, in addition to the above-mentioned factors. Clinicians should pay greater attention to the risk of gastrointestinal bleeding when considering prescription of anticoagulants to patients ≥ 85 years old with atrial fibrillation.

Direct-Acting Oral Anticoagulants Versus Warfarin in Medicare Patients With Chronic Kidney Disease and Atrial Fibrillation

Background and Purpose:

The comparative effectiveness of direct-acting oral anticoagulants, compared with warfarin, for risks of stroke/systemic embolism, major bleeding, or death have not been studied in Medicare beneficiaries with atrial fibrillation and nondialysis-dependent chronic kidney disease.

Methods:

Medicare data from 2011 to 2017 were used to identify patients with stages 3, 4, or 5 chronic kidney disease and new atrial fibrillation who received a new prescription for warfarin, apixaban, rivaroxaban, or dabigatran. We estimated marginal hazard ratios with 95% CIs for the association of each direct-acting oral anticoagulant, compared with warfarin, for the outcomes of interest using inverse-probability-of-treatment weighted Cox proportional hazards models in as-treated and intention-to-treat analyses.

Results:

A total of 22 739 individuals met criteria (46.3% warfarin, 29.6% apixaban, 17.2% rivaroxaban, 6.9% dabigatran). Across the groups of anticoagulant users, mean age was 78.4 to 79.0 years; 50.3% to 51.4% were women, and 80.3% to 82.8% had stage 3 chronic kidney disease. In the as-treated analysis, for stroke/systemic embolism, hazard ratios, all compared with warfarin, were 0.70 (0.51–0.96) for apixaban, 0.80 (0.54–1.17) for rivaroxaban, and 1.15 (0.69–1.94) for dabigatran. For major bleeding, analogous hazard ratios were 0.47 (0.37–0.59) for apixaban, 1.05 (0.85–1.30) for rivaroxaban, and 0.95 (0.70–1.31) for dabigatran. There was no difference in the risk of all-cause mortality between the direct-acting oral anticoagulants and warfarin. Results of the intention-to-treat analysis were similar.

Conclusions:

Apixaban, compared with warfarin, was associated with decreased risk of stroke/systemic embolism and major bleeding; risks for both outcomes with rivaroxaban and dabigatran did not differ from risks with warfarin.