Systematic DOACs oral anticoagulation in patients with atrial fibrillation and chronic kidney disease: the nephrologist's perspective

Direct Oral Anticoagulants Exhibit Lower Risks of Mortality and Bleeding Compared to Vitamin K Antagonists in Atrial Fibrillation Patients on Chronic Hemodialysis: A Systematic Review and Meta-Analysis

This meta-analysis aimed to assess the outcomes of patients with atrial fibrillation undergoing chronic hemodialysis, comparing the effectiveness of direct oral anticoagulants (DOACs) and vitamin K antagonists. A systematic search was conducted across various databases including PubMed, Embase, and Google Scholar. Efficacy outcomes focused on the risk of stroke and mortality, whereas safety outcomes assessed the risk of bleeding. Review Manager generated forest plots for data synthesis. Statistical significance was set at P < 0.05, and random-effects models were used. Subgroup analysis identified the sources of heterogeneity. Nine studies met the inclusion criteria for the final analysis. The risk of all-cause stroke [risk ratio (RR): 0.64; 95% confidence interval (CI): 0.51-0.81; P = 0.0001; I2 = 0%], ischemic stroke (RR: 0.53; 95% CI: 0.29-0.96; P = 0.04; I2 = 0%), all-cause mortality (RR: 0.73; 95% CI: 0.60-0.88; P = 0.001; I2 = 71%), major bleeding (RR: 0.63; 95% CI: 0.52-0.76; P < 0.00001; I2 = 44%), gastrointestinal bleeding (RR: 0.67; 95% CI: 0.53-0.85; P = 0.0009; I2 = 36%), intracranial hemorrhage (RR: 0.57; 95% CI: 0.38-0.84; P = 0.004; I2 = 0%) were lower in the DOAC group compared with the vitamin K antagonist group. The risk of cardiovascular-related death (RR: 1.34; 95% CI: 0.69-2.60; P = 0.39; I2 = 0%), clinically relevant nonmajor bleeding (RR: 0.90; 95% CI: 0.75-1.08; P = 0.26; I2 = 28%), and hemorrhagic stroke (RR: 0.36; 95% CI: 0.06-2.24; P = 0.28; I2 = 10%) showed no significant differences. In conclusion, the risks of all-cause stroke, ischemic stroke, all-cause mortality, major bleeding, gastrointestinal bleeding, and intracranial hemorrhage in patients with atrial fibrillation undergoing chronic hemodialysis were lower in the DOAC group.

Comparison of the DOAC Dipstick Test on Urine Samples With Chromogenic Substrate Methods on Plasma Samples in Outpatients Treated With Direct Oral Anticoagulants

Identifying adherence to direct oral anticoagulants (DOACs) plays a major role in treatment efficacy and safety. The DOAC Dipstick can detect DOACs in urine samples of acutely diseased patients at plasma thresholds of about 30 ng/mL. A prospective observational consecutive cohort study was performed on outpatients taking DOACs. The presence of direct oral factor Xa inhibitors (DXIs) in patient urine samples were independently evaluated by visual interpretation of the DOAC Dipstick pad colors. DOAC plasma concentration was assessed using STA®-Liquid Anti-Xa and STA®-Liquid Anti-IIa chromogenic substrate assays. Positive DOAC Dipstick results were compared with a threshold plasma of DOAC concentration ≥30 ng/mL. Of 120 patients (age 55.4  +  16.1 years, female n  =  63), 77 were on rivaroxaban and 43 on apixaban. Plasma concentrations were 129  ±  118 ng/mL for rivaroxaban, and 163  ±  130 ng/mL for apixaban, DOAC Dipstick test has a sensitivity of 97.2% and a positive predictive value of 89.5% at 30 ng/mL. No differences occurred between DXIs. Specificity and negative predictive value could not be determined due to the low number of true negative values. There were no differences in the interpretation of rivaroxaban and apixaban pad colors between observers (Kappa 1.0). Results show that DOAC Dipstick may be a useful tool for identifying DXIs in urine samples in an outpatient setting at a plasma threshold ≥ 30 ng/mL. Further studies should include patients treated with dabigatran, vitamin K antagonists, or other anticoagulants.

Efficacy and safety of warfarin in patients with non-valvular atrial fibrillation and CKD G3-G5D

Background

Observational data comparing warfarin with no treatment for patients with non-valvular atrial fibrillation (NVAF) and severely reduced glomerular filtration rate (GFR) are conflicting and randomized controlled trials (RCTs) are lacking. Most studies do not provide information on warfarin treatment quality, making them difficult to compare.

Methods

This national cohort study investigates the risk of ischaemic stroke and major bleeding during warfarin treatment compared with no oral anticoagulants in patients with NVAF, GFR category 3-5 (G3-G5) or on dialysis (G5D), with kidney transplant recipients excluded, between 2009 and 2018. Data extracted from high-quality Swedish national healthcare registries, including the Swedish Renal Registry, AuriculA-the Swedish national quality registry for atrial fibrillation and anticoagulation-and the Stroke Registry.

Results

At enrolment of 12 106 patients, 21.4% were G3, 43.5% were G4, 11.6% were G5 and 23.6% were G5D. The mean time in the therapeutic range was 70%. Warfarin compared with no treatment showed a lower risk for ischaemic stroke for G3 {hazard ratio [HR] 0.37 [95% confidence interval (CI) 0.18-0.76]}, G4 [0.53 (0.38-0.74)] and G5 [0.49 (0.30-0.79)] and an increased risk of major bleeding in G4 [HR 1.22 (1.02-1.46)], G5 [1.52 (1.15-2.01)] and G5D [1.23 (1.00-1.51)]. All-cause mortality was more than halved on warfarin compared with no treatment in all GFR categories.

Conclusions

Warfarin treatment is associated with a lower risk of ischaemic stroke for patients with NVAF and G3, G4 and G5D at the cost of a higher risk of major bleeding for G4-G5D. Existing observational data are conflicting, stressing the need for RCTs on warfarin compared with no treatment in G4-G5D. Awaiting RCTs, it seems reasonable to treat selected patients on dialysis and NVAF with warfarin.

Validation of risk scores for ischaemic stroke in atrial fibrillation across the spectrum of kidney function

Aims 

The increasing prevalence of ischaemic stroke (IS) can partly be explained by the likewise growing number of patients with chronic kidney disease (CKD). Risk scores have been developed to identify high-risk patients, allowing for personalized anticoagulation therapy. However, predictive performance in CKD is unclear. The aim of this study is to validate six commonly used risk scores for IS in atrial fibrillation (AF) patients across the spectrum of kidney function.

Methods and results 

Overall, 36 004 subjects with newly diagnosed AF from SCREAM (Stockholm CREAtinine Measurements), a healthcare utilization cohort of Stockholm residents, were included. Predictive performance of the AFI, CHADS₂, Modified CHADS₂, CHA₂DS₂-VASc, ATRIA, and GARFIELD-AF risk scores was evaluated across three strata of kidney function: normal kidney function [estimated glomerular filtration rate (eGFR) >60 mL/min/1.73 m²], mild CKD (eGFR 30–60 mL/min/1.73 m²), and advanced CKD (eGFR <30 mL/min/1.73 m²). Predictive performance was assessed by discrimination and calibration. During 1.9 years, 3069 (8.5%) patients suffered an IS. Discrimination was dependent on eGFR: the median c-statistic in normal eGFR was 0.75 (range 0.68–0.78), but decreased to 0.68 (0.58–0.73) and 0.68 (0.55–0.74) for mild and advanced CKD, respectively. Calibration was reasonable and largely independent of eGFR. The Modified CHADS₂ score showed good performance across kidney function strata, both for discrimination [c-statistic: 0.78 (95% confidence interval 0.77–0.79), 0.73 (0.71–0.74) and 0.74 (0.69–0.79), respectively] and calibration.

Conclusion 

In the most clinically relevant stages of CKD, predictive performance of the majority of risk scores was poor, increasing the risk of misclassification and thus of over- or undertreatment. The Modified CHADS₂ score performed good and consistently across all kidney function strata, and should therefore be preferred for risk estimation in AF patients.

Traditional and Non-traditional Risk Factors for Osteoporosis in CKD

Osteoporosis is a state of bone fragility with reduced skeletal resistance to trauma, and consequently increased risk of fracture. A wide range of conditions, including traditional risk factors, lifestyle choices, diseases and their treatments may contribute to bone fragility. It is therefore not surprising that the multi-morbid patient with chronic kidney disease (CKD) is at a particularly high risk. CKD is associated with reduced bone quantity, as well as impaired bone quality. Bone fragility in CKD is a composite of primary osteoporosis, accumulation of traditional and uremia-related risk factors, assaults brought on by systemic disease, and detrimental effects of drugs. Some risk factors are modifiable and represent potential targets for intervention. This review provides an overview of the heterogeneity of bone fragility in CKD.

Thromboembolic and Bleeding Risk in Atrial Fibrillation Patients with Chronic Kidney Disease: Role of Anticoagulation Therapy

Atrial fibrillation (AF) and chronic kidney disease (CKD) are strictly related; several independent risk factors of AF are often frequent in CKD patients. AF prevalence is very common among these patients, ranging between 15% and 20% in advanced stages of CKD. Moreover, the results of several studies showed that AF patients with end stage renal disease (ESRD) have a higher mortality rate than patients with preserved renal function due to an increased incidence of stroke and an unpredicted elevated hemorrhagic risk. Direct oral anticoagulants (DOACs) are currently contraindicated in patients with ESRD and vitamin K antagonists (VKAs), remaining the only drugs allowed, although they show numerous critical issues such as a narrow therapeutic window, increased tissue calcification and an unfavorable risk/benefit ratio with low stroke prevention effect and augmented risk of major bleeding. The purpose of this review is to shed light on the applications of DOAC therapy in CKD patients, especially in ESRD patients.

Outcomes on safety and efficacy of left atrial appendage occlusion in end stage renal disease patients undergoing dialysis

BACKGROUND

In patients with end stage renal disease and atrial fibrillation (AF), undergoing chronic dialysis, direct oral agents are contraindicated and warfarin does not fully prevent embolic events while increasing the bleeding risk. The high hemorrhagic risk represents the main problem in this population. Aim of the study was to estimate the safety and efficacy for thromboembolic prevention of left atrial appendage (LAA) occlusion in a cohort of dialysis patients with AF and high hemorrhagic risk.

METHODS

Ninety-two dialysis patients with AF who underwent LAA occlusion were recruited. For comparative purposes, two cohorts of dialysis patients with AF, one taking warfarin (oral anticoagulant therapy, OAT cohort, n = 114) and the other not taking any OAT (no-therapy cohort, n = 148) were included in the study. Primary endpoints were (1) incidence of peri-procedural complications, (2) incidence of 2-year thromboembolic and hemorrhagic events, (3) mortality at 2 years. In order to evaluate the effect of the LAA occlusion on the endpoints with respect to the OAT and No-therapy cohorts, a multivariable Cox regression model was applied adjusted for possible confounding factors.

RESULTS

The device was successfully implanted in 100% of cases. Two major peri-procedural complications were reported. No thromboembolic events occurred at 2-year follow-up. The adjusted multivariable Cox regression model showed no difference in bleeding risk in the OAT compared to the LAA occlusion cohort in the first 3 months of follow-up [HR 1.65 (95% CI 0.43-6.33)], when most of patients were taking two antiplatelet drugs. In the following 21 months the bleeding incidence became higher in OAT patients [HR 6.48 (95% CI 1.32-31.72)]. Overall mortality was greater in both the OAT [HR 2.76 (95% CI 1.31-5.86)] and No-Therapy [HR 3.09 (95% CI 1.59-5.98)] cohorts compared to LAA occlusion patients.

CONCLUSIONS

The study could open the way to a non-pharmacological option for thromboembolic protection in dialysis patients with AF and high bleeding risk.