Warfarin anticoagulation in hemodialysis patients: a systematic review of bleeding rates

Safety and efficacy of apixaban versus vitamin K antagonists in patients undergoing dialysis: a systematic review and meta-analysis

BACKGROUND

This review aims to evaluate the safety and efficacy of apixaban vs. vitamin K antagonists (VKAs) in patients on dialysis.

METHODS

All types of studies published on PubMed, Embase, CENTRAL, and Web of Science up to 10 September 2023 and comparing outcomes of apixaban vs. VKA in dialysis patients were eligible.

RESULTS

Two randomized controlled trials (RCTs) and six retrospective studies were included. Apixaban treatment was associated with significantly lower risk of major bleeding (RR: 0.61; 95% CI: 0.48, 0.77; I2 = 50%) and clinically relevant non-major bleeding (RR: 0.82, 95% CI: 0.68, 0.98, I2 = 9%) compared to VKA. Meta-analysis also showed that the risk of gastrointestinal bleeding (RR: 0.74, 95% CI: 0.64, 0.85, I2 = 16%) and intracranial bleeding (RR: 0.64, 95% CI: 0.49, 0.84, I2 = 0%) was significantly reduced with apixaban. Meta-analysis showed no difference in the risk of ischemic stroke (RR: 0.40, 95% CI: 0.06, 2.69, I2 = 0%), mortality (RR: 1.26, 95% CI: 0.74, 2.16, I2 = 94%) and recurrent venous thromboembolism (RR: 1.02, 95% CI: 0.87, 1.21, I2 = 0%) between the two groups. Subgroup analysis of RCTs showed no difference in bleeding outcomes.

CONCLUSIONS

Low-quality evidence from a mix of RCTs and retrospective studies shows that apixaban may have better safety and equivalent efficacy as compared to VKA in dialysis patients. Apixaban treatment correlated with significantly reduced risk of major bleeding and clinically relevant nonmajor bleeding in observational studies but not in RCTs. The predominance of retrospective data warrants caution in the interpretation of results.

Thirty-year outcomes of low-intensity anticoagulation for mechanical aortic valve

The long-term safety, efficacy, and outcomes of low-intensity anticoagulation for mechanical heart valves remain unclear. This study aimed to evaluate the long-term outcomes of low-intensity anticoagulation therapy after aortic valve replacement (AVR) with a mechanical prosthesis. This retrospective cohort study consulted medical records and conducted a questionnaire to investigate 519 patients who underwent single AVR with the St. Jude Medical bileaflet valve and were in sinus rhythm. All patients were followed up with an international normalized ratio (INR) target of 1.6-2.5, and their INR values were checked throughout the follow-up period. The survival rate, incidence of major adverse cardiac and cerebrovascular events (MACCE), and risk factors for cardiac death and MACCE were investigated. The total follow-up was 9793 patient-years, and the follow-up periods were 19.9 (standard deviation [SD]: 7.9) years. The mean INR was 2.03 (SD: 0.54). Survival rates from cardiac death were 93.6% in 20 years and 85.2% in 30 years. Advanced age ≥ 70 years was the only significant risk factor for cardiac death and MACCE, and the INR < 2.0 was not significant risk factor for MACCE including thromboembolism or bleeding events. Low-intensity anticoagulation with an INR of 1.6-2.5 for patients with sinus rhythm after AVR with a bileaflet mechanical valve is safe and effective, even over 30 years.

Efficacy and safety of direct oral anticoagulants vs vitamin K antagonists in patients with atrial fibrillation and end-stage renal disease on hemodialysis: A systematic review and meta-analysis

BACKGROUND

The prevalence of atrial fibrillation (AF) in individuals with end-stage renal disease (ESRD) on chronic hemodialysis is increasing. The optimal anticoagulant choice in this population is unclear since these patients were excluded from the pivotal randomized controlled trials (RCTs) of direct oral anticoagulants (DOACs) vs. vitamin K antagonists (VKAs) in the general AF population. We aimed to assess the efficacy and safety of DOACs vs. VKAs in patients with AF and ESRD on chronic hemodialysis through a systematic review and meta-analysis of all available evidence.

PATIENTS/METHODS

We performed a systematic search in MEDLINE and Scopus for RCTs or observational studies of patients with AF and ESRD on chronic hemodialysis who were treated with DOACs or VKAs. The outcomes of interest included ischemic stroke, the composite of ischemic stroke or systemic embolism, major bleeding, gastrointestinal bleeding, minor bleeding events and all-cause mortality.

RESULTS

Among 397 studies identified from the literature search, six studies (three RCTs and three observational studies) were included in the meta-analysis. Compared with VKA-treated patients, those treated with DOACs had similar risk of ischemic stroke (RR:0.76, 95% CI:0.41-1.41), ischemic stroke or systemic embolism (RR:0.65, 95% CI:0.38-1.10), major bleeding (RR:0.79, 95% CI:0.49-1.28) and all-cause death (RR:0.79, 95% CI:0.56-1.12). The risk of gastrointestinal bleeding was lower in DOAC- vs VKA-treated patients in three eligible observational studies (RR:0.73, 95% CI: 0.54-0.99, I2 = 79%) but this was not confirmed in two eligible RCTs (RR:0.69, 95% CI: 0.33-1.43, I2 = 0%).

CONCLUSIONS

Among AF patients with ESRD on chronic hemodialysis, the risk of ischemic stroke, ischemic stroke or systemic embolism, minor bleeding, major bleeding, and all-cause mortality is similar in patients treated with DOACs compared to VKAs. Given that the meta-analysis of RCTs on gastrointestinal bleeding did not confirm the results of the meta-analysis of the observational studies, it cannot be concluded that gastrointestinal bleeding is lower among DOAC-treated patients.

PROTOCOL REGISTRATION

PROSPERO CRD42023391966.

Effect of conventional hemodialysis on the apixaban plasma concentration

PURPOSE

Apixaban is a factor Xa inhibitor used in patients undergoing hemodialysis treatment. The objective of this study is to investigate the effect of hemodialysis on apixaban plasma concentrations.

METHODS

This observational study is on patients treated with apixaban 2.5 mg twice daily on conventional hemodialysis with standard low-molecular-weight heparin (LMWH) anticoagulation (nadroparin 3800-7600 IU). Plasma blood samples were collected before starting dialysis (t1), 2 h after starting dialysis (t2), and directly after dialysis (t3). Apixaban concentration was measured before and after dialysis. Anti-Xa activity was measured for all three samples.

RESULTS

A significant difference was observed between the apixaban concentration before and after dialysis (mean before dialysis 141.03 ng/mL; mean after dialysis 102.71 ng/mL; p = 0.003). Nonetheless, both apixaban plasma concentrations and anti-Xa levels remained within the reference range. Anti-Xa levels had a strong correlation with the apixaban concentrations (r = 0.935, p = 0.000). Thus, anti-Xa activity might be used as a surrogate for apixaban plasma concentration.

CONCLUSION

There seems to be no need for dose adjustments of apixaban; co-administration of LMWH next to apixaban might also be unnecessary.

Obesity drives secondary procedures to achieve access maturation in end-stage renal disease

BACKGROUND

Establishing long-term arteriovenous access is an important component in the long-term care of a patient with end-stage renal disease. The increasing frequency of obesity is reported to impact the access management of end-stage renal disease patients. This study aims to evaluate the outcomes of arteriovenous fistulae (AVF) in obese and nonobese patients.

METHODS

A retrospective review of all patients over ten years with primary autogenous AVF (radiocephalic, brachiocephalic, and brachial-basilic) was undertaken at a single center. Patients were subcategorized by body mass index into nonobese, class I, II, and III obesity. Outcomes of maturation (successful progression to hemodialysis), reintervention, functional dialysis (continuous hemodialysis for 3 consecutive months), and patency were examined.

RESULTS

From January 1999 to December 2019, 2311 patients (67% female; mean age, 61 ± 15 years) underwent primary AVF placement (12% radiocephalic, 53% brachiocephalic, and 35% brachial basilic). Forty-one percent were nonobese, 29% had class I obesity, 19% had class II obesity, and 11% had class III obesity. The majority of patients were diabetic and Hispanic. The 30-day major adverse cardiovascular event rate was elevated in class II (0.20%) and class III (0.50%) obesity compared with class I obesity (0.15%) and nonobese (0.05%). The 30-day morbidity rate was higher in all classes of obesity (0.5% vs0.3% vs 0.2% vs 0.05% for class III vs class II vs class I obesity and nonobese, respectively). Early thrombosis was significantly increased in class II (9%) and class III obesity (12%) compared with class I obesity (5%) and nonobese (3%). There was a two-fold increase in procedures to effect maturation in class II (51%) and class III (74%) obesity compared with class I obesity (22%) and nonobese (34%). Secondary patency at 3 years was significantly lower in class III (62 ± 4%) and class II (79 ± 3%) compared with class I obesity (87 ± 2%) and nonobese (93 ± 4%). All classes of obesity required significantly more secondary Interventions per year compared with nonobese (3.9 vs 3.1 vs 2.5 vs 1.4 secondary interventions per year for class III vs class II vs class I obesity and nonobese, respectively).

CONCLUSIONS

Advancing obesity class is associated with an increased number of procedures to achieve AVF maturation and is associated with poorer patency and functionality as the category of obesity advances.

Prosthesis Choice in Dialysis Patients Undergoing Mitral Valve Replacement

BACKGROUND

Patients with renal disease on dialysis have significant comorbidity limiting life expectancy; however, these patients may experience accelerated prosthetic valve degeneration. The purpose of this study was to examine the impact of prosthesis choice on outcomes in dialysis patients undergoing mitral valve replacement (MVR) at our high-volume academic center.

METHODS

Adults undergoing MVR were retrospectively reviewed between January 2002 and November 2019. Patients were included if they had documented renal failure and dialysis requirements before presentation. Patients were stratified by mechanical vs bioprosthetic prosthesis. Death and recurrent severe valve failure (3+ or greater) or redo mitral operation were used as primary outcomes.

RESULTS

There were 177 dialysis patients identified who underwent MVR. Of these, 118 (66.7%) received bioprosthetic valves, whereas 59 (33.3%) received mechanical valves. Those who received mechanical valves were younger (48 vs 61 years; P < .001) and had less diabetes (32% vs 51%; P = .019). Prevalence of endocarditis and atrial fibrillation was similar. Postoperative length of stay was not different between groups. Risk-adjusted hazard for 5-year mortality was similar between groups (P = .668). Early mortality was high, with both groups having <50% actuarial survival at 2 years. No differences were noted in rates of structural valve deterioration or reintervention. More stroke events were noted on follow-up in patients receiving mechanical valves (15% vs 6%; P = .041). Endocarditis was the leading reason for reintervention; 4 patients received repeated surgery for bioprosthetic valve failure.

CONCLUSIONS

MVR in dialysis patients carries significant morbidity and increased midterm mortality. Decreased life expectancy should be considered in the tailoring of prosthesis choice to dialysis-dependent patients.

Nontraumatic subdural hematoma in patients on hemodialysis with end-stage kidney disease: a systematic review and pooled analysis

Background

The original treatment may aggravate when hemodialysis (HD) patients have nontraumatic subdural hematoma (NSDH). End-stage kidney disease patients are at increased risk for NSDH, but its risk factors and outcomes are not sufficiently explored at present.

Methods

Electronic databases, including PubMed, EMBASE, and Web of Science were searched by using various combinations of the keywords "Hemodialysis," "Renal Insufficiency," "Extracorporeal Dialysis," "Subdural Hematoma," "Subdural Hemorrhage," "Subdural Hematomas," and "Subdural Hemorrhages" in accordance with the PRISMA guidelines. Sixteen papers were selected. Relevant patient data were extracted, aggregated, and analyzed.

Results

A total of 74 patients were analyzed, including 37 male, 26 female, and 11 with no gender data, with a mean age of 56 years (range, 16-81 years). There were 43 patients with hypertension, 36 patients with diabetes, 16 patients who used oral anticoagulants before dialysis, and 10 patients with atrial fibrillation. The diagnosis of subdural hematoma (SDH) was made by computed tomography (CT) (n = 51), carotid arteriography (n = 7), surgical exploration (n = 3), and autopsy (n = 2). Forty cases underwent surgical treatment, including craniotomy and burr hole (or twist drill) drainage. The 1 year mortality rate of NSDH was 45.9%. The mortality rate after conservative treatment (61.8%) was higher than that after surgical intervention (32.5%). The mortality rate of NSDH in dialysis patients with atrial fibrillation and in those who used oral anticoagulants before hemodialysis (HD) was 90 and 81%, respectively.

Conclusion

NSDH is rare in HD, and mortality is high if NSDH occurs in dialysis patients. Surgical intervention reduces the mortality from NSDH in patients on HD (p < 0.02). Patients with atrial fibrillation and those who were taking oral anticoagulants before dialysis have a higher NSDH mortality (p < 0.01).

Development and Validation of a Predictive Risk Algorithm for Bleeding in Individuals on Long-term Hemodialysis: An International Prospective Cohort Study (BLEED-HD)

Background

Individuals with kidney disease are at a high risk of bleeding and as such tools that identify those at highest risk may aid mitigation strategies.

Objective

We set out to develop and validate a prediction equation (BLEED-HD) to identify patients on maintenance hemodialysis at high risk of bleeding.

Design

International prospective cohort study (development); retrospective cohort study (validation).

Settings

Development: 15 countries (Dialysis Outcomes and Practice Patterns Study [DOPPS] phase 2-6 from 2002 to 2018); Validation: Ontario, Canada.

Patients

Development: 53 147 patients; Validation: 19 318 patients.

Measurements

Hospitalization for a bleeding event.

Methods

Cox proportional hazards models.

Results

Among the DOPPS cohort (mean age, 63.7 years; female, 39.7%), a bleeding event occurred in 2773 patients (5.2%, event rate 32 per 1000 person-years), with a median follow-up of 1.6 (interquartile range [IQR], 0.9-2.1) years. BLEED-HD included 6 variables: age, sex, country, previous gastrointestinal bleeding, prosthetic heart valve, and vitamin K antagonist use. The observed 3-year probability of bleeding by deciles of risk ranged from 2.2% to 10.8%. Model discrimination was low to moderate (c-statistic = 0.65) with excellent calibration (Brier score range = 0.036-0.095). Discrimination and calibration of BLEED-HD were similar in an external validation of 19 318 patients from Ontario, Canada. Compared to existing bleeding scores, BLEED-HD demonstrated better discrimination and calibration (c-statistic: HEMORRHAGE = 0.59, HAS-BLED = 0.59, and ATRIA = 0.57, c-stat difference, net reclassification index [NRI], and integrated discrimination index [IDI] all P value <.0001).

Limitations

Dialysis procedure anticoagulation was not available; validation cohort was considerably older than the development cohort.

Conclusion

In patients on maintenance hemodialysis, BLEED-HD is a simple risk equation that may be more applicable than existing risk tools in predicting the risk of bleeding in this high-risk population.

Acute problems of hemodialysis access: Thrombosis, aneurysms, symptomatic high-flow fistulas, and complications related to central lines

Hemodynamic complications frequently affect vascular access and are important causes of morbidity and mortality. We present a review of acute complications affecting vascular accesses, focusing on classical and new treatments. Acute complications in hemodialysis vascular access are often underestimated and undertreated, and can present a challenge for both vascular surgeons and anesthesiologists. Accordingly, we considered different anesthesiologic approaches to both hemorrhagic and nonhemorrhagic patients. A strict collaboration among nephrologists, surgeons, and anesthesiologists can potentially improve prevention and management of acute complications and quality of life.

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.

Long-Term Outcomes of Bioprosthetic or Mechanical Valve Replacement in End-Stage Renal Disease: A Nationwide Population-Based Retrospective Study

Background: Valve replacement is associated with worse outcomes in individuals who have end-stage renal disease (ESRD) and require a long-term renal replacement therapy. Prosthetic valve selection in patients with ESRD has remained controversial.

Objective: We aimed to investigate long-term outcomes of mechanical and bioprosthetic valve replacement in individuals with ESRD.

Methods: We conducted a population-based retrospective cohort study using data obtained from the Taiwan National Health Insurance Research Database. In total, 10,202 patients, including 912 ESRD and 9,290 non-ESRD patients, were selected after a 1:1 propensity-score matching based on the type of prosthetic valve used. The long-term mortality outcomes were then analyzed.

Results: During a median follow-up period of 59.6 months, the Kaplan–Meier survival analysis revealed that ESRD patients who underwent mechanical valve replacement had higher rates of all-cause mortality and CV deaths than those who underwent bioprosthetic valve replacement (Log-rank test, p = 0.03 and 0.02, respectively). Multivariable regression analyses demonstrated that ESRD patients who underwent bioprosthetic valve replacement had lower rates of all-cause mortality (p &lt; 0.001, hazard ratio: 0.88, 95% confidence interval: 0.82–0.93) and cardiovascular (CV) death (p &lt; 0.001, hazard ratio: 0.83, 95% confidence interval: 0.76–0.90) than those who had mechanical valve replacement.

Conclusion: Bioprosthetic valve replacement is significantly associated with lower rates of all-cause mortality and CV death in the ESRD population.

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

BACKGROUND

Evidence supporting the use of anticoagulation for the prevention of stroke and thromboembolism in patients with kidney failure on hemodialysis (HD) and atrial fibrillation (AF) is limited. We prospectively assessed the incidences of stroke and major bleeding, as well as anticoagulation strategies in patients on HD with AF.

METHODS

We recruited 625 prevalent HD patients into a population-based observational cohort study. The primary prospective outcomes were thromboembolic events (stroke, transient ischemic attack, systemic embolism) and major bleeding. Secondary outcomes included a composite of thromboembolic events, major bleeding, and cardiovascular death to determine net clinical harm.

RESULTS

A total of 238 patients (38.1%) had AF, 165 (26.4%) already at baseline and 73 (15.9%) developed AF during a median follow up of 870 days. Forty (6.4%) thromboembolic events and 89 (14.2%) major bleedings occurred. Overall, 256 patients died (41.0%). In AF patients, use of vitamin K antagonists (VKAs) in 61 patients (25.6%) was not significantly associated with reduced risk of the primary thromboembolic outcome (subdistribution hazard ratio [SHR] 1.41 adjusted for age, sex, congestive heart failure, hypertension, stroke/transient ischemic attack/thromboembolism, vascular disease, and diabetes history score and antiplatelet co-medication (95% CI, 0.49-4.07), but with increased risk of major bleeding (SHR: 2.28; 95% CI, 1.09-4.79) compared with AF patients without anticoagulation (N = 139, 58.4%). Use of VKAs was associated with net clinical harm (adjusted SHR: 2.07; 95% CI, 1.25-3.42).

CONCLUSIONS

Although the nonrandomized nature of the study is prone to bias, anticoagulation with VKAs was not associated with decreased thromboembolic risk, but rather with increased risk of major bleeding and may be net harmful to patients with AF on HD.

Comparison of the accuracy of measuring blood glucose in whole blood of arteriovenous mixed blood by two kinds of blood glucose meters

BACKGROUND

Portable blood glucose meters are the main method for detecting the blood glucose status of clinical patients.

OBJECTIVE

To investigate the accuracy of detecting blood glucose in haemodialysis patients by sampling two blood glucose meters through the haemodialysis line.

METHODS

Convenient sampling was used to select 80 patients with maintenance haemodialysis. The patients were sampled through the arterial end of the haemodialysis line within three minutes of being put on the machine. One specimen was tested by glycemeter1, which can identify the type of blood in the arteries and veins, and glycemeter2, which can only detect blood glucose in the capillaries for bedside blood glucose testing. The other specimen was sent to the laboratory biochemical analyser for blood glucose testing.

RESULTS

When the blood glucose value of the first blood glucose meter (No. 1) was compared with the laboratory biochemical analyser, the correlation coefficient was r = 0.805 (p < 0.05), the out of value of the first blood glucose meter accounted for 4.4%, and the consistency reached 95% (p < 0.05). When the blood glucose value of the second blood glucose meter (No. 2) was compared with the laboratory biochemical analyser, the correlation coefficient was r = 0.800 (p < 0.05), the out of value of the second blood glucose meter accounted for 4.4%, and the consistency reached 95% (p < 0.05).

CONCLUSIONS

For patients with maintenance haemodialysis, the blood glucose values detected by the two bedside blood glucose meters using arteriovenous mixed blood in the pipeline do not affect the accuracy and can respond more realistically.

Safety and Efficacy of Apixaban, Rivaroxaban, and Warfarin in End-Stage Renal Disease With Atrial Fibrillation: A Systematic Review and Meta-Analysis

BACKGROUND

The use of warfarin in patients with atrial fibrillation (AF) and end-stage renal disease (ESRD) has been implicated with efficacy and safety concerns. Evidence on the role of direct oral anticoagulants (DOACs) in this population is limited.

METHODS

Electronic databases were searched and articles comparing the safety and efficacy of warfarin with apixaban or rivaroxaban were identified. Pooled hazard ratios (HR) were computed using a random-effects model.

RESULTS

A total of eight articles consisting of 30,806 patients; (rivaroxaban 2196, apixaban 2745 and warfarin 25,865) were identified. The pooled HR for major bleeding events favored apixaban over warfarin (0.53, 95% confidence interval (CI) 0.33-0.84, p = 0.008). Apixaban was similar to warfarin in terms of clinically relevant non-major bleeding (HR 1.08, 95% CI 0.64-1.84, p = 0.77) and stroke events (HR 1.09, 95% CI 0.85, 1.39, p = 0.99). There was no significant difference in the risk of major bleeding events (HR 0.95, 95% CI 0.50-1.81, p = 0.88) and stroke between rivaroxaban (HR 1.39, 95% CI, 0.59-3.29, p = 0.09) and warfarin. The combined results of major bleeding in the apixaban group were not affected by the sensitivity analysis.

CONCLUSIONS

Apixaban may have a lower risk of major bleeding and comparable risk of stroke when compared with warfarin in AF patients with ESRD.

Evaluation and Management of Aortic Stenosis in Chronic Kidney Disease: A Scientific Statement From the American Heart Association

Aortic stenosis with concomitant chronic kidney disease (CKD) represents a clinical challenge. Aortic stenosis is more prevalent and progresses more rapidly and unpredictably in CKD, and the presence of CKD is associated with worse short-term and long-term outcomes after aortic valve replacement. Because patients with advanced CKD and end-stage kidney disease have been excluded from randomized trials, clinicians need to make complex management decisions in this population that are based on retrospective and observational evidence. This statement summarizes the epidemiological and pathophysiological characteristics of aortic stenosis in the context of CKD, evaluates the nuances and prognostic information provided by noninvasive cardiovascular imaging with echocardiography and advanced imaging techniques, and outlines the special risks in this population. Furthermore, this statement provides a critical review of the existing literature pertaining to clinical outcomes of surgical versus transcatheter aortic valve replacement in this high-risk population to help guide clinical decision making in the choice of aortic valve replacement and specific prosthesis. Finally, this statement provides an approach to the perioperative management of these patients, with special attention to a multidisciplinary heart-kidney collaborative team-based approach.

Catheter-related giant right atrial thrombosis mimicking a myxoma: A case report

Despite the development of imagistic methods, the differential diagnosis of a right atrial mass may be difficult to be established, the most common pathologies which should be taken in consideration being represented by thrombus, tumors, prominent crista terminalis, or vegetation of infectious endocarditis. In this study, we present the case of a 63-year-old man with chronic kidney disease, in hemodialysis (HD) with a silicone central venous catheter (CVC) with the incidental transthoracic echocardiography (transthoracic echocardiogram, TTE) finding of a tumoral mass of 35x26 mm in the right atrium (RA), not related with the catheter, which was diagnosed as right atrial myxoma and underwent surgical excision. After reviewing the histopathology probe, the diagnosis of right atrial thrombus was confirmed. In conclusion, differentiating intracardiac right atrial masses (RAMs) could may prove challenging. In our patient, clinical presentation and the preoperative investigations could not differentiate the right atrial thrombus from a myxoma, and only the postoperative histopathology diagnosis was able to guide correct diagnosis.

Anticoagulation in hemodialysis: A narrative review

Systemic anticoagulation in maintenance hemodialysis (HD) has historically been considered necessary to maintain the extracorporeal circuit (ECC) and preserve dialysis efficiency. Unfractionated heparin (UFH) is the most commonly used anticoagulant due to low cost and staff familiarity. Despite widespread use, there is little standardization of heparin dosing protocols in the United States. Although the complication rates with UFH are low for the general population, certain contraindications have led to exploration in alternative anticoagulants in patients with end-stage kidney disease (ESKD). Here we review the current evidence regarding heparin dosing protocols, complications associated with heparin use, and discuss alternatives to UFH including anticoagulant-free routine HD.

Vitamin K antagonist has a higher impact than heparin in preventing circuit clotting in chronic haemodialysis patients

Background

In dialysis sessions, some data suggest that decreasing or even avoiding additional anticoagulation by heparin is possible among patients already treated with oral anticoagulation. However, the required dose of heparin may actually depend on the pre-dialysis international normalized ratio (INR), which varies from one session to another. The aim of our study was to determine the respective role of INR and heparin dosing in the risk of circuit clotting during chronic haemodialysis.

Methods

From early 2012 to July 2016, we analysed the totality of dialysis sessions performed at Brest University Hospital among haemodialysis patients treated by vitamin K antagonists (VKA). We established a prediction of circuit clotting on the basis of a simplified score obtained by combining INR and heparin dosing.

Results

In total, 7184 dialysis sessions among chronic haemodialysis patients under VKA were identified, including 233 with clotting events. The mean INR without clotting events was 2.5 versus 1.8 with clotting events (P < 0.001). Frequencies of circuit clotting were different according to INR group (INR <2.0, INR 2.0-3.0, INR >3.0; P < 0.0001). The protective role of VKA was higher than heparin, as shown by discriminant factor analysis (P < 0.0001). Conclusion. Our study established a predictive model of thrombosis risk of dialysis circuits in patients treated by VKA for a given heparin dose and a given INR. This model shows a marginal contribution of heparin to protect against the risk of thrombosis compared with VKA. Moreover, heparin would not appear to be necessary for patients with an INR >2.2.

Mechanical or biological heart valve for dialysis-dependent patients? A meta-analysis

OBJECTIVE

The optimal selection of prosthetic heart valve for dialysis-dependent patients remains controversial. We investigated the comparative effectiveness and safety of mechanical prosthesis (MP) and bioprosthesis (BP) for these patients.

METHODS

After the systematic review, we included studies that involved patients on dialysis undergoing aortic valve replacement or mitral valve replacement (MVR) and reported comparative outcomes of MP and BP. Meta-analysis was performed using random-effects model. We conducted a subgroup analysis based on the valve position and postoperative international normalized ratio (INR), which was extracted from either tables or methods of each study. A meta-regression was used to examine the effects of study-level covariates.

RESULTS

We included 24 retrospective studies without randomized-controlled trials, involving 10,164 participants (MP = 6934, BP = 3230). Patients undergoing aortic valve replacement with MP exhibited a better long-term survival effectiveness (hazard ratio, 0.64; 95% confidence interval [CI], 0.47-0.86). Conversely, studies including MVR demonstrated little difference in survival (hazard ratio, 0.90; 95% CI, 0.73-1.12). A meta-regression revealed that age had little effect on long-term survival difference between MP and BP (β = -0.0135, P = .433). MP had a significantly greater bleeding risk than did BP when INR was above 2.5 (incidence rate ratio, 10.58; 95% CI, 2.02-55.41). However, when INR was below 2.5, bleeding events were comparable (incidence rate ratio, 1.73; 95% CI, 0.78-3.82). The structural valve deterioration rate was significantly lower in MP (risk ratio, 0.24; 95% CI, 0.14-0.44).

CONCLUSIONS

MP is a reasonable choice for dialysis-dependent patients without additional thromboembolic risk requiring aortic valve replacement, for its better long-term survival, durability, and noninferior bleeding risk compared with BP. Conversely, BP might be an appropriate selection for patients with MVR, given its similar survival rate and lower bleeding risk. Although our meta-regression demonstrates little influence of age on long-term survival difference between MP and BP, further studies stratifying patients based on age cut-off are mandatory.

Stroke Prophylaxis in Patients with Atrial Fibrillation and End-Stage Renal Disease

Atrial fibrillation (AF) is an important comorbidity in patients with end-stage renal disease (ESRD) undergoing dialysis that portends increased health care utilization, morbidity, and mortality in this already high-risk population. Patients with ESRD have a particularly high stroke risk, which is further compounded by AF. However, the role of anticoagulation for stroke prophylaxis in ESRD and AF is debated. The ESRD population presents a unique challenge because of the combination of elevated stroke and bleeding risks. Warfarin has been traditionally used in this population, but it is associated with significant risks of minor and major bleeding, particularly intracranial, thus leading many clinicians to forgo anticoagulation altogether. When anticoagulation is prescribed, rates of adherence and persistence are poor, leaving many patients untreated. The direct oral anticoagulants (DOACs) may offer an alternative to warfarin in ESRD patients, but these agents have not been extensively studied in this population and uncertainties regarding comparative effectiveness (versus warfarin, each other, and no treatment) remain. In this review, we discuss the current evidence on the risk and benefits of anticoagulants in this challenging population and comparisons between warfarin and DOACs, and review future directions including options for non-pharmacologic stroke prevention.

Modified regional citrate anticoagulation is optimal for hemodialysis in patients at high risk of bleeding: a prospective randomized study of three anticoagulation strategies

BACKGROUND

Recommended regular saline flushing presents clinical ineffectiveness for hemodialysis (HD) patients at high risk of bleeding with heparin contraindication. Regional citrate anticoagulation (RCA) has previously been used with a Ca²⁺ containing dialysate with prefiltered citrate in one arm (RCA-one). However, anticoagulation is not always achievable and up to 40% results in serious clotting in the venous expansion chamber. In this study, we have transferred one-quarter of the TSC from the prefiltered to the post filter based on RCA-one, which we have called RCA-two. The objective of this study was to compare the efficacy and safety of RCA-two with either saline flushing or RCA-one in HD patients with a high bleeding risk.

METHOD

In this investigator-initiated, multicenter, controlled, prospective, randomized clinical trial, 52 HD patients (77 sessions) were randomized to the RCA-2 and RCA-one group in part one of the trial, and 45 patients (64 sessions) were randomized to the RCA-2 and saline group in part two of the trial. Serious clotting events, adverse events and blood analyses were recorded.

RESULTS

Serious clotting events in the RCA-two group were significantly lower compared with the RCA-one and saline group (7.89% vs. 30.77%, P = 0.011; 3.03% vs. 54.84%, P < 0.001, respectively). The median circuit survival time was 240 min (IQR 240 to 240) in the RCA-two group, was significantly longer than 230 min (IQR 155 to 240, P < 0.001) in the RCA-one group and 210 min (IQR 135 to 240, P = 0.003) in the saline group. The majority of the AEs were hypotension, hypoglycemia and chest tightness, most of which were mild in intensity. Eight patients (20.51%) in the RCA-one group, 4 patients (12.90%) in the saline group and 10 patients (26.31%) in the RCA-two group, P > 0.05.

CONCLUSIONS

Our data demonstrated that the modified anticoagulation protocol was more effective and feasible during hemodialysis therapy for patients at high risk of bleeding.

TRIAL REGISTRATION

GDREC, GDREC2017250H. Registered February 2, 2018; retrospectively registered.

Warfarin-induced spontaneous retroperitoneal hemorrhage from the renal vein: A rare case with an uncommon etiology

The overall rate of major bleeding in patients with atrial fibrillation receiving warfarin therapy is approximately 4%. Among these 4% patients, spontaneous retroperitoneal hemorrhage (SRH) is a rare but potentially lethal complication with a nonspecific presentation that can lead to missed or delayed diagnosis. The current literature provides little direction for diagnosis and management of such cases. Anticoagulation-related SRH is associated with a high mortality rate (approximately 20%). Despite the vague presentation, prompt diagnosis is crucial to reverse the anticoagulation and prevent further bleeding. Contrast-enhanced computed tomography (CT) of the abdomen is the imaging modality of choice in suspected cases. Patients with SRH require aggressive treatment with blood transfusions, interventional radiological procedures, percutaneous drainage or surgical evacuation of the hematoma. We report a case of warfarin-induced SRH from the renal vein in a patient who presented to our emergency department with acute, nonspecific abdominal pain and shock. We diagnosed the patient with warfarin-induced SRH on the basis of clinical suspicion and characteristic CT findings. We initially treated the patient conservatively, followed by embolization of the right renal artery during the late course of hospital stay, and he was discharged with good recovery. SRH should be considered in the differential diagnosis of abdominal pain, hypotension, and/or decreased hemoglobin levels in patients receiving anticoagulation therapy, especially in those with preexisting end-stage renal disease.

Warfarin Dosing and Outcomes in Chronic Kidney Disease: A Closer Look at Warfarin Disposition

BACKGROUND

Chronic Kidney Disease (CKD) is a prevalent worldwide health problem. Patients with CKD are more prone to developing cardiovascular complications such as atrial fibrillation and stroke. This warrants the use of oral anticoagulants, such as warfarin, in this population. While the efficacy and safety of warfarin in this setting remain controversial, a growing body of evidence emphasizes that warfarin use in CKD can be problematic. This review discusses 1) warfarin use, dosing and outcomes in CKD patients; and 2) possible pharmacokinetic mechanisms for altered warfarin dosing and response in CKD.

METHODS

Structured search and review of literature articles evaluating warfarin dosing and outcomes in CKD. Data and information about warfarin metabolism, transport, and pharmacokinetics in CKD were also analyzed and summarized.

RESULTS

The literature data suggest that changes in warfarin pharmacokinetics such as protein binding, nonrenal clearance, the disposition of warfarin metabolites may partially contribute to altered warfarin dosing and response in CKD.

CONCLUSION

Although the evidence to support warfarin use in advanced CKD is still unclear, this synthesis of previous findings may help in improving optimized warfarin therapy in CKD settings.

Role of cardiovascular implantable electronic devices in delivering individualized disease-guided management of patients with non-valvular atrial fibrillation and high bleeding risk

BACKGROUND

Many patients with non-valvular atrial fibrillation (NVAF) with high risk for thromboembolic stroke and bleeding may not wish to continue long-term oral anticoagulants (OACs) to avoid bleeding complications. We aimed to investigate whether AF burden assessment by cardiovascular implantable electronic devices (CIEDs) would allow an individualised disease-guided approach for safe withdrawal of long-term OAC in high-risk patients.

METHODS AND RESULTS

We studied 145 patients (age 77.6 ± 10.6 years; 49.7% females) with NVAF, CHA₂DS₂-VASc score ≥2, HAS-BLED score ≥3, in whom CIEDs were implanted. These patients wished to stay off long-term OAC based on their previous adverse bleeding event/s or due to similar events witnessed in the family or friend circle. These patients were grouped into 'low AF burden' [n = 121 (83%)], or 'high AF burden' [n = 24 (17%)] defined as <24 hours or >24 hours cumulatively in 30 consecutive days respectively, and followed for 51.2 ± 29.8 months. All patients with 'low AF burden' were allowed to discontinue OAC, but OAC was resumed in 1 patient who experienced TIA. Bleeding events developed in 9 out of 24 (37.5%) patients with 'high AF burden' who were maintained on OAC, as compared to 3 out of 121 (2.47%) patients with 'low AF burden' who were off OAC (p <.05). There were 9 (6.2%) deaths unrelated to AF treatment approach.

CONCLUSIONS

In NVAF patients, AF burden assessment by CIEDs allows an individualised disease-guided approach to safe withdrawal of long-term OAC in patients with high bleeding risk who do not wish to continue long-term anticoagulation.

Demystifying the Benefits and Harms of Anticoagulation for Atrial Fibrillation in Chronic Kidney Disease

Patients with CKD represent a vulnerable population where the risks of atrial fibrillation, ischemic stroke, and bleeding are all heightened. Although large randomized, controlled trials in the general population clearly demonstrate that the benefits of warfarin and direct-acting oral anticoagulants outweigh the risks of bleeding, no such studies have been conducted in patients when their creatinine clearance falls below 25-30 ml/min. Without randomized, controlled trial data, the role of anticoagulation in patients with CKD with atrial fibrillation remains unclear and our practice is informed by a growing body of imperfect literature such as observational and pharmacokinetic studies. This article aims to present a contemporary literature review of the benefits versus harms of anticoagulation in atrial fibrillation for patients with CKD stages 3, 4, 5, and 5 on dialysis. Although unanswered questions and areas of clinical equipoise remain, this piece serves to assist physicians in interpreting the complex body of literature and applying it to their clinical care.

Effects of Pre-Existing Comorbidities on Outcomes in Patients with Chronic Subdural Hematoma

OBJECTIVE

The number of patients with chronic subdural hematoma (CSDH) showing comorbidities and/or impaired activities of daily living (ADL) before the onset of CSDH has increased with the recent aging of society. The purposes of this study were to evaluate ADL worsening by comparing premorbid ADL and ADL at discharge and to investigate the effects of pre-existing comorbidity-related clinical factors on the outcomes.

METHODS

A total of 570 patients with CSDH admitted from 2006 to 2016 were studied retrospectively. Clinical factors, including pre-existing comorbidities, related to outcomes were identified by multivariate analysis. A variation of the modified Rankin Scale (mRS) using 5 united categories of mRS scores 0/1, 2, 3/4, 5, and dead was used for evaluation of ADL.

RESULTS

Of 570 patients, 390 (68.4%) had pre-existing comorbidities and 120 (21.1%) showed premorbid impaired ADL (mRS scores 2 and worse). Considering pre-existing impaired ADL, ADL deteriorated after CSDH in 92 patients (16.1%), whereas ADL impairment at discharge was found in 173 patients (30.4%). Comorbidities related to ADL deterioration on multivariate analysis were hemodialysis and chronic heart failure. Antithrombotic use for cardiovascular diseases was a predictor of acute-on-chronic subdural hematoma, which was the sole common predictor for ADL deterioration and the occurrence of surgical complications.

CONCLUSIONS

In patients with CSDH, pre-existing comorbidity-linked factors related to outcomes were hemodialysis, chronic heart failure, and antithrombotic use. Patients with acute-on-chronic subdural hematoma with these factors should be regarded as a high-risk group.

Practical issues in clinical scenarios involving CKD patients requiring antithrombotic therapy in light of the 2017 ESC guideline recommendations

BACKGROUND

The choice of the most appropriate antithrombotic regimen that balances ischemic and bleeding risks was addressed by the August 2017 European Society of Cardiologists (ESC)/European Association for Cardio-Thoracic Surgery Focused Update recommendations, which propose new evaluation scores and protocols for patients requiring a coronary stent or patients with an acute coronary syndrome, atrial fibrillation, or a high bleeding risk and indication for oral anticoagulation therapy.

DISCUSSION

Numerous questions remain regarding antithrombotic regimens and risk management algorithms for both ischemic and hemorrhagic events in patients with chronic kidney disease (CKD) in various clinical scenarios. Limitations of current studies include a general ack of advanced CKD patients in major randomized controlled trials, of evidence on algorithm implementation, and of robust assessment tools for hemorrhagic risk. Herein, we aim to analyze the ESC Update recommendations and the newly implemented risk scores (DAPT, PRECISE-DAPT, PARIS) from the point of view of CKD, providing suggestions on drug choice (which combination has the best evidence), dosage, and duration (the same or different as for non-CKD population) of antithrombotics, as well as to identify current shortcomings and to envision directions of future research.

CONCLUSION

We provide an evidence-based perspective on the new proposed bleeding management protocol, with focus on the CKD population. Despite previous important steps on antithrombotic therapy of renal patients, there remain many unsolved questions for which our suggestions could fundament new randomized controlled trials and specific protocols.

Nonvitamin K Oral Anticoagulants in Patients With Atrial Fibrillation and Severe Renal Dysfunction

Both atrial fibrillation (AF) and chronic kidney disease (CKD) are highly prevalent, especially with increasing age and associated comorbidities, such as hypertension, diabetes, heart failure, and vascular disease. The relationship between both AF and CKD seems to be bidirectional: CKD predisposes to AF while onset of AF seems to lead to progression of CKD. Stroke prevention is the cornerstone of AF management, and AF patients with CKD are at higher risk of stroke, mortality, cardiac events, and bleeding. Stroke prevention requires use of oral anticoagulants, which are either vitamin K antagonists (eg, warfarin), or the nonvitamin K antagonist oral anticoagulants (NOACs). While NOACs have been shown to be effective in mild-to-moderate renal dysfunction, there are a paucity of data regarding NOACs in severe and end-stage renal dysfunction. This review first discusses the evidence for NOACs in CKD. Second, we summarize the current knowledge regarding the efficacy and safety of NOACs to prevent AF-related stroke and systemic embolism in severe and end-stage renal disease.

Safety and effectiveness of apixaban compared to warfarin in dialysis patients

Background: The use of apixaban for stroke prophylaxis or for the treatment of venous thromboembolism in end stage renal disease (ESRD) patients maintained on dialysis is based on one single-dose pharmacokinetic study. There is a deficiency of clinical evidence supporting safety in this population.Objective: The purpose of this study was to determine the safety and efficacy of apixaban compared with warfarin in dialysis patients.Patients/methods: This is a retrospective cohort study conducted at the University of Virginia Medical Center. A total of 124 ESRD patients maintained on dialysis who either received apixaban (n = 74) or warfarin (n = 50) between January 1, 2014 and October 31, 2016 were included in the study. We used multivariable logistic regression to compare the likelihood of patients experiencing a bleeding event based on anticoagulant therapy.Results: The apixaban group experienced fewer overall bleeding events than the warfarin group (18.9% vs 42.0%; P = .01); this significant difference persisted in adjusted analysis (OR = 0.15; 95% CI = 0.05-0.46; P = .001). Major bleeding events were less frequent in the apixaban group compared with patients on warfarin (5.4% vs 22.0%; P = .01). There were no recurrent ischemic strokes in either groups. A lower, non-significant, incidence of recurrent VTE was found in patients on apixaban compared with warfarin (4.4% vs 28.6%; P = .99).Conclusion: Compared to warfarin, our findings suggest that apixaban is a safe and effective alternative in patients with ESRD maintained on dialysis, with apixaban patients experiencing fewer bleeding events than warfarin patients.

Is anticoagulating haemodialysis patients with non-valvular atrial fibrillation too risky?

There is an increasing understanding of the risks from atrial fibrillation (AF) in the current era. In patients with end-stage renal disease (ESRD) on dialysis, the prevalence of AF is significantly higher compared to the general population and those with earlier stages of CKD. Although anticoagulation of these patients may seem appropriate, there is a lack of conclusive evidence that it provides the same protection from thromboembolic complications as it does in patients not on dialysis. In addition, the increased risk of bleeding in patients requiring dialysis makes the use of anticoagulants less favourable. This article aims to discuss the problem of AF in dialysis patients, summarise the current evidence around the use of oral anticoagulants for AF in ESRD and provide some practical suggestions on management of AF in the haemodialysis population.

Bleeding in advanced CKD patients on antithrombotic medication - A critical appraisal

Patients with advanced chronic kidney disease (CKD) are at an increased risk of bleeding, especially in the context of the complex therapeutic schemes of coronary artery disease (CAD) (from stable angina to acute coronary syndromes), atrial fibrillation or venous thromboembolism. The bleeding issue increases morbidity and mortality, a serious problem in daily medical practice. However, these patients are largely excluded from major randomized clinical trials, which results in the lack of medical evidence-based foundation for specific recommendations regarding antithrombotic treatment in a high bleeding risk setting. Within this framework, the clinician does not benefit from a clear set of algorithms and measures in the exploration and balancing of bleeding and thrombosis risks. We discuss a diversity of scenarios, encompassing all categories of advanced CKD patients with CAD or/and atrial fibrillation, and with various combinations of drugs, such as antiplatelet therapy or/and oral anticoagulation. Our review highlights the most recent research as well as existing gaps in the recommendations of European Society of Cardiology Guidelines. We evaluate the existence or lack of assessment tools for the bleeding risk, strength, reliability and usefulness of the bleeding risk scores. Also, we identify all the measures recommended after risk evaluation, including specific plans, dose adjustments and particular therapeutic approaches. Finally, we provide with suggestions for improving the management of this patient population.

Warfarin Use and Increased Mortality in End-Stage Renal Disease

BACKGROUND

Controversy exists regarding the benefits and risks of warfarin therapy in chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients. In this study, we assessed mortality and cardiovascular outcomes associated with warfarin treatment in patients with stages 3-5 CKD and ESRD admitted to the University of California-Irvine Medical Center.

METHODS

In a retrospective matched cohort study, we identified 59 adult patients with stages 3-6 CKD initiated on warfarin during the period 2011-2013, and 144 patients with stages 3-6 CKD who had indications for anticoagulation therapy but were not initiated on warfarin. All-cause mortality risk associated with warfarin treatment was estimated using Cox proportional hazard regression analysis, and the risk of significant bleeding and major adverse cardiovascular events were analyzed with Poisson regression analysis. Adjustment models were used to account for age, gender, diabetes mellitus, use of antiplatelet agents, and preexisting cardiovascular disease, and stratified by pre-dialysis CKD stages 3-5 vs. ESRD.

FINDINGS

During 5.8 years of follow-up, unadjusted mortality risk was higher in CKD patients on warfarin therapy (hazard ratio [HR] 2.34 with 95% CI 1.25-4.39; p < 0.01). After multivariate adjustment and stratification by CKD stage, the mortality risk remained significant in ESRD patients receiving warfarin (HR 6.62 with 95% CI 2.56-17.16; p < 0.001). Furthermore, adjusted rates of significant bleeding (incident rate ratio, IRR 3.57 with 95% CI 1.51-8.45; p < 0.01) and myocardial infarction (IRR 4.20 with 95% CI 1.78-9.91; p < 0.01) were higher among warfarin users. No differences in rates of ischemic or hemorrhagic strokes were found between the 2 groups.

CONCLUSIONS

Warfarin use was associated with several-fold higher risk of death, bleeding, and myocardial infarction in dialysis patients. If additional studies suggest similar associations, the use of warfarin in dialysis patients warrants immediate reconsideration.

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.

A Multicenter Analysis of Factors Associated With Apixaban-Related Bleeding in Hospitalized Patients With End-Stage Renal Disease on Hemodialysis

BACKGROUND

In 2014, the United States Food and Drug Administration approved a labeling change for apixaban to include recommendations for patients with severe renal impairment and patients with end-stage renal disease (ESRD) on hemodialysis (HD), though these recommendations are largely based on pharmacokinetic and pharmacodynamic data.

OBJECTIVE

Identify variables associated with bleeding events in hospitalized patients with ESRD on HD receiving apixaban.

METHODS

This retrospective, multicenter cohort study evaluated hospitalized patients with ESRD on HD receiving apixaban from January 1, 2013, through March 31, 2016. Correlational analysis and logistic regression were completed to identify factors associated with bleeding.

RESULTS

A total of 114 adults were included in the analysis. The median length of stay (LOS) was 6.2 (interquartile range = 3.8-11.9) days and bleeding events occurred in a total of 17 patients (15%). A weak correlation was identified for higher cumulative apixaban exposure, increased number of HD sessions while receiving apixaban, and increased hospital LOS ( P < 0.05; correlation coefficient < 0.40). When controlling for confounders, logistic regression revealed that composite bleeding events were independently increased by continuation of outpatient apixaban (odds ratio = 13.07; 95% CI = 1.54-110.54; P = 0.018), increased total daily dose of apixaban (odds ratio = 1.72; 95% CI = 1.20 to 2.48; P = 0.003), and total HD sessions while receiving apixaban (odds ratio = 2.04; 95% CI = 1.06-3.92; P = 0.033).

CONCLUSION

The association between these factors and increased bleeding should prompt concern for long-term anticoagulation with apixaban in patients with ESRD receiving chronic HD.

Antithrombotic therapy in end-stage renal disease

The delicate balance of risk vs. benefit of using antiplatelet and antithrombotic agents in the general population is well established. The decision to use these agents in the end stage renal disease (ESRD) population remains complex and difficult. The concomitant association of a prothombotic state with high risk of bleeding in the ESRD population requires individualization and careful clinical judgment before implementing such therapy. There remains a paucity of clinical trials and lack of substantial evidence in literature for safe and effective use of antithrombotic drugs in patients with advanced chronic kidney disease. The current review summarizes the pros and cons of using antiplatelet and antithrombotic agents in primary and secondary prevention of cardiovascular events, evaluate the risks with routine use of anticoagulation for cerebrovascular stroke prevention with nonvalvular atrial fibrillation and role of newer oral anticoagulants as alternate agents in the dialysis population.

Hemodialysis Tunneled Catheter Noninfectious Complications

Noninfectious hemodialysis catheter complications include catheter dysfunction, catheter-related thrombus, and central vein stenosis. The definitions, causes, and treatment strategies for catheter dysfunction are reviewed below. Catheter-related thrombus is a less common but serious complication of catheters, requiring catheter removal and systemic anticoagulation. In addition, the risk factors, clinical manifestation, and treatment options for central vein stenosis are outlined.

Antithrombotic medications in dialysis patients: a double-edged sword

In the clinical context of end-stage renal disease (ESRD), thrombosis and bleeding risks are simultaneously increased and may have devastating consequences. While anticoagulant and antiplatelet drugs are indispensable for the prevention of thromboembolic events, the significantly higher bleeding risk makes their handling extremely complicated. In ESRD, they are frequently administered for a wide array of conditions. For example, atrial fibrillation is quite common in ESRD and warrants the use of anticoagulants like warfarin. Unfractionated heparin and low molecular weight heparins are typically used for clotting prevention in the hemodialysis extracorporeal circuit. The antithrombotics use dilemma has worsened because ESRD patients have been excluded from major clinical trials that defined standard indications, contraindications and optimal management of these medications. That limits our knowledge and results in that the process of decision-making depends on weaker data. Besides the substantial bleeding risk, warfarin may also increase cardiovascular risk because it is implicated in the pathogenesis of vascular calcifications in ESRD. The present article attempts to offer a comprehensive overview of practical considerations for the use of the most common antithrombotic medications in ESRD linking them, at the same time, to the best available evidence from randomized controlled trials and observational studies.

Vitamin K antagonism aggravates chronic kidney disease-induced neointimal hyperplasia and calcification in arterialized veins: role of vitamin K treatment?

Arteriovenous fistula (AVF) is the common vascular access type for a hemodialysis patient. Its failure is due to neointimal hyperplasia. Vitamin K antagonists are given to lower thrombosis tendency, but have side effects that enhance arterial calcifications. Here, we investigated the effects of vitamin K antagonists and vitamin K2 (K2) treatment on neointimal hyperplasia development and calcification in rats and in arterialized human veins. AVF was generated in female rats while chronic kidney disease (CKD) was induced using an adenine-enriched diet. Arterialization, CKD, and vitamin K antagonists all significantly enhanced venous neointimal hyperplasia. K2 treatment, additional to vitamin K antagonists, significantly reduced neointimal hyperplasia in arterialized veins in healthy rats but not in rats with CKD. Arterialization, CKD, and vitamin K antagonism all significantly increased, whereas K2 supplementation attenuated calcification in healthy rats and rats with CKD. K2 significantly enhanced matrix Gla protein carboxylation in control rats and rats with CKD. Arterialized human vein samples contained inactive matrix Gla protein at calcification and neointimal hyperplasia sites, indicating local vitamin K deficiency. Thus, vitamin K antagonists have detrimental effects on AVF remodeling, whereas K2 reduced neointimal hyperplasia and calcification indicating vasoprotective effects. Hence, K2 administration may be useful to prevent neointimal hyperplasia and calcification in arterialized veins

Warfarin use and stroke, bleeding and mortality risk in patients with end stage renal disease and atrial fibrillation: a systematic review and meta-analysis

Background

Patients with end stage renal disease (ESRD), including stage 5 chronic kidney disease (CKD), hemodialysis (HD) and peritoneal dialysis (PD), are at high risk for stroke-related morbidity, mortality and bleeding. The overall risk/benefit balance of warfarin treatment among patients with ESRD and AF remains unclear.

Methods

We systematically reviewed the associations of warfarin use and stroke outcome, bleeding outcome or mortality in patients with ESRD and AF. We conducted a comprehensive literature search in Feb 2016 using key words related to ESRD, AF and warfarin in PubMed, Embase and Cochrane Library without language restriction. We searched for randomized trials and observational studies that compared the use of warfarin with no treatment, aspirin or direct oral anticoagulants (DOACs), and reported quantitative risk estimates on these outcomes. Paired reviewers screened articles, collected data and performed qualitative assessment using the Cochrane Risk of Bias Assessment Tool for Non-randomized Studies of Interventions. We conducted meta-analyses using the random-effects model with the DerSimonian - Laird estimator and the Knapp-Hartung methods as appropriate.

Results

We identified 2709 references and included 20 observational cohort studies that examined stroke outcome, bleeding outcome and mortality associated with warfarin use in 56,146 patients with ESRD and AF. The pooled estimates from meta-analysis for the stroke outcome suggested that warfarin use was not associated with all-cause stroke (HR = 0.92, 95 % CI 0.74–1.16) or any stroke (HR = 1.01, 95 % CI 0.81–1.26), or ischemic stroke (HR = 0.80, 95 % CI 0.58–1.11) among patients with ESRD and AF. In contrast, warfarin use was associated with significantly increased risk of all-cause bleeding (HR = 1.21, 95 % CI 1.01–1.44), but not associated with major bleeding (HR = 1.18, 95 % CI 0.82–1.69) or gastrointestinal bleeding (HR = 1.19, 95 % CI 0.81–1.76) or any bleeding (HR = 1.21, 95 % CI 0.99–1.48). There was insufficient evidence to evaluate the association between warfarin use and mortality in this population (pooled risk estimate not calculated due to high heterogeneity). Results on DOACs were inconclusive due to limited relevant studies.

Conclusions

Given the absence of efficacy and an increased bleeding risk, these findings call into question the use of warfarin for AF treatment among patients with ESRD.

Hemodialysis Tunneled Catheter Noninfectious Complications

Noninfectious hemodialysis catheter complications include catheter dysfunction, catheter-related thrombus, and central vein stenosis. The definitions, causes, and treatment strategies for catheter dysfunction are reviewed below. Catheter-related thrombus is a less common but serious complication of catheters, requiring catheter removal and systemic anticoagulation. In addition, the risk factors, clinical manifestation, and treatment options for central vein stenosis are outlined.