Improvement of anticoagulant treatment using a dynamic decision support algorithm: a Danish Cohort study

Efficacy and safety of warfarin in patients with non-valvular atrial fibrillation and CKD G3-G5D

Background

Observational data comparing warfarin with no treatment for patients with non-valvular atrial fibrillation (NVAF) and severely reduced glomerular filtration rate (GFR) are conflicting and randomized controlled trials (RCTs) are lacking. Most studies do not provide information on warfarin treatment quality, making them difficult to compare.

Methods

This national cohort study investigates the risk of ischaemic stroke and major bleeding during warfarin treatment compared with no oral anticoagulants in patients with NVAF, GFR category 3-5 (G3-G5) or on dialysis (G5D), with kidney transplant recipients excluded, between 2009 and 2018. Data extracted from high-quality Swedish national healthcare registries, including the Swedish Renal Registry, AuriculA-the Swedish national quality registry for atrial fibrillation and anticoagulation-and the Stroke Registry.

Results

At enrolment of 12 106 patients, 21.4% were G3, 43.5% were G4, 11.6% were G5 and 23.6% were G5D. The mean time in the therapeutic range was 70%. Warfarin compared with no treatment showed a lower risk for ischaemic stroke for G3 {hazard ratio [HR] 0.37 [95% confidence interval (CI) 0.18-0.76]}, G4 [0.53 (0.38-0.74)] and G5 [0.49 (0.30-0.79)] and an increased risk of major bleeding in G4 [HR 1.22 (1.02-1.46)], G5 [1.52 (1.15-2.01)] and G5D [1.23 (1.00-1.51)]. All-cause mortality was more than halved on warfarin compared with no treatment in all GFR categories.

Conclusions

Warfarin treatment is associated with a lower risk of ischaemic stroke for patients with NVAF and G3, G4 and G5D at the cost of a higher risk of major bleeding for G4-G5D. Existing observational data are conflicting, stressing the need for RCTs on warfarin compared with no treatment in G4-G5D. Awaiting RCTs, it seems reasonable to treat selected patients on dialysis and NVAF with warfarin.

Incidence and outcomes of patients with atrial fibrillation and major bleeding complications: from the TREAT-AF study

PURPOSE

Optimal stroke prevention strategies for patients with atrial fibrillation (AF) who experience a major bleed are poorly defined. We sought to estimate the effectiveness and safety of oral anticoagulation (OAC) represcription after an OAC contraindication.

METHODS

TREAT-AF is a retrospective cohort study of patients with newly diagnosed AF (2004-2012), treated in the Veterans Health Administration. From this cohort, we identified patients with a contraindication to OAC after AF diagnoses, defined as incident intracranial bleeding, non-intracranial bleeding requiring hospitalization, or unrepaired cerebral aneurysm or aortic dissection. We used multivariate Cox proportional hazards to estimate the association of OAC prescription in the 90 days following OAC contraindication to ischemic stroke and rebleeding.

RESULTS

Among 167,190 patients with newly diagnosed AF (70 ± 11 years, 1.7% female, CHA₂DS₂-VASc 2.7 ± 1.7), 19,285 patients (11.5%) had an incident bleed (n = 18,342) or an unrepaired cerebral aneurysm or aortic dissection (n = 943). For OAC-contraindicated patients with a CHA₂DS₂-VASc ≥2 (N = 16,194), OAC was represcribed in 4075 patients (25%) and was associated with a higher risk of non-intracranial bleeding (HR 1.49; 95% CI 1.37-1.61; p < 0.0001) but no difference in intracranial bleeding. There was a trend toward decreased stroke risk (HR 0.85; 95% CI 0.71-1.02; p 0.09).

CONCLUSIONS

Development of contraindication to OAC after diagnosis of AF is common (11.5%), with most events requiring hospitalization. OAC reinitiation was associated with non-intracranial bleeding risk, with a trend toward reduced stroke risk. These data suggest that stroke prevention approaches after major bleeding events could be beneficial if bleeding risk can be successfully mitigated.

Potential Causes and Implications of Low Target Therapeutic Ratio in Warfarin-Treated Patients for Thrombosis Prophylaxis: A Single-Center Experience

Time in therapeutic range (TTR) of international normalized ratio is crucial for the safety and efficacy of anticoagulation with warfarin and it is influenced by many factors. There are limited data about the quality of warfarin therapy and its effects on clinical outcomes in Turkey. The aim of this study is to demonstrate the quality of anticoagulant therapy with warfarin and evaluate the parameters that affect the quality of warfarin therapy. A total of 170 patients with atrial fibrillation (AF; mean age: 62.2 ± 13.3; 69.2% female) treated with warfarin were included in this study. The mean follow-up period was 20 ± 8.4 months. The mean TTR levels of all patients were found to be 54.2% ± 21.4%. The TTR levels were similar in patients with valvular AF (VAF) and nonvalvular AF (NVAF). Logistic regression analysis revealed that elderly, heart failure (HF), and renal dysfunction were independent predictors of lower TTR. There were no significant differences between the VAF and NVAF subgroups regarding the incidence of mortality, stroke, and myocardial infarction. Cox regression analysis revealed that HF, coronary artery disease, and renal dysfunction were independent predictors of clinical outcomes in addition to lower TTR. Our results provide data regarding the quality of anticoagulation with warfarin from a single tertiary center in Istanbul, Turkey. The questions remain in seeking quality improvement in anticoagulation.

Factors affecting the quality of anticoagulation with warfarin: experience of one cardiac centre

Introduction

The risk of complications in anticoagulation therapy can be reduced by maximising the percentage of time spent by the patient in the optimal therapeutic range (TTR). However, little is known about the predictors of anticoagulation control. The aim of this paper was to assess the quality of anticoagulant therapy in patients on warfarin and to identify the factors affecting its deterioration.

Material and methods

We studied 149 patients who required anticoagulant therapy with warfarin due to non-valvular atrial fibrillation and/or venous thromboembolism. Each patient underwent proper training regarding the implemented treatment and remained under constant medical care.

Results

The mean age of the patients was 68.8 ± 12.6 years, and 59% were male. A total of 2460 international normalised ratio (INR) measurements were collected during the 18-month period. The mean TTR in the studied cohort was 76 ± 21%, and the median was 80%. The level at which high-quality anticoagulation was recorded for this study was based on TTR values above 80%. Seventy-five patients with TTR ≥ 80% were included in the stable anticoagulation group (TTR ≥ 80%); the remaining 74 patients constituted the unstable anticoagulation group (TTR < 80%). According to multivariate stepwise regression analysis, the independent variables increasing the risk of deterioration of anticoagulation quality were: arterial hypertension (OR 2.74 [CI 95%: 1.06-7.10]; p = 0.038), amiodarone therapy (OR 4.22 [CI 95%: 1.30-13.70]; p = 0.017), and obesity (OR 1.11 [CI 95%: 1.02-1.21]; p = 0.013).

Conclusions

The presence of obesity, hypertension, or amiodarone therapy decreases the quality of anticoagulation with warfarin. High quality of anticoagulation can be achieved through proper monitoring and education of patients.

International warfarin genotype-guided dosing algorithms in the Turkish population and their preventive effects on major and life-threatening hemorrhagic events

AIM

To determine the accuracy of international warfarin pharmacogenetic algorithms developed on large multiethnic cohorts (comprising more than 1000 subjects) to predict therapeutic warfarin doses in Turkish patients.

MATERIALS & METHODS

We investigated two Turkish warfarin-treated cohorts: patients with no history of hemorrhagic or thromboembolic event and patients with major and life-threatening hemorrhagic events.

RESULTS

International pharmacogenetic algorithms showed good performances in predicting the therapeutic dose of patients with no history of bleedings, but they did not significantly detect the incorrect warfarin dose of patients with major and life-threatening hemorrhagic events.

CONCLUSION

Although genetic information can predict the therapeutic warfarin dose, the accuracy of the international pharmacogenetic algorithms is not sufficient to be used for warfarin screening in Turkish patients.

Patients' time in therapeutic range on warfarin among US patients with atrial fibrillation: Results from ORBIT-AF registry

BACKGROUND

Time in therapeutic range (TTR) of international normalized ratio (INR) of 2.0 to 3.0 is important for the safety and effectiveness of warfarin anticoagulation. There are few data on TTR among patients with atrial fibrillation (AF) in community-based clinical practice.

METHODS

Using the US Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF), we examined TTR (using a modified Rosendaal method) among 5,210 patients with AF on warfarin and treated at 155 sites. Patients were grouped into quartiles based on TTR data. Multivariable logistic regression modeling with generalized estimating equations was used to determine patient and provider factors associated with the lowest (worst) TTR.

RESULTS

Overall, 59% of the measured INR values were between 2.0 and 3.0, with an overall mean and median TTR of 65% ± 20% and 68% (interquartile range [IQR] 53%-79%). The median times below and above the therapeutic range were 17% (IQR 8%-29%) and 10% (IQR 3%-19%), respectively. Patients with renal dysfunction, advanced heart failure, frailty, prior valve surgery, and higher risk for bleeding (ATRIA score) or stroke (CHA2DS2-VASc score) had significantly lower TTR (P < .0001 for all). Patients treated at anticoagulation clinics had only slightly higher median TTR (69%) than those not (66%) (P < .0001).

CONCLUSIONS

Among patients with AF in US clinical practices, TTR on warfarin is suboptimal, and those at highest predicted risks for stroke and bleeding were least likely to be in therapeutic range.

Pharmacist-managed clinics for patient education and counseling in Japan: current status and future perspectives

To improve the adherence to and knowledge about pharmacotherapy in outpatients and to maximize the efficacy and minimize the adverse drug events, the first pharmacist-managed clinic (PMC) in Japan was established for anticoagulation therapy at Nagoya University Hospital in 2000. Since then, various PMCs such as for asthma/chronic obstructive pulmonary disease, Alzheimer's disease, hypercholesterolemia, chronic hepatitis C, cancer chemotherapy, palliative care, chronic kidney disease, and continuous ambulatory peritoneal dialysis have been established and expanded to many hospitals in Japan. Accumulating evidences suggest that PMCs have some beneficial effects on patients' adherence to and knowledge about their pharmacotherapy as well as the clinical outcome, besides being cost-effective. Notably, PMCs for cancer chemotherapy have been approved as a new medical service in hospitals in 2014, which is covered by the universal health coverage in Japan. In this review article, the current status of PMCs for patient education and counseling in Japan and their impact on pharmaceutical care and management are critically reviewed. Furthermore, future perspectives on PMCs are discussed.