Recommendations for point-of-care home International Normalized Ratio testing in children on vitamin K antagonist therapy

Guiding warfarin self-management in children: development of a warfarin nomogram

Background

Warfarin therapy in children is impacted by many variables. To support the implementation of a self-management program within a pediatric anticoagulation service, a pediatric-specific warfarin nomogram was needed. A literature review revealed no published pediatric nomograms; therefore, a nomogram was developed drawing upon an evidence-based "Warfarin Information for Clinicians" hospital guideline.

Objectives

This study aimed to evaluate the suitability of a pediatric warfarin nomogram.

Methods

A retrospective audit of electronic medical records compared the dosing and international normalized ratio (INR) retest decisions made by hematology clinicians to the dosing and retesting recommended by a new warfarin nomogram at a pediatric hospital. Children (aged 6 months-18 years) receiving warfarin therapy for >6 months were included. Data were collected between September 2019 and February 2020. Descriptive data analysis was performed. The study was approved by the hospital's Human Research Ethics Committee.

Results

Warfarin dosing and INR retest decisions for 39 children were included, equating to 521 INRs. The nomogram matched 81.4% of clinicians dosing decisions and 30% of INR retest decisions. Moreover, 59% of the clinician-recommended retest dates were earlier than the nomogram recommendation. In the INR 2.0-3.0 group, 84.4% of dosing decisions and 72% of retest decisions matched the nomogram.

Conclusions

These results suggest that this pediatric nomogram is a suitable tool for warfarin dosing, as recommended warfarin doses matched the majority of clinicians' decisions. Modification may be needed to nomogram recommendations for the time to retest. This nomogram can be used to support warfarin self-management and may assist clinicians and patients or families in making evidence-based dosing decisions.

Using an electronic medical record patient portal for warfarin self-management: Empowering children and parents

Background

Many children taking warfarin perform their international normalized ratio (INR) at home, with results phoned to a clinician who instructs warfarin dosing. Data suggest that parents can be supported to make warfarin dosing decisions themselves, a process known as patient self-management (PSM).

Objectives

This study aimed to determine the suitability and acceptability of warfarin PSM in children using the Epic Patient Portal.

Methods

Children currently performing INR patient self-testing were eligible. Participation involved an individualized education session, adherence to the PSM program, and participation in phone interviews. Clinical outcomes (INR time in therapeutic range and safety outcomes), patient portal functionality, and family experience were assessed. The hospital human research ethics committee approved the study and consent was obtained from parents/guardians.

Results

Twenty-four families undertook PSM. The median age of children was 11 years and all children had congenital heart disease. A median of 13 INRs was uploaded to the portal per family (range, 8-47) across a 10-month period. Before PSM, the mean time the INR was in therapeutic range was 71%; this increased to 79.9% during PSM (difference: P < .001). No adverse events were encountered. Eight families participated in a phone interview. The major theme identified was empowerment; minor themes that emerged included "gaining knowledge," "trust and responsibility builds confidence," "saving time," and "resources as a safety net."

Conclusion

This study demonstrates that communication via the Epic Patient Portal is satisfactory to families and offers a suitable option for PSM for children. Importantly, PSM empowers and builds confidence in families to facilitate management of their child's health.

Management of thrombosis in children and neonates: practical use of anticoagulants in children

Venous thrombosis (VTE) in children and neonates presents numerous management challenges. Although increasing in frequency, VTE in children and neonates is still uncommon compared with adults. The epidemiology of VTE is vastly different in neonates vs children vs adolescents vs adults. In reality, pediatric thrombosis should be viewed as a multitude of rare diseases (eg, renal vein thrombosis, spontaneous thrombosis, catheter-related thrombosis, cerebral sinovenous thrombosis), all requiring different approaches to diagnosis and with different short- and long-term consequences, but linked by the use of common therapeutic agents. Further, children have fundamentally different physiology in terms of blood flow, developmental hemostasis, and, likely, endothelial function. The American Society of Hematology 2017 Guidelines for Management of Venous Thromboembolism: Treatment of Pediatric VTE provides up-to-date evidence-based guidelines related to treatment. Therefore, this article will focus on the practical use of therapeutic agents in the management of pediatric VTE, especially unfractionated heparin, low-molecular-weight heparin, and oral vitamin K antagonists, as the most common anticoagulants used in children. Direct oral anticoagulants (DOACs) remain in clinical trials in children and should not be used outside of formal trials for the foreseeable future.

Safety and Efficacy of Warfarin Therapy in Kawasaki Disease

OBJECTIVE

To describe the safety and efficacy of warfarin for patients with Kawasaki disease and giant coronary artery aneurysms (CAAs, ≥8 mm). Giant aneurysms are managed with combined anticoagulation and antiplatelet therapies, heightening risk of bleeding complications.

STUDY DESIGN

We reviewed the time in therapeutic range; percentage of international normalization ratios (INRs) in range (%); bleeding events, clotting events; INRs ≥6; INRs ≥5 and <6; and INRs <1.5.

RESULTS

In 9 patients (5 male), median age 14.4 years (range 7.1-22.8 years), INR testing was prescribed weekly to monthly and was done by home monitor (n = 5) or laboratory (n = 3) or combined (1). Median length of warfarin therapy was 7.2 years (2.3-13.3 years). Goal INR was 2.0-3.0 (n = 6) or 2.5-3.5 (n = 3), based on CAA size and history of CAA thrombosis. All patients were treated with aspirin; 1 was on dual antiplatelet therapy and warfarin. The median time in therapeutic range was 59% (37%-85%), and median percentage of INRs in range was 68% (52%-87%). INR >6 occurred in 3 patients (4 events); INRs ≥5 <6 in 7 patients (12 events); and INR <1.5 in 5 patients (28 events). The incidence of major bleeding events and clinically relevant nonmajor bleeding events were each 4.3 per 100 patient-years (95% CI 0.9-12.6). New asymptomatic coronary thrombosis was detected by imaging in 2 patients.

CONCLUSIONS

Bleeding and clotting complications are common in patients with Kawasaki disease on warfarin and aspirin, with INRs in range only two-thirds of the time. Future studies should evaluate the use of direct oral anticoagulants in children as an alternative to warfarin.

Safety and Efficacy Outcomes of Home and Hospital Warfarin Management Within a Pediatric Anticoagulation Clinic

The complexity of managing children with chronic disease has led to an increase in the use of long-term warfarin therapy. Time in therapeutic range (TTR) is the preferred method for determining efficacy and stability of warfarin management. This study aimed to determine the TTR achievement and incidence of adverse events among pediatric warfarin patients managed by an anticoagulation clinic over 12 months and to compare TTR achievement between patients self-testing (PST) at home and those monitored using routine methods. International normalized ratio (INR) results reported for 2012 for children currently having their warfarin therapy managed by a dedicated pediatric anticoagulation clinic were analyzed. Warfarin-related adverse events were recorded. A total of 164 patients were included. In total, 93 children performed PST and 71 children tested their INR at a hospital or pathology service. TTR achievement for the cohort was 67.1% (95% confidence interval, 64.4-69.7). A total of 69.2% of INR tests conducted at home were within the TTR compared with 64.3% of INR tests conducted at a hospital or pathology service (P=0.07). One major bleeding event occurred and there was 1 thrombotic episode. PST demonstrated noninferior warfarin stability compared with routine methods. Routine outcome evaluation of pediatric anticoagulation management within single institutions is necessary to confirm the success of such programs.

The journey for adolescents and young adults with chronic conditions transitioning to adult care with successful warfarin management

Health transition of youth from a child-centered care model to the adult model has been recognized to be of critical importance due to the increasing numbers of children now surviving chronic conditions. A formalized transition process is required adequately assess the AYA's readiness for transition and to move towards adult care. Indefinite warfarin therapy poses challenges as warfarin is a narrow therapeutic index drug that requires frequent monitoring and attentiveness to warfarin interactions and affects.

OBJECTIVE

The objective of this study was to evaluate transition to adult care for AYAs requiring indefinite warfarin therapy within a structured self-management program.

OUTCOME MEASURES

Results were compared between Phase 1 (enrollment to patient self-management) and Phase 2 (independent warfarin management) 6months following confirmation of transition to adult care. There was no statistical difference between outcome measures except INR testing frequency, and no adverse events.

CONCLUSIONS

This transition process resulted in successful transition as measured by TTR and other clinical end-points from pediatric to adult care. Implementing a formal transition process for young adults with chronic health conditions that considers patient preferences motivates and empowers them over time to develop autonomy with warfarin self-management, results in successful transition and warfarin management.

EMPoWARed: Edmonton pediatric warfarin self-management study

BACKGROUND

Patient self-management (PSM) in adults is safer and more cost effective than conventional management. Warfarin is a narrow therapeutic index drug with individual patient response to changes and frequently a long-term therapy. Children and their families are proposed to be able to effectively manage their child's warfarin therapy. Increased health related quality of life is highly associated with effective therapy in patients with chronic conditions.

OBJECTIVES

The aim of this study is to evaluate the safety and efficacy of PSM over time including HRQOL and variables that may influence PFU success at PSM.

PATIENTS/METHODS

Children and their family units (PFUs) current performing patient self-testing/monitoring for ≥ 3 months were enrolled in this cohort study. PFUs participated in comprehensive education on warfarin testing and management followed by an apprenticeship. Socio-demographic, clinical, and laboratory data were collected to evaluate safety and efficacy and health related quality of life. Outcomes were compared between the first 6 months on PSM (phase 1) and the last 6 months data collected on PSM (phase 2).

RESULTS

Forty-two patients performed PSM for a median of 2.7 years (range: 1.1-6.2 years). Time in therapeutic range was 90% and 92.9% (p=0.30) in phases 1 and 2 respectively. All measures were strongly associated with improved heath related quality of life. PFUs socio-demographic status did not influence success at PSM. All PFUs maintained warfarin knowledge and INR testing competency. Warfarin dosing decision errors median 0 (range: 0-5, p=0.73) and a median 0 (range 0-4, p=0.55) per patient in phases 1 and 2 respectively. There were no adverse hemorrhagic or thrombotic events.

CONCLUSIONS

Empowering PFUs to self-manage warfarin results in increased knowledge and understanding of their health condition, improved commitment to their health care and adherence to medication regimens and is demonstrated to be sustainable over time.