Chronic Kidney Disease, Time in Therapeutic Range and Adverse Clinical Outcomes in Anticoagulated Patients with Non-valvular Atrial Fibrillation: Observations from the SPORTIF Trials

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.

Clinical complexity and impact of the ABC (Atrial fibrillation Better Care) pathway in patients with atrial fibrillation: a report from the ESC-EHRA EURObservational Research Programme in AF General Long-Term Registry

BACKGROUND

Clinical complexity is increasingly prevalent among patients with atrial fibrillation (AF). The 'Atrial fibrillation Better Care' (ABC) pathway approach has been proposed to streamline a more holistic and integrated approach to AF care; however, there are limited data on its usefulness among clinically complex patients. We aim to determine the impact of ABC pathway in a contemporary cohort of clinically complex AF patients.

METHODS

From the ESC-EHRA EORP-AF General Long-Term Registry, we analysed clinically complex AF patients, defined as the presence of frailty, multimorbidity and/or polypharmacy. A K-medoids cluster analysis was performed to identify different groups of clinical complexity. The impact of an ABC-adherent approach on major outcomes was analysed through Cox-regression analyses and delay of event (DoE) analyses.

RESULTS

Among 9966 AF patients included, 8289 (83.1%) were clinically complex. Adherence to the ABC pathway in the clinically complex group reduced the risk of all-cause death (adjusted HR [aHR]: 0.72, 95%CI 0.58-0.91), major adverse cardiovascular events (MACEs; aHR: 0.68, 95%CI 0.52-0.87) and composite outcome (aHR: 0.70, 95%CI: 0.58-0.85). Adherence to the ABC pathway was associated with a significant reduction in the risk of death (aHR: 0.74, 95%CI 0.56-0.98) and composite outcome (aHR: 0.76, 95%CI 0.60-0.96) also in the high-complexity cluster; similar trends were observed for MACEs. In DoE analyses, an ABC-adherent approach resulted in significant gains in event-free survival for all the outcomes investigated in clinically complex patients. Based on absolute risk reduction at 1 year of follow-up, the number needed to treat for ABC pathway adherence was 24 for all-cause death, 31 for MACEs and 20 for the composite outcome.

CONCLUSIONS

An ABC-adherent approach reduces the risk of major outcomes in clinically complex AF patients. Ensuring adherence to the ABC pathway is essential to improve clinical outcomes among clinically complex AF 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.

The short-term effect of the COVID-19 pandemic on the management of warfarin therapy

Aim    The aim of this study was to investigate the short-term effect of the COVID-19 pandemic on the management of warfarin therapy used for atrial fibrillation (AF) and prosthetic valve disease.Material and methods    The study included 139 Atrial fibrillation (AF) patients and 173 prosthetic valve patients (PVP) who were using warfarin. The time in therapeutic range (TTR), International Normalized Ratio (INR) averages, the numbers of INR tests, and the non-adherence to INR monitoring (NIM) were compared for the pre-covid period (PCP) and the COVID-19 period (CP). Also, adherence to warfarin therapy was evaluated with a questionnaire.Results    For all patients, the INR values were higher in the CP (2.47 vs 2.60, p&lt;0.001), and the NIM percentage was higher (19.2 % vs 71.5 %, p&lt;0.001) in the CP. The number of INR tests was lower during the CP (p&lt;0.001).The percentage of patients with TTR≥70 % was lower during the CP (41.7 % vs 33 % p=0.017). Subgroup analysis showed that for PVP, TTR values and the percentage of patients with TTR ≥70 % were similar in both the PCP and CP periods. The questionnaire showed that for 94.1 % of respondents, the major cause of NIM in the CP was the COVID-19 pandemic. However, during the CP, adherence to warfarin medication was high (95.5 %).Conclusion    Lower TTR during the COVID-19 pandemic can increase bleeding and thromboembolic cases.Therefore, patients taking warfarin should be followed more closely, and more practical ways should be considered for INR testing.

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.

Preoperative Cardiovascular Assessment of the Renal Transplant Recipient: A Narrative Review

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

Integrated care and outcomes in patients with atrial fibrillation and comorbidities

BACKGROUND

Integrated care for management of atrial fibrillation (AF) patients has been associated with a reduction in adverse events. The 'Atrial fibrillation Better Care (ABC) pathway' has been proposed to streamline such integrated management. In this paper, we analysed the impact of ABC pathway adherent clinical management on outcomes in AF patients with high-risk 'metabolic' comorbidities (i.e. diabetes mellitus [DM], chronic kidney disease [CKD], metabolic syndrome [MetS].

METHODS

Patients from the SPORTIF III and V trials and with available data to evaluate ABC criteria were analysed. DM, CKD and MetS were evaluated according to baseline data. A composite of major adverse cardiovascular events and all-cause death was the study outcome.

RESULTS

A total of 3637 patients (median age 72 [IQR 66-77], 30.3% female) were analysed. DM was evident in 23.4%, CKD in 25.8% and MetS in 31.5% among the overall cohort. Respectively, 23.2% were ABC pathway adherent in the DM subgroup, 21.2% in CKD and 23.7% in MetS subgroups. Composite outcome occurred less frequently in patients managed adherent to ABC pathway than those nonadherents, in all three groups. In the final multivariate model, ABC adherent care was inversely associated with a lower risk of composite outcome in the DM (HR 0.45, 95% CI 0.23-0.88), CKD (HR 0.60, 95% CI 0.36-0.98) and MetS (HR 0.37, 95% CI 0.19-0.71) subgroups.

CONCLUSIONS

In high-risk AF patients with DM, CKD and MetS, ABC pathway adherent management was associated with a lowered risk of the composite outcome of cardiovascular events, cardiovascular and all-cause death.

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.

Pathophysiology of atrial fibrillation and chronic kidney disease

Atrial fibrillation (AF) and chronic kidney disease (CKD) are closely related conditions with shared risk factors. The growing prevalence of both AF and CKD indicates that more patients will suffer from concurrent conditions. There are various complex interlinking mechanisms with important implications for the management of these patients. Furthermore, there is uncertainty regarding the use of oral anticoagulation (OAC) in AF and CKD that is reflected by a lack of consensus between international guidelines. Therefore, the importance of understanding the implications of co-existing AF and CKD should not be underestimated. In this review, we discuss the pathophysiology and association between AF and CKD, including the underlying mechanisms, risk of thrombo-embolic and bleeding complications, influence on stroke management, and evidence surrounding the use of OAC for stroke prevention.

Clinical outcomes associated with kidney function changes in anticoagulated atrial fibrillation patients: An ancillary analysis from the BOREALIS trial

BACKGROUND

Patients with atrial fibrillation (AF) and chronic kidney disease represent a high-risk group for thromboembolism and bleeding.

AIMS

To explore the relationship between kidney function changes and outcomes of stroke/systemic embolism (SE), major bleeding and all-cause death in anticoagulated AF patients participating in the BOREALIS trial comparing efficacy and safety of once-weekly s.c. idrabiotaparinux to that of warfarin.

METHODS

Changes in kidney function by estimated glomerular filtration rate (eGFR) were calculated using the Chronic Kidney Disease Epidemiology Collaboration equation in 2765 AF patients. Trial adjudicated outcomes were determined.

RESULTS

After a mean follow-up of 394 days, in 94.4% of the included patients kidney function changed ranging from -30 mL/min to 30 mL/min. The incidence of stroke/SE and major bleeding was similar between patients with deteriorated (reduction in eGFR from baseline over follow-up) and preserved kidney function change (increase or no change in eGFR from baseline over follow-up) [stroke/SE: incidence rate (IR): 1.33%/year vs 1.80%/year; hazard ratio (HR) 0.74, 95% confidence interval (CI) 0.41-1.32, P = .30; major bleeding: IR 1.63%/year vs 1.49%/year, HR 1.10, 95% CI 0.61-1.97, P = .76]. On Cox regression analysis, patients with deteriorated kidney function were at higher risk for all-cause death, compared to patients with preserved kidney function (HR: 1.64, 95% CI: 1.02-2.63, P = .04).

CONCLUSION

In the BOREALIS trial, the risk of adjudicated stroke/SE, major bleedings, and all-cause death was not related to mild-moderate follow-up changes in kidney function (±30 mL/min). The risk of all-cause death was significantly increased in AF patients with abruptly deteriorating kidney function.

Temporal trends of time in therapeutic range and incidence of cardiovascular events in patients with non-valvular atrial fibrillation

BACKGROUND

Optimal time in therapeutic range (TTR) of vitamin K antagonists (VKAs) is crucial for cardiovascular events (CVEs) prevention in non-valvular atrial fibrillation (NVAF). The relationship between temporal changes of TTR and the incidence of CVEs has been poorly investigated. We investigated 1) temporal trends of TTR in a long-term follow-up of NVAF patients; 2) the incidence of CVEs according to changes of TTR.

METHODS

Prospective observational study including 1341 NVAF outpatients (mean age 73.5 years, 42.5% male) starting VKAs. Patients were divided into 4 groups: Group 0: Optimal TTR, consistently ≥70% (n = 241); Group 1: Temporally worsening TTR, from above to below 70% (n = 263); Group 2: Temporally improving TTR, from below to above 70% (n = 270); Group 3: Suboptimal TTR, consistently <70% (n = 567).

RESULTS

In a mean follow-up of 37.7 months (4214.2 patient-years), 108 CVEs occurred (2.6%/year). Survival analysis showed a graded increased risk of CVEs in relation to temporal changes in TTR, with the worst outcomes in Groups 1 and 3 (log-rank test p = 0.013). Multivariable Cox proportional hazards regression analysis showed that Group 1 vs. 0 (HR: 2.096; 95%CI 1.061-4.139, p = 0.033), Group 3 vs. 0 (HR: 2.292; 95%CI 1.205-4.361, p = 0.011), CHA₂DS₂VASc score (HR:1.316; 95%CI 1.153-1.501, p < 0.001) and PPIs (HR:0.453; 95%CI 0.285-0.721, p = 0.001) were independently associated with CVEs.

CONCLUSION

A decrease of TTR <70% over time is observed in almost 20% of NVAF patients. Patients with worsening TTR temporally (ie. from initially above 70% to below 70%) have similar risk of CVEs of patients with consistently suboptimal anticoagulation.

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.

Relationship between atrial fibrillation and cognitive decline in individuals aged 80 and older

BACKGROUND

Atrial fibrillation (AF) and dementia are largely prevalent and incident in progressively older subjects, suggesting a link between the two conditions. While in the general population there are several findings supporting a causal relationship between AF and dementia, it is unclear whether or not this association is still present in individuals aged 80 and older.

RESULTS

So far, the few studies that analysed this issue did not provide enough evidence supporting the causative role of AF in increasing the risk of cognitive decline or dementia in patients aged 80 and older. Conversely, a relevant role of optimal anticoagulation control in determining a significant reduction in the risk of cognitive decline is suggested, in AF subjects aged 80years or older.

CONCLUSIONS

Further data, coming from population-based studies specifically investigating very old individuals and based upon large samples and comprehensive cognitive assessments, are needed to fully elucidate the relationship between AF and dementia in very old individuals.

Pharmacokinetics of Tecarfarin and Warfarin in Patients with Severe Chronic Kidney Disease

Chronic kidney disease (CKD) complicates warfarin anticoagulation partially through its effect on CYP2C9 activity. Tecarfarin, a novel vitamin K antagonist, is not metabolized by CYP2C9. To evaluate the effect of CKD on their metabolism, we measured PK parameters of warfarin and tecarfarin in subjects with and without CKD. CKD subjects with estimated glomerular filtration rate < 30 mL/min not on dialysis (n = 13) were matched to healthy volunteers (HVs) (n = 10). Each subject was randomized to either warfarin 10 mg or tecarfarin 30 mg and was later crossed over to the other drug. PK parameters were measured following each drug. Mean plasma concentrations of (S)-warfarin and (R,S)-warfarin were higher (44 and 27%, respectively) in the subjects with CKD than in the healthy subjects. Both of these values fell outside of the 90% confidence interval of equivalence. For tecarfarin, the difference was less than 15% higher. Elimination half-life (t_1/2) increased by 20% for (S)-warfarin and by 8% for (R,S)-warfarin and decreased by 8% for tecarfarin. The mean plasma concentration for tecarfarin's inactive metabolite ATI-5900 increased by approximately eightfold. CKD increased the effect of CYP2C9 genetic variation on (S)-warfarin and (R,S)-warfarin metabolism. Tecarfarin exposure was similar between the HVs and the CKD subjects regardless of CYP2C9 genotype. There were neither serious adverse events (SAEs) nor treatment-emergent adverse events (TEAEs) for any subject in the study. CKD inhibits metabolism of (S)-warfarin and (R,S)-warfarin, but not tecarfarin. The safety of repeated dosing of tecarfarin in CKD patients remains unknown. However, if the PK findings of this single-dose study are present with repeated dosing, tecarfarin may lead to dosing that is more predictable than warfarin in CKD patients who require anticoagulation therapy.

The relationship of renal function to outcome: A post hoc analysis from the EdoxabaN versus warfarin in subjectS UndeRgoing cardiovErsion of Atrial Fibrillation (ENSURE-AF) study

The ENSURE-AF study (NCT 02072434) of anticoagulation for electrical cardioversion in nonvalvular atrial fibrillation (NVAF) showed comparable low rates of bleeding and thromboembolism between the edoxaban and the enoxaparin-warfarin treatment arms. This post hoc analysis investigated the relationship between renal function and clinical outcomes.

METHODS

ENSURE-AF was a multicenter, PROBE evaluation trial of edoxaban 60 mg, or dose reduced to 30 mg/d for weight≤60 kg, creatinine clearance (CrCl; Cockcroft-Gault) ≤50 mL/min, or concomitant P-glycoprotein inhibitors compared with therapeutically monitored enoxaparin-warfarin in 2,199 NVAF patients undergoing electrical cardioversion. Efficacy and safety outcomes and time in therapeutic range in the warfarin arm were analyzed in relation to CrCl in prespecified ranges ≥15 and ≤30, >30 and ≤50, >50 and <80, and ≥80 mL/min, and an exploratory ≥95-mL/min analysis.

RESULTS

A total of 1,095 subjects were randomized to edoxaban and 1,104 to enoxaparin-warfarin. Mean age was 64.3±10 and 64.2±11 years. Mean time in therapeutic range was progressively lower with reducing CrCl strata, being 66.8% in those with CrCl >30 to ≤50 compared with 71.8% in those with CrCl ≥80. The odds ratios for the primary efficacy and safety end points were comparable for the different predefined renal function strata; given the small numbers, the 95% CI included 1.0. In the subset of those with CrCl ≥95, the odds ratios showed consistency with the other CrCl strata. When CrCl was assessed as a continuous variable, there was a nonsignificant trend toward higher major or clinically relevant nonmajor bleeding with reducing CrCl levels, with no significant differences between the 2 treatment arms. When we assessed CrCl at baseline compared with end of treatment, there were no significant differences in CrCl change between the edoxaban and enoxaparin-warfarin arms. The proportions with worsening of renal function (defined as a decrease of >20% from baseline) were similar in the 2 treatment arms.

CONCLUSION

Given the small number of events in ENSURE-AF, no effect of renal (dys)function was demonstrated in comparing edoxaban to enoxaparin-warfarin for cardioversion; efficacy and safety of edoxaban remained consistent even in patients with normal or supranormal renal function.

Anticoagulation Control in Warfarin-Treated Patients Undergoing Cardioversion of Atrial Fibrillation (from the Edoxaban Versus Enoxaparin-Warfarin in Patients Undergoing Cardioversion of Atrial Fibrillation Trial)

In the Edoxaban Versus Enoxaparin-Warfarin in Patients Undergoing Cardioversion of Atrial Fibrillation (ENSURE-AF) study (NCT 02072434), edoxaban was compared with enoxaparin-warfarin in 2,199 patients undergoing electrical cardioversion of nonvalvular atrial fibrillation (AF). In this multicenter prospective randomized open blinded end-point trial, we analyzed patients randomized to enoxaparin-warfarin. We determined time to achieve therapeutic range (TtTR); time in therapeutic range (TiTR); their clinical determinants; relation to sex, age, medical history, treatment, tobacco use, race risk (SAMe-TT₂R₂) score; and impact on primary end points (composite of stroke, systemic embolic event[SEE], myocardial infarction [MI], and cardiovascular death [CVD] and composite of major + clinically relevant nonmajor bleeding). Among 1,104 patients randomized to enoxaparin-warfarin, 27% were naïve to oral anticoagulants. Mean age was 64.2 ± 11 years and mean congestive heart failure, hypertension, age ≥75 (doubled), diabetes mellitus, prior stroke or transient ischemic attack (doubled), vascular disease, age 65-74, female (CHA₂DS₂-VASc) score was 2.6. Mean TtTR was 7.7 days (median 7 days) and mean TiTR after reaching an international normalized ratio of 2.0 to 3.0 was 71%. In 695 patients who had an INR <2.0 before the first dose and who reached an INR ≥2.0, 436 had a SAMe-TT₂R₂ score ≤2 and 259 had a score >2. On multivariate regression, an independent predictor of extended TtTR was creatinine clearance (p = 0.02). TtTR was marginally related to stroke/SEE/MI/CVD (p = 0.06; odds ratio  0.23, 95% confidence interval 0.02 to 1.17) but not to any bleeding. Independent predictors of TiTR were previous vitamin K antagonist experience (p<0.01) and low hypertension, abnormal renal or liver function, stroke, bleeding, labile INRs, age >65, concomitant drugs or alcohol (HAS-BLED) score (p = 0.02). TiTR was related to any bleeding (p = 0.02; odds ratio  0.39, 95% confidence interval 0.16 to 0.88), but not stroke/SEE/MI/CVD. In this cohort of warfarin users with a high TiTR no difference was seen between TtTR and TiTR in relation to SAMe-TT₂R₂ score. In conclusion, even in this short-term study, TiTR was significantly related to bleeding events.

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.

Renal Function Considerations for Stroke Prevention in Atrial Fibrillation

Renal impairment increases risk of stroke and systemic embolic events and bleeding in patients with atrial fibrillation. Direct oral anticoagulants (DOACs) have varied dependence on renal elimination, magnifying the importance of appropriate patient selection, dosing, and periodic kidney function monitoring. In randomized controlled trials of nonvalvular atrial fibrillation, DOACs were at least as effective and associated with less bleeding compared with warfarin. Each direct oral anticoagulant was associated with reduced risk of stroke and systemic embolic events and major bleeding compared with warfarin in nonvalvular atrial fibrillation patients with mild or moderate renal impairment. Renal function decrease appears less impacted by DOACs, which are associated with a better risk-benefit profile than warfarin in patients with decreasing renal function over time. Limited data address the risk-benefit profile of DOACs in patients with severe impairment or on dialysis.

Time in therapeutic range and major adverse outcomes in atrial fibrillation patients undergoing percutaneous coronary intervention: The Atrial Fibrillation Undergoing Coronary Artery Stenting (AFCAS) registry

BACKGROUND

Combination of oral anticoagulation (OAC) and antiplatelets is used in atrial fibrillation (AF) patients undergoing percutaneous coronary intervention and stent (PCI-S) procedure but is associated with increased bleeding when triple antithrombotic therapy (TAT) is used. Our aim was to analyze the impact of time in therapeutic range (TTR) on outcomes, in patients prescribed with TAT.

METHODS

Ancillary analysis from the AFCAS registry in patients assigned to TAT. TTR was calculated with Rosendaal method. Outcomes were analyzed according to TTR tertiles (T1 [≤56.8%] vs. T2 [56.9-93.8%] vs. T3 [≥93.9%]). Major bleeding was the primary outcome.

RESULTS

Of 963 patients enrolled, 470(48.8%) were prescribed with TAT at discharge and qualified for this analysis. Median [IQR] TTR was 80.0% [45.3-100%]. After 359 [341-370] days, major bleeding rates were progressively lower with increasing TTR tertiles (T1 vs. T2 vs. T3: 10.3% vs. 4.7% vs. 2.3%, P=.006). Kaplan-Meier analysis demonstrated a progressively lower risk for major bleeding across tertiles (P=.006). Patients in the highest TTR tertile had a non-significant lower risk for major adverse coronary and cerebrovascular events (MACCE) (log-rank: 4.905, P=.086). Cox regression analysis showed that T2 and T3 were inversely associated with major bleeding (hazard ratio [HR]:0.39, P=.050 and HR: 0.21, P=.005). Continuous TTR was inversely associated with major bleeding (HR: 0.98, P<.001). For MACCE, adjusted Cox analysis found a non-significant lower risk for T3 (HR: 0.64, P=.128).

CONCLUSIONS

In AF patients undergoing PCI-S prescribed TAT, good quality anticoagulation control (as reflected by TTR) was closely related to bleeding outcomes during follow-up. Despite some suggestive trends for an inverse relationship between TTR and MACCE, no definitive conclusions can be drawn, and further large studies are needed.

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.

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.

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.