Renal impairment and ischemic stroke risk assessment in patients with atrial fibrillation: the Loire Valley Atrial Fibrillation Project

Estimated glomerular filtration rate and the risk of stroke in individuals with diabetes mellitus and atrial fibrillation insight from a large contemporary population study

BACKGROUND

Diabetes mellitus (DM) is associated with increased risk of embolic complications in non-valvular atrial fibrillation (NVAF). Impaired renal function (IRF) increases the risk of stroke as well, but this finding is not consistent among all studies. Our aim was to assess the incidence rates and risk of ischemic stroke and mortality by baseline Estimated Glomerular Filtration Rate (eGFR) levels Among individuals with AF and DM.

METHODS

A prospective, historical cohort study using the Clalit Health Services electronic medical records database. Among patients with AF and DM, we compared three groups according to eGFR levels: eGFR ≥ 60, between 30 and 60, and ≤ 30 (mL/min/1.73m2).

RESULTS

A total of 17,567 cases were included in the final analysis; of them, 11,013 (62.7%) had eGFR ≥ 60, 4930 (28%) had eGFR between 30 and 60, and 1624 (9.24%) with eGFR ≤ 30. The incidence of stroke per 100 person-years in the three study groups was: 1.88, 2.69, and 3.34, respectively (p < 0.001). IRF was associated with increased risk of stroke in univariate analysis, but not after multivariate adjustment (Adjusted Hazard Ratio (AHR) 0.96 {95%CI; 0.74-1.25} for eGFR 30-60 and 0.96 {95%CI; 0.60-1.55} for eGFR ≤ 30). Mortality per 100 person-years was 10.78, 21.49, and 41.55, respectively (p < 0.001). IRF was associated with increased mortality risk in univariate analysis, as well as in multivariate analysis (AHR 1.08 {95%CI; 0.98-1.18} for eGFR 30-60, and 1.59 {95%CI; 1.37-1.85} for eGFR ≤ 30.

CONCLUSION

In patients with NVAF and DM, IRF was not associated with an increased risk of stroke, but severe IRF (eGFR ≤ 30) was associated with increased mortality risk.

Phenotypes and outcomes in non-anticoagulated patients with atrial fibrillation: An unsupervised cluster analysis

BACKGROUND

Patients with atrial fibrillation are characterized by great clinical heterogeneity and complexity. The usual classifications may not adequately characterize this population. Data-driven cluster analysis reveals different possible patient classifications.

AIMS

To identify different clusters of patients with atrial fibrillation who share similar clinical phenotypes, and to evaluate the association between identified clusters and clinical outcomes, using cluster analysis.

METHODS

An agglomerative hierarchical cluster analysis was performed in non-anticoagulated patients from the Loire Valley Atrial Fibrillation cohort. Associations between clusters and a composite outcome comprising stroke/systemic embolism/death and all-cause death, stroke and major bleeding were evaluated using Cox regression analyses.

RESULTS

The study included 3434 non-anticoagulated patients with atrial fibrillation (mean age 70.3±17 years; 42.8% female). Three clusters were identified: cluster 1 was composed of younger patients, with a low prevalence of co-morbidities; cluster 2 included old patients with permanent atrial fibrillation, cardiac pathologies and a high burden of cardiovascular co-morbidities; cluster 3 identified old female patients with a high burden of cardiovascular co-morbidities. Compared with cluster 1, clusters 2 and 3 were independently associated with an increased risk of the composite outcome (hazard ratio 2.85, 95% confidence interval 1.32-6.16 and hazard ratio 1.52, 95% confidence interval 1.09-2.11, respectively) and all-cause death (hazard ratio 3.54, 95% confidence interval 1.49-8.43 and hazard ratio 1.88, 95% confidence interval 1.26-2.79, respectively). Cluster 3 was independently associated with an increased risk of major bleeding (hazard ratio 1.72, 95% confidence interval 1.06-2.78).

CONCLUSION

Cluster analysis identified three statistically driven groups of patients with atrial fibrillation, with distinct phenotype characteristics and associated with different risks for major clinical adverse events.

Association of atrial myopathy in mitral valve disease on safety outcomes in left atrial appendage closure

BACKGROUND

Patients undergoing left atrial appendage (LAA) occlusion (LAAO) are multi-morbid, including mitral valve disease (MVD) which is associated with anatomic changes of the left atrium (LA). This study aims to identify how atrial myopathy in MVD influences outcomes in LAAO.

METHODS

Atrial myopathy in MVD was defined as LA diameter > 45 mm (♀) and > 48 mm (♂) and existing MVD or history of surgical/interventional treatment. Patients were compared with controls from the prospective, multicentre LAArge registry of LAAO.

RESULTS

A total of 528 patients (52 MVD, 476 no-MVD) were included. The MVD group was significantly more likely to be older (78.2 years vs 75.9 years, p = 0.036) and female (59.6% vs 37.8%, p = 0.002). Altered LA anatomy was observed in MVD with significantly larger LA diameter (53 mm vs. 48 mm, p < 0.001) and LAA Ostia [at 135° 23.0 mm (20.5, 26.0) vs 20.0 mm (18.0, 23.0), p = 0.002]. Implant success was high with 96.2% and 97.9%, respectively, without differences in severe complications (7.7% vs 4.6%, p = 0.31). One-year mortality (17.8% vs 11.5%, p = 0.19) and a combined outcome of death, stroke, and systemic embolism (20.3% vs 12.4%, p = 0.13) were not different. Independent predictors of the combined outcome were peripheral artery disease (HR 2.41, 95% CI 1.46-3.98, p < 0.001) and chronic kidney disease (HR 3.46, 95% CI 2.02-5.93, p < 0.001) but not MVD and atrial myopathy.

CONCLUSION

Patients with MVD present with altered LA anatomy with increased LA and LAA diameter. However, procedural success and safety in LAAO are not compromised. One-year mortality is numerically higher in patients with MVD but driven by comorbidities.

Efficacy and Safety of Renal Function on Edoxaban Versus Warfarin for Atrial Fibrillation: A Systematic Review and Meta-Analysis

Background: Edoxaban is a novel oral anticoagulant which may decrease the risk of stroke and systemic embolism in patients suffering from atrial fibrillation (AF). However, the decreased efficacy of edoxaban versus warfarin for the avoidance of stroke and systemic embolism in AF with creatinine clearance (CrCl) > 95 mL/min has been reported. The purpose of this meta-analysis is to further clarify the safety (major bleeding) and efficacy (stroke or systemic embolism) of edoxaban for AF patients with various CrCl. Methods: A systematic search of studies on edoxaban and warfarin in AF patients related to renal function was conducted in PubMed, Medline, Web of Science databases, EBSCO, Embase, and the Cochrane Central Register of Controlled Trials. In this meta-analysis (protocol number: PROSPERO CRD 42021245512), we included studies that provide specific data on three outcomes: ischemic stroke or systemic embolism (S/SE), bleeding, and all-cause mortality. Results: This meta-analysis enrolled two randomized controlled trials (RCTs) studies and two retrospective studies that enrolled 28,065 patients. According to CrCl, subjects are divided into three groups (CrCl 30−50 mL/min, CrCl 50−95 mL/min, CrCl > 95 mL/min). In AF patients with CrCl 30−50 mL/min, edoxaban 30 mg daily is similar to warfarin in the prevention of ischemic S/SE and all-cause mortality, resulting in lower bleeding rate and better net clinical outcome (ischemic S/SE: hazard ratio (HR), 0.85, 95% confidence interval (CI), 0.19−1.87; all-cause mortality: HR, 0.65, 95% CI, 0.35−1.19; bleeding: HR, 0.75, 95% CI, 0.60−0.93; net clinical outcome: HR, 0.75, 95% CI, 0.63−0.90). In the group of CrCl 50−95 mL/min, the net clinical outcome was more favorable with edoxaban 60 mg daily than warfarin (HR, 0.81, 95% CI: 0.68−0.96), and there was no significant difference between edoxaban 60 mg daily and warfarin in terms of prevention of bleeding, ischemic S/SE, and all-cause mortality. For AF patients with CrCl > 95 mL/min, there was a statistically significant difference in lower bleeding rate between edoxaban 60 mg daily and warfarin (bleeding: HR: 0.70, 95% CI: 0.58−0.84). There was no differential safety in ischemic S/SE, all-cause mortality, and net clinical outcome. Conclusion: Overall, edoxaban was superior to warfarin in terms of net clinical outcome in various groups of CrCl with AF patients. Although there was no significant difference in net clinical outcome between edoxaban and warfarin for AF patients with CrCl > 95 mL/min, edoxaban is not inferior to warfarin in safety and effectiveness in the various levels of CrCl. Edoxaban may be a more effective and safe treatment than warfarin for patients with chronic kidney disease (CKD) who require anticoagulation. More high-quality and long-term clinical research are needed to further estimate the effects of edoxaban.

A review of risk concepts and models for predicting the risk of primary stroke

Predicting an individual's risk of primary stroke is an important tool that can help to lower the burden of stroke for both the individual and society. There are a number of risk models and risk scores in existence but no review or classification designed to help the reader better understand how models differ and the reasoning behind these differences. In this paper we review the existing literature on primary stroke risk prediction models. From our literature review we identify key similarities and differences in the existing models. We find that models can differ in a number of ways, including the event type, the type of analysis, the model type and the time horizon. Based on these similarities and differences we have created a set of questions and a system to help answer those questions that modelers and readers alike can use to help classify and better understand the existing models as well as help to make necessary decisions when creating a new model.

Comprehensive comparison of stroke risk score performance: a systematic review and meta-analysis among 6 267 728 patients with atrial fibrillation

AIMS

Multiple risk scores to predict ischaemic stroke (IS) in patients with atrial fibrillation (AF) have been developed. This study aims to systematically review these scores, their validations and updates, assess their methodological quality, and calculate pooled estimates of the predictive performance.

METHODS AND RESULTS

We searched PubMed and Web of Science for studies developing, validating, or updating risk scores for IS in AF patients. Methodological quality was assessed using the Prediction model Risk Of Bias ASsessment Tool (PROBAST). To assess discrimination, pooled c-statistics were calculated using random-effects meta-analysis. We identified 19 scores, which were validated and updated once or more in 70 and 40 studies, respectively, including 329 validations and 76 updates-nearly all on the CHA2DS2-VASc and CHADS2. Pooled c-statistics were calculated among 6 267 728 patients and 359 373 events of IS. For the CHA2DS2-VASc and CHADS2, pooled c-statistics were 0.644 [95% confidence interval (CI) 0.635-0.653] and 0.658 (0.644-0.672), respectively. Better discriminatory abilities were found in the newer risk scores, with the modified-CHADS2 demonstrating the best discrimination [c-statistic 0.715 (0.674-0.754)]. Updates were found for the CHA2DS2-VASc and CHADS2 only, showing improved discrimination. Calibration was reasonable but available for only 17 studies. The PROBAST indicated a risk of methodological bias in all studies.

CONCLUSION

Nineteen risk scores and 76 updates are available to predict IS in patients with AF. The guideline-endorsed CHA2DS2-VASc shows inferior discriminative abilities compared with newer scores. Additional external validations and data on calibration are required before considering the newer scores in clinical practice.

CLINICAL TRIAL REGISTRATION

ID CRD4202161247 (PROSPERO).

Chronic kidney disease and risks of adverse clinical events in patients with atrial fibrillation

BACKGROUND

Chronic kidney disease (CKD) is highly prevalent in patients with atrial fibrillation (AF). However, the association between CKD and clinical consequences in AF patients is still under debate.

METHODS

We included 19,079 nonvalvular AF patients with available estimated glomerular filtration rate (eGFR) values in the Chinese Atrial Fibrillation Registry from 2011 to 2018. Patients were classified into no CKD (eGFR ≥ 90 mL/min per 1.73 m²), mild CKD (60 ≤ eGFR < 90 mL/min per 1.73 m ²), moderate CKD (30 ≤ eGFR < 60 mL/min per 1.73 m ²), and severe CKD (eGFR < 30 mL/min per 1.73 m ²) groups. The risks of thromboembolism, major bleeding, and cardiovascular mortality were estimated with Fine-Gray regression analysis according to CKD status. Cox regression was performed to assess the risk of all-cause mortality associated with CKD.

RESULTS

Over a mean follow-up of 4.1 ± 1.9 years, there were 985 thromboembolic events, 414 major bleeding events, 956 cardiovascular deaths, and 1,786 all-cause deaths. After multivariate adjustment, CKD was not an independent risk factor of thromboembolic events. As compared to patients with no CKD, those with mild CKD, moderate CKD, and severe CKD had a 45%, 47%, and 133% higher risk of major bleeding, respectively. There was a graded increased risk of cardiovascular mortality associated with CKD status compared with no CKD group: adjusted hazard ratio [HR] was 1.34 (95% CI: 1.07-1.68,P = 0.011) for mild CKD group, 2.17 (95% CI: 1.67-2.81,P < 0.0001) for moderate CKD group, and 2.95 (95% CI: 1.97-4.41, P < 0.0001) for severe CKD group, respectively. Risk of all-cause mortality also increased among patients with moderate or severe CKD.

CONCLUSIONS

CKD status was independently associated with progressively higher risks of major bleeding and mortality, but didn't seem to be an independent predictor of thromboembolism in AF patients.

Comparison of Low and Full Dose Apixaban Versus Warfarin in Patients With Atrial Fibrillation and Renal Dysfunction (from a National Registry)

The use of direct oral anticoagulants for stroke prevention in patients with non-valvular atrial fibrillation (NVAF) is robust. However, the efficacy and safety of different dosage in patients with renal dysfunction is still a clinical challenge. We aimed to evaluate the clinical characteristics and outcomes of patients treated with apixaban in its different doses. A multicenter prospective cohort study, where consecutive eligible apixaban or warfarin treated patients with NVAF and renal impairment, were registered. Patients were followed-up for clinical events over a mean period of 1 year. Analyses were performed according to the dose of apixaban given, with consideration to the standard indications for dose reduction. Primary outcome was a composite of 1-year mortality, stroke or systemic embolism, major bleeding and myocardial infarction, while secondary outcomes included those components separated. Among the study population (n = 2,140), risk of composite outcome was significantly lower in the high dose apixaban group (10%, n = 491) than the low dose group (18%, n = 673) and the warfarin group (18%, n = 976) p <0.001. Results of 1-year mortality were similar. Apixaban dosing analysis revealed 65% of patients were appropriately dosed, while 31% were under-dosed and 4% were over-dosed. Furthermore, 53% of patients treated with low dose apixaban were under-dosed. Propensity score analysis revealed that patients who were appropriately treated with low-dose apixaban had a trend towards better composite outcome and mortality than 1:1 matched warfarin treated patients (18% vs 24%, p = 0.09 and 16% vs 23%, p = 0.06, respectively). Overall, appropriately dosed apixaban treated patients at any dose had significantly better outcomes than matched warfarin treated patients (composite outcome probability of 13.1% vs 18.6%, p = 0.007). In conclusion, apixaban at any dose is a reasonable alternative to warfarin in patients with renal impairment, possibly associated with improved outcomes.

Efficacy of R2CHA2DS2-VA score for predicting thromboembolism in Thai patients with non-valvular atrial fibrillation

Background

There is no data specific to the addition of renal dysfunction and age 50–64 years as risk parameters to the CHA₂DS₂-VA score, which is known as the R₂CHA₂DS₂-VA score, among NVAF patients. Accordingly, the aim of this study was to validate the R₂CHA₂DS₂-VA score for predicting thromboembolism in Thai NVAF patients.

Methods

Thai NVAF patients were prospectively enrolled in a nationwide multicenter registry from 27 hospitals during 2014–2020. Each component of the CHA₂DS₂-VA and R₂CHA₂DS₂-VA scores was scored and recorded. The main outcomes were thromboembolism, including ischemic stroke, transient ischemic attack (TIA), and/or systemic embolism. The annual incidence rate of thromboembolism among patients in each R₂CHA₂DS₂-VA and CHA₂DS₂-VA risk score category is shown as hazard ratio (HR) and 95% confidence interval (95% CI). The performance of the R₂CHA₂DS₂-VA and CHA₂DS₂-VA scores was demonstrated using c-statistics. Net reclassification index was calculated. Calibration plat was used to assess agreement between observed probabilities and predicted probabilities of both scoring system.

Results

A total of 3402 patients were enrolled during 2014–2020. The average age of patients was 67.38 ± 11.27 years. Of those, 46.9% had renal disease, 30.7% had a history of heart failure, and 17.1% had previous stroke or TIA. The average R₂CHA₂DS₂-VA and CHA₂DS₂-VA scores were 3.92 ± 1.92 and 2.98 ± 1.43, respectively. Annual thromboembolic risk increased with incremental increase in R₂CHA₂DS₂-VA and CHA₂DS₂-VA scores. Oral anticoagulants had benefit in stroke prevention in NVAF patients with an R₂CHA₂DS₂-VA score of 2 or more (adjusted HR: 0.630, 95% CI 0.413–0.962, p = 0.032). The c-statistics were 0.630 (95% CI 0.61–0.65) and 0.627 (95% CI 0.61–0.64), for R₂CHA₂DS₂-VA and CHA2DS2-VA scores respectively. NRI was 2.2%. The slope and R2 of the calibration plot were 0.73 and 0.905 for R₂CHA₂DS₂-VA and 0.70 and 0.846 for CHA₂DS₂-VA score respectively.

Conclusions

R₂CHA₂DS₂-VA score was found to be at least as good as CHA₂DS₂-VA score for predicting thromboembolism in Thai patients with NVAF. Similar to CHA₂DS₂-VA score, thromboembolism increased with incremental increase in R₂CHA₂DS₂-VA score.

Association of kidney function and atrial fibrillation progression to clinical outcomes in patients with cardiac implantable electronic devices

BACKGROUND

Kidney function may promote progression of AF.

OBJECTIVE

We evaluated the association of kidney function to AF progression and resultant clinical outcomes in patients with cardiac implantable electronic devices (CIED).

METHODS

We performed a retrospective cohort study using national clinical data from the Veterans Health Administration linked to CIED data from the Carelink® remote monitoring data warehouse (Medtronic Inc, Mounds View, MN). All devices had atrial leads and at least 75% of remote monitoring transmission coverage. Patients were included at the date of the first AF episode lasting ≥6 minutes, and followed until the occurrence of persistent AF in the first year, defined as ≥7 consecutive days with continuous AF. We used Cox regression analyses with persistent AF as a time-varying covariate to examine the association to stroke, myocardial infarction, heart failure and death.

RESULTS

Of, 10,323 eligible patients, 1,771 had a first CIED-detected AF (mean age 69 ± 10 years, 1.2% female). In the first year 355 (20%) developed persistent AF. Kidney function was not associated with persistent AF after multivariable adjustment including CHA₂DS₂-VASc variables and prior medications. Only higher age increased the risk (HR: 1.37 per 10 years; 95% CI:1.22-1.54). Persistent AF was associated to higher risk of heart failure (HR: 2.27; 95% CI: 1.88-2.74) and death (HR: 1.60; 95% CI: 1.30-1.96), but not stroke (HR: 1.28; 95% CI: 0.62-2.62) or myocardial infarction (HR: 1.43; 95% CI: 0.91-2.25).

CONCLUSION

Kidney function was not associated to AF progression, whereas higher age was. Preventing AF progression could reduce the risk of heart failure and death.

Renal function and outcome of patients with non-valvular atrial fibrillation

AIMS

Atrial fibrillation and renal dysfunction are associated with increased cardiovascular risk. We examined the association between renal function and incident ischaemic stroke or myocardial infarction in patients with atrial fibrillation treated with direct oral anticoagulants (DOACs).

METHODS AND RESULTS

This study was conducted using a large health record database. Included were 19 713 patients with first time diagnosis of non-valvular atrial fibrillation treated with DOACs between 2010 and 2018. Patients were categorized into four groups according to the estimated glomerular filtration rate (eGFR) (<30, 30-59, 60-89, and ≥90 mL/min/1.73 m2). Ischaemic stroke and acute myocardial infarction rates were compared between the groups. During 55 086 person-years of follow-up, there were 2295 (11.6%) cases of ischaemic stroke and 1158 (5.9%) cases of acute myocardial infarction. There was a significant inverse association between eGFR and the risk of myocardial infarction. A multivariate analysis using the group with eGFR ≥90 mL/min/1.73 m2 as a reference demonstrated an increased risk of myocardial infarction with lower eGFR [hazard ratio (HR) = 1.2 95% confidence interval (CI) 0.9-1.4, HR = 1.4, 95% CI 1.2-1.7, and HR = 2.5, 95% CI 1.8-3.4 for patients with eGFR 60-89, 30-59, and <30 mL/min/1.73 m2, respectively, P < 0.001]. Each 10 mL decrease in eGFR was associated with an 8% increase in the risk of myocardial infarction. There was no association between eGFR and the risk of ischaemic stroke (HR = 0.9 95% CI 0.8-1.1, HR = 0.93, 95% CI 0.8-1.1, and HR = 1.1, 95% CI 0.8-1.4 for patients with eGFR 60-89, 30-59, and <30 mL/min/1.73 m2, respectively, P = 0.325).

CONCLUSIONS

Renal dysfunction is associated with an increased risk of myocardial infarction but not of ischaemic stroke among patients with atrial fibrillation treated with DOACs.

Chronic Kidney Disease and Cerebrovascular Disease: Consensus and Guidance From a KDIGO Controversies Conference

The global health burden of chronic kidney disease is rapidly rising, and chronic kidney disease is an important risk factor for cerebrovascular disease. Proposed underlying mechanisms for this relationship include shared traditional risk factors such as hypertension and diabetes, uremia-related nontraditional risk factors, such as oxidative stress and abnormal calcium-phosphorus metabolism, and dialysis-specific factors such as cerebral hypoperfusion and changes in cardiac structure. Chronic kidney disease frequently complicates routine stroke risk prediction, diagnosis, management, and prevention. It is also associated with worse stroke severity, outcomes and a high burden of silent cerebrovascular disease, and vascular cognitive impairment. Here, we present a summary of the epidemiology, pathophysiology, diagnosis, and treatment of cerebrovascular disease in chronic kidney disease from the Kidney Disease: Improving Global Outcomes Controversies Conference on central and peripheral arterial disease with a focus on knowledge gaps, areas of controversy, and priorities for research.

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.

Optimizing indices of AF susceptibility and burden to evaluate AF severity, risk and outcomes

Atrial fibrillation (AF) has heterogeneous patterns of presentation concerning symptoms, duration of episodes, AF burden, and the tendency to progress towards the terminal step of permanent AF. AF is associated with a risk of stroke/thromboembolism traditionally considered dependent on patient-level risk factors rather than AF type, AF burden, or other characterizations. However, the time spent in AF appears related to an incremental risk of stroke, as suggested by the higher risk of stroke in patients with clinical AF vs. subclinical episodes and in patients with non-paroxysmal AF vs. paroxysmal AF. In patients with device-detected atrial tachyarrhythmias, AF burden is a dynamic process with potential transitions from a lower to a higher maximum daily arrhythmia burden, thus justifying monitoring its temporal evolution. In clinical terms, the appearance of the first episode of AF, the characterization of the arrhythmia in a specific AF type, the progression of AF, and the response to rhythm control therapies, as well as the clinical outcomes, are all conditioned by underlying heart disease, risk factors, and comorbidities. Improved understanding is needed on how to monitor and modulate the effect of factors that condition AF susceptibility and modulate AF-associated outcomes. The increasing use of wearables and apps in practice and clinical research may be useful to predict and quantify AF burden and assess AF susceptibility at the individual patient level. This may help us reveal why AF stops and starts again, or why AF episodes, or burden, cluster. Additionally, whether the distribution of burden is associated with variations in the propensity to thrombosis or other clinical adverse events. Combining the improved methods for data analysis, clinical and translational science could be the basis for the early identification of the subset of patients at risk of progressing to a longer duration/higher burden of AF and the associated adverse outcomes.

Renal Disease and Atrial Fibrillation

Incidence and prevalence of atrial fibrillation (AF) and chronic kidney disease are increasing, and the two conditions commonly coexist. Renal impairment further increases the risk of ischemic stroke and systemic thromboembolism in patients with AF but also paradoxically predisposes to bleeding. Renal function should be monitored closely in patients with AF requiring oral anticoagulation therapy, particularly those receiving direct oral anticoagulants. Vitamin K antagonists can be used as part of a dose-adjusted anticoagulation regimen in patients with mild to moderate renal dysfunction. Dialysis-dependent patients taking vitamin K antagonists are at increased risk of sustaining major hemorrhage.

Chronic kidney disease and cardiovascular mortality in patients with atrial fibrillation: European Society of Hypertension project - ESH A Fib

Our aim was to analyze characteristics of atrial fibrillation (AF) patients with chronic kidney disease (CKD) from the Croatian cohort of the ESH A Fib survey and to determine the association of estimated glomerular filtration rate (eGFR) with cardiovascular (CV) mortality after 24 months of follow-up.Consecutive sample of 301 patients with AF were enrolled in the period 2014 to 2018. Hypertension was defined as BP > 140/90 mm Hg and/or antihypertensive drugs treatment, CKD was defined as eGFR (CKD Epi) < 60 ml/min/1.73 m2 which was confirmed after 3 months.CKD was diagnosed in 45.2% of patients (13.3% in CKD stage > 3b). CKD patients were older than non-CKD and had significantly more frequent coronary heart disease, heart failure and valvular disease. CKD patients had significantly higher CHA2DS2-VASc score and more CKD than non-CKD patients had CHA2DS2-VASc > 2. Crude CV mortality rate per 1000 population at the end of the first year of the follow-up was significantly higher in CKD vs non-CKD group who had shorter mean survival time. CV mortality was independently associated with eGFR, male gender, CHA2DS2VASc and R2CHA2DS2VASc scores.Prevalence of CKD, particularly more advanced stages of CKD, is very high in patients with AF. Observed higher CV mortality and shorter mean survival time in CKD patients could be explained with higher CHA2DS2VASc score which is a consequence of clustering of all score components in CKD patients. However, eGFR was independently associated with CV mortality. In our cohort, R2CHA2DS2VASc score was not associated significantly more with CV mortality than CHA2DS2VASc score.

Application of net reclassification index to non-nested and point-based risk prediction models: a review

Much of medical risk prediction involves externally derived prediction equations, nomograms, and point-based risk scores. These settings are vulnerable to misleading findings of incremental value based on versions of the net reclassification index (NRI) in common use. By applying non-nested models and point-based risk scores in the setting of stroke risk prediction in patients with atrial fibrillation (AF), we demonstrate current recommendations for presentation and interpretation of the NRI. We emphasize pitfalls that are likely to occur with point-based risk scores that are easy to neglect when statistical methodology is focused on continuous models. In order to make appropriate decisions about risk prediction and personalized medicine, physicians, researchers, and policy makers need to understand the strengths and limitations of the NRI.

Chronic Kidney Disease and Its Impact on a Prothrombotic State in Patients with Atrial Fibrillation

It is unclear whether chronic kidney disease (CKD) increases thromboembolism in atrial fibrillation (AF). We conducted a retrospective cross-sectional analysis of 502 non-anticoagulated AF patients (median age, 66 (60–73) years, median CHA₂DS₂-VASc score, 3.0 (2.0–4.0)) with an estimated glomerular filtration rate (eGFR) ≥ 15 mL/min/1.73 m². Endogenous thrombin potential (ETP), clot permeability (K_s), and clot lysis time (CLT), among others, were determined. Patients with stage 4 CKD (n = 87; 17.3%) had higher ETP and prolonged CLT compared with those with stage 3 CKD. In patients with stages 3 to 4 CKD (n = 180; 35.9%) N-terminal pro-B-type natriuretic peptide predicted low K_s (the lowest quartile, odds ratio [OR] per 100 pg/mL: 1.03, 95% confidence interval [CI]: 1.01–1.06) and prolonged CLT (the top quartile, OR per 100 pg/mL: 1.05, 95% CI: 1.02–1.08), but not high ETP. In the whole cohort, after adjustment for CHA₂DS₂-VASc score, stage 4 CKD, but not stage 3 CKD, predicted high ETP (OR: 9.06; 95% CI: 4.44−18.46) and prolonged CLT (OR: 3.58; 95% CI: 1.76–7.28), but not low K_s. compared to the reference eGFR category. This study is the first to demonstrate the prothrombotic and antifibrinolytic alterations in AF patients with stage 4 CKD, but not stage 3 CKD irrespective of clinical stroke risk factors.

Factors Associated with a Large Decline in Renal Function or Progression to Renal Insufficiency in Hospitalized Atrial Fibrillation Patients with Early-Stage CKD

Clinicians must consider renal function when administering anticoagulants for atrial fibrillation (AF). Determination of risk factors for renal function decline may enable identification of patients who require closer monitoring. We investigated the characteristics associated with renal function decline in patients with AF. The study cohort consisted of 631 AF patients who had at least one readmission during the follow-up period and stages 1-3 chronic kidney disease (CKD). The primary outcome measure was large renal function decline (≥30% decrease from baseline estimated glomerular filtration rate [eGFR]). The secondary outcome measure was a final eGFR < 60 mL/minute/1.73 m² for those with a baseline eGFR above this level. The mean eGFR was 74.4 ± 18.5 mL/minute/1.73 m², and the mean follow-up time was 30.2 ± 13.2 months. The primary outcome occurred in 155 patients (24.6%) and was associated with congestive heart failure (CHF), proteinuria, type of AF, and left atrial diameter (LAD) ≥ 45 mm. Among 478 patients with a baseline eGFR ≥ 60 mL/minute/1.73 m², 137 (28.7%) progressed to renal failure (eGFR < 60 mL/minute/1.73 m²). A decreasing eGFR was associated with age ≥ 75 years, CHF, lower baseline eGFR, and LAD ≥ 45 mm. CHF, proteinuria, type of AF, and LAD ≥ 45 mm were associated with eGFR decline ≥ 30% in AF patients with CKD stages 1-3. Advanced age, CHF, lower baseline eGFR, and LAD ≥ 45 mm were associated with progression to renal insufficiency. These results should be considered when identifying patients who require more frequent monitoring of eGFR.

Stroke and Bleeding Risk Assessments in Patients With Atrial Fibrillation: Concepts and Controversies

Risk assessments are an important element in the management of patients with atrial fibrillation (AF). In this review, we aim to discuss the concepts and controversies surrounding the various risk factors for stroke and bleeding in AF. Indeed, there are a variety of clinical, electrical, biological, and genetic markers to guide stroke and bleeding risk assessments in AF. The more common factors have been used to formulate risk stratification scores. Some risk factors have shown promise, but others remain less well-defined. Our aim is to discuss concepts and controversies surrounding current evidence of risk factors for stroke and bleeding assessments in AF.

Risk of Stroke, Bleeding, and Death in Patients with Nonvalvular Atrial Fibrillation and Chronic Kidney Disease

INTRODUCTION

Atrial fibrillation (AF) and chronic kidney disease (CKD) are both associated with increased risk of stroke, and CKD carries a higher bleeding risk. Oral anticoagulation (OAC) treatment is used to reduce the risk of stroke in patients with nonvalvular AF (NVAF); however, the risk versus benefit of OAC for advanced CKD is continuously debated. We aim to assess the management and outcomes of NVAF patients with impaired renal function within a population-based cohort.

METHODS

We conducted a retrospective observational cohort study using ICD-9 healthcare coding. Patients with incident NVAF between 2004 and 2015 were identified stratified by CKD stage. We compared treatment strategies and estimated risks of stroke, death, or any major bleeding based on CKD stages and OAC treatment.

RESULTS

We identified 85,116 patients with incident NVAF. Patients with impaired renal function were older and had more comorbidities. OAC was most common among stage 2 CKD patients (49%) and least in stages 4-5 CKD patients (27.6%). Higher CKD stages were associated with worse outcomes. Stroke rates increased from 1.04 events per 100 person-years (PY) in stage 1 CKD to 3.72 in stages 4-5 CKD. Mortality increased from 3.42 to 32.95 events/100 PY, and bleeding rates increased from 0.89 to 4.91 events/100 PY. OAC was associated with reduced stroke and intracranial bleeding risk regardless of CKD stage, and with a reduced mortality risk in stages 1-3 CKD.

CONCLUSION

Among NVAF patients, advanced renal failure is associated with higher risk of stroke, death, and bleeding. OAC was associated with reduced stroke and intracranial bleeding risk, and with improved survival in stages 1-3 CKD.

Usefulness of transesophageal echocardiography before cardioversion in atrial arrhythmias

BACKGROUND

Although many thromboembolism risk factors are well defined, formation of thrombus or dense spontaneous contrast (sludge) in the left atrium remains enigmatic and confounding. Exclusion of the thrombus is extremely important with respect to planned reversal of sinus rhythm. Data regarding the routine transesophagal echocardiography (TEE) before cardioversion are inconclusive. The authors focused on analyzing the usefulness of TEE before cardioversion by assessment of factors influencing the risk of thrombus and/or dense spontaneous echo contrast with the intention of extending indications for TEE in the group with a high risk of thrombus or to forgo TEE in the low risk group.

METHODS

Two hundred sixty-nine consecutive patients with persistent (> 48 h) atrial fibrillation or atrial flutter, in whom a direct current cardioversion was planned, were undergoing TEE for the detection of the left atrial thrombus or dense spontaneous echo contrast. Additional clinical and echocardiographic data were collected. The relationship between both thrombus and dense spontaneous echo contrast and covariates was analyzed with the use of binary logistic regression.

RESULTS

Left atrium (LA) appendage (LAA) thrombus and/or sludge were detected in 79 (29%) patients. Signs of dementia in mini-mental state examination (hazard ratio [HR]: 1.16; p = 0.005), low velocities in LAA (HR: 3.38; p = 0.032); presence of spontaneous echo contrast in LA (HR: 3.38; p = 0,003) consecutive episode of AF (HR: 2.27; p = 0,046); longer duration of atrial fibrillation (HR: 1.009; p = 0.022); were significant predictors of thrombus and/or dense spontaneous echo contrast. None of the patients with a CHA2DS2VASc score ≤ 1 had thrombus or sludge in the LAA. Among patients with a CHA2DS2VASc score > 1, the prevalence of thrombus or sludge in LAA was independent of the CHA2DS2VASc score value.

CONCLUSIONS

Amongst many factors, including an established as risk for thromboembolism only a few of them increased the risk for the presence of thrombus in LAA: low velocities in LAA, presence of spontaneous echo contrast, longer duration of arrhythmia, consecutive (not first) arrhythmia episode and signs of dementia from a mini-mental state examination questionnaire. It was believed that there could be a need for an extension of indications of TEE in vast majority of the patients with atrial arrhythmias, due most often to an unpredictable occurrence of thrombus and potentially disastrous thromboembolism. The only exception could have been the group of the patients with a CHA2DS2VASc score ≤ 1.

Stroke risk stratification in atrial fibrillation: a review of common risk factors

Atrial Fibrillation (AF) has become a major global health concern being the most common sustained arrhythmia in clinical practice. Risk factors for AF include congestive heart failure, hypertension, increasing age and diabetes. Many of these factors also increase the risk for thromboembolism and ischemic stroke in AF patients. Great efforts have been made from the latter part of the 20th century towards developing an ideal stroke risk stratification tool in AF with the aim of reducing the incidence of stroke in AF patients and the limiting unnecessary use of thromboprophylaxis. The thromboembolic risks posed by AF with valvular heart disease are an important subgroup that contributes to a significant proportion of stroke in AF patients globally. We review the evolution of stroke risk stratification and summarize the guidelines for stroke prevention in non-valvular AF as well as AF with valvular heart disease, and the most recent recommendations on stroke prevention in AF patients. Abbreviations: AF: Atrial Fibrillation; ACS: Acute Coronary Syndrome; CAD: Coronary Artery Disease; CCF: Congestive Cardiac Failure; DM: Diabetes Mellitus; EHRA: Evaluated Heartvalves, Rheumatic or Artificial; ICH: Intracranial Hemorrhage; NOACs: Novel Oral Anticoagulants; OAC: Oral Anticoagulants; PAD: Peripheral Arterial Disease ; TIA: Transient Ischemic Attack; VHD: Valvular Heart Disease.

Impact of creatinine clearance on outcomes in patients with non-valvular atrial fibrillation: a subanalysis of the J-RHYTHM Registry

Aims

To clarify the influence of renal function on adverse outcomes in patients with non-valvular atrial fibrillation (NVAF), a post hoc analysis of the J-RHYTHM Registry was performed.

Methods and results

A consecutive series of outpatients with atrial fibrillation (AF) were enrolled from 158 institutions and followed for 2 years or until the occurrence of an event. Among 7406 patients with non-valvular AF, 6052 patients (69.8 ± 10.0 years, 71.2% men) with creatinine clearance (CrCl) value at baseline were divided into four groups according to CrCl level (<30, 30–49.9, 50–79.9, and ≥80 mL/min). Patients with CrCl <80 mL/min showed increased incidence of thromboembolism, major haemorrhage, all-cause and cardiovascular death, and composite events as compared with patients with CrCl ≥80 mL/min. After adjustment for multiple confounders, lower CrCl values emerged as independent predictors for thromboembolism [CrCl 30–49.9, hazard ratio (HR) 2.27, 95% confidence interval (CI) 1.09–4.72, P = 0.029; and CrCl 50–79.9, HR 1.99, 95% CI 1.07–3.72, P = 0.030] and all-cause death (CrCl <30, HR 6.44, 95% CI 3.03–13.7, P < 0.001; and CrCl 30–49.9, HR 3.14, 95% CI 1.54–6.41, P = 0.002), with CrCl ≥80 mL/min serving as a reference, whereas not for major haemorrhage. Warfarin treatment was associated with lower rates of composite events in patients with lower CrCl values of <80 mL/min.

Conclusion

Renal impairment was an independent predictor of adverse clinical outcomes except for major haemorrhage in Japanese patients with non-valvular AF. Warfarin was associated with lower rates of composite events in patients with lower CrCl values.

Clinical Trial Registration:

http://www.umin.ac.jp/ctr/. Unique identifier: UMIN000001569.

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.

Predicting Thromboembolic and Bleeding Event Risk in Patients with Non-Valvular Atrial Fibrillation: A Systematic Review

BACKGROUND

 Atrial fibrillation (AF) is a common cardiac arrhythmia that increases the risk of stroke. Medical therapy for decreasing stroke risk involves anticoagulation, which may increase bleeding risk for certain patients. In determining the optimal therapy for stroke prevention for patients with AF, clinicians use tools with various clinical, imaging and patient characteristics to weigh stroke risk against therapy-associated bleeding risk.

AIM

 This article reviews published literature and summarizes available risk stratification tools for stroke and bleeding prediction in patients with AF.

METHODS

 We searched for English-language studies in PubMed, Embase and the Cochrane Database of Systematic Reviews published between 1 January 2000 and 14 February 2018. Two reviewers screened citations for studies that examined tools for predicting thromboembolic and bleeding risks in patients with AF. Data regarding study design, patient characteristics, interventions, outcomes, quality, and applicability were extracted.

RESULTS

 Sixty-one studies were relevant to predicting thromboembolic risk and 38 to predicting bleeding risk. Data suggest that CHADS₂, CHA₂DS₂-VASc and the age, biomarkers, and clinical history (ABC) risk scores have the best evidence for predicting thromboembolic risk (moderate strength of evidence for limited prediction ability of each score) and that HAS-BLED has the best evidence for predicting bleeding risk (moderate strength of evidence).

LIMITATIONS

 Studies were heterogeneous in methodology and populations of interest, setting, interventions and outcomes analysed.

CONCLUSION

 CHADS₂, CHA₂DS₂-VASc and ABC scores have the best prediction for stroke events, and HAS-BLED provides the best prediction for bleeding risk. Future studies should define the role of imaging tools and biomarkers in enhancing the accuracy of risk prediction tools.

PRIMARY FUNDING SOURCE

 Patient-Centered Outcomes Research Institute (PROSPERO #CRD42017069999).

Oral Anticoagulation in Chronic Kidney Disease and Atrial Fibrillation

BACKGROUND

Cardiological societies recommend, in their guidelines, that patients with atrial fibrillation and an intermediate (or higher) risk of stroke and systemic embolization should be treated with oral anticoagulant drugs. For patients who do not have mitral valve stenosis or a mechanical valve prosthesis, non-vitamin-K dependent oral anticoagulants (NOAC) are preferred over vitamin K antagonists (VKA) for this purpose. It is unclear, however, whether patients with chronic kidney disease and atrial fibrillation benefit from oral anticoagulation to the same extent as those with normal kidney function. It is also unclear which of the two types of anti - coagulant drug is preferable for patients with chronic kidney disease; NOAC are, in part, renally eliminated.

METHODS

This review is based on pertinent publications retrieved by a selective literature search, and on international guidelines.

RESULTS

Current evidence suggests that patients with atrial fibrillation who have chronic kidney disease with a glomerular filtration rate (GFR) above 15 mL/ min/1.73 m² should be treated with an oral anticoagulant drug if they have an at least intermediate risk of embolization, as assessed with the CHA2DS2-VASc score. For patients with advanced chronic kidney disease (GFR from 15 to 29 mL/ min/1.73 m²), however, this recommendation is based only on registry studies. For dialysis patients with atrial fibrillation, decisions whether to give oral anticoagulant drugs should be taken on an individual basis, in view of the elevated risk of hemorrhage and the unclear efficacy of such drugs in these patients. The subgroup analyses of the NOAC approval studies show that, for patients with atrial fibrillation and chronic kidney disease with a creatinine clearance of >25-30 mL/min, NOAC should be given in preference to VKA, as long as the patient does not have mitral valve stenosis or a mechanical valve prosthesis. For those whose creatinine clearance is less than 25 mL/min, the relative merits of NOAC versus VKA are still debated.

CONCLUSION

The cardiological societies' recommendation that patients with atrial fibrillation should be given oral anticoagulant drugs applies to the majority of such patients who also have chronic kidney disease.

Changes in glomerular filtration rate and outcomes in patients with atrial fibrillation

BACKGROUND

Patients with kidney disease are more likely to develop atrial fibrillation (AF) than individuals with normal renal function, and more likely to suffer ischemic stroke (IS)/thromboembolism (TE). We investigated the relationship of kidney function evolution to IS/TE, mortality and bleeding in AF patients.

METHODS

In a cohort of 8962 AF patients, 2653 had serum creatinine data, with 10894 patient-years of follow-up. Patients were stratified into quartiles of estimated glomerular filtration rate (eGFR) evolution (in mL/min per 1.73 m²/year).

RESULTS

Rates of events (IS/TE, bleeding, mortality) increased with worsening eGFR by quartiles. The risk of events was particularly increased when patients in the 4th quartile were compared to others. Renal impairment per se was not an independent predictor of IS/TE but was an independent predictor of bleeding, whilst eGFR worsening was an independent predictor both for IS/TE (Hazard Ratio [HR] 1.573, 95%CI 1.160-2.134 for patients in the last quartile) and for bleeding events (HR 1.543, 95%CI 1.157-2.004). Worsening eGFR did not improve the predictive ability of the CHA₂DS₂VASc and HAS-BLED scores for identifying a higher risk of IS/TE or bleeding events, respectively. When the benefit of IS reduction was balanced against the increased risk of bleeding events, the net clinical benefit was positive in favor of OAC use (vs non-use) in patients with worsening eGFR.

CONCLUSIONS

Rates of IS/TE, mortality and bleeding increased with worsening eGFR >4.81 mL/min per 1.73 m². Worsening eGFR was an independent predictor of IS/TE and of bleeding, and a better predictor of IS/TE than renal impairment in AF.

Use of oral anticoagulants in patients with atrial fibrillation and renal dysfunction

Atrial fibrillation (AF) and chronic kidney disease (CKD) are increasingly prevalent in the general population and share common risk factors such as older age, hypertension and diabetes mellitus. The presence of CKD increases the risk of incident AF, and, likewise, AF increases the risk of CKD development and/or progression. Both conditions are associated with substantial thromboembolic risk, but patients with advanced CKD also exhibit a paradoxical increase in bleeding risk. In the landmark randomized clinical trials that compared non-vitamin K antagonist oral anticoagulants (NOACs) with warfarin for thromboprophylaxis in patients with AF, the efficacy and safety of NOACs in patients with mild-to-moderate CKD were similar to those in patients without CKD. Dose adjustment of NOACs as per the prescribing label is required in this population. Owing to limited trial data, evidence-based recommendations for the management of patients with AF and severe CKD or end-stage renal disease on dialysis are lacking. Observational cohort studies have reported conflicting results, and the management of these particularly vulnerable patients remains challenging and requires careful assessment of stroke and bleeding risk and, where appropriate, use of warfarin with good-quality anticoagulation control.

Decreased Renal Function Is Associated with Elevated CHA2DS2VASC and R2CHADS2 Scores in Non-Valvular Atrial Fibrillation Patients Presenting with Stroke

Introduction

Atrial fibrillation (AF), the most common cardiac arrhythmia, affects approximately 2.3 million patients in the United States, costing around $26 billion. Atrial fibrillation is associated with a two- to seven-fold increased risk of stroke, one of the most serious complications. Chronic kidney disease affects approximately 13% of the US population and has been associated with higher rates of AF than the general population. In patients with chronic kidney disease (CKD), the risk of stroke increases as the glomerular filtration rate (GFR) decreases, especially in CKD stages three and four.

Several risks stratification scores such as CHADS2 (congestive heart failure, hypertension, age, diabetes mellitus, stroke), CHA2DS2VASc (congestive heart failure, hypertension, age, diabetes mellitus, stroke, vascular disease, age, sex), and R2CHADS2 (renal failure, congestive heart failure, age, diabetes, stroke) scores are used for stroke risk assessment in patients with non-valvular atrial fibrillation (NVAF). This study investigates the association between renal functions and risk stratification scoring systems in patients with non-valvular AF presenting with stroke.

Methods

Using the convenience sampling method, 171 subjects were selected from the eligible population (n = 386). A Pearson product-moment correlation coefficient was calculated to determine the association between the GFR and each of the CHA2DS2VASc and R2CHADS2 scores. In addition, a Pearson product-moment correlation coefficient was calculated to determine the association between the CHA2DS2VASc and R2CHADS2 scores.

Results

The selected population represented 44.3% of the eligible subjects. Of these, 88% were Caucasian, 60% were female, and the mean age was 78 years. The mean CHA2DS2VASc score was six (range 2-9). The mean eGFR was 69.77 (range 6-108). Both the mode and the median CHA2DS2VASc score was four (range 2-8). A weak, but significant, negative correlation was found between renal function (eGFR) and the CHA2DS2VASc score (r = -0.263; p = 0.0005). There was a stronger negative correlation between the eGFR and R2CHADS2score (r = -0.70; p < 0.00001). The CHA2DS2VASc and R2CHADS2scoring schemes were significantly and positively correlated (r = 0.627; p < 0.00001).

Discussion

In NVAF patients presenting with stroke, renal failure is associated with higher CHA2DS2VASc and R2CHADS2 scores. One must consider renal failure (end-stage or non-end stage renal failure) as an additional potential risk factor for stroke when recommending anticoagulation in non-valvular atrial fibrillation. 

Comparison of the CHADS2, CHA2DS2-VASc and R2CHADS2 Scores in Japanese Patients with Non-valvular Paroxysmal Atrial Fibrillation Not Receiving Anticoagulation Therapy

Objective It remains unclear whether the CHADS2, CHA2DS2-VASc, or R2CHADS2 score is the most useful for the risk stratification of ischemic stroke/systemic thromboembolism (IS/SE) in Japanese patients with paroxysmal non-valvular atrial fibrillation (PNVAF). Methods We investigated the incidence of IS/SE on the basis of the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores in 332 consecutive PNVAF patients (224 men, mean age: 65±13 years) who had not been administered anticoagulation therapy but who were administered antiarrhythmic drug therapy to maintain sinus rhythm between August 1995 and July 2008 before the 2008 Japanese Circulation Society guideline was issued (mean follow-up period: 53±35 months). Results The annual rates of IS/SE without underlying antiarrhythmic drug therapy are shown in the table included in this article. Higher CHADS2, CHA2DS2-VASc, and R2CHADS2 scores were associated with greater annual rates of IS/SE (p<0.001). In a multivariate logistic regression analysis adjusted for potentially confounding variables, the CHADS2 scores [odds ratio (OR): 4.74, 95% confidence interval (CI): 2.80-8.00, p<0.001], CHA2DS2-VASc scores (OR: 4.15, 95% CI: 2.57-6.71, p<0.001), and R2CHADS2 scores (OR: 1.94, 95% CI: 1.48-2.53, p<0.001) were significant independent predictors of IS/SE. The area under the receiver-operator characteristic curve for predicting IS/SE was 0.89 for CHA2DS2-VASc scores, 0.87 for CHADS2 scores, and 0.85 for R2CHADS2 scores (all, p<0.001), with no significant difference among the three scores. Conclusion In Japanese patients with PNVAF, the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores are all useful for the risk stratification of IS/SE cases.

Influence of renal function on anticoagulation control in patients with non-valvular atrial fibrillation taking vitamin K antagonists

BACKGROUND AND PURPOSE

Chronic kidney disease (CKD) has been related to poor anticoagulation control and an increased risk of bleeding. This study aims to evaluate the association between impaired renal function (eGFR <60 mL/min/1.73 m² ) and anticoagulation control in patients with non-valvular atrial fibrillation (AF) on vitamin K antagonists (VKA) therapy. We also assessed whether the predictive value of the SAMe-TT₂ R₂ score prevailed for subgroups both with and without CKD.

METHODS

This is an ancillary analysis of 1381 patients from the PAULA study, which was a cross-sectional, retrospective and nationwide multicenter study.

RESULTS

A total of 370 patients had eGFR <60 mL/min/1.73 m² . Anticoagulation control levels progressively worsened across each stage of CKD. Multiple linear regression analysis showed CKD as an independent predictor of time in therapeutic range (TTR). In the subgroup of patients with preserved renal function, female sex, diet affecting INR, polypharmacy and amiodarone were associated with poorer TTR. The SAMe-TT₂ R₂ score had a significant but modest predictive value for TTR<65% (AUC, area under the curve 0.558, P = .002). In the subgroup of patients with CKD, the SAMe-TT₂ R₂ (>2 points) showed no significant predictive capacity for TTR (AUC 0.528, P = .354). The average TTR was similar for both sexes (P = .255), but with a higher percentage of males subjects with TTR ≥65% (P = .013).

CONCLUSION

Chronic kidney disease is associated with poor anticoagulation control in patients with non-valvular AF taking VKA. The SAMe-TT₂ R₂ score was not predictive of poor TTR in the subgroup with CKD, although a modest predictive value for poor TTR was found in those without CKD.

Impact of Chronic Kidney Disease on the Presentation and Outcome of Patients Hospitalized With Atrial Fibrillation: Insights From Qatar

Atrial fibrillation (AF) with coexistent chronic kidney disease (CKD) is poorly described in the literature. We compared the presenting symptoms, clinical characteristics, treatment, and outcome of patients hospitalized with AF with and without CKD in a large clinical registry. Data of patients hospitalized with AF between 1991 and 2012 in Qatar were analyzed. Of 5201 patients hospitalized for AF, 264 (5.1%) had CKD. Patients with AF and CKD were older with higher prevalence of other comorbidities and left ventricular dysfunction and were more likely to present with shortness of breath and chest pain compared with patients with AF alone who were more likely to present with palpitation. The crude in-hospital mortality was 3 times higher in patients with dual disease. On multivariable adjustments, CKD was an independent predictor of mortality (odds ratio: 2.84; 95% confidence interval: 1.33-6.08, P = .001). Further studies are warranted to try to reduce the increased mortality observed in this high-risk population.

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.

2017 consensus of the Asia Pacific Heart Rhythm Society on stroke prevention in atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia, causing a 2-fold increase in mortality and a 5-fold increase in stroke. The Asian population is rapidly aging, and in 2050, the estimated population with AF will reach 72 million, of whom 2.9 million may suffer from AF-associated stroke. Therefore, stroke prevention in AF is an urgent issue in Asia. Many innovative advances in the management of AF-associated stroke have emerged recently, including new scoring systems for predicting stroke and bleeding risks, the development of non-vitamin K antagonist oral anticoagulants (NOACs), knowledge of their special benefits in Asians, and new techniques. The Asia Pacific Heart Rhythm Society (APHRS) aimed to update the available information, and appointed the Practice Guideline sub-committee to write a consensus statement regarding stroke prevention in AF. The Practice Guidelines sub-committee members comprehensively reviewed updated information on stroke prevention in AF, emphasizing data on NOACs from the Asia Pacific region, and summarized them in this 2017 Consensus of the Asia Pacific Heart Rhythm Society on Stroke Prevention in AF. This consensus includes details of the updated recommendations, along with their background and rationale, focusing on data from the Asia Pacific region. We hope this consensus can be a practical tool for cardiologists, neurologists, geriatricians, and general practitioners in this region. We fully realize that there are gaps, unaddressed questions, and many areas of uncertainty and debate in the current knowledge of AF, and the physician׳s decision remains the most important factor in the management of AF.

Real-world stroke prevention strategies in nonvalvular atrial fibrillation in patients with renal impairment

BACKGROUND

The data regarding stroke prevention strategies in nonvalvular atrial fibrillation (NVAF) are limited especially in patients with renal impairment (RI). We sought to evaluate management dilemmas in patients with concurrent NVAF and RI in RAMSES (ReAl-life Multicenter Survey Evaluating Stroke Prevention Strategies inTurkey) study.

METHODS

We conducted a prospective, multicenter, nation-wide registry in NVAF patients in outpatient cardiology clinics. All consecutive patients with NVAF were enrolled in RAMSES study (ClinicalTrials.gov identifier NCT02344901). The baseline data were collected. Glomerular filtration rate (GFR) was estimated by Cockcroft-Gault equation.

RESULTS

A total number of 6273 patients from 29 provinces of Turkey with the contribution of 83 investigators were enrolled to the study. Of the study population, 1964(33%) patients had RI which was defined as GFR < 60 mL/min. Patients with RI had significantly higher CHA₂ DS₂ VASc and HAS-BLED scores compared to those without RI (3·9 ± 1·5 vs. 2·9 ± 1·5, and 2·0 ± 1 vs. 1·4 ± 1; P < 0·001). Prior history of major bleeding (6·9% vs. 4·1%, P < 0·001) and stroke (16·2% vs. 11·8%, P < 0·001) was significantly higher among individuals with concomitant RI and NVAF. Although RI patients had a higher risk for thromboembolism, number of the patients who did not receive any anticoagulant therapy was higher in patients with RI than without RI (30·1 vs. 26·4%, P = 0·003).

CONCLUSION

RAMSES study showed that one-third of the patients with NVAF had RI in the real-world setting. Although it is mandatory in most of the patients with concomitant NVAF and RI, nearly one-third of these patients did not receive any anticoagulant therapy.

Synergic impact of oral anticoagulation control and renal function in determining major adverse events in atrial fibrillation patients undergoing percutaneous coronary intervention: insights from the AFCAS registry

Background

In patients with atrial fibrillation (AF), quality of oral anticoagulation control as well as impaired renal function are associated with adverse outcomes. Our objective was to analyze if there was a synergistic impact of these factors in determining adverse outcomes in AF patients undergoing percutaneous coronary intervention and stent (PCI-S).

Methods

Post-hoc analysis from the Atrial Fibrillation Undergoing Coronary Artery Stenting (AFCAS) registry. Poor oral anticoagulation control was defined as time in therapeutic range (TTR) <65%, while impaired renal function as creatinine clearance (CrCl) <60 ml/min.

Results

Of the whole cohort, 448 were eligible for this post-hoc analysis. Of these, 27.9% had TTR <65%only (Group I), 19.2% had CrCl <60 ml/min only (Group II), while 13.8% had both conditions (Group III). At follow-up, patients in Group III had a higher rate of major adverse cardiovascular and cerebrovascular events (MACCE) (p = 0.007), while patients in Groups I and III had higher rates of major bleeding. Kaplan–Meier analyses showed that patients in Group III had higher risk for MACCE (LogRank: 14.406, p = 0.003), while Group I and Group III patients had higher risk for major bleeding (LogRank: 12.290, p = 0.006). On Cox regression, presence of both conditions independently increased MACCE risk (p = 0.001), while TTR <65% alone and the presence of both conditions were independently associated with major bleeding (p = 0.004 and p = 0.028, respectively).

Conclusions

There was a synergic impact of oral anticoagulation control and renal function in determining major adverse events in AF patients undergoing PCI-S. Use of poor anticoagulation control and impaired renal function in combination would help identify AF patients undergoing PCI-S at risk for MACCE and/or major bleeding.

Electronic supplementary material

The online version of this article (doi:10.1007/s00392-016-1071-0) contains supplementary material, which is available to authorized users.

Application of Biomarkers for Risk Stratification in Patients with Atrial Fibrillation

BACKGROUND

Atrial fibrillation is the most common sustained arrhythmia and an important contributor to cardiovascular morbidity and mortality. Several strategies have been proposed for prediction of outcomes and individualization of treatments to better balance the benefits of stroke prevention and risks of bleeding during anticoagulation.

CONTENT

The availability of analytically more specific and sensitive methods to measure circulating biomarkers of cellular and organ stress and dysfunction has led to testing of their utility in several cardiovascular conditions. In patients with atrial fibrillation, biomarkers of myocardial injury (troponin) and cardiovascular stress and dysfunction (natriuretic peptides, growth differentiation factor 15), myocardial fibrosis (galectin-3), renal dysfunction (creatinine, cystatin C), inflammation (C-reactive protein, cytokines) and coagulation activity (d-dimer) have been found associated with underlying pathophysiology, clinical outcomes and effects of treatment. Measurements of these markers might therefore expand the understanding of the pathophysiology, improve risk assessment and optimize treatment in individual patients with atrial fibrillation.

SUMMARY

Biomarkers for risk stratification have potential roles as tools for evaluation of patients with atrial fibrillation and for selection of the best treatment strategies to prevent stroke, major bleeding, and mortality.

Use of Oral Anticoagulation in the Management of Atrial Fibrillation in Patients with ESRD: Con

Among patients with atrial fibrillation, prophylaxis for stroke prevention with the use of anticoagulation is well established in the general population. A number of randomized controlled trials and evidence-based risk prediction tools clearly delineate the benefit and risks of therapy. Despite the high incidence of atrial fibrillation in the late stage CKD and ESRD populations, little high quality evidence exists in these populations. Is it appropriate then to extrapolate findings from the general population to those with CKD/ESRD? In our view, too much uncertainty exists regarding proof of efficacy with clear signals of harm. Routine anticoagulation for stroke prevention in atrial fibrillation is not recommended for the majority of CKD and ESRD patients.

Are Existing Risk Scores for Nonvalvular Atrial Fibrillation Useful for Prediction or Risk Adjustment in Patients With Chronic Kidney Disease?

BACKGROUND

Comparative effectiveness studies are common in patients with nonvalvular atrial fibrillation (NVAF) and chronic kidney disease (CKD), but the accuracy of current thromboembolic (n = 4) and bleeding (n = 3) prediction scores used for risk adjustment are uncertain in these patients because previous studies have included few CKD patients.

METHODS

This was a retrospective cohort study, using Cox models adjusted for time-varying coefficients, of nonanticoagulated adults with incident NVAF and kidney function (defined into Kidney Disease: Improving Global Outcomes [KDIGO] CKD categories) between 2002 and 2013.

RESULTS

Of 58,451 patients (mean age 66 years, 31.3% with CKD) followed for a median of 31 months, 21.3% died, 12.6% had a thromboembolic event (4.2 per 100 patient-years), and 7.8% had a major bleed (2.6 per 100 patient-years). There were graded associations between kidney function and all-cause mortality (adjusted hazard ratio [aHR], 1.88 [95% confidence interval (CI), 1.79-1.98] for very high vs low risk KDIGO category), major bleeding (aHR, 1.61 [95% CI, 1.47-1.76]), and thromboembolic events (aHR, 1.13 [95% CI, 1.04-1.23]). All 7 prediction scores had significantly poorer c statistics in patients with CKD: 0.50-0.59; all P < 0.0001 compared with those with normal kidney function (c statistics 0.69-0.70 for the 4 thromboembolic risk scores and 0.60-0.68 for the 3 bleeding risk scores). Inclusion of KDIGO category did not improve calibration or discrimination statistics for current prediction scores.

CONCLUSIONS

Existing NVAF risk scores exhibit poor discrimination in patients with CKD, limiting their utility for clinical decision-making or for risk adjustment in comparative effectiveness studies. Although CKD is an independent risk factor for adverse events, adding KDIGO class to current risk scores did not improve their performance.

Renal Dysfunction, CHADS2 Score, and Adherence to the Anticoagulant Treatment in Nonvalvular Atrial Fibrillation

We investigated the risk of stroke associated with renal dysfunction and the impact of warfarin therapies in Chinese patients with nonvalvular atrial fibrillation (NVAF). Information was collected on age, sex, height, weight, type of atrial fibrillation, and serum creatinine within the previous 6 months, together with the variables needed to calculate the CHADS2 score. For patients not taking warfarin, reasons why not were recorded. Three thousand seventeen eligible patients with NVAF, mean (1 standard deviation [SD]) age of 67.7 (13.0) years, from 50 Chinese hospitals were included from May 2012 to October 2012, with a mean (1SD) CHADS2 score of 2.0 (1.5). Of these, 58.3% were male and 86.2% were at high risk of stroke with a CHADS2 score ≥1. Only 42.6% were on warfarin, and 22.5% of the patients had moderate or severe renal impairment (estimated glomerular filtration rate < 60 mL/min/1.73 m2). After adjustment for the CHADS2 score, renal dysfunction remained moderately but significantly associated with the risk of stroke/TIA (odds ratio = 1.005, 95% confidence interval: 1.002-1.009, P = .002). There was, however, no significant difference in anticoagulant usage between patients with or without impaired renal dysfunction. The most common anticoagulant concerns were the low proportion of patients with regular international normalized ratio monitoring (43.0%) and the risk of bleeding (33.3%). Renal impairment was common and independently associated with the risk of cerebrovascular embolism in Chinese patients with NVAF but not independently related to underuse of anticoagulant treatment.