Estimated glomerular filtration rate is associated with major bleeding complications but not thromboembolic events, in anticoagulated patients taking warfarin

Kinetic-pharmacodynamic model of warfarin for prothrombin time-international normalized ratio in Japanese patients

AIMS

Genotype-guided dosing algorithms can explain about half of the interindividual variability in prothrombin time-international normalized ratio (PT-INR) under warfarin treatment. This study aimed to refine a published kinetic-pharmacodynamic model and guide warfarin dosage for an optimal PT-INR based on renal function.

METHODS

Using a retrospective cohort of adult patients (>20 years) who were administered warfarin and underwent PT-INR measurements, we refined the kinetic-pharmacodynamic model with age and the genotypes of cytochrome P450 2C9 and vitamin K epoxide reductase complex subunit 1 using the PRIOR subroutine in the nonlinear-mixed-effect modelling programme. We searched the significant covariates for parameters, such as the dose rate for 50% inhibition of coagulation (EDR50 ), using a stepwise forward and backward method. Monte Carlo simulation determined a required daily dose of warfarin with a target range of PT-INR (2.0-3.0 or 1.6-2.6) based on the significant covariates.

RESULTS

A total of 350 patients with 2762 PT-INR measurements were enrolled (estimated glomerular filtration rate [eGFR]: 47.5 [range: 2.6-199.0] mL/min/1.73 m2 ). The final kinetic-pharmacodynamic model showed that the EDR50 changed power functionally with body surface area, serum albumin level and eGFR. Monte Carlo simulation revealed that a lower daily dose of warfarin was required to attain the target PT-INR range as eGFR decreased.

CONCLUSIONS

Model-informed precision dosing of warfarin is a valuable approach for estimating its dosage in patients with renal impairment.

The impact of renal function on clinical outcomes of patients with cancer-associated isolated distal deep vein thrombosis: Insights from the ONCO DVT study

BACKGROUND

The multicenter, open-label, randomized clinical trial ONCO DVT compared 3-month and 12-month edoxaban treatment regimens for isolated distal deep vein thrombosis (DVT) and suggested potential benefits of prolonged edoxaban treatment in terms of thrombotic risk. However, the risk-benefit balance of prolonged edoxaban treatment in patients with renal function remains unclear.

OBJECTIVES

To compare the safety and efficacy of 3-month and 12-month edoxaban treatment regimens in patients with cancer-associated isolated distal DVT and different renal functions.

METHODS

This pre-specified subgroup analysis of the ONCO DVT study included 601 patients divided into subgroups according to renal function using a 50 mL/min creatinine clearance (Ccr) cutoff. The primary endpoint was symptomatic recurrent venous thromboembolism (VTE) and VTE-related death at 12 months and the major secondary endpoint was major bleeding at 12 months.

RESULTS

Among the 601 patients, 131 (21.8 %) comprised the renal dysfunction subgroup. The primary endpoint occurred in 6 (9.7 %) and 1 (1.4 %) patients in the 3-month and 12-month edoxaban groups in the renal dysfunction subgroup, respectively, and in 16 (6.6 %) and 2 (0.9 %) patients in the no renal dysfunction subgroup, respectively. The major secondary endpoint occurred in 9 (14.5 %) and 7 (10.1 %) patients in the 12-month and 3-month edoxaban groups in the renal dysfunction subgroup, and in 13 (5.3 %) and 21 (9.3 %) patients in the no renal dysfunction subgroup, respectively.

CONCLUSIONS

A 12-month edoxaban regiment was superior to a 3-month treatment in terms of thrombotic risk irrespective of renal function. A higher bleeding risk was not identified in patients with renal dysfunction who received prolonged edoxaban treatment.

Percutaneous coronary intervention improves quality of life of patients with chronic total occlusion and low estimated glomerular filtration rate

Background

A low estimated glomerular filtration rate (eGFR <90 mL/min/1.73 m²) is widely recognized as a risk factor for major adverse cardiac events (MACE) after percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). However, the impact of successful CTO-PCI on quality of life (QOL) of patients with low eGFR remains unknown.

Objectives

The aim of this prospective study was to assess the QOL of CTO patients with low eGFR after successful PCI.

Methods

Consecutive patients undergoing elective CTO-PCI were prospectively enrolled and subdivided into four groups: eGFR ≥90 mL/min/1.73 m² (n = 410), 90 > eGFR ≥ 60 mL/min/1.73 m² (n = 482), 60 > eGFR ≥ 30 mL/min/1.73 m² (n = 161), and eGFR <30 mL/min/1.73 m² (n = 23). The primary outcomes included QOL, as assessed with the European Quality of Life-5 Dimensions (EQ-5D) questionnaire, and symptoms, as assessed with the Rose Dyspnea Scale (RDS) and Seattle Angina Questionnaire (SAQ), at 1 month and 1 year after successful PCI.

Results

With the decline of eGFR, CTO patients were more likely to present with comorbidities of hypertension, diabetes, hyperuricemia, and previous stroke, in addition to lower hemoglobin levels and left ventricular ejection fraction (p < 0.05). Low eGFR was associated with greater incidences of in-hospital pericardiocentesis, major bleeding, acute renal failure, and subcutaneous hematoma, but not in-hospital MACE (p < 0.05). Symptoms of dyspnea and angina were alleviated in all CTO patients with eGFR ≥30 mL/min/1.73 m² at 1 month and 1 year after successful CTO-PCI, but only at 1 month for those with eGFR <30 mL/min/1.73 m² (p < 0.01). Importantly, QOL was markedly improved at 1 month and 1 year after successful PCI (p < 0.01), notably at a similar degree between patients with low eGFR and those with normal eGFR (p > 0.05).

Conclusion

Successful PCI effectively improved symptoms and QOL of CTO patients with low eGFR.

Predictive ability of creatinine clearance versus estimated glomerular filtration rate for outcomes in patients with non-valvular atrial fibrillation: Subanalysis of the J-RHYTHM Registry

BACKGROUND

Renal impairment is a risk factor for various adverse events, especially for death. In general, creatinine clearance (CrCl) is used for dose-adjustments of many drugs including oral anticoagulants, and estimated glomerular filtration rate (eGFR) is adopted for the diagnosis of chronic kidney disease. Predictive ability of CrCl versus eGFR for outcomes in patients with non-valvular atrial fibrillation (NVAF) remains controversial; therefore, this was compared using data from the J-RHYTHM Registry.

METHODS

Out of 7406 outpatients with NVAF from 158 institutions, 6004 (age, 69.7 ± 9.9 years; men, 71.2%) having data of CrCl (mL/min, by the Cockcroft-Gault formula), eGFR (mL/min/1.73 m2, by the equations of the Japanese Society of Nephrology), and body surface area (BSA) were analyzed. C-statistics (area under the receiver-operating characteristic curve) of CrCl and eGFR for events were compared by DeLong's test.

RESULTS

Thromboembolism, major hemorrhage, and all-cause death occurred in 107 (1.8%), 117 (1.9%), and 154 (2.6%) patients during the 2-year follow-up period. C-statistics of CrCl for each event were 0.609 (95% confidence interval, 0.559-0.658), 0.599 (0.548-0.657), and 0.746 (0.706-0.786); and those of eGFR were 0.542 (0.487-0.597), 0.573 (0.519-0.626), and 0.677 (0.631-0.723), respectively. C-statistics of CrCl for thromboembolism and all-cause death were significantly higher than those of eGFR (P < 0.001 for both). These results were consistent when BSA-unadjusted eGFR was used instead of eGFR (P = 0.002 for thromboembolism and P < 0.001 for all-cause death).

CONCLUSIONS

CrCl was superior to eGFR in the prediction of adverse outcomes, i.e., thromboembolism and all-cause death in Japanese patients with NVAF.

Renal dysfunction and long-term clinical outcomes in patients with venous thromboembolism: From the COMMAND VTE Registry

INTRODUCTION

Patients with renal dysfunction are at high risk for developing venous thromboembolism (VTE). However, the impact of renal dysfunction on recurrent VTE remains to be clarified. We assessed the relationship between estimated glomerular filtration rate (eGFR) at diagnosis and long-term clinical outcomes in VTE patients.

MATERIALS AND METHODS

The COMMAND VTE Registry is a multicenter registry enrolling consecutive patients with acute symptomatic VTE among 29 centers in Japan between January 2010 and August 2014. Patients with available creatinine values (N = 2829) were divided into the reference eGFR (≥60 mL/min/1.73 m²) group (N = 1760) and the low eGFR (<60 mL/min/1.73 m²) group (N = 1069). The low eGFR group was further subdivided into the moderately low eGFR (30-59 mL/min/1.73 m²) group (N = 898) and very low eGFR (<30 mL/min/1.73 m²) group (N = 171).

RESULTS

The low eGFR group was independently associated with the increased risk for recurrent VTE (adjusted HR 1.55, 95%CI 1.15-2.08). When the low eGFR group was subdivided into the moderately low and very low eGFR groups, the risk for recurrent VTE increased with decreasing eGFR (adjusted HR 1.43, 95%CI 1.04-1.95, and adjusted HR 2.54, 95%CI 1.42-4.28). The risk for major bleeding was higher in the very low eGFR group, but not in the moderately low eGFR group (adjusted HR 1.70, 95%CI 1.06-2.61, and adjusted HR 0.85, 95%CI 0.73-1.28).

CONCLUSIONS

Renal dysfunction measured by eGFR was associated with an increased risk for recurrent VTE, which was more prominent in severe renal dysfunction. Severe renal dysfunction was also associated with a higher risk for major bleeding.

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

Aims

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

Methods and results

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

Conclusion

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

Clinical Trial Registration:

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

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.

Dabigatran versus Warfarin for Acute Venous Thromboembolism in Elderly or Impaired Renal Function Patients: Pooled Analysis of RE-COVER and RE-COVER II

Management of acute venous thromboembolism (VTE) with anticoagulants in elderly patients and those with chronic kidney disease poses special challenges. The RE-COVER and RE-COVER II trials showed that dabigatran 150 mg twice daily was as effective as warfarin over 6 months in preventing recurrent VTE, with a lower bleeding risk. We now assess the effects of old age and renal impairment (RI) on pooled trial outcomes in 5,107 patients: 4,504 aged <75 years and 603 aged ≥75 years. The primary efficacy outcome was symptomatic VTE/VTE-related death. Safety outcomes were centrally adjudicated major bleeding events (MBEs), MBEs or clinically relevant non-major bleeding events (MBEs/CRBEs) and any bleeds. Baseline renal function was categorized as normal, mild RI or moderate RI. A total of 3,698 had normal renal function and 1,100 and 237 had mild and moderate RI, respectively (23 patients with severe RI and 49 with missing creatinine clearance data were not included). For dabigatran, VTE/VTE-related death decreased from 3.1% (normal renal function) to 1.9% for mild RI and to 0.0% for moderate RI. For warfarin, the event rates were 2.6, 1.6 and 4.1%, respectively. Overall, major bleeding increased with increasing RI (p = 0.0037) and with age (p = 0.4350), with no apparent difference between the dabigatran and warfarin patients. Dabigatran shows better efficacy than warfarin in RI and in the elderly patients, probably because of an increase in the concentration of dabigatran. However, bleeding risk increases with both dabigatran and warfarin in the presence of RI.

Application of Biomarkers for Risk Stratification in Patients with Atrial Fibrillation

BACKGROUND

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

CONTENT

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

SUMMARY

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

Glomerular filtration rate and association to stroke, major bleeding, and death in patients with mechanical heart valve prosthesis

AIMS

The impact of estimated glomerular filtration rate (eGFR) on adverse events in patients with mechanical heart valves (MHVs) is unknown. We analyzed the independent association of eGFR and thromboembolism (TE), major bleeding, and mortality in patients with MHV in an observational cohort study.

METHODS AND RESULTS

All patients (n = 520) with MHV replacement on anticoagulation treatment were followed up prospectively regarding TE, major bleeding, and death at 2 anticoagulation centers during 2008 to 2011. The mean age was 69 years, 72% with aortic valve replacement, and time in therapeutic range 2.0 to 4.0 was 91%. The incidence of the combined end point of major bleeding, TE, and death increased sharply with each decreasing eGFR stratum: 5.5, 8.4, 16, and 32 per 100 patient-years for eGFR >60, 45 to 60, 30 to 45, and <30 mL/min per 1.73 m(2), respectively. After multivariate adjustment for comorbidities, every unit decrease in eGFR increased the risk of major bleeding by 2%, death by 3%, and the combined end point by 1%. There was no association between eGFR and TE. There was an increased proportion of international normalized ratio >3.0 and >4.0 and decreasing time in therapeutic range for each decreasing eGFR stratum (P < .001 for trend). The hazard ratios of the combined end point for eGFR <30, 30 to 45, and 45 to 60 mL/min per 1.73 m(2) were 3.2 (95% CI 1.8-5.6), 1.5 (95% CI 0.9-2.5), and 0.9 (95% CI 0.6-1.5), respectively, compared to eGFR >60 mL/min per 1.73 m(2).

CONCLUSION

In patients with MHV on anticoagulation, eGFR is an independent predictor of major bleeding and death and not TE.

Understanding and Managing Atrial Fibrillation in Patients with Kidney Disease

Chronic kidney disease (CKD) is on the rise due to the increased rate of related comorbidities such as diabetes and hypertension. Patients with CKD are at higher risk of cardiovascular events and atrial fibrillation is more common in this patient population. It is estimated that the prevalence of chronic atrial fibrillation in patients with CKD is two to three times higher than general population. Furthermore, patients with CKD are less likely to stay in sinus rhythm. Atrial fibrillation presents a major burden in this population due to difficult treatment decisions in the setting of a lack of evidence from randomized clinical trials. Patients with CKD have higher risk of stroke with more than half having a CHADS2 score ≥ 2. Anticoagulation have been shown to significantly decrease embolic stroke risk, however bleeding complications such as hemorrhagic stroke is twofold higher with warfarin. Although newer novel anticoagulation drugs have shown promise with lower intracranial hemorrhage risk in comparison to warfarin, lack clinical trial data in CKD and the unavailability of an antidote remains an issue. In this review, we discuss the treatment options available including anticoagulation and the evidence behind them in patients with chronic kidney disease suffering from atrial fibrillation.

Hemorrhage as a life-threatening complication after valve replacement in end-stage renal disease patients

OBJECTIVE

Hemodialysis patients have an increased risk of hemorrhage compared to other patients. This study reports the frequencies of hemorrhage and its impact on the survival of hemodialysis patients after valve replacement.

METHODS

A total of 77 consecutive dialysis patients who underwent prosthetic valve surgery from 1991 to 2011 were retrospectively reviewed. Their mean age was 65.8 ± 9.2 years. Forty-three patients (56%) were male. Fifty-nine patients (77%) had aortic valve replacement, and 23 patients (30%) had mitral valve replacement. Bioprosthetic valves were used in 17 patients (22%).

RESULTS

There were seven in-hospital mortalities (9.1%). The overall estimated Kaplan-Meier survival after 3, 5 and 7 years was 66.6 ± 5.6, 51.1 ± 6.3 and 34.4 ± 6.8%, respectively. Seventeen (22%) bleeding events were observed (5.9% per patient-years) in the follow-up period. Six of the nine patients with cerebral hemorrhages and two of the six with gastrointestinal hemorrhages died. There were no differences in the frequencies of hemorrhage between the patients treated with bioprostheses and mechanical valves.

CONCLUSIONS

This study found that 22% of dialysis patients had hemorrhagic events after valve replacement, and approximately half of them died. Particularly, cerebral hemorrhage was fatal and two thirds of the patients died. So we should meditate the methods to reduce hemorrhage. Therefore, new methods to reduce the risk of hemorrhage are urgently needed.

Efficacy and safety of vitamin K-antagonists (VKA) for atrial fibrillation in non-dialysis dependent chronic kidney disease

Background

Essential information regarding efficacy and safety of vitamin K-antagonists (VKA) treatment for atrial fibrillation (AF) in non-dialysis dependent chronic kidney disease (CKD) is still lacking in current literature. The aim of our study was to compare the risks of stroke or transient ischemic attack (TIA) and major bleeds between patients without CKD (eGFR >60 ml/min), and those with moderate (eGFR 30–60 ml/min), or severe non-dialysis dependent CKD (eGFR <30 ml/min).

Methods

We included 300 patients without CKD, 294 with moderate, and 130 with severe non-dialysis dependent CKD, who were matched for age and sex. Uni- and multivariate Cox regression analyses were performed reporting hazard ratios (HRs) for the endpoint of stroke or TIA and the endpoint of major bleeds as crude values and adjusted for comorbidity and platelet-inhibitor use.

Results

Overall, 6.2% (45/724, 1.7/100 patient years) of patients developed stroke or TIA and 15.6% (113/724, 4.8/100 patient years) a major bleeding event. Patients with severe CKD were at high risk of stroke or TIA and major bleeds during VKA treatment compared with those without renal impairment, HR 2.75 (95%CI 1.25–6.05) and 1.66 (95%CI 0.97–2.86), or with moderate CKD, HR 3.93(1.71–9.00) and 1.86 (95%CI 1.08–3.21), respectively. These risks were similar for patients without and with moderate CKD. Importantly, both less time spent within therapeutic range and high INR-variability were associated with increased risks of stroke or TIA and major bleeds in severe CKD patients.

Conclusions

VKA treatment for AF in patients with severe CKD has a poor safety and efficacy profile, likely related to suboptimal anticoagulation control. Our study findings stress the need for better tailored individualised anticoagulant treatment approaches for patients with AF and severe CKD.

Stroke in Atrial Fibrillation - Long-term Follow-up of Cardiovascular Events

The incidence of atrial fibrillation (AF) was around 1.5 per 1000 person-years in Taiwan. Systemic thromboembolism is the most severe complication of AF. Risk stratification and adequate thromboembolism prophylaxis is the cornerstone of treatment in AF patients. The CHA2DS2-VASc score is powerful in selecting "truly low-risk" patients who are not necessary to receive anticoagulation therapies. It is also useful in predicting thromboembolic events and mortality for patients undergoing AF ablation. Recently, more and more biomarkers and imaging parameters were reported to be associated with adverse events in AF patients. How could these biomarkers and imaging tools change the current strategy of stroke prevention in AF deserves further investigations.

Evidence-based cardiology in hemodialysis patients

Cardiac events are the major cause of death in hemodialysis patients. Because of the paucity of randomized clinical trials (RCTs) in hemodialysis patients, most cardiovascular therapies in this population are based on observational studies or results extrapolated from studies that excluded hemodialysis patients. However, associations discovered in observational studies do not prove causality, and these studies often report surrogate outcomes rather than clinical end points. Furthermore, interventions that show effectiveness in the general population may have drastically different outcomes and side effect profiles in hemodialysis patients. This review discusses the results of RCTs undertaken recently to evaluate cardiovascular therapies in hemodialysis patients and emphasizes clinically relevant outcomes. Although some interventions have produced similar outcomes in hemodialysis patients and the general population, others have not, suggesting that the management of cardiovascular disease in hemodialysis patients may require strategies that differ from the best practice guidelines applied to general population.