Anticoagulation use and the risk of stroke and major bleeding in patients on hemodialysis: From the VIVALDI, a population-based prospective cohort study

Transfer RNAs are Linked to Ischemic Stroke and Major Bleeding in Patients with End-Stage Kidney Disease

BACKGROUND

 Patients with end-stage kidney disease (ESKD) are at very high risk for thromboembolism and bleeding. This study aimed to identify small noncoding RNAs (sncRNAs), specifically microRNAs and transfer-RNA (tRNA)-derived fragments (tRFs), as potential novel biomarkers for predicting thromboembolism and bleeding in this high-risk population.

METHODS

 In this sncRNA discovery research, we leveraged the VIVALDI cohort, consisting of 625 ESKD patients on hemodialysis, to conduct two nested case-control studies, each comprising 18 participants. The primary outcomes were ischemic stroke in the first study and major bleeding in the second. Plasma samples were processed using the miND pipeline for RNA-seq analysis to investigate differential expression of microRNAs and tRNA/tRFs between cases and their respective matched controls, with results stringently adjusted for the false discovery rate (FDR).

RESULTS

 No significant differential expression of microRNAs for either ischemic stroke or major bleeding outcomes was observed in the two nested case-control studies. However, we identified four tRNAs significantly differentially expressed in ischemic stroke cases and seven in major bleeding cases, compared with controls (FDR < 0.1). Coverage plots indicated that specific tRNA fragments (tRFs), rather than full-length tRNAs, were detected, however. Alternative mapping approaches revealed challenges and technical limitations that precluded in-depth differential expression analyses on these specific tRFs. Yet, they also underscored the potential of tRNAs and tRFs as markers for thromboembolism and bleeding.

CONCLUSION

 While microRNAs did not show significant differential expression, our study identifies specific tRNAs/tRFs as potential novel biomarkers for ischemic stroke and major bleeding in ESKD patients.

Telomere Length Is Associated with Increased Risk of Cardiovascular Events in Patients with End-Stage Kidney Disease on Hemodialysis

INTRODUCTION

Patients with chronic kidney disease, especially those with end-stage kidney disease (ESKD) on hemodialysis (HD), are at increased risk for cardiovascular disease (CVD), including myocardial infarction and ischemic stroke. A shortening in telomere length, as a parameter for accelerated vascular aging, is an established biomarker for CVD in the general population. We aimed to elucidate the role of telomere length in ESKD patient on HD and its association with cardiovascular outcomes.

METHODS

Telomere length was measured in a prospective population-based cohort study of prevalent HD patients. DNA was isolated from whole blood, sampled at baseline, and analyzed for telomere length via a qPCR-based approach. The risk for the occurrence of the independently adjudicated three-point major adverse cardiovascular event outcome (myocardial infarction, ischemic stroke, and cardiovascular death) was statistically analyzed considering the competing risk of non-cardiovascular death.

RESULTS

In the cohort of 308 patients with ESKD (115 [37.3%] women, median [25th-75th percentile] age: 67.0 [56.8-76.0]), the median telomere length was 1.51 kb (25th-75th percentile 0.6-3.2 kb). The 3P-MACE outcome occurred with an incidence rate of 9.4 per 100 patient-years. Patients with longer telomere length more frequently had vascular nephropathy compared to patients with shorter telomere length. Interestingly, patients in the highest quartile of telomere length had a 1.8-fold increased risk for 3P-MACE (95% CI: 1.051-3.201, p = 0.033), after multivariable adjustment for age, history of stroke, myocardial infarction, venous thromboembolism, presence of heart valve replacement, atrial fibrillation, smoking, anticoagulation, or immunosuppressive use.

CONCLUSION

Surprisingly, in this high-risk cohort of patients with ESKD on HD, longer telomere lengths were associated with increased risk of cardiovascular events.

Growth differentiation factor-15 predicts major bleeding, major adverse cardiac events and mortality in patients with end-stage kidney disease on haemodialysis: findings from the VIVALDI study

BACKGROUND

Patients with end-stage kidney disease (ESKD) are at high risk of cardiovascular events and bleeding. Optimizing risk assessment of ESKD patients regarding the risk of thromboembolism and bleeding complications in comorbid conditions, including atrial fibrillation and coronary heart disease, is challenging. To improve risk prediction we investigated growth differentiation factor-15 (GDF-15), a promising cardiovascular biomarker, and its relation to adverse outcomes.

METHODS

In this prospective, multicentre, population-based cohort study, GDF-15 was measured in 594 ESKD patients on haemodialysis (median age 66 years, 38% female), who were followed up for a median of 3.5 years. The association of GDF-15 with major bleeding, arterial thromboembolism, major adverse cardiac events (MACE) and death was analysed within a competing risk framework. Further, we evaluated the additive predictive value of GDF-15 to cardiovascular and death risk assessment.

RESULTS

GDF-15 levels were in median 5475 ng/l (25th-75th percentile 3964-7533) and independently associated with major bleeding {subdistribution hazard ratio [SHR] 1.31 per double increase [95% confidence interval (CI) 1.00-1.71]}, MACE [SHR 1.47 (95% CI 1.11-1.94)] and all-cause mortality [SHR 1.58 (95% CI 1.28-1.95)] but not arterial thromboembolism [SHR 0.91 (95% CI 0.61-1.36)]. The addition of GDF-15 to the HAS-BLED score significantly improved discrimination and calibration for predicting major bleeding [C-statistics increased from 0.61 (95% CI 0.52-0.70) to 0.68 (95% CI 0.61-0.78)]. Furthermore, we established an additive predictive value of GDF-15 beyond current risk models for predicting MACE and death.

CONCLUSION

GDF-15 predicts the risk of major bleeding, cardiovascular events and death in ESKD patients on haemodialysis and might be a valuable marker to guide treatment decisions in this challenging patient population.

Outcomes of venous thromboembolism care: future directions

The complete picture of the outcomes of venous thromboembolism (VTE) care consists of conventional binary clinical outcomes (death, recurrent VTE, and bleeding), patient-centered outcomes, and society-level outcomes. Combined, these allow for the introduction of outcome-driven patient-centered health care. The emerging concept of valuing health care from such a holistic point of view, ie, value-based health care, holds a huge potential to revolutionize-and improve-the organization and evaluation of care. The ultimate goal of this approach was to achieve a high value for patients, ie, the best possible clinical outcomes at the right cost, providing a framework for evaluation and comparisons of different management strategies, patient pathways, or even complete health care delivery systems. To facilitate this, outcomes of care from a patient perspective, such as symptom burden, functional limitations, and quality of life, need to be routinely captured in clinical practice and trials, complementary to the conventional clinical outcomes, to fully capture the patients' values and needs. The aim of this review was to discuss the relevant outcomes of VTE care, explore value in VTE care from different perspectives, and propose future directions to inspire change. This is a call to action to shift the focus to outcomes that matter and make a larger difference in the lives of patients.

Atrial fibrillation and anticoagulation are associated with hospitalisations in patients with end-stage kidney disease on haemodialysis: a prospective population-based cohort study

BACKGROUND

Patients with end-stage kidney disease on haemodialysis suffer from frequent complications requiring hospitalisation. Atrial fibrillation is a burdensome comorbidity amongst patients on haemodialysis. We aimed to assess frequency, reasons, and duration of hospitalisations in haemodialysis patients and their association with atrial fibrillation and anticoagulation.

METHODS

Prevalent patients with end-stage kidney disease on haemodialysis were recruited into a prospective cohort study and observed for a median observation time of 3.4 years. Hospitalisations were recorded from discharge letters, medical records, and patient interviews. The association of atrial fibrillation, anticoagulation, and time-in-therapeutic range of vitamin K antagonist treatment with hospitalisations was analysed using negative binomial regression.

RESULTS

Out of 625 patients, 238 (38.1%) had atrial fibrillation. Median number of hospitalisations per patient was 3.0 (1.0-5.0). Incidence rate of hospitalisation was 1.7 per patient-year in all and 1.9 in atrial fibrillation patients, median duration per hospitalisation was 7.9 (4.8-12.9) and 8.8 (5.7-13.3) days, respectively. Most frequent reasons for hospitalisation were vascular access complication/intervention (11.7%) and infection/fever (11.4%), while bleeding events comprised 6.0% of all hospitalisations. Atrial fibrillation patients had 27% higher risk of hospitalisation than patients without atrial fibrillation (incidence rate ratio [IRR] 1.27, 95% confidence interval [CI] 1.10-1.47). In atrial fibrillation patients, anticoagulation (enoxaparin or phenprocoumon, 41.6% of AF patients) was associated with increased risk of all-cause (IRR 1.38, 95%CI 1.14-1.69) and bleeding-related hospitalisation (IRR 1.96, 95%CI 1.06-3.63). There was no association between anticoagulation and stroke-related hospitalisation. In atrial fibrillation patients on phenprocoumon, increasing time-in-therapeutic range was associated with decreased risk of all-cause (IRR 0.35, 95%CI 0.14-0.87), but not bleeding-related hospitalisation (IRR 0.13, 95%CI 0.01-1.38).

CONCLUSION

In haemodialysis patients, presence of atrial fibrillation and, among those with atrial fibrillation, anticoagulation were associated with higher risk of all-cause hospitalisation, including bleeding-related hospitalisation in the latter. Increasing time-in-therapeutic range in patients on vitamin K antagonist treatment was associated with decreased risk of all-cause, but not bleeding-related hospitalisation.

A systematic review of the efficacy and safety of anticoagulants in advanced chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) have an increased risk of venous thromboembolism (VTE) and atrial fibrillation (AF). Anticoagulants have not been studied in randomised controlled trials with CrCl < 30 ml/min. The objective of this review was to identify the impact of different anticoagulant strategies in patients with advanced CKD including dialysis.

METHODS

We conducted a systematic review of randomized controlled trials and cohort studies, searching electronic databases from 1946 to 2022. Studies that evaluated both thrombotic and bleeding outcomes with anticoagulant use in CrCl < 50 ml/min were included.

RESULTS

Our initial search yielded 14,503 papers with 53 suitable for inclusion. RCTs comparing direct oral anticoagulants (DOACs) versus warfarin for patients with VTE and CrCl 30-50 ml/min found no difference in recurrent VTE events (RR 0.68(95% CI 0.42-1.11)) with reduced bleeding (RR 0.65 (95% CI 0.45-0.94)). Observational data in haemodialysis suggest lower risk of recurrent VTE and major bleeding with apixaban versus warfarin. Very few studies examining outcomes were available for therapeutic and prophylactic dose low molecular weight heparin for CrCl < 30 ml/min. Findings for patients with AF on dialysis were that warfarin or DOACs had a similar or higher risk of stroke compared to no anticoagulation. For patients with AF and CrCl < 30 ml/min not on dialysis, anticoagulation should be considered on an individual basis, with limited studies suggesting DOACs may have a preferable safety profile.

CONCLUSION

Further studies are still required, some ongoing, in patients with advanced CKD (CrCl < 30 ml/min) to identify the safest and most effective treatment options for VTE and AF.

Patient specific approach to analysis of shear-induced platelet activation in haemodialysis arteriovenous fistula

Shear-induced platelet activation (SIPAct) is an important mechanism of thrombosis initiation under high blood flow. This mechanism relies on the interaction of platelets with the von Willebrand factor (VWF) capable of unfolding under high shear stress. High shear stress occurs in the arteriovenous fistula (AVF) commonly used for haemodialysis. A novel patient-specific approach for the modelling of SIPAct in the AVF was proposed. This enabled us to estimate the SIPAct level via computational fluid dynamics. The suggested approach was applied for the SIPAct analysis in AVF geometries reconstructed from medical images. The approach facilitates the determination of the SIPAct level dependence on both biomechanical (AVF flow rate) and biochemical factors (VWF multimer size). It was found that the dependence of the SIPAct level on the AVF flow rate can be approximated by a power law. The critical flow rate was a decreasing function of the VWF multimer size. Moreover, the critical AVF flow rate highly depended on patient-specific factors, e.g., the vessel geometry. This indicates that the approach may be adopted to elucidate patient-specific thrombosis risk factors in haemodialysis patients.

Bleeding Risk Assessment in End-Stage Kidney Disease: Validation of Existing Risk Scores and Evaluation of a Machine Learning-Based Approach

BACKGROUND

 Patients with end-stage kidney disease (ESKD) on hemodialysis (HD) are at increased risk for bleeding. However, despite relevant clinical implications regarding dialysis modalities or anticoagulation, no bleeding risk assessment strategy has been established in this challenging population.

METHODS

 Analyses on bleeding risk assessment models were performed in the population-based Vienna InVestigation of Atrial fibrillation and thromboemboLism in patients on hemoDialysIs (VIVALDI) study including 625 patients. In this cohort study, patients were prospectively followed for a median observation period of 3.5 years for the occurrence of major bleeding. First, performances of existing bleeding risk scores (i.e., HAS-BLED, HEMORR2HAGES, ATRIA, and four others) were evaluated in terms of discrimination and calibration. Second, four machine learning-based prediction models that included clinical, dialysis-specific, and laboratory parameters were developed and tested using Monte Carlo cross-validation.

RESULTS

 Of 625 patients (median age: 66 years, 37% women), 89 (14.2%) developed major bleeding, with a 1-year, 2-year, and 3-year cumulative incidence of 6.1% (95% confidence interval [CI]: 4.2-8.0), 10.3% (95% CI: 8.0-12.8), and 13.5% (95% CI: 10.8-16.2), respectively. C-statistics of the seven contemporary bleeding risk scores ranged between 0.54 and 0.59 indicating poor discriminatory performance. The HAS-BLED score showed the highest C-statistic of 0.59 (95% CI: 0.53-0.66). Similarly, all four machine learning-based predictions models performed poorly in internal validation (C-statistics ranging from 0.49 to 0.55).

CONCLUSION

 Existing bleeding risk scores and a machine learning approach including common clinical parameters fail to assist in bleeding risk prediction of patients on HD. Therefore, new approaches, including novel biomarkers, to improve bleeding risk prediction in patients on HD are needed.

Factor XI Inhibitors for Prevention and Treatment of Venous Thromboembolism: A Review on the Rationale and Update on Current Evidence

Although anticoagulation therapy has evolved from non-specific drugs (i.e., heparins and vitamin K antagonists) to agents that directly target specific coagulation factors (i.e., direct oral anticoagulants, argatroban, fondaparinux), thrombosis remains a leading cause of death worldwide. Direct oral anticoagulants (i.e., factor IIa- and factor Xa-inhibitors) now dominate clinical practice because of their favorable pharmacological profile and ease of use, particularly in venous thromboembolism (VTE) treatment and stroke prevention in atrial fibrillation. However, despite having a better safety profile than vitamin K antagonists, their bleeding risk is not insignificant. This is true for all currently available anticoagulants, and a high bleeding risk is considered a contraindication to anticoagulation. As a result, ongoing research focuses on developing future anticoagulants with an improved safety profile. Several promising approaches to reduce the bleeding risk involve targeting the intrinsic (or contact activation) pathway of coagulation, with the ultimate goal of preventing thrombosis without impairing hemostasis. Based on epidemiological data on hereditary factor deficiencies and preclinical studies factor XI (FXI) emerged as the most promising candidate target. In this review, we highlight unmet clinical needs of anticoagulation therapy, outlay the rationale and evidence for inhibiting FXI, discuss FXI inhibitors in current clinical trials, conduct an exploratory meta-analysis on their efficacy and safety, and provide an outlook on the potential clinical application of these novel anticoagulants.