Assessing outcome measures of oral anticoagulation management in children

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.

A regional anticoagulation program improves safety and outcomes for both children and adults

BACKGROUND

Evidence-based anticoagulation programs usually serve a local, adult patient population. Here we report outcomes for a regional combined pediatric-adult program.

AIMS

The aims of this study were: (1) Compare the pre- vs. post-implementation quality of therapy (% time in therapeutic range (%TTR) and compliance). (2) Assess anticoagulant-relevant outcomes (bleeding and thrombotic complications).

METHODS

Data were collected for the years 2014-2019. Rosendaal linear interpolation was used to calculate %TTR. Bleeding complications were categorized using ISTH-SSC standard nomenclature and new thrombotic events were reviewed.

RESULTS

The patients were divided into a long-term warfarin group (N = 308), 80.2% of whom had cardiac-related therapeutic indications (median age 24y), and a second group (N = 114) comprised of short-term and non-warfarin long-term anticoagulation (median age 16y). Median %TTR for those on long-term warfarin was 78.9%. The incidence of major and clinically relevant non-major bleeding events was 1.65 and 2.43 /100 person-years of warfarin use, respectively. Thromboembolism (TE) incidence was 0.78/100 patient-years of warfarin use. Neither bleeding nor thrombosis was associated with %TTR (p = 0.48). Anticoagulant indication was the only variable associated with bleeding risk (p = 0.005). The second group had no on-therapy TE events but 7.9% experienced bleeding. Complete data were available for a randomly sampled pre-program warfarin group (N = 26). Median %TTR improved from 17.5 to 87% pre- vs. post-implementation. Similarly, compliance (defined as ≥ 1 INR/month) improved by 34.3%.

CONCLUSIONS

In conclusion, this program significantly improved and sustained %TTR and compliance. The lack of association between bleeding and thrombosis events and %TTR may be related to the high median %TTR (> 70%) achieved by this approach.

Online KidClot education for patients and families initiating warfarin therapy: The eKITE study

Anticoagulation with Vitamin K antagonists (VKA) has always posed challenges in terms of monitoring requirements. These challenges were further exacerbated in the setting of the COVID-19 pandemic, with limited access to and/or avoidance of laboratory testing. The importance of utilizing point of care (POC) health technology for individualized patient management is salient. The foundation of effective home INR monitoring is establishing patient knowledge about their therapy and INR testing proficiency. The eKITE series was developed to support patients in establishing foundational knowledge required for VKA (warfarin) management and INR monitoring. The primary objectives were to evaluate eKITE, a patient-oriented innovative online education program for warfarin therapy, participant learning stress, and patient preference for online learning. This multi-center prospective study provided patients access to warfarin online education. Participants were required to complete written quizzes assessing warfarin knowledge of key concepts proficiency and identifying knowledge deficits. Patient preference, evaluating calm (lack of anxiety) while learning, and an INR on a home meter was completed. Participants performed INR tests at home and reported INRs by telephone. The analysis included 144 children and caregivers enrolled at five US and CDN sites. Most indications for anticoagulation were cardiac (congenital or acquired heart disease) with varied INR target ranges. Mean knowledge scores for warfarin and INR self-testing modules were 97%, with low anxiety with TTR of 84%. Patient preferred online learning. eKITE is an effective teaching modality for warfarin/home INR monitoring with safe INR testing and warfarin management that is appropriate for pediatrics and adults alike. PROLOGUE: The whir in the hallways is deafening. Lights bright, alarms are ringing in a chorus of unsynchronized beeps and screeches. It has been more than a week since I have slept. Snuggled beside me is my precious child, whining and equally irritated with the asynchronous symphony, further compounded by anxiety, procedures, and pain. The sun has broken. The staff smiles are welcoming and incessant, as one after one, they approach hurried, urgent, assiduous, their need to coach me for our upcoming departure to the warmth of home. Each provides essential information that I will require to keep my child, my treasure, safe and healthy. Yet, my eyes are heavy, blurred, and my brain foggy, trapped in a dark heavy cloud. How am I to follow? Comprehend? and retain anything? As they instruct, my precious child yearns for loving arms, compassion and love, whining, crying in disquiet. Overwhelmed does not adequately describe my ineffable exhaustion. Amidst this, how am I to learn about warfarin? Such a challenging medication, with so much to know. Concentrate, I tell myself, focus; now is my only opportunity to learn. I must be alert. It seems to be nonsensical.

A systematic review of adherence to anticoagulation regimens in pediatric patients

Thromboembolic disease rates are increasing in pediatric patients. Anticoagulation is prescribed for treatment and prevention of thromboembolic disease. While nonadherence to anticoagulation regimens predicts poor health outcomes in adults, data in anticoagulated pediatric patients are limited. We systematically reviewed the rates, outcomes, and predictors of anticoagulation nonadherence in the pediatric population. Out of a total of 3581 unique articles identified for review, 17 studies met inclusion criteria. These studies primarily evaluated patients with cardiac disease treated with vitamin K antagonists. Overall nonadherence rates varied from 3% to 42%, based upon population, definition of adherence, and measurement strategy. Patient age, goal international normalized ratio (INR), and number of concurrent potentially interacting medications correlated with nonadherence. Data examining the relationship between nonadherence and health outcomes were included in only two studies. Limitations of current literature, as well as critical knowledge gaps that require future study, are discussed.

Increased Risk for Thromboembolism After Fontan Surgery: Considerations for Thromboprophylaxis

The Fontan circulation introduces an increased risk of thromboembolism which is associated with substantial mortality and morbidity. Adverse outcomes of thromboembolic complications post-Fontan surgery vary in both nature and severity, ranging from local tissue infarction and pulmonary embolism to Fontan failure and ischemic stroke. Furthermore, recent studies have identified that subclinical stroke is common yet underdiagnosed in Fontan patients. Fontan patients are commonly treated with antiplatelet agents and/or anticoagulants as primary thromboprophylaxis. Optimal thromboprophylaxis management in the Fontan population is still unclear, and clinical consensus remains elusive despite the growing literature on the subject. This perspective will describe the nature of thromboembolism post-Fontan surgery and provide evidence for the use of both current and emerging thromboprophylaxis options for children and adults living with Fontan circulation.

Drive-through Anticoagulation Clinic During The COVID-19 Pandemic

An innovative approach to anticoagulation management during the COVID-19 pandemic was used at our center that allowed patients to stay in their vehicle while our anticoagulation advanced practice registered nurse obtained blood for point-of-care international normalized ratio (INR) testing while education and counseling were completed. A significant improvement in the median percentage of INR within the therapeutic range was observed among the patients who used the drive-through clinic. A small group of patients improved compliance to anticoagulation monitoring. Clinical care models, such as this clinic approach may improve patient compliance and adherence to anticoagulation beyond the pandemic needs.

Long-term outcomes of warfarin versus aspirin after Fontan surgery

OBJECTIVES

Because of the nature of the Fontan physiology, patients are at an increased risk of thromboembolic complications. As such, warfarin or aspirin is generally prescribed lifelong for thromboprophylaxis. This study aimed to compare long-term rates of cerebrovascular injury, thrombosis, bleeding, bone mineral density, and quality of life in people living with Fontan circulation receiving warfarin compared with aspirin.

METHODS

This was a multicenter study of a selected cohort from the Australia and New Zealand Fontan population. Participants underwent cerebral magnetic resonance imaging to detect the presence of cerebrovascular injury (n = 84) and dual-energy X-ray absorptiometry to assess bone mineral density (n = 120). Bleeding (n = 100) and quality of life (n = 90) were assessed using validated questionnaires: Warfarin and Aspirin Bleeding assessment tool and Pediatric Quality of Life Inventory, respectively.

RESULTS

Stroke was detected in 33 participants (39%), with only 7 (6%) being clinically symptomatic. There was no association between stroke and Fontan type or thromboprophylaxis type. Microhemorrhage and white matter injury were detected in most participants (96% and 86%, respectively), regardless of thromboprophylaxis type. Bleeding rates were high in both groups; however, bleeding was more frequent in the warfarin group. Bone mineral density was reduced in our cohort compared with the general population; however, this was further attenuated in the warfarin group. Quality of life was similar between the warfarin and aspirin groups. Home international normalized ratio monitoring was associated with better quality of life scores in the warfarin group.

CONCLUSIONS

Cerebrovascular injury is a frequent occurrence in the Australia and New Zealand Fontan population regardless of thromboprophylaxis type. No benefit of long-term warfarin prophylaxis could be demonstrated over aspirin; however, consideration must be given to important clinical features such as cardiac function and lung function. Furthermore, the association of reduced bone health in children receiving warfarin warrants further mechanistic studies.

Participant-reported Warfarin Adherence in Community-based Pediatric Patients

Warfarin is the most commonly prescribed anticoagulant for children in the outpatient setting in Australia. Pediatric patients likely have different challenges to warfarin adherence compared with their adult counterparts; however, little is known about warfarin adherence among this population. This study aimed to understand warfarin adherence among community-based pediatric patients by using an online survey design. The survey instrument incorporated parent or patient self-reported warfarin doses missed in the preceding month, a validated warfarin adherence assessment tool, the 13-item Self-Efficacy for Appropriate Medication use Scale (SEAMS-13), and an open-ended question asking about the challenges of warfarin adherence. The indication of warfarin administration and patient's time in therapeutic range were obtained from medical records. The study recruited outpatients managed by a tertiary pediatric hospital who had previously consented to participate in warfarin research. In total, 53 families were contacted with 43 responses (81% response rate) and 41 completed surveys. The median age of the children from participating families was 10.6 years (range, 4.1 to 18.9 y). The majority of these children (n=42) used warfarin prophylactically and only 1 child used it to treat deep venous thrombosis. The time in therapeutic range achievement of this cohort was 64.4% (95% confidence interval, 58.7-70.2). The mean SEAMS-13 score was 33.5 (95% confidence interval, 31.75-35.37) and the total missed doses was 2.5%. Participants also identified barriers and enablers of warfarin adherence. This study was the first of its kind and thus it provides baseline data for future research. The warfarin adherence of this cohort was likely optimized because of frequent clinical contact and access to self-testing. Future studies are required to examine the different approaches aiming to improve the anticoagulant adherence after the emergence of direct oral anticoagulants with a wider therapeutic index and minimal monitoring that could contribute to less clinical contact.

Characteristics and quality of oral anticoagulation treatment in pediatric patients in the Netherlands based on the CAPS cohort

Essentials The knowledge of quality and safety of acenocoumarol and phenprocoumon use in children is limited. We used data from a multicenter retrospective follow-up study in children in the Netherlands. The quality of anticoagulation control in the first month of use was low, but improved thereafter. No thromboembolic events occurred, however bleeding events occurred in 1-3 out of 10 patients.

SUMMARY

Background The use of vitamin-K antagonists in pediatric patients is rare and information on the quality and safety of treatment with acenocoumarol and phenprocoumon is limited. Objectives To assess the quality, safety and effectiveness during the first year of acenocoumarol and phenprocoumon treatment in pediatric patients in the Netherlands. Methods The Children Anticoagulation and Pharmacogenetics Study (CAPS) was designed as a multicenter retrospective follow-up study. Patients who used acenocoumarol or phenprocoumon at an age of ≤ 18 years, were selected from four pediatric hospitals and one anticoagulation clinic in the Netherlands. The quality of treatment was assessed by calculating the percentage of time in therapeutic INR range (TTR) for the first month and for every 3 months of use during the first year of treatment. Effectiveness and safety were assessed by the number of thromboembolic and bleeding events. Results In total, 213 patients participated, of whom 187 (155 acenocoumarol; 32 phenprocoumon) were included in this analysis. The mean TTR was 47.0% and 51.4% in the first month of use for acenocoumarol and phenprocoumon, respectively. After the first 3 months the mean TTR for both VKAs was above 64%. In 14.6% (acenocoumarol) and 31.3% (phenprocoumon) of the patients a bleeding event occurred during the first year of treatment; no thromboembolic events were reported. Conclusions The quality of anticoagulation treatment was low during the first month of use and leaves room for improvement. After the first month it increased to an acceptable level. However, bleeding events occurred frequently during the first year.

Self-testing and self-management of oral anticoagulation therapy in children

Children and adolescents on oral anticoagulation therapy (OAT) present special challenges in terms of rapid fluctuations in International Normalised Ratio (INR) values, interruption in daily life due to frequent hospital/doctor visits, and difficulties and pain in the performance of venepuncture. Optimised management of OAT improves the quality of treatment, potentially accomplished by new methods such as patient self-testing (PST) and patient self-management (PSM). A review was performed, identifying 11 trials with children and adolescents. All studies had different methodological problems, predominantly by being non-randomised trials. A total of 284 patients were included with a mean follow-up of 22 months, finding a time within therapeutic INR target range between 63% and 84%. The coagulometers used for estimating the INR values were found to have sufficient precision and accuracy for clinical use, but external quality control is probably advisable. It can be concluded that PST and PSM are at least as good treatment options as conventional management in highly selected children. Larger studies, preferably randomised, controlled trials using clinical endpoints, are obviously needed in order to elucidate whether these new regimens of treatment are superior to conventional management of oral anticoagulation therapy.

International normalized ratio self-testing and self-management: improving patient outcomes

Long term oral anti-coagulation with vitamin K antagonists is a risk factor of hemorrhagic or thromebomlic complications. Periodic laboratory testing of international normalized ratio (INR) and a subsequent dose adjustment are therefore mandatory. The use of home testing devices to measure INR has been suggested as a potential way to improve the comfort and compliance of the patients and their families, the frequency of monitoring and, finally, the management and safety of long-term oral anticoagulation. In pediatric patients, increased doses to obtain and maintain the therapeutic target INR, more frequent adjustments and INR testing, multiple medication, inconstant nutritional intake, difficult venepunctures, and the need to go to the laboratory for testing (interruption of school and parents’ work attendance) highlight those difficulties. After reviewing the most relevant published studies of self-testing and self-management of INR for adult patients and children on oral anticoagulation, it seems that these are valuable and effective strategies of INR control. Despite an unclear relationship between INR control and clinical effects, these self-strategies provide a better control of the anticoagulant effect, improve patients and their family quality of life, and are an appealing solution in term of cost-effectiveness. Structured education and knowledge evaluation by trained health care professionals is required for children, to be able to adjust their dose treatment safely and accurately. However, further data are necessary in order to best define those patients who might better benefit from this multidisciplinary approach.

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.

Atrial fibrillation and quality of life related to disease and treatment: focus on anticoagulation

ABSTRACT: 

Anticoagulation therapy is essential to reduce the risk of stroke in patients with atrial fibrillation. Traditionally, clinical trials have focused only on determining the efficacy and safety of anticoagulation but not on quality of life. In the last few years there has been a growing interest in determining the quality of life of patients treated with oral anticoagulation. In fact, specific tools that can evaluate quality of life related to atrial fibrillation and anticoagulation have been developed. Vitamin K antagonists have been shown to be effective in the prevention of thromboembolic complications. However, the use of vitamin K antagonists implies changes in behavior and lifestyle modifications that may have a negative impact on the quality of life. It has been suggested that self-monitoring of international normalized ratio could improve this impact. On the other hand, as new oral anticoagulants overcome these limitations, they may improve quality of life related with anticoagulant therapy. Unfortunately, although encouraging, the clinical experience with them is still quite limited.

[Evaluation of an educational program for oral anticoagulation in children with the INR home-monitoring CoaguChek XS(®)]

OBJECTIVE

To assesses the results of our education program relative to anticoagulation therapy and self-monitoring of INR.

MATERIALS AND METHODS

All children treated with oral anticoagulation therapy and followed using INR self-monitoring in Tours and Nantes, France, were included. A questionnaire on the treatment and its management was sent to the patients and their family. We analyzed the quality of anticoagulation using the proportion of INR within the target range.

RESULTS

Thirty-three children were included, with a mean age of 10.9years. Thirty-one questionnaires could be analyzed. Insufficient knowledge on the treatment objective and risks, the INR target range, and the interpretation of the INR was observed. We found 65.8% of INRs within the target range. The proportion of INRs within the target range was better with the INR self-testing than with the laboratory test (69.7% vs. 49.1%, P=0.003). There was no major complication observed during the study period. A moderate correlation (K=0.57) was noted between the INRs measured with the point-of-care monitor and the laboratory test on the same day.

CONCLUSION

However, home-monitoring of oral anticoagulation therapy increases the quality of anticoagulation. Both education and the training program need improvement in order to provide patients and their families with better knowledge on anticoagulation therapy.

Budd-Chiari syndrome in children and outcome after liver transplant

BCS is a rare form of portal hypertension in children. The authors describe two cases of BCS with differing presentations. Case 1: Previously healthy four-yr-old girl. BCS was diagnosed during the course of an episode of acute gastroenteritis with dehydration. Despite conservative therapy for two months, the condition was progressive resulting in liver failure leading ultimately to LT. Molecular studies showed that she was heterozygous for the Factor (F) V Leiden. At follow-up, six yr post-LT (two yr without anticoagulation therapy), no thromboembolic/bleeding events were apparent. Case 2: Three-yr-old boy with IgA deficiency and liver disease. Following a febrile episode, he developed fulminant liver failure requiring urgent LT from a living donor (father). Molecular studies disclosed MTHFR C677T homozygosity and FV Leiden heterozygosity. The father was homozygous for the MTHFR mutation. Three months post-LT, persistent graft dysfunction was associated with stenosis of the IVC, which improved upon stent placement. He received dipyridamole and aspirin for five yr, after which time dipyridamole was discontinued. Evidence is sparse on the follow-up of BCS cases with liver transplant. The authors discuss their findings, particularly the need for long-term anticoagulation.

Management of warfarin in children with heart disease

Warfarin is an important therapy for children with heart disease. We assessed the impact of a computerized warfarin-dosing software program on measured INR values using a historical case-control design. Children (infant to 20 years of age) with cardiac disease managed with warfarin between September 1, 2006, and August 31, 2009 were included in the analysis. Warfarin therapy was tailored to specific underlying conditions based on consensus guidelines. Before the use of dosing software, medication adjustments were made by physicians using published guidelines. After software implementation, dosing adjustments were based on the software algorithm. There were 86 subjects in this analysis, and the most common indication for warfarin was prosthetic valve. Overall, the incidence of adverse bleeding events was 1.3% per patient-year. An analysis of patient-related factors associated with a low percentage of time within goal range demonstrated that both female sex (P = 0.048) and nonwhite race (P = 0.037) were significantly associated with less time in the target range. Use of the software program was associated with an increase in the percentage of time during which the INR was within the target range from 41.4 to 53.1% (P < 0.001). Incorporation of a computerized software program to assist dosing can improve the percentage of time that children with cardiac disease requiring warfarin remain within the target therapeutic range. Strategies to improve management and decrease sex and racial disparities in this population are needed.

Safety and efficacy of warfarin in paediatric patients with prosthetic cardiac valves: a retrospective audit

INTRODUCTION

Guidelines for warfarin management in children are essentially extrapolated from adult evidence. This study aimed to address that lack of paediatric-specific data regarding warfarin safety and efficacy for this population.

MATERIALS AND METHODS

A retrospective clinical audit was conducted within a cardiac referral centre incorporating a paediatric anticoagulation service. Children (0-16 years) with a prosthetic cardiac valve were included. Warfarin related outcomes were collected between January 1st 2004 and December 31st 2009. Analysis included the percentage of INR tests within, above, or below the target therapeutic range (TTR). Adverse event data was collected regarding major bleeding and thrombotic events.

RESULTS

75 patient years of warfarin therapy were recorded. 44.0% of INR tests were within the TTR. INR tests not within the TTR were twice as likely to be sub-therapeutic. Children with aortic prosthetic valves achieved their TTR less frequently than children with prosthetic mitral or tricuspid valves. There were no thrombotic events and 3 major bleeding events.

CONCLUSIONS

Although less than 50% of INR results were within the TTR, oral anticoagulant management resulted in acceptable safety and efficacy outcomes for this cohort. Further studies are needed to confirm optimal paediatric-specific warfarin management strategies for children with prosthetic heart valves.