Improvement of HAS-BLED bleeding score predictive capability by changing the definition of renal dysfunction in Japanese atrial fibrillation patients on anticoagulation therapy

Adverse Clinical Outcomes and Associated Predictors in Rivaroxaban-Treated Atrial Fibrillation Patients With Renal Impairment

Renal impairment confers worse prognosis in patients with atrial fibrillation (AF) but there is scarce evidence about the influence of direct-acting oral anticoagulants in routine clinical practice. Herein, we compared clinical outcomes between patients with AF with and without renal impairment on rivaroxaban and investigated predictors for clinical outcomes in patients with AF with renal impairment. This was a multicenter study including patients with AF on rivaroxaban for at least 6 months. During 2.5 years follow-up, ischemic strokes (IS)/transient ischemic attacks (TIA)/systemic embolisms (SE)/myocardial infarctions (MI), major bleeding, and major adverse cardiovascular events (MACE) were recorded. Creatinine clearance (CrCl) was estimated using the Cockroft-Gault equation, renal impairment was defined as a CrCl <60 ml/min, and 1,433 patients (34.8% with CrCl <60 ml/min) were included. Patients with CrCl <60 ml/min showed higher event rates for major bleeding (1.87%/year vs 0.62%/year; p = 0.003) and MACE (1.97%/year vs 0.62%/year; p = 0.002) but similar event rates for IS/TIA/SE/MI (0.66%/year vs 0.67%/year; p = 0.955). In patients with renal impairment, CHA2DS2-VASc was associated with higher risk of IS/TIA/SE/MI; HAS-BLED and any dependency level were associated with higher risk of major bleeding; and male gender and heart failure were associated with higher risk of MACE. Antiplatelets were independently associated with increased risk of IS/TIA/SE/MI and MACE. In conclusion, in patients with AF on rivaroxaban, the incidence of IS/TIA/SE/MI did not increase in those with renal impairment, suggesting that rivaroxaban may be an effective option in this subgroup. In patients with AF, male gender, heart failure, dependency, antiplatelets, CHA2DS2-VASc, and HAS-BLED were associated with increased risk of adverse outcomes.

A Novel Creatinine-Based Equation to Estimate Glomerular Filtration Rate in Chinese Population With Chronic Kidney Disease: Implications for DOACs Dosing in Atrial Fibrillation Patients

Background: Over/under-estimating renal function may increase inappropriate dosing strategy associated adverse outcomes; however, previously reported equations to estimate renal function have limited accuracy in chronic kidney disease (CKD) patients. Consequently, we intended to develop a novel equation to precisely estimate renal function and subsequently guide clinical treatment for CKD patients. Methods: A novel approach, Xiangya-s equation, to estimate renal function for CKD patients was derived by linear regression analysis and validated in 1885 patients with measured glomerular filtration rate (mGFR) < 60 ml/min/1.73 m2 by renal dynamic imaging at three representative hospitals in China, with the performance evaluated by accuracy, bias and precision. In the meanwhile, 2,165 atrial fibrillation (AF) patients who initiated direct oral anticoagulants (DOACs) between December 2015 and December 2018 were identified and renal function was assessed by estimated creatinine clearance (eCrCl). Events per 100 patient-years was calculated. Cox proportional hazards regression was applied to compare the incidence of outcomes of each group. Results: Xiangya-s equation demonstrated higher accuracy, lower bias and improved precision when compared with 12 creatinine-based and 2 CysC-based reported equations to estimate GFR in multi-ethnic Chinese CKD patients. When we applied Xiangya-s equation to patients with AF and CKD prescribed DOACs, wide variability was discovered in eCrCl calculated by the Cockcroft-Gault (CG), Modification of Diet in Renal Disease Study (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Xiangya equation which we had developed for generally patients and Xiangya-s equations, which persisted after grouping by different renal function stages. Equation choice affected drug-dosing adjustments, with the formulas agreeing for only 1.19%, 5.52%, 33.22%, 26.32%, and 36.61% of potentially impacted patients for eCrCl cutoffs of <15, <30, 15-49, 30-49, ≥50 ml/min, respectively. Relative to CG equation, accordance in DOACs dosage was 81.08%, 88.54%, 62.25%, and 47.68% for MDRD, CKD-EPI, Xiangya and Xiangya-s equations for patients with CrCl < 50 ml/min (eCrCl cutoffs of <30, 30-49, ≥50 ml/min), respectively. Reclassification of renal function stages by Xiangya-s equation was significantly associated with stroke or systemic embolism, non-major clinically relevant bleeding and any bleeding events. Conclusion: Xiangya-s equation provides more accurate GFR estimates in Chinese CKD patients who need consecutive monitoring of renal function, which may assist clinicians in choosing appropriate drug dosages.

Association of Genetic Variants With Warfarin-Associated Bleeding Among Patients of African Descent

IMPORTANCE

Major warfarin-related bleeding occurs more frequently in African Americans than in other populations. Identification of potential genetic factors related to this adverse event may help identify at-risk patients.

OBJECTIVE

To identify genetic factors associated with warfarin-related bleeding in patients of African descent at an international normalized ratio (INR) of less than 4.

DESIGN, SETTING, AND PARTICIPANTS

A case-control genome-wide association study involving patients of African descent taking warfarin was conducted in a discovery cohort (University of Chicago [2009-2011] and the University of Illinois at Chicago [2002-2011]), and associations were confirmed in a replication cohort (University of Chicago [2015-2016]). Potential population stratification was examined in the discovery cohort by principal component analysis. Odds ratios (ORs) and 95% CIs were computed for bleeding risk by logistic regression analysis. Summary statistics from the discovery and the replication cohorts were analyzed with a fixed effects meta-analysis. The potential influence of single-nucleotide polymorphisms (SNPs) on gene expression was studied by luciferase expression assays.

EXPOSURES

Single-nucleotide polymorphisms associated with warfarin-related bleeding.

MAIN OUTCOMES AND MEASURES

Major bleeding-defined as bleeding requiring hospitalization, causing a decrease in hemoglobin level of more than 2 g/dL, requiring blood transfusion, or any combination of the 3-while taking warfarin at an INR of less than 4.

RESULTS

The discovery cohort consisted of 31 cases (mean age, 60.1 years [SD, 14.9 years], 26 women [83.9%]) and 184 warfarin-treated controls (mean age, 57.1 years [SD, 15.7 years]) with no documented bleeding. The replication cohort consisted of 40 cases (mean age, 55.6 years [SD, 17.3 years], 27 women [67.5%]), and 148 warfarin-treated controls (mean age, 55.4 years [SD, 17.1 years]; 98 women [66.2%]) with no documented bleeding. In the discovery cohort, 4 SNPs in linkage disequilibrium on chromosome 6 (rs115112393, rs16871327, rs78132896, and rs114504854) were associated with warfarin-related bleeding but did not reach genome-wide significance. The SNP rs78132896 occurred in 11 cases (35.5%) and 9 controls (4.9%) in the discovery cohort (OR, 8.31; 95% CI, 3.2-21.5; P < 6.21 × 10-8), and the association was confirmed in the replication cohort (the SNP was present in 14 cases [35.0%] and 7 controls [4.8%]; OR, 8.24; 95% CI, 3.1-25.3, P = 5.64 × 10-5). Genome-wide significance of this SNP was achieved when the cohorts were combined via meta-analysis (OR, 8.27; 95% CI, 4.18-16.38; P = 2.05 × 10-11). These SNPs are found only in people of African descent. In vitro luciferase expression assays demonstrated that rs16871327 (enhancer SNP) and rs78132896 (promoter SNP) risk alleles together increased EPHA7 gene (Entrez Gene 2045) transcription by a mean of 14.95 (SD, 1.7) compared with wild-type alleles (mean, 9.56 [SD, 0.84]; difference, 5.39; 95% CI, 4.1-6.6; P < .001).

CONCLUSIONS AND RELEVANCE

In this preliminary study involving patients of African descent taking warfarin, 4 single-nucleotide polymorphisms in linkage disequilibrium on chromosome 6 were associated with an increased risk of major bleeding at INR of less than 4. Validation of these findings in an independent prospective cohort is required.

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

BACKGROUND

It is unclear whether renal dysfunction affects warfarin control in patients with non-valvular atrial fibrillation (NVAF).

METHODS AND RESULTS

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

CONCLUSIONS

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

Edoxaban for the management of elderly Japanese patients with atrial fibrillation ineligible for standard oral anticoagulant therapies: Rationale and design of the ELDERCARE-AF study

Edoxaban-a non-vitamin K antagonist oral anticoagulant (NOAC)- 60-mg and 30-mg once-daily dose regimens are noninferior versus well-managed warfarin for the prevention of stroke or systemic embolic events (SEE) with less major bleeding in patients with nonvalvular atrial fibrillation (NVAF). There are no published data from phase 3 clinical trials specifically evaluating the use of NOACs in elderly NVAF patients, especially those considered ineligible for available oral anticoagulants. The Edoxaban Low-Dose for EldeR CARE AF patients (ELDERCARE-AF) study is a phase 3, randomized, double-blind, placebo-controlled, parallel-group, multicenter study that will compare the safety and efficacy of once-daily edoxaban 15 mg versus placebo in Japanese patients with NVAF ≥80 years of age who are considered ineligible for standard oral anticoagulant therapy. A total of 800 patients (400 in each treatment group) are planned for randomization (1:1) to either edoxaban or placebo using a stratified randomization method with CHADS₂ index score (2 points, ≥3 points) as a factor. The primary efficacy end point is the time to first onset of stroke or SEE. The net clinical outcome is the composite of stroke, SEE, major bleeding, and all-cause mortality. The primary safety end point is the incidence of major bleeding. The treatment period will continue until 65 patients with the primary efficacy events (ie, stroke or SEE) have been observed (2- to 2.5-year expected mean treatment period). The results of ELDERCARE-AF may provide clarity as to the efficacy and safety of edoxaban for the prevention of stroke or SEE in this high-risk population.

Evaluation of the predictive performance of bleeding risk scores in patients with non-valvular atrial fibrillation on oral anticoagulants

WHAT IS KNOWN AND OBJECTIVE

Bleeding risk scores (BRSs) aid in the assessment of oral anticoagulant-related bleeding risk in patients with atrial fibrillation. Ideally, the applicability of a BRS needs to be assessed, prior to its routine use in a population other than the original derivation cohort. Therefore, we evaluated the performance of 6 established BRSs to predict major or clinically relevant bleeding (CRB) events associated with the use of oral anticoagulant (OAC) among Malaysian patients.

METHODS

The pharmacy supply database and the medical records of patients with non-valvular atrial fibrillation (NVAF) receiving warfarin, dabigatran or rivaroxaban at two tertiary hospitals were reviewed. Patients who experienced an OAC-associated major or CRB event within 12 months of follow-up, or who have received OAC therapy for at least 1 year, were identified. The BRSs were fitted separately into patient data. The discrimination and the calibration of these BRSs as well as the factors associated with bleeding events were then assessed.

RESULTS

A total of 1017 patients with at least 1-year follow-up period, or those who developed a bleeding event within 1 year of OAC use, were recruited. Of which, 23 patients experienced a first major bleeding event, whereas 76 patients, a first CRB event. Multivariate logistic regression results show that age of 75 or older, prior bleeding and male gender are associated with major bleeding events. On the other hand, prior gastrointestinal bleeding, a haematocrit value of less than 30% and renal impairment are independent predictors of CRB events. All the BRSs show a satisfactory calibration for major and CRB events. Among these BRSs, only HEMORR₂ HAGES (C-statistic = 0.71, 95% CI 0.60-0.82, P < .001) and ATRIA score (C-statistic = 0.70, 95% CI 0.58-0.82, P < .001) show acceptable discrimination performance for major bleeding events. All the 6 BRSs, however, lack acceptable predictive performance for CRB events.

WHAT IS NEW AND CONCLUSION

To the best of our knowledge, this is the first evaluation study of the predictive performance of these 6 BRSs on clinically relevant bleeding events applied to the same cohort consisting of mainly Asian novel oral anticoagulant users. These BRSs show poor to acceptable predictive performance on OAC-induced major or CRB events. An improvement in the existing BRSs for OAC users is warranted.

The Risk of Major Hemorrhage with CKD

New staging systems for CKD account for both reduced eGFR and albuminuria; whether each measure associates with greater risk of hemorrhage is unclear. In this retrospective cohort study (2002-2010), we grouped 516,197 adults ≥40 years old by eGFR (≥90, 60 to <90, 45 to <60, 30 to <45, 15 to <30, or <15 ml/min per 1.73 m(2)) and urine albumin-to-creatinine ratio (ACR; >300, 30-300, or <30 mg/g) to examine incidence of hemorrhage. The 3-year cumulative incidence of hemorrhage increased 20-fold across declining eGFR and increasing urine ACR groupings (highest eGFR/lowest ACR: 0.5%; lowest eGFR/highest ACR: 10.1%). Urine ACR altered the association of eGFR with hemorrhage (P<0.001). In adjusted models using the highest eGFR/lowest ACR grouping as the referent, patients with eGFR=15 to <30 ml/min per 1.73 m(2) had adjusted relative risks of hemorrhage of 1.9 (95% confidence interval [95% CI], 1.5 to 2.4) with the lowest ACR and 3.7 (95% CI, 3.0 to 4.5) with the highest ACR. Patients with the highest eGFR/highest ACR had an adjusted relative risk of hemorrhage of 2.3 (95% CI, 1.8 to 2.9), comparable with the risk for patients with the lowest eGFR/lowest ACR. The associations attenuated but remained significant after adjustment for anticoagulant and antiplatelet use in patients ≥66 years old. The risk of hemorrhage differed by urine ACR in high risk subgroups. Our data show that declining eGFR and increasing albuminuria each independently increase hemorrhage risk. Strategies to reduce hemorrhage events among patients with CKD are warranted.

Is the ORBIT Bleeding Risk Score Superior to the HAS-BLED Score in Anticoagulated Atrial Fibrillation Patients?

BACKGROUND

Several bleeding risk scores have been validated in patients with atrial fibrillation (AF). The ORBIT score has been recently proposed as a simple score with the best ability to predict major bleeding. The present study aimed to test the hypothesis that the ORBIT score was superior to the HAS-BLED score for predicting major bleeding and death in "real world" anticoagulated AF patients.

METHODS AND RESULTS

We analyzed the predictive performance for bleeding and death of 406 AF patients who underwent 571 electrical cardioversion procedures and 1,276 patients with permanent/persistent AF from the FANTASIIA registry. In the cardioversion population, 21 patients had major bleeding events and 26 patients died. The predictive performance for major bleeding of HAS-BLED and ORBIT were not significantly different (c-statistics 0.77 (95% CI 0.66-0.88) and 0.82 (95% CI 0.77-0.93), respectively; P=0.080). For the FANTASIIA population, 46 patients had major bleeding events and 50 patients died. The predictive performances for major bleeding of HAS-BLED and ORBIT were not significantly different (c-statistics 0.63 (95% CI 0.56-0.71) and 0.70 (95% CI 0.62-0.77), respectively; P=0.116). For death, the predictive performances of HAS-BLED and ORBIT were not significantly different in both populations. The ORBIT score categorized most patients as "low risk".

CONCLUSIONS

Despite the original claims in its derivation paper, the ORBIT score was not superior to HAS-BLED for predicting major bleeding and death in a "real world" oral anticoagulated AF population. (Circ J 2016; 80: 2102-2108).

Impact of moderate to severe renal impairment on long-term clinical outcomes in patients with atrial fibrillation

BACKGROUND

The deleterious effect of renal impairment in non-valvular atrial fibrillation (AF) patients has recently been reported. We investigated the impact of moderate to severe renal impairment on long-term clinical outcomes in AF patients.

METHODS

A total of 2126 AF patients were enrolled and divided into two groups according to ≥ or <60mL/min estimated glomerular filtration rate (eGFR). Clinical outcomes including all-cause death, cardiac death, ischemic stroke (IS), bleeding, and admission for heart failure (HF) were analyzed.

RESULTS

Compared to the ≥60mL/min eGFR group, <60mL/min eGFR patients were older; had a higher proportion of females; were more likely to have diabetes, hypertension, and history of stroke; and had higher CHADS₂, CHA₂DS₂-VAS_c, and HAS-BLED scores. During the follow-up period (median 6.23 years), all-cause death, bleeding, admission for HF, and progression to persistent or permanent AF were significantly increased in the <60mL/min eGFR group compared to the ≥60mL/min eGFR group. After multivariate Cox regression analyses, <60mL/min eGFR increased the risk of all-cause death [hazard ratio (HR): 1.84; 95% confidence interval (CI): 1.03-3.28, p=0.04] and bleeding (HR: 1.28; 95% CI: 1.04-1.57, p=0.02). IS was only significantly increased in the <60mL/min eGFR group not receiving antithrombotic treatment.

CONCLUSION

Moderate to severe renal impairment is a poor prognostic factor of long-term clinical outcomes in AF patients.

Predictive performance of HAS-BLED risk score for long-term survival in patients with non-ST elevated myocardial infarction without atrial fibrillation

BACKGROUND

Predictive value of the Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile international normalized ratio, Elderly, Drugs or alcohol use (HAS-BLED) score for clinical outcomes has been investigated in patients with and without atrial fibrillation. Many factors in the HAS-BLED model have been reported to be prognostic predictors in patients with post-myocardial infarction (MI). However, few studies have investigated the predictive value of HAS-BLED score on long-term survival in patients with post-MI.

METHODS

A total of 617 patients with non-ST elevation MI (NSTEMI) without atrial fibrillation were enrolled. The Thrombolysis In Myocardial Infarction (TIMI), Global Registry of Acute Coronary Events (GRACE), Can Rapid Risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA guidelines (CRUSADE), and HAS-BLED risk scores were calculated for each patient.

RESULTS

The C-statistics of TIMI, GRACE, CRUSADE, and HAS-BLED scores for 3-year survival were 0.658, 0.749, 0.756, and 0.765, respectively. For 3-year survival prediction, GRACE, CRUSADE, and HAS-BLED scores, respectively demonstrated superior performance than TIMI score and there was no significant difference between these three scores (GRACE vs. TIMI: z=1.615, p=0.027; CRUSADE vs. TIMI: z=1.371, p=0.043; HAS-BLED vs. TIMI: z=1.899, p=0.014; CRUSADE vs. GRACE: z=0.078, p=0.234; HAS-BLED vs. GRACE: z=0.435, p=0.166; HAS-BLED vs. CRUSADE: z=0.353, p=0.181). Multivariate analysis showed left ventricular ejection fraction <40%, old age, stroke history, bleeding history, and abnormal renal and liver function were independent predictors for 3-year mortality.

CONCLUSIONS

HAS-BLED scoring system is similar to the GRACE and CRUSADE systems but better than TIMI system to predict long-term survival outcomes in patients with NSTEMI without atrial fibrillation. However, HAS-BLED score is easier to calculate than GRACE and CRUSADE scores.

Underutilization of warfarin for stroke prophylaxis in patients with atrial fibrillation or atrial flutter in Korea

OBJECTIVE

Anticoagulation therapy with warfarin is recommended for stroke prevention in patients with atrial fibrillation (AF) or atrial flutter (AFL) whose risks for stroke are high. However, previous studies suggest that warfarin is markedly underused. This study aims to investigate the incidence and risk factors of warfarin underutilization in patients with high risk of stroke in Korea.

METHODS

This was a cross-sectional study using the data of 2009 from National Patients Sample compiled by the Health Insurance Review and Assessment Service. Patients with high risk of thromboembolism were identified with congestive heart failure, hypertension, age ≥75 years, diabetes, and prior stroke (CHADS2) score ≥2. High-risk patients of bleeding were excluded using Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) score >4. Warfarin and antithrombotic therapy underutilization were defined and estimated in high-risk patients. Any demographic and clinical factors associated with warfarin and antithrombotic therapy underutilization were explored using a logistic regression model.

RESULTS

Of the national patient sample, 15,885 patients were identified with AF or AFL. Among them, a total of 8475 patients who had an admission history, CHADS2 ≥2, and ATRIA score ≤4 were included in the analysis. From the study sample, warfarin underutilization and antithrombotic therapy underutilization were estimated to be 64.0% and 20.4%, respectively. Predictors of warfarin underutilization include female sex, age ≥80 years, lower CHADS2 score, and insurance type (Medical Aid program).

CONCLUSIONS

A high portion of AF/AFL patients with CHADS2 score ≥2 were undertreated with warfarin. As ischemic stroke is one of the leading causes of death in Korea, a more aggressive approach to prevent stroke in patients with AF/AFL is required.