Chronic kidney disease and arrhythmias: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Oral Anticoagulation in Patients With End-Stage Kidney Disease on Dialysis and Atrial Fibrillation

Patients with end-stage kidney disease (ESKD) have an elevated incidence of atrial fibrillation (AF) and are at increased risk for thromboembolic events. However, these patients are also at increased risk for bleeding and it is unclear whether they benefit from an oral anticoagulant. Point prevalent on July 1, 2015, only ~28% of dialysis patients with AF were on oral anticoagulation. Warfarin was the most commonly used oral anticoagulant, followed by apixaban, while dabigatran and rivaroxaban were rarely used. This article reviews the current evidence regarding each oral anticoagulant especially as they relate to patients with ESKD.

Longitudinal kidney function trajectories predict major bleeding, hospitalization and death in patients with atrial fibrillation and chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD), commonly described by estimated glomerular filtration rate (eGFR), is a frequent comorbidity in patients with atrial fibrillation (AF) and associated with thromboembolic and bleeding complications. Instead of single eGFR measurements, kidney function decline over time may better predict clinical outcomes but this has not been studied so far.

METHODS

Patients with AF and stage 3/4 CKD were prospectively followed within a primary care electronic database from the United Kingdom (IMS-THIN). The associations between the longitudinal eGFR trajectory of these patients and stroke/systemic embolism, major bleeding, first hospitalization-for-any-cause, and death-from-any-cause were estimated with joint models of longitudinal and time-to-event data.

RESULTS

18,240 patients were included (median age 80.4 years, median CHA₂DS₂-VASc score 4). In 133,676 eGFR measurements (mean: 6 per patient) median "baseline" eGFR was 49 ml/min/1.73m² [41-55] and mean eGFR decline was 0.54 ml/min/1.73m²/year (95%CI: 0.47-0.62). During follow-up (median 3.2 years; 50,841 patient-years at risk), 5-year cumulative incidence estimates were 9%, 3%, 32% and 76% for stroke/systemic embolism, major bleeding, hospitalization and death, respectively. In joint modeling, an accelerated decline in kidney function strongly predicted for a higher risk of major bleeding (hazard ratio [HR] 1.09 per ml/min/1.73m²/year increase in eGFR decline), hospitalization (HR 1.06), and death-from-any-cause (HR 1.11; all p < 0.05), but not for stroke/systemic embolism (HR 0.97; p = 0.239).

CONCLUSIONS

Declining kidney function is a critical determinant of unfavourable outcomes in patients with AF and CKD. Longitudinal kidney function trajectories may enable a much more individualized prediction of adverse outcomes in this vulnerable patient population.

Demystifying the Benefits and Harms of Anticoagulation for Atrial Fibrillation in Chronic Kidney Disease

Patients with CKD represent a vulnerable population where the risks of atrial fibrillation, ischemic stroke, and bleeding are all heightened. Although large randomized, controlled trials in the general population clearly demonstrate that the benefits of warfarin and direct-acting oral anticoagulants outweigh the risks of bleeding, no such studies have been conducted in patients when their creatinine clearance falls below 25-30 ml/min. Without randomized, controlled trial data, the role of anticoagulation in patients with CKD with atrial fibrillation remains unclear and our practice is informed by a growing body of imperfect literature such as observational and pharmacokinetic studies. This article aims to present a contemporary literature review of the benefits versus harms of anticoagulation in atrial fibrillation for patients with CKD stages 3, 4, 5, and 5 on dialysis. Although unanswered questions and areas of clinical equipoise remain, this piece serves to assist physicians in interpreting the complex body of literature and applying it to their clinical care.

Practical issues in clinical scenarios involving CKD patients requiring antithrombotic therapy in light of the 2017 ESC guideline recommendations

BACKGROUND

The choice of the most appropriate antithrombotic regimen that balances ischemic and bleeding risks was addressed by the August 2017 European Society of Cardiologists (ESC)/European Association for Cardio-Thoracic Surgery Focused Update recommendations, which propose new evaluation scores and protocols for patients requiring a coronary stent or patients with an acute coronary syndrome, atrial fibrillation, or a high bleeding risk and indication for oral anticoagulation therapy.

DISCUSSION

Numerous questions remain regarding antithrombotic regimens and risk management algorithms for both ischemic and hemorrhagic events in patients with chronic kidney disease (CKD) in various clinical scenarios. Limitations of current studies include a general ack of advanced CKD patients in major randomized controlled trials, of evidence on algorithm implementation, and of robust assessment tools for hemorrhagic risk. Herein, we aim to analyze the ESC Update recommendations and the newly implemented risk scores (DAPT, PRECISE-DAPT, PARIS) from the point of view of CKD, providing suggestions on drug choice (which combination has the best evidence), dosage, and duration (the same or different as for non-CKD population) of antithrombotics, as well as to identify current shortcomings and to envision directions of future research.

CONCLUSION

We provide an evidence-based perspective on the new proposed bleeding management protocol, with focus on the CKD population. Despite previous important steps on antithrombotic therapy of renal patients, there remain many unsolved questions for which our suggestions could fundament new randomized controlled trials and specific protocols.

Incident Atrial Fibrillation and the Risk of Stroke in Adults with Chronic Kidney Disease: The Stockholm CREAtinine Measurements (SCREAM) Project

BACKGROUND AND OBJECTIVES

Patients with CKD have a high risk of atrial fibrillation. Both CKD and atrial fibrillation are associated with higher risk of stroke and death. However, the effect of incident atrial fibrillation on stroke risk among patients with CKD is unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our study included adults with CKD (eGFR<60 ml/min per 1.73 m2) without previously documented atrial fibrillation who had been in contact with health care in Stockholm, Sweden during 2006-2011. Incident atrial fibrillation was identified by administrative diagnostic codes in outpatient or inpatient care and treated as a time-updated exposure in the analysis of stroke and death risk. Stroke events and deaths were ascertained from regional and national registers with complete coverage. Covariates included demographics, comorbidities, therapeutic procedures, and medications. Multivariable Cox regression analysis and competing risk analysis (accounting for death) were used to estimate the association between incident atrial fibrillation and stroke.

RESULTS

Among 116,184 adults with CKD, 13,412 (12%) developed clinically recognized atrial fibrillation during a mean follow-up of 3.9 years (interquartile range, 2.3-5.7 years). Incidence of atrial fibrillation increased across lower eGFR strata: from 29.4 to 46.3 atrial fibrillations per 1000 person-years in subjects with eGFR=45-60 and <30 ml/min per 1.73 m2, respectively; 1388 (53.8 per 1000 person-years) cases of stroke and 5592 (205.1 per 1000 person-years) deaths occurred after incident atrial fibrillation compared with 6850 (16.6 per 1000 person-years) cases of stroke and 28,613 (67.5 per 1000 person-years) deaths during periods without atrial fibrillation. After adjustment, incident atrial fibrillation was associated with higher risk of stroke (hazard ratio, 2.00; 95% confidence interval, 1.88 to 2.14) and death (hazard ratio, 1.76; 95% confidence interval, 1.71 to 1.82). This was attributed to both ischemic stroke (hazard ratio, 2.11; 95% confidence interval, 1.96 to 2.28) and intracranial bleeds (hazard ratio, 1.64; 95% confidence interval, 1.42 to 1.90). Stroke risk was similar across all eGFR strata. In competing risk analyses accounting for death, the association between incident atrial fibrillation and stroke was attenuated but remained higher (subhazard ratio, 1.49; 95% confidence interval, 1.39 to 1.60).

CONCLUSIONS

Patients with CKD who develop atrial fibrillation are at higher risk of stroke and death.

Non-Vitamin K-Dependent Oral Anticoagulants for Nonvalvular Atrial Fibrillation in Patients With CKD: Pragmatic Considerations for the Clinician

Management of atrial fibrillation (AF) in patients with advanced chronic kidney disease (CKD) poses a complex conundrum because of higher risks for both thromboembolic and bleeding complications compared to the general population. This makes it particularly important for clinicians to carefully weigh the risks versus benefits of anticoagulation therapy to determine the individualized net clinical benefit for every patient. During the past few years, 4 non-vitamin K-dependent oral anticoagulant (NOAC) agents have supplemented warfarin in the therapeutic armamentarium for the prevention of systemic thromboembolism in nonvalvular AF. However, the use of NOACs in CKD specifically mandates a nuanced understanding due to their varying dependence on renal clearance, with resultant safety implications related to either underdosing (thromboembolism) or excessive drug exposure (bleeding). This pragmatic review highlights unique considerations pertaining to accurate estimation and temporal monitoring of kidney function in the context of NOAC use with specific clinical deliberations and variables when determining whether an NOAC is appropriate for a patient with CKD. The dependence of NOACs on renal clearance and several troubling safety signals in the published literature suggest that it is vital for nephrologists to be active members of a multidisciplinary team caring for these high-risk patients with CKD and AF.