Time in Therapeutic Range and Outcomes After Warfarin Initiation in Newly Diagnosed Atrial Fibrillation Patients With Renal Dysfunction

Treatment strategies of the thromboembolic risk in kidney failure patients with atrial fibrillation

The incidence and prevalence of atrial fibrillation (AF) in patients affected by kidney failure, i.e. glomerular filtration rate <15 ml/min/1.73 m2, is high and probably underestimated. Numerous uncertainties remain regarding how to prevent thromboembolic events in this population because both cardiology and nephrology guidelines do not provide clear recommendations. The efficacy and safety of oral anticoagulant therapy (OAC) in preventing thromboembolism in patients with kidney failure and AF has not been demonstrated for either vitamin K antagonists (VKAs) or direct anticoagulants (DOACs). Moreover, it remains unclear which is more effective and safer, because estimated creatinine clearance <25-30 ml/min was an exclusion criterion in the randomized controlled trials (RCTs). Three RCTs comparing DOACs and VKAs in kidney failure failed to reach the primary endpoint, as they were underpowered. The left atrial appendage is the main source of thromboembolism in the presence of AF. Left atrial appendage closure (LAAC) has recently been proposed as an alternative to OAC. RCTs comparing the efficacy and safety of LAAC versus OAC in kidney failure were terminated prematurely due to recruitment failure. A recent prospective study showed a reduction in thromboembolic events in haemodialysis patients with AF and undergoing LAAC compared with patients taking or not taking OAC. We review current treatment standards and discuss recent developments in managing the thromboembolic risk in kidney failure patients with AF. The importance of shared decision-making with the multidisciplinary team and the patient to consider individual risks and benefits of each treatment option is underlined.

Drug stewardship in chronic kidney disease to achieve effective and safe medication use

People living with chronic kidney disease (CKD) often experience multimorbidity and require polypharmacy. Kidney dysfunction can also alter the pharmacokinetics and pharmacodynamics of medications, which can modify their risks and benefits; the extent of these changes is not well understood for all situations or medications. The principle of drug stewardship is aimed at maximizing medication safety and effectiveness in a population of patients through a variety of processes including medication reconciliation, medication selection, dose adjustment, monitoring for effectiveness and safety, and discontinuation (deprescribing) when no longer necessary. This Review is aimed at serving as a resource for achieving optimal drug stewardship for patients with CKD. We describe special considerations for medication use during pregnancy and lactation, during acute illness and in patients with cancer, as well as guidance for the responsible use of over-the-counter drugs, herbal remedies, supplements and sick-day rules. We also highlight inequities in medication access worldwide and suggest policies to improve access to quality and essential medications for all persons with CKD. Further strategies to promote drug stewardship include patient education and engagement, the use of digital health tools, shared decision-making and collaboration within interdisciplinary teams. Throughout, we position the person with CKD at the centre of all drug stewardship efforts.

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.

Practical guide on left atrial appendage closure for the non-implanting physician: an international consensus paper

A significant proportion of patients who suffer from atrial fibrillation (AF) and are in need of thromboembolic protection are not treated with oral anticoagulation or discontinue this treatment shortly after its initiation. This undertreatment has not improved sufficiently despite the availability of direct oral anticoagulants which are associated with less major bleeding than vitamin K antagonists. Multiple reasons account for this, including bleeding events or ischaemic strokes whilst on anticoagulation, a serious risk of bleeding events, poor treatment compliance despite best educational attempts, or aversion to drug therapy. An alternative interventional therapy, which is not associated with long-term bleeding and is as effective as vitamin K anticoagulation, was introduced over 20 years ago. Because of significant improvements in procedural safety over the years, left atrial appendage closure, predominantly achieved using a catheter-based, device implantation approach, is increasingly favoured for the prevention of thromboembolic events in patients who cannot achieve effective anticoagulation. This management strategy is well known to the interventional cardiologist/electrophysiologist but is not more widely appreciated within cardiology or internal medicine. This article introduces the devices and briefly explains the implantation technique. The indications and device follow-up are more comprehensively described. Almost all physicians who care for adult patients will have many with AF. This practical guide, written within guideline/guidance boundaries, is aimed at those non-implanting physicians who may need to refer patients for consideration of this new therapy, which is becoming increasingly popular.

Comparative Safety and Effectiveness of Warfarin or Rivaroxaban Versus Apixaban in Patients With Advanced CKD and Atrial Fibrillation: Nationwide US Cohort Study

RATIONALE & OBJECTIVE

Head-to-head data comparing the effectiveness and safety of oral anticoagulants in patients with atrial fibrillation (AF) and advanced chronic kidney disease (CKD) are lacking. We compared the safety and effectiveness of warfarin or rivaroxaban versus apixaban in patients with AF and non-dialysis-dependent CKD stage 4/5.

STUDY DESIGN

Propensity score-matched cohort study.

SETTING & PARTICIPANTS

2 nationwide US claims databases, Medicare and Optum's deidentified Clinformatics Data Mart Database, were searched for the interval from January 1, 2013, through March 31, 2022, for patients with nonvalvular AF and CKD stage 4/5 who initiated warfarin versus apixaban (matched cohort, n=12,488) and rivaroxaban versus apixaban (matched cohort, n = 5,720).

EXPOSURES

Warfarin, rivaroxaban, or apixaban.

OUTCOMES

Primary outcomes included major bleeding and ischemic stroke. Secondary outcomes included all-cause mortality, major gastrointestinal bleeding, and intracranial bleeding.

ANALYTICAL APPROACH

Cox regression was used to estimate HRs, and 1:1 propensity-score matching was used to adjust for 80 potential confounders.

RESULTS

Compared with apixaban, warfarin initiation was associated with a higher rate of major bleeding (HR, 1.85; 95% CI, 1.59-2.15), including major gastrointestinal bleeding (1.86; 1.53-2.25) and intracranial bleeding (2.15; 1.42-3.25). Compared with apixaban, rivaroxaban was also associated with a higher rate of major bleeding (1.69; 1.33-2.15). All-cause mortality was similar for warfarin (1.08; 0.98-1.18) and rivaroxaban (0.94; 0.81-1.10) versus apixaban. Furthermore, no statistically significant differences for ischemic stroke were observed for warfarin (1.14; 0.83-1.57) or rivaroxaban (0.71; 0.40-1.24) versus apixaban, but the CIs were wide. Similar results were observed for warfarin versus apixaban in the positive control cohort of patients with CKD stage 3, consistent with randomized trial findings.

LIMITATIONS

Few ischemic stroke events, potential residual confounding.

CONCLUSIONS

In patients with AF and advanced CKD, rivaroxaban and warfarin were associated with higher rates of major bleeding compared with apixaban, suggesting a superior safety profile for apixaban in this high-risk population.

PLAIN-LANGUAGE SUMMARY

Different anticoagulants have been shown to reduce the risk of stroke in patients with atrial fibrillation, such as warfarin and direct oral anticoagulants like apixaban and rivaroxaban. Unfortunately, the large-scale randomized trials that compared direct anticoagulants versus warfarin excluded patients with advanced chronic kidney disease. Therefore, the comparative safety and effectiveness of warfarin, apixaban, and rivaroxaban are uncertain in this population. In this study, we used administrative claims data from the United States to answer this question. We found that warfarin and rivaroxaban were associated with increased risks of major bleeding compared with apixaban. There were few stroke events, with no major differences among the 3 drugs in the risk of stroke. In conclusion, this study suggests that apixaban has a better safety profile than warfarin and rivaroxaban.

Warfarin treatment quality and outcomes in patients with non-valvular atrial fibrillation and CKD G3-G5D

INTRODUCTION

Warfarin treatment quality is calculated as time in therapeutic range (TTR). TTR ≥ 70 % is considered reducing the risk of adverse events for patients with atrial fibrillation (AF). The association of TTR and adverse events in chronic kidney disease (CKD) is however poorly investigated. The aim is to explore this further.

MATERIALS AND METHODS

Swedish cohort study based on national healthcare registers between 2009 and 2018, including Swedish Renal Registry, Swedish Stroke Register and AuriculA - the Swedish national quality register for AF and anticoagulation. Investigating the effect of individual TTR (iTTR) and iTTR ≥ 70 % versus <70 % on the risk of ischemic stroke, major bleeding and death for patients with CKD GFR category 3-5 (G3-G5) including patients on dialysis (G5D) and non-valvular AF (NVAF).

RESULTS

Of 2379 included patients 21.9 % had G3, 47.5 % G4, 10.8 % G5 and 19.8 % G5D. TTR in G3 was 75.6 %, G4 72.2 %, G5 67.6 % and G5D 62.0 %. Increase by 10 percentage points iTTR conferred lower risk of major bleeding, ischemic stroke and death for all patients (hazard ratio 0.91 (95 % Confidence interval 0.87-0.94), 0.92 (0.85-0.99) and 0.88 (0.85-0.90)). iTTR≥ 70 % versus <70 % was associated with lower risk of bleeding and death in all patients (0.63 (0.51-0.77) and (0.51 (0.43-0.61)), and a non-significant tendency towards lower stroke risk (0.67 (0.43-1.06)).

CONCLUSIONS

Warfarin treatment quality worsens with decreasing GFR. Higher iTTR confers lower risk of bleeding, ischemic stroke and death in patients with NVAF and G3-G5D. iTTR ≥ 70 % was associated with better safety profile. Close monitoring of patients with CKD on warfarin is recommended.

Cardiorenal Outcomes Among Patients With Atrial Fibrillation Treated With Oral Anticoagulants

RATIONALE & OBJECTIVE

Direct oral anticoagulants (DOACs) have progressively replaced vitamin K antagonists (VKAs) for stroke prevention in patients with nonvalvular atrial fibrillation (AF). DOACs cause fewer bleeding complications, but their other advantages, particularly related to kidney outcomes, remain inconclusive. We studied the risks of chronic kidney disease (CKD) progression and acute kidney injury (AKI) after DOAC and VKA administration for nonvalvular AF.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Cohort study of Swedish patients enrolled in the Stockholm Creatinine Measurements (SCREAM) project with a diagnosis of nonvalvular AF during 2011-2018.

EXPOSURE

Initiation of DOAC or VKA treatment.

OUTCOME

Primary outcomes were CKD progression (composite of >30% estimated glomerular filtration rate [eGFR] decline and kidney failure) and AKI (by diagnosis or KDIGO-defined transient creatinine elevations). Secondary outcomes were death, major bleeding, and the composite of stroke and systemic embolism.

ANALYTICAL APPROACH

Propensity score weighted Cox regression was used to balance 50 baseline confounders. Sensitivity analyses included falsification end points, subgroups, and estimation of per-protocol effects.

RESULTS

We included 32,699 patients (56% initiated DOAC) who were observed for a median of 3.8 years. Their median age was 75 years, 45% were women, and 27% had an eGFR <60mL/min/1.73m². The adjusted HRs for DOAC versus VKA were 0.87 (95% CI, 0.78-0.98) for the risk of CKD progression and 0.88 (95% CI, 0.80-0.97) for AKI. HRs were 0.77 (95% CI, 0.67-0.89) for major bleeding, 0.93 (95% CI, 0.78-1.11) for the composite of stroke and systemic embolism, and 1.04 (95% CI, 0.95-1.14) for death. The results were similar across subgroups of age, sex, and baseline eGFR when restricting to patients at high risk for thromboembolic events and when censoring follow up at treatment discontinuation or change in type of anticoagulation.

LIMITATIONS

Missing information on time in therapeutic range and treatment dosages.

CONCLUSIONS

Among patients with nonvalvular AF treated in routine clinical practice compared with VKA use, DOAC use was associated with a lower risk of CKD progression, AKI, and major bleeding but a similar risk of the composite of stroke, systemic embolism, or death.

Oral Anticoagulation in Patients with Chronic Kidney Disease and Non-Valvular Atrial Fibrillation: The FAERC Study

Atrial fibrillation (AF) is the most common arrhythmia in patients with chronic kidney disease (CKD), and its presence is associated with a higher risk of stroke and mortality.

MATERIAL AND METHODS

The FAERC study performed a retrospective multicentre analysis of historical cohorts in which data were collected from arrhythmia diagnosis onwards.

RESULTS

We analysed a Spanish cohort of 4749 patients with CKD (mean eGFR 33.9 mL/min) followed up in the nephrology clinic, observing a 12.2% prevalence of non-valvular AF. In total, 98.6% of these patients were receiving anticoagulant treatment, mainly with coumarins (79.7%). Using direct-acting oral anticoagulants (DOACs) was associated with fewer cerebrovascular events than using acenocoumarol, but in contrast with other studies, we could not corroborate the association of risk of bleeding, coronary events, or death with a type of anticoagulant prescribed.

CONCLUSIONS

Atrial fibrillation is highly prevalent in renal patients. Direct-acting anticoagulants seem to be associated with fewer ischemic-embolic complications, with no differences in bleeding, coronary events, or mortality rates.

Association between time in therapeutic range of tacrolimus blood concentration and acute rejection within the first three months after lung transplantation

BACKGROUND

Tacrolimus is a key drug in immunosuppressive therapy following lung transplantation. The blood tacrolimus levels are likely to fluctuate in the early postoperative period, and failure to maintain the tacrolimus trough level in target ranges is a risk factor for rejection. However, there is little information about the relationship between the time in therapeutic range (TTR) of the tacrolimus trough level (tacrolimus TTR) and clinical outcomes. This study aimed to evaluate the association between tacrolimus TTR and acute rejection (AR) within the first three months after lung transplantation.

METHODS

This was a retrospective study of patients who underwent lung transplantation at a single center. The target tacrolimus trough levels were 10-15 ng/mL, and tacrolimus TTR was calculated using the Rosendaal method. The cut-off value of the tacrolimus TTR was estimated by receiver operating characteristic analysis based on AR.

RESULTS

The study included 90 patients. AR was observed in 26 patients. In this study, ''early-AR'' was defined as any AR within 2 weeks post-transplant (n = 22) and ''late-AR'' was defined as any AR after 1-month post-transplant (n = 4). For early AR, the relationship between tacrolimus TTR and the onset of AR was examined. There were no differences in the tacrolimus TTR between the early-AR group and non-AR group (35.7 ± 22.4 vs 31.5 ± 19.9%, P = 0.416). For late-AR, the relationship with tacrolimus TTR was examined every 10 d. The tacrolimus TTR during postoperative days (POD) 21-30 and POD 31-onset was significantly lower in the late-AR group than the no-AR group (50.0 ± 7.1 vs. 71.8 ± 18.0% and 37.0 ± 26.6 vs. 68.9 ± 31.5%, P < 0.05, respectively). The cutoff value of the tacrolimus TTR during POD 21-30 was estimated as 55.0%.

CONCLUSIONS

Our findings suggest that a lower tacrolimus TTR is a predictor of late AR. A tacrolimus TTR of 55% or higher is necessary to reduce the risk of AR during this period after lung transplantation.

Oral anticoagulants, time in therapeutic range and renal function over time in real-life patients with atrial fibrillation and chronic kidney disease

Aims

To describe the use of warfarin and direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) and chronic kidney disease (CKD), to evaluate changes in renal function over time and predictors of rapid decline, and to describe time in therapeutic range (TTR) and predictors of poor TTR among patients on warfarin.

Methods and results

Using data from AuriculA, the Swedish oral anticoagulation registry, patients with AF on warfarin or DOAC were identified between 2013 and 2018 (N=6567). Estimated glomerular filtration rate (eGFR) was calculated and categorised into normal (≥90 mL/min/1.73 m²), mild CKD (60–89 mL/min/1.73 m²), moderate CKD (30–59 mL/min/1.73 m²), severe CKD (15–29 mL/min/1.73 m²) and end-stage CKD (<15 mL/min/1.73 m²)/dialysis. TTR was estimated using international normalised ratio (INR) measurements. Predictors of eGFR decline over time and of poor TTR were estimated using regression analysis. Between 2013 and 2018, use of DOAC increased from 9.2% to 89.3%, with a corresponding decline in warfarin. A similar trend was observed in patients with mild to moderate CKD, while DOAC over warfarin increased slower among patients with severe to end-stage CKD/dialysis. In patients treated with warfarin, the median TTR was 77.1%. Worse TTR was observed among patients with severe CKD (70.0%) and end-stage CKD/dialysis (67.5%). A gradual annual decline in eGFR was observed (−1.1 mL/min/1.73 m²), with a more rapid decline among patients with older age, female sex, diabetes mellitus and/or heart failure.

Conclusion

In patients with AF, use of DOAC has steadily increased across different CKD stages, but not in patients with severe to end-stage CKD/dialysis despite these patients having poor INR control. Patients with AF have a gradual decline in renal function, with a more rapid decline among a subgroup of patients.

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.

Prognostic impact of the presence of chronic kidney disease on percutaneous left trial appendage closure for atrial fibrillation: A single center experience

BACKGROUND

Percutaneous left atrial appendage closure (LAAC) has been proposed as an alternative to anticoagulation therapy in patients with nonvalvular atrial fibrillation (NVAF) to decrease the thromboembolic risk, while avoiding the risks of chronic anticoagulation. This option may be attractive in patients with NVAF and chronic kidney disease (CKD), since they exhibit both high thromboembolic and bleeding risks.

OBJECTIVE

To evaluate the prognostic impact of the presence of CKD in patients with atrial fibrillation undergoing LAAC peri-procedure and during the follow-up as compared with patients with preserved renal function.

METHODS

Retrospective, observational study that included 124 consecutive patients with atrial fibrillation undergoing LAAC in a university hospital, and the results were evaluated according to the baseline renal function of the patients.

RESULTS

The median age was 75,5 years (IQR 67,6-80) and 62,1% were men, the median of CHA₂DS₂-Vasc and HASBLED scores was 4 (IQR 3-4) for both scores. Up to 57,3% of the total sample had CKD. Baseline characteristics were similar between groups, but CKD patients were older and had a higher HASBLED score. During the procedure, no thromboembolic, bleeding events, or deaths were observed. Combining the time of hospitalization and follow-up, no significant differences were observed between groups in the annual rate of thromboembolic events (0.97/100 patient-years [100PY] vs 4.06/100PY, P =,09), but there was a higher rate of bleeding events (5.67/100PY vs. 13.3/100PY, P =,033) and mortality among CKD patients (6.50/100PY vs. 17.2/100PY, P =,009), with an odds ratio of 2.711 (95% CI 1,96-6,95). In the multivariate analysis a preserved eGFR was independently associated with a lower mortality risk.

CONCLUSIONS

LAAC is a valid alternative to oral anticoagulation in patients with CKD and atrial fibrillation, with a low rate of peri- and post-procedure complications, although CKD patients exhibited a higher risk of bleeding and mortality during the follow-up. However, these higher rates may not be necessarily related to the procedure.

The Stockholm CREAtinine Measurements (SCREAM) project: Fostering improvements in chronic kidney disease care

SCREAM (Stockholm CREAtinine Measurements project) was initiated in 2010 in collaboration with the healthcare provider of Stockholm County healthcare to quantify potential medication errors, estimate the burden of chronic kidney disease (CKD) and to illustrate the value of incorporating measures of kidney function into the medical decision process. Because most patients are unaware of their CKD and diagnoses are seldom issued, SCREAM took advantage of the commonness of serum/plasma creatinine testing, which can be used to estimate the glomerular filtration rate (eGFR) and classify the stage of CKD severity. SCREAM is periodically updated, and at present contains healthcare information of all residents in Stockholm region during 2006-2019 (about 3 million people), enriched with a broad range of laboratory measurements for those in whom creatinine or albuminuria has been measured (about 1.8 million people). This health information was linked with national administrative and quality registries via the unique personal identification number of each Swedish citizen, conforming the richest characterization in Sweden of the population's journey through health and disease. This review discusses the context of its creation, strengths and weakness, key findings and plans for the future. We summarize our findings related to the burden of CKD in Sweden, its adverse health risks (such as risk of infections, cancer or dementia) and how underlying kidney function alters the risk-benefit ratio of common medications. Results have had clinical impact and demonstrate the importance of population-based research in the spectrum of clinical research to improve health.

Dry Needling and Antithrombotic Drugs

Many clinicians increasingly use dry needling in clinical practice. However, whether patients' intake of antithrombotic drugs should be considered as a contraindication for dry needling has not been investigated to date. As far as we know, there are no publications in analyzing the intake of antiplatelet or anticoagulant agents in the context of dry needling techniques. A thorough analysis of existing medications and how they may impact various needling approaches may contribute to improved evidence-informed clinical practice. The primary purpose of this paper is to review the current knowledge of antithrombotic therapy in the context of dry needling. In addition, reviewing guidelines of other needling approaches, such as electromyography, acupuncture, botulinum toxin infiltration, and neck ultrasound-guided fine-needle aspiration biopsy, may provide specific insights relevant for dry needling. Based on published data, taking antithrombotic medication should not be considered an absolute contraindication for dry needling techniques. As long as specific dry needling and individual risks are properly considered, it does not change the risk and safety profile of dry needling. Under specific circumstances, the use of ultrasound guidance is recommended when available.

Time in Therapeutic Range Using a Nomogram for Dose Adjustment of Warfarin in Patients on Hemodialysis With Atrial Fibrillation

Background:

Patients treated with hemodialysis and prescribed warfarin typically have lower time in therapeutic range (TTR) compared to the general population. This may result in less benefit or increased risk of over anticoagulation in these patients.

Objective:

To assess effectiveness of use of an electronic nomogram for the management of warfarin therapy in patients treated with hemodialysis.

Design:

Retrospective chart review.

Setting:

Adult patients treated with hemodialysis.

Patients:

Patients on hemodialysis receiving warfarin for the management of atrial fibrillation (AF) with therapy managed by nursing led electronic nomogram.

Measurements:

Time in therapeutic range (as fraction and Rosendaal).

Methods:

Retrospective chart review over 1 year of international normalized ratio (INR) results was completed, and TTR was calculated. Comparison of patients with TTR greater than 60% to those less than 60% was completed using chi-square analysis.

Results:

Of 43 patients with warfarin therapy managed by the nomogram, the mean TTR was 55.2% (calculated by fraction method) or 61.2% (calculated by Rosendaal method). More than half of the patients (63.5%) had moderate to good control, defined as TTR greater than 60%. Female sex, liver disease, or history of substance use and more medication holds were associated with lower TTR.

Limitations:

Small sample size and retrospective nature of review.

Conclusions:

The results of this review supports the use of an electronic, nursing-led nomogram for the maintenance management of warfarin therapy in stable patients treated with hemodialysis, as use results in TTR greater than 60% for more than half of patients.

Non-valvular Atrial Fibrillation in CKD: Role of Vitamin K Antagonists and Direct Oral Anticoagulants. A Narrative Review

Atrial fibrillation (AF) is the most common arrhythmia in chronic kidney disease (CKD), with a close bidirectional relationship between the two entities. The presence of CKD in AF increases the risk of thromboembolic events, mortality and bleeding. Vitamin K antagonists (VKA) have been the mainstay of treatment for the prevention of thromboembolic events in AF until recently, with confirmed benefits in AF patients with stage 3 CKD. However, the risk-benefit profile of VKA in patients with AF and stages 4-5 CKD is controversial due to the lack of evidence from randomized controlled trials. Treatment with VKA in CKD patients has been associated with conditions such as poorer anticoagulation quality, increased risk of bleeding, faster progression of vascular/valvular calcification and higher risk of calciphylaxis. Direct oral anticoagulants (DOACs) have shown equal or greater efficacy in stroke/systemic embolism prevention, and a better safety profile than VKA in post-hoc analysis of the pivotal randomized controlled trials in patients with non-valvular AF and stage 3 CKD, yet evidence of its risk-benefit profile in more advanced stages of CKD is scarce. Observational studies associate DOACs with a good safety/effectiveness profile compared to VKA in non-dialysis CKD patients. Further, DOACs have been associated with a lower risk of acute kidney injury and CKD development/progression than VKA. This narrative review summarizes the evidence of the efficacy and safety of warfarin and DOACs in patients with AF at different CKD stages, as well as their effects on renal function, vascular/valvular calcification and bone health.

Prognostic impact of the presence of chronic kidney disease on percutaneous left trial appendage closure for atrial fibrillation: A single center experience

BACKGROUND

Percutaneous left atrial appendage closure (LAAC) has been proposed as an alternative to anticoagulation therapy in patients with nonvalvular atrial fibrillation to decrease the thromboembolic risk, while avoiding the risks of chronic anticoagulation. This option may be attractive in patients with nonvalvular atrial fibrillation and chronic kidney disease (CKD), since they exhibit both high-thromboembolic and bleeding risks.

OBJECTIVE

To evaluate the prognostic impact of the presence of CKD in patients with atrial fibrillation undergoing LAAC peri-procedure and during the follow-up as compared with patients with preserved renal function.

METHODS

Retrospective, observational study that included 124 consecutive patients with atrial fibrillation undergoing LAAC in a university hospital, and the results were evaluated according to the baseline renal function of the patients.

RESULTS

The median age was 75.5 years (IQR 67.6-80) and 62.1% were men, the median of CHA2DS2-Vasc and HASBLED scores was 4 (IQR 3-4) for both scores. Up to 57.3% of the total sample had CKD. Baseline characteristics were similar between groups, but CKD patients were older and had a higher HASBLED score. During the procedure, no thromboembolic, bleeding events, or deaths were observed. Combining the time of hospitalization and follow-up, no significant differences were observed between groups in the annual rate of thromboembolic events (0.97/100 patient-years [100PY] vs. 4.06/100PY, p=.09), but there was a higher rate of bleeding events (5.67/100PY vs. 13.3/100PY, p=.033) and mortality among CKD patients (6.50/100PY vs. 17.2/100PY, p=.009), with an odds ratio of 2.711 (95% CI 1.96-6.95). In the multivariate analysis, a preserved eGFR was independently associated with a lower mortality risk.

CONCLUSIONS

LAAC is a valid alternative to oral anticoagulation in patients with CKD and atrial fibrillation, with a low-rate of peri- and post-procedure complications, although CKD patients exhibited a higher risk of bleeding and mortality during the follow-up. However, these higher rates may not be necessarily related to the procedure.

Relationship between Chronic Kidney Disease, Time-in-Therapeutic Range, and Adverse Outcomes in Atrial Fibrillation: A post hoc Analysis from the AMADEUS Trial

BACKGROUND

The benefit of anticoagulation therapy in atrial fibrillation (AF) and chronic kidney disease (CKD) remains controversial. We aimed to evaluate the impact of renal function on the quality of anticoagulation control, and the effects of both these factors on outcomes in AF.

METHODS

Post hoc analysis of the AMADEUS trial. Trial-related outcomes were adjudicated and we studied the composite of first stroke/major bleeding/all-cause mortality, ischaemic stroke, major bleeding, all-cause mortality, and cardiovascular mortality.

RESULTS

We included 2,282 vitamin K antagonist (VKA)-treated patients {n = 787 (34.5%) females; median age 72 (interquartile ranges [IQR] 64-77) years}. Median follow-up was 365 (IQR 189-460) days. There were 1,922 (84.2%) non-CKD and 360 (15.8%) CKD patients. Renal function was inversely correlated with time-in-therapeutic range (r = -0.047, p = 0.025). There was no statistical difference in terms of crude study outcomes based on renal function. Multivariable regression analysis demonstrated that moderate renal failure with estimated glomerular filtration rate of less than 60 mL/min/1.73 m2 (p = 0.032) and percentage of time-in-therapeutic range (p = 0.011) were independent predictors for the composite outcome of stroke, major bleeding, and all-cause mortality.

CONCLUSION

Deteriorated renal function has a small negative impact on the quality of anticoagulation control with VKA which is linked to poor outcomes in AF. However, moderate renal failure itself was an independent risk factor for increased risk of stroke, major bleeding, and all-cause mortality amongst patients with AF.

Unmet Clinical Needs in Elderly Patients Receiving Direct Oral Anticoagulants for Stroke Prevention in Non-valvular Atrial Fibrillation

Vitamin K antagonists have been used for many years as the treatment of choice for long-term oral anticoagulation in patients with non-valvular atrial fibrillation. Unfortunately, the use of those drugs in the real-world setting, particularly among elderly patients, is suboptimal because of their limitations in management. Therefore, many patients were not adequately anticoagulated. Direct oral anticoagulants have been demonstrated to overcome almost all the limitations derived from the use of vitamin K antagonists. Direct oral anticoagulants are at least as effective as vitamin K antagonists in preventing thromboembolic events in patients with non-valvular atrial fibrillation and safer in reducing the risk of intracranial haemorrhage and all-cause mortality. However, as a result of the strict inclusion and exclusion criteria applied to patients, data coming from randomized controlled trials might not apply to the general population. Furthermore, elderly patients were scarcely represented in randomized controlled trials with direct oral anticoagulants. Therefore in elderly patients with non-valvular atrial fibrillation, unmet clinical needs still exist. This review article highlights some of them and provides potential answers based on the results coming from randomized clinical trials, real-world data, and the authors' clinical experience.

The Clinical Outcomes of Different eGFR Strata and Time in Therapeutic Range in Atrial Fibrillation Patients with Chronic Kidney Disease: A Nationwide Cohort Study

Chronic kidney disease (CKD) is associated with increased risk of stroke, major bleeding, morbidity and overall mortality in atrial fibrillation patients. The aim of this study is to demonstrate the effect of different eGFR strata and the TTR on clinical outcomes in AF patients with CKD.NVAF patients were consecutively enrolled from hospitals across Thailand. eGFR were categorized into three different eGFR categories; eGFR >60, 30-59 and <30 mL/min/1.73 m². TTR values were also categorized into TTR >75%, TTR 60-75 and TTR <60%. We identified 1,739 patients who received warfarin. Among patients who acquired TTR<60, those with eGFR <30 ml/min/1.73 m² demonstrated the highest stroke/SSE rate of 8.5% (P<0.001). Patients with eGFR <30 ml/min/1.73 m², in addition to the presence of TTR<60, were at the highest risk to developing major bleeding with the rate of 17.9% (p <0.001). However, intracranial hemorrhage (ICH) appeared towards increasing rate with the combination of eGFR at even <60 ml/min/1.73 m² and TTR <60. Death was also considerably high with the rate of 17.9% in patients with the combination of TTR <60 and eGFR <30 ml/min/1.73 m². Severe CKD resulted in higher risks of stroke/SSE, major bleeding and death in patients with low TTR. Patients with TTR >60, especially TTR >75%, is associated with reduced risk of stroke/SSE, major bleeding and death irrespective of eGFR level. The combination of low TTR <60 and eGFR level less than 60 ml/min/1.73 m² substantially increased risks of all cardiovascular outcomes.

Rivaroxaban versus warfarin in patients with nonvalvular atrial fibrillation and stage IV-V chronic kidney disease

BACKGROUND

There is limited evidence on the effectiveness and safety of direct-acting oral anticoagulants in patients with nonvalvular atrial fibrillation (NVAF) and advanced chronic kidney disease (CKD). This study compared the risks of ischemic stroke/systemic embolism (ISSE) and major bleeding in patients with NVAF and stage IV-V CKD treated with rivaroxaban or warfarin.

METHODS

Patients with NVAF and stage IV-V CKD who initiated rivaroxaban or warfarin treatment between November 2011 and June 2018 were selected from the Optum® Deidentified Electronic Health Record Database. Propensity score matching was used to balance rivaroxaban and warfarin patients on 112 measured baseline covariates. ISSE and major bleeding events over 2 years following treatment initiation were ascertained with validated end point definitions. Outcomes were analyzed as time-to-event data using Kaplan-Meier survival estimators and Cox regression.

RESULTS

A total of 781 eligible rivaroxaban-treated patients were propensity score-matched to 1,536 warfarin-treated patients; baseline covariates were well balanced after matching (absolute standardized differences <0.1). The average patient age was 80 years; 60.5% were female; 81.3% and 18.7% had CKD stage IV and V, respectively. Hazard ratios for rivaroxaban compared to warfarin were 0.93 (95% CI 0.46-1.90, P = .85) for the risk of ISSE and 0.91 (95% CI 0.65-1.28, P = .60) for major bleeding.

CONCLUSIONS

No statistically significant difference in the risk of ISSE or major bleeding was found between rivaroxaban- and warfarin-treated patients. Although further study is needed, rivaroxaban appears to be a reasonable alternative to warfarin for ISSE prevention in the setting of NVAF and stage IV-V CKD.

Secondary stroke prophylaxis in atrial fibrillation patients with chronic kidney disease: a nationwide cohort study

AIMS

Oral anticoagulation (OAC) therapy as secondary stroke prophylaxis in atrial fibrillation (AF) patients with chronic kidney disease (CKD) remains unexplored and poses a clinical treatment dilemma. We assessed the long-term risk of thromboembolic events according to post-stroke OAC therapy in AF patients with CKD after their first ischaemic stroke.

METHODS AND RESULTS

We identified Danish AF patients with CKD who presented with first-time ischaemic stroke from 2005 to 2014. Chronic kidney disease was defined as a diagnosis code for CKD before baseline, defined as 100 days after stroke discharge. Post-stroke antithrombotic therapy (OAC therapy and antiplatelet therapy) was identified from prescription claims from discharge to baseline. Cumulative incidences and adjusted hazard ratios (HRs) of thromboembolic events according to post-stroke OAC therapy were examined. Of 1252 AF patients with CKD presenting with ischaemic stroke, 631 (50.4%) patients were on OAC therapy and 621 (49.6%) were on antiplatelet therapy alone at baseline [median age 76 (interquartile range, IQR 71-83) and 80 (IQR 72-86), respectively]. The median follow-up period was 1.9 years (IQR 0.8-3.6). Cumulative incidence rates of thromboembolic events and bleeding showed no significant difference between those on OAC therapy and antiplatelet therapy. The results from the multivariable analysis revealed similar results: thromboembolic risk was not modified by OAC treatment [adjusted HR 0.89, 95% confidence interval (CI) 0.73-1.09] nor was the risk of bleeding (adjusted HR 0.88, 95% CI 0.67-1.17).

CONCLUSION

Oral anticoagulation in patients with CKD and prior stroke was not associated with a reduced risk of recurrent thromboembolic events compared with antiplatelet therapy.

Pros and cons of antithrombotic therapy in end-stage kidney disease: a 2019 update

Dialysis patients manifest both an increased thrombotic risk and a haemorrhagic tendency. A great number of patients with chronic kidney disease requiring dialysis have cardiovascular comorbidities (coronary artery disease, atrial fibrillation or venous thromboembolism) and different indications for treatment with antithrombotics (primary or secondary prevention). Unfortunately, few randomized controlled trials deal with antiplatelet and/or anticoagulant therapy in dialysis. Therefore cardiology and nephrology guidelines offer ambiguous recommendations and often exclude or ignore these patients. In our opinion, there is a need for an expert consensus that provides physicians with useful information to make correct decisions in different situations requiring antithrombotics. Herein the European Dialysis Working Group presents up-to-date evidence about the topic and encourages practitioners to choose among alternatives in order to limit bleeding and minimize atherothrombotic and cardioembolic risks. In the absence of clear evidence, these clinical settings and consequent therapeutic strategies will be discussed by highlighting data from observational studies for and against the use of antiplatelet and anticoagulant drugs alone or in combination. Until new studies shed light on unclear clinical situations, one should keep in mind that the objective of treatment is to minimize thrombotic risk while reducing bleeding events.

Percutaneous left atrial appendage closure, a safe alternative to anticoagulation for patients with nonvalvular atrial fibrillation and end-stage renal disease on hemodialysis: A single center experience

The evidence about the effectiveness and safety of oral anticoagulation in patients on hemodialysis is conflicting and scarce. Percutaneous left atrial appendage occlusion (LAAO) has demonstrated to be a valid alternative therapeutic option for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF). The aim of this study is to present the outcomes of percutaneous LAAO in patients with end-stage renal disease (ESRD) on hemodialysis and NVAF in our center. We conducted a retrospective review of clinical records, demographics, LAAO procedure, complications, and outcomes of patients with NVAF and ESRD on hemodialysis who underwent a percutaneous LAAO in our center between January 2017 and January 2019. In the period of the study, eight patients with ESRD on hemodialysis underwent a percutaneous LAAO in our center. The overall mean age was 67.5 years (range 56-81; SD ± 7.2). All patients had permanent NVAF. The total mean dialysis duration was 8.49 years (range 0.83-14.8; SD ± 6.2). The mean CHA2DS2-VASc and HAS-BLED scores were high (4.75 [SD ± 1.16] and 4.62 [SD ± 0.91], respectively). All patients had history of a major hemorrhagic event (BARC Score ≥3). Most patients (n = 6) showed left ventricular hypertrophy, and the average LVEF was 54% (SD ± 6.5). All devices were implanted successfully. Postprocedural antithrombotic regimen prescribed was based on antiplatelet therapy. No deaths, cardioembolic events, or major bleeding (according to the BARC scale) were reported during a mean follow-up of 14.24 months (SD ± 9.44). Percutaneous LAAO could be of particular interest in patients with NVAF and CKD in hemodialysis. Further studies will be necessary to confirm this hypothesis.

Increasing Time in Therapeutic Range of Tacrolimus in the First Year Predicts Better Outcomes in Living-Donor Kidney Transplantation

Background: The aim of the present study was to investigate the impact of time in therapeutic range TTR on long-term outcomes of living kidney transplants.

Methods: We included 1,241 living kidney transplants and randomized them into development and validation cohorts with a ratio of 2:1. The tacrolimus TTR percentage was calculated by linear interpolation with a target range (5–10 ng/ml months 0–3, 4–8 ng/ml months 4–12). The optimal TTR cutoff was estimated by the receiver operating characteristic curve analysis on the basis of acute rejection (AR) within 12 months in the development cohort. Outcomes were analyzed between patients with high TTR and low TTR in the development and validation cohorts, respectively. The TTR was also compared with other tacrolimus measures.

Results: The optimal TTR cutoff value was 78%. In the development cohort, patients with TTR > 78% had significantly higher rejection- and infection-free survival. TTR < 78% was an independent risk factor for AR (OR: 2.97, 95%CI: 1.82–4.84) and infection (OR: 1.55, 95%CI: 1.08–2.22). Patient and graft survival were significantly higher in those with TTR>78%, and TTR<78% was associated with graft loss (OR: 3.2, 95%CI: 1.38–7.42) and patient death (OR: 6.54, 95%CI: 1.34–31.77). These findings were confirmed in the validation cohort. Furthermore, we divided all included patients into a high and low TTR group. TTR was more strongly associated with patient and graft survival than mean level, standard deviation, and intrapatient variability (IPV).

Conclusions: Increasing the TTR of tacrolimus in the first year was associated with improved long-term outcomes in living kidney transplants, and TTR may be a novel valuable strategy to monitor tacrolimus exposure.

Group-based Trajectory Models to Assess Quality of INR Control and Its Association With Clinical Outcomes

Supplemental Digital Content is available in the text.

The Time in Therapeutic Range (TTR) is the gold-standard measure used to assess the quality of oral anticoagulation with vitamin K antagonists. However, TTR is a static measure, and International Normalized Ratio (INR) control is a dynamic process. Group-based Trajectory Models (GBTM) can address this dynamic nature by classifying patients into different trajectories of INR control over time.

De Ritis ratio as a significant prognostic factor of international normalized ratio ≥4 in the initial 10 days of warfarin therapy

Aim: To assess the relationship between the De Ritis ratio on admission and warfarin sensitivity in the initial 10 days of anticoagulation therapy. Methods: We retrospectively reviewed data from 906 patients who underwent heart valve replacement surgery. Results: A De Ritis ratio of 1.19 was identified as the optimal cutoff according to the ROC curve. Patients with a high De Ritis ratio achieved an international normalized ratio (INR) ≥4 more easily and earlier than those with a low De Ritis ratio in the initial 10 days of warfarin therapy. Multivariate analysis showed that a high De Ritis ratio was an independent predictor of an INR ≥4 (HR: 2.567; p < 0.001). Conclusion: A De Ritis ratio ≥1.19 on admission was significantly associated with an INR ≥4 in the initial 10 days of warfarin therapy among patients underwent heart valve replacement surgery.

Association of preceding antithrombotic therapy in atrial fibrillation patients with ischaemic stroke, intracranial haemorrhage, or gastrointestinal bleed and mortality

Aims

To analyse 90-day mortality in atrial fibrillation (AF) patients after a stroke or a severe bleed and assess associations with the type of antithrombotic treatment at the event.

Methods and results

From the Stockholm Healthcare database, we selected 6017 patients with a known history of AF who were diagnosed with ischaemic stroke, 3006 with intracranial haemorrhage, and 4291 with a severe gastrointestinal bleed (GIB). The 90-day mortality rates were 25.1% after ischaemic stroke, 31.6% after intracranial haemorrhage, and 16.2% after severe GIB. We used Cox regression and propensity score-matched analyses to test the association between antithrombotic treatment at the event and 90-day mortality. After intracranial haemorrhage, there was a significantly higher mortality rate in warfarin compared to non-vitamin K oral anticoagulant (NOAC)-treated patients [adjusted hazard ratio (aHR) 1.36, 95% confidence interval (CI) 1.04–1.78]. After an ischaemic stroke and a severe GIB, patients receiving antiplatelets or no antithrombotic treatment had significantly higher mortality rates compared to patients on NOACs, but there was no difference comparing warfarin to NOACs (aHR 0.84, CI 0.63–1.12 after ischaemic stroke, aHR 0.91, CI 0.66–1.25 after severe GIB). Propensity score-matched analysis yielded similar results.

Conclusion

Mortality rates were high in AF patients suffering from an ischaemic stroke, an intracranial haemorrhage, or a severe GIB. NOAC treatment was associated with a lower 90-day mortality after intracranial haemorrhage than warfarin.

Differences in the quality of oral anticoagulation therapy with vitamin K antagonists in German GP practices - results of the cluster-randomized PICANT trial (Primary Care Management for Optimized Antithrombotic Treatment)

Background

In Germany, patients receiving oral anticoagulation (OAC) are often treated by general practitioners (GPs), and large proportions of patients receive vitamin K antagonists (VKAs). The quality of OAC in German GP practices, differences between various practices, and improvement potential through implementation of case management, have not yet been investigated satisfactorily.

Based on results of a cluster-randomized controlled trial, we aimed to assess whether OAC quality can be improved, any variations between practices exist and determine practice- and patient-level factors.

Methods

The PICANT trial (2012–2015) was performed in 52 GP practices in Hesse, Germany. Adult patients with long-term indication for OAC received best practice case management in the intervention group. International normalized ratio (INR) values were recorded from anticoagulation passes. The Rosendaal method was used to calculate Time in Therapeutic Range (TTR) at patient level, and mean pooling to obtain center-specific TTR (cTTR) at practice level. The quality of OAC was assessed by TTR and cTTR. Linear model analyses were used to investigate associations between practice−/ patient-level factors and TTR.

Results

Inclusion of 736 patients (49.6% intervention and 50.4% control patients); 690 (93.8%) received phenprocoumon. Within 24 months, the TTR was 75.1% (SD 17.6) in the intervention versus 74.3% (SD 17.8) in the control group (p = 0.670). The cTTR averaged 75.1% (SD 6.5, range: 60.4 to 86.7%) in the intervention versus 74.3% (SD 7.2, range: 52.7 to 85.7%) in the control group (p = 0.668). At practice level, the TTR was significantly lower in practices with a male physician and certification in quality management. At patient level, the TTR was significantly higher in patients with moderate to high compliance, in men, and in patients that performed self-management. The TTR was significantly lower in patients with certain comorbidities, and who were hospitalized.

Conclusions

The intervention did not effectively improve OAC quality compared to routine care. Quality of INR control was generally good, but considerable variation existed between GP practices. The variability indicates optimization potential in some practices. The demonstrated association between patient-level factors and TTR highlights the importance of considering patient characteristics that may impede achieving high quality therapeutic outcomes.

Trial registration

ISRCTN registry, ISRCTN41847489, registered 27 February 2012.

Electronic supplementary material

The online version of this article (10.1186/s12913-019-4372-y) contains supplementary material, which is available to authorized users.

Risk factors for thromboembolic and bleeding events in anticoagulated patients with atrial fibrillation: the prospective, multicentre observational PREvention oF thromboembolic events - European Registry in Atrial Fibrillation (PREFER in AF)

OBJECTIVES

We identified factors associated with thromboembolic and bleeding events in two contemporary cohorts of anticoagulated patients with atrial fibrillation (AF), treated with either vitamin K antagonists (VKA) or non-VKA oral anticoagulants (NOACs).

DESIGN

Prospective, multicentre observational study.

SETTING

461 centres in seven European countries.

PARTICIPANTS

5310 patients receiving a VKA (PREvention oF thromboembolic events - European Registry in Atrial Fibrillation (PREFER in AF), derivation cohort) and 3156 patients receiving a NOAC (PREFER in AF Prolongation, validation cohort) for stroke prevention in AF.

OUTCOME MEASURES

Risk factors for thromboembolic events (ischaemic stroke, systemic embolism) and major bleeding (gastrointestinal bleeding, intracerebral haemorrhage and other life-threatening bleeding).

RESULTS

The mean age of patients enrolled in the PREFER in AF registry was 72±10 years, 40% were female and the mean CHA₂DS₂-VASc Score was 3.5±1.7. The incidence of thromboembolic and major bleeding events was 2.34% (95% CI 1.93% to 2.74%) and 2.84% (95% CI 2.41% to 3.33%) after 1-year of follow-up, respectively.Abnormal liver function, prior stroke or transient ischaemic attack, labile international normalised ratio (INR), concomitant therapy with antiplatelet or non-steroidal anti-inflammatory drugs, heart failure and older age (≥75 years) were independently associated with both thromboembolic and major bleeding events.With the exception of unstable INR values, these risk factors were validated in patients treated with NOACs (PREFER in AF Prolongation Study, 72±9 years, 40% female, CHA₂DS₂-VASc 3.3±1.6). For each single point decrease on a modifiable bleeding risk scale we observed a 30% lower risk for major bleeding events (OR 0.70, 95% CI 0.64 to 0.76, p<0.01) and a 28% lower rate of thromboembolic events (OR 0.72, 95% CI 0.66 to 0.82, p<0.01).

CONCLUSION

Attending to modifiable risk factors is an important treatment target in anticoagulated AF patients to reduce thromboembolic and bleeding events. Initiation of anticoagulation in those at risk of stroke should not be prevented by elevated bleeding risk scores.

Management and 1-Year Outcomes of Patients With Newly Diagnosed Atrial Fibrillation and Chronic Kidney Disease: Results From the Prospective GARFIELD - AF Registry

Background Using data from the GARFIELD - AF (Global Anticoagulant Registry in the FIELD -Atrial Fibrillation), we evaluated the impact of chronic kidney disease ( CKD ) stage on clinical outcomes in patients with newly diagnosed atrial fibrillation ( AF ). Methods and Results GARFIELD - AF is a prospective registry of patients from 35 countries, including patients from Asia (China, India, Japan, Singapore, South Korea, and Thailand). Consecutive patients enrolled (2013-2016) were classified with no, mild, or moderate-to-severe CKD , based on the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative guidelines. Data on CKD status and outcomes were available for 33 024 of 34 854 patients (including 9491 patients from Asia); 10.9% (n=3613) had moderate-to-severe CKD , 16.9% (n=5595) mild CKD , and 72.1% (n=23 816) no CKD . The use of oral anticoagulants was influenced by stroke risk (ie, post hoc assessment of CHA 2 DS 2- VAS c score), but not by CKD stage. The quality of anticoagulant control with vitamin K antagonists did not differ with CKD stage. After adjusting for baseline characteristics and antithrombotic use, both mild and moderate-to-severe CKD were independent risk factors for all-cause mortality. Moderate-to-severe CKD was independently associated with a higher risk of stroke/systemic embolism, major bleeding, new-onset acute coronary syndrome, and new or worsening heart failure. The impact of moderate-to-severe CKD on mortality was significantly greater in patients from Asia than the rest of the world ( P=0.001). Conclusions In GARFIELD - AF , moderate-to-severe CKD was independently associated with stroke/systemic embolism, major bleeding, and mortality. The effect of moderate-to-severe CKD on mortality was even greater in patients from Asia than the rest of the world. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01090362.

Individual and monitoring centre influences upon anticoagulation control of AF patients on warfarin: A longitudinal multi-centre UK-based study

OBJECTIVES

Time within therapeutic INR range (TTR) predicts benefits/risk of warfarin therapy. Identification of individual- and centre-related factors that influence TTR, and addressing them to improve anticoagulation control, are important. This study examined the impact of individual and centre-related factors upon long-term anticoagulation control in atrial fibrillation patients in seven UK-based monitoring services.

METHODS

Data between 2000 and 2014 on 25 270 patients (equating to 203 220 patient years) [18 120 (71.7%) in general practice, 2348 (9.3%) in hospital-based clinics and 4802 (19.0%) in domiciliary service] were analysed.

RESULTS

TTR increased with increasing age, peaking around 77% at 70-75 years, and then declined, was lower in females than males, and in dependent home-monitored patients than those attending clinic (P < 0.0001). TTR, number of dose changes and INR monitoring events and the probability of TTR ≤ 65%, differed across the centres (P < 0.0001).

CONCLUSIONS

Although all the participating centres ostensively followed a standard dosing algorithm, our results indicate that variations in practice do occur between different monitoring sites. We suggest feedback on TTR for individual monitoring sites gauged against the average values reported by others would empower the individual centres to improve quality outcomes of anticoagulation therapy by identifying and adjusting contributory factors within their management system.

Renal Dysfunction Affects Anticoagulation Control With Warfarin and Outcomes in Japanese Elderly Patients With Non-Valvular Atrial Fibrillation

BACKGROUND

It is unclear whether renal dysfunction affects warfarin control in patients with non-valvular atrial fibrillation (NVAF). Methods and Results: Using a dataset from the J-RHYTHM Registry, time in therapeutic range (TTR) of the international normalized ratio (INR) of prothrombin time, and creatinine clearance (CrCl) were determined in elderly patients aged ≥70 years. Target INR values were 1.6-2.6 following Japanese guidelines. Incidences of thromboembolism, major hemorrhage, and all-cause death were determined over 2 years. Of 7,406 NVAF patients enrolled in the registry, 2,782 elderly patients (mean age, 75 years) had data for CrCl measured at baseline and TTR. TTR values were lower in the lower CrCl groups (P<0.001 for trend). CrCl <30 mL/min was independently associated with TTR <65% (odds ratio, 1.49; 95% confidence interval, 1.13-1.95; P=0.004). In the multivariate analysis, TTR <65% was independently associated with thromboembolism (hazard ratio, 2.26; 95% confidence interval, 1.37-3.72; P=0.001), but CrCl was not (CrCl <30 mL/min, 1.68, 0.41-6.85, P=0.473). However, CrCl <30 mL/min and TTR <65% were independently associated with all-cause death (5.32, 1.56-18.18, P=0.008 and 1.60, 1.07-2.38, P=0.022, respectively) and the composite event (thromboembolism, major hemorrhage and all-cause death) (2.03, 1.10-3.76, P=0.024 and 1.58, 1.22-2.04, P=0.001, respectively).

CONCLUSIONS

Elderly NVAF patients with renal dysfunction had poor warfarin control, which was associated with higher risk of thromboembolism and all-cause death.

Long-term prognostic impact of anticoagulation on patients with atrial fibrillation undergoing hemodialysis

INTRODUCTION AND OBJECTIVES

Evidence for the efficacy and safety of oral anticoagulation with dicumarines in patients with atrial fibrillation (AF) on hemodialysis is controversial. The aim of our study is to evaluate the long-term prognostic implications of anticoagulation with dicumarines in a cohort of patients with non-valvular AF on a hemodialysis program due to end-stage renal disease.

METHODS

Retrospective, observational study with consecutive inclusion of 74 patients with AF on hemodialysis. The inclusion period was from January 2005 to October 2016. The primary variables were all-cause mortality, non-scheduled readmissions and bleeding during follow-up.

RESULTS

Mean age was 75±10 years; 66.2% were men and 43 patients (58.1%) received acenocoumarol. During a median follow-up of 2.40 years (IQR=0.88-4.15), acenocoumarol showed no survival benefit [HR=0.76, 95% CI (0.35-1.66), p=0.494]. However, anticoagulated patients were at increased risk of recurrent cardiovascular hospitalizations [IRR=3.94, 95% CI (1.06-14.69), p=0.041]. There was a trend towards an increase in repeated hospitalizations of ischemic cause in anticoagulated patients [IRR=5.80, 95% CI (0.86-39.0), p=0.071]. There was a statistical trend towards a higher risk of recurrent total bleeding in patients treated with acenocoumarol [IRR=4.43, 95% CI (0.94-20.81), p=0.059].

CONCLUSIONS

In this study, oral anticoagulation with acenocoumarol in patients with AF on hemodialysis did not increase survival. However, it was associated with an increased risk of hospitalizations of cardiovascular causes and a tendency to an increased risk of total bleeding.

Primary Prevention of Stroke in Chronic Kidney Disease Patients: A Scientific Update

BACKGROUND

Although chronic kidney disease (CKD) is an independent risk factor for stroke, official recommendations for the primary prevention of stroke in CKD are generally lacking.

SUMMARY

We searched PubMed and ISI Web of Science for randomised controlled trials, observational studies, reviews, meta-analyses and guidelines referring to measures of stroke prevention or to the treatment of stroke-associated risk factors (cardiovascular disease in general and atrial fibrillation (AF), arterial hypertension or carotid artery disease in particular) among the CKD population. The use of oral anticoagulation in AF appears safe in non-end stage CKD, but it should be individualized and preferably based on thromboembolic and bleeding stratification algorithms. Non-vitamin K antagonist oral anticoagulants with definite dose adjustment are generally preferred over vitamin K antagonists in mild and moderate CKD and their indications have started being extended to severe CKD and dialysis also. Aspirin, but not clopidogrel, has limited indications for reducing the risk for atherothrombotic events in CKD due to its increased bleeding risk. Carotid endarterectomy has shown promising results for stroke risk reduction in CKD patients with high-grade symptomatic carotid stenosis. The medical treatment of arterial hypertension in CKD often fails to efficiently lower blood pressure values, but recent data regarding the use of interventional procedures such as renal denervation, baroreflex activation therapy or renal artery stenting are encouraging. Key Messages: In the absence of clear guidelines and protocols, primary prevention of stroke in CKD patients remains a subtle art in the hands of the clinicians. Nevertheless, refraining CKD patients from standard therapies often worsens their prognosis.

Laboratory characteristics of ischemic stroke patients with atrial fibrillation on or off therapeutic warfarin

BACKGROUND

In patients with atrial fibrillation (AF), despite adequate anticoagulation, ischemic stroke (IS) is an uncommon yet concerning occurrence.

HYPOTHESIS

Specific laboratory parameters may affect the efficacy of warfarin despite therapeutic international normalized ratio (INR) in patient with AF who present with IS.

METHODS

We used the database from a multicenter clinical trial to identify AF patients who presented with IS. We trichotomized the cohort into patients with therapeutic INR on warfarin, subtherapeutic INR on warfarin, and on no anticoagulants. We then compared baseline laboratory characteristics and other baseline features among the groups.

RESULTS

Patients with therapeutic INR presented with higher serum creatinine (P = 0.01) and blood urea nitrogen (P = 0.02) and lower glomerular filtration rates (P = 0.001) compared with other groups. Other laboratory parameters were not different among the 3 groups. Patients with therapeutic INR also presented with milder stroke symptoms (P = 0.01). Medical history of the 3 groups was not different, except for history of valvular heart disease, which was more prevalent in patients with therapeutic INR (P = 0.004). In-hospital mortality rates and 90-day disability were not different among the 3 groups.

CONCLUSIONS

AF patients who presented with IS on therapeutic warfarin had higher average serum creatinine and blood urea nitrogen, and lower glomerular filtration rates, compared with others. Impaired renal function may be a factor contributing to occurrence of IS in AF patients despite adequate anticoagulation. Larger, targeted studies are needed to confirm these findings.

Chronic kidney disease and anticoagulation: from vitamin K antagonists and heparins to direct oral anticoagulant agents

Anticoagulation in patients with impaired kidney function can be challenging since drugs' pharmacokinetics and bioavailability are altered in this setting. Patients with chronic kidney disease (CKD) treated with conventional anticoagulant agents [vitamin K antagonist (VKA), low-molecular weight heparin (LMWH) or unfractionated heparin (UFH)] are at high risk of bleeding events (both non-major and major clinically relevant bleeding). While anticoagulation reduces the risk of thromboembolic events, the co-existing bleeding risk and the fact that the most commonly used anticoagulation agents are eliminated via the kidneys pose additional challenges. More recently, two classes of direct oral anticoagulant agents (DOACs) have been investigated for the prevention and management of venous thromboembolic events: the direct factor Xa inhibitors rivaroxaban, apixaban and edoxaban, and the direct thrombin inhibitor dabigatran. In this review, we discuss the complex challenges and the practical considerations associated with the management of anticoagulation treatment in patients with CKD, with a special focus on DOACs.

Factors influencing warfarin control in Australia and Singapore

INTRODUCTION

Warfarin is widely used for patients with non-valvular atrial fibrillation (NVAF). Variations in warfarin control, as measured by time in therapeutic range (TTR), have been reported across different regions and ethnicities, particularly between Western and Asian countries. However, there is limited data on comparative factors influencing warfarin control in Caucasian and Asian patients. Therefore, the aim of this study was to determine warfarin control and potential factors influencing this in patients with NVAF in Australia and Singapore.

METHODS

Retrospective data was collected for patients receiving warfarin for January to June 2014 in Australia and Singapore. TTR was calculated for individuals with mean patient TTR used for analysis. Possible influential factors on TTR were analysed including age, gender, concurrent co-morbidities, and concurrent medication.

RESULTS

The mean TTR was significantly higher in Australia (82%) than Singapore (58%). At both sites, chronic kidney disease significantly lowered this TTR. Further factors influencing control were anaemia and age<60years in Australia, and vascular disease, CHA₂DS₂-VASc score of 6, and concurrent platelet inhibitor therapy in Singapore.

DISCUSSION

Warfarin control was significantly higher in Australia compared to Singapore, however chronic kidney disease reduced control at both sites. The different levels of control in these two countries, together with patient factors further reducing control may impact on anticoagulant choice in these countries with better outcomes from warfarin in Australia compared to Singapore.

Predicting in a predicament: Stroke and hemorrhage risk prediction in dialysis patients with atrial fibrillation

Whether to anticoagulate dialysis patients with atrial fibrillation is a common clinical dilemma with limited high-quality data to inform decision-making. While the efficacy and safety of anticoagulation for stroke prevention in dialysis patients with atrial fibrillation has long been debated and remains unclear, the more upstream issue of stroke risk assessment from atrial fibrillation has received relatively little attention. In the general population, a handful of risk scores to help predict stroke and hemorrhage risk in the setting of atrial fibrillation are widely validated and applied in clinical practice. But are they applicable to the dialysis population? The most commonly used stroke risk scores, CHADS2 and CHA2DS2-VASC, have limited validation in the dialysis population, and when validated, have shown poor performance (c-statistics <0.70). Stroke risk scores derived in the general atrial fibrillation population may perform poorly in dialysis patients for a number of reasons. Dialysis patients have unique stroke risk factors, such as chronic inflammation and vascular calcification, and a much higher competing risk of death, none of which are accounted for in current risk scores. Further complicating the dilemma of anticoagulation is hemorrhage risk, which is known to be exceedingly high in dialysis patients. Currently available hemorrhage risk scores, such as HAS-BLED, have not been validated in dialysis patients and will likely underestimate hemorrhage risk. Moving forward, risk tools specific to the dialysis population are needed to accurately assess and balance stroke and hemorrhage risks in dialysis patients with atrial fibrillation.

Direct oral anticoagulants in patients with chronic kidney disease: patient selection and special considerations

Many patients with chronic kidney disease (CKD) receive anticoagulation or antiplatelet therapy due to atrial fibrillation, coronary artery disease, thromboembolic disease, or peripheral artery disease. The treatment usually includes vitamin K antagonists (VKAs) and/or platelet aggregation inhibitors. The direct oral anticoagulants (DOAC) inhibiting factor Xa or thrombin represent an alternative for VKAs. In patients with acute and chronic kidney disease, caution is warranted, as DOACs can accumulate as they are partly eliminated by the kidneys. Thus, they can potentially increase the bleeding risk in patients with CKD. In patients with an estimated glomerular filtration rate (eGFR) above 60 mL/min, DOACs can be used safely with greater efficacy and safety as compared to VKAs. In patients with CKD 3, DOACs are as effective as VKAs with a lower bleeding rate. The more the renal function declines, the lower is the advantage of DOACs over VKAs. Thus, use of DOACs should be avoided in patients with an eGFR below 30 mL/min, particularly, the compounds with a high renal elimination. Available data suggest that DOACs can also be used safely in older patients. In this review, use of DOACs in comparison with VKAs, heparins, and heparinoids, together with special considerations in patients with impaired renal function will be discussed.