Compliance of antithrombotic management at a tertiary paediatric hospital with international guidelines: A 100-Day audit

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.

Variation in Anticoagulation Practices in the Congenital Cardiac Catheterization Lab: Results of a Multinational PICES Survey

The complex nature of congenital heart disease (CHD) has hindered the establishment of management standards for peri-catheterization anticoagulation. We sought to describe anticoagulation practice variability among providers performing cardiac catheterization in children and adults with CHD. A web-based survey ( http://www.surveymonkey.com ) was distributed to pediatric and congenital interventional cardiologists. Respondents were queried on their training, practice setting, years in practice, and case volume. Clinical questions focused on general anticoagulation strategies and on five common clinical scenarios: two diagnostic (biventricular circulation, single ventricle physiology) and three interventional cardiac catheterizations (atrial septal defect closure, pulmonary artery stenting in Fontan circulation, stent placement for coarctation of aorta). Seventy-seven pediatric and congenital interventional cardiologists responded to the survey (81% in the United States). Twenty-six (36%) worked in a public medical institution; 57% worked in a free-standing children's hospital. Twenty-six percent had been in practice for < 5 years and 32% for > 15 years; 75% completed additional training in interventional congenital cardiology. The median number of cases performed was 200/year (IQR 110); median number of interventional cases was 100/year (IQR 100). Responses to general queries and specific clinical scenarios suggested significant variation in anticoagulation practices, including monitoring of anticoagulation during catheterization, protamine use, and outpatient anticoagulation after catheterization. Practices not only varied between providers but also between different clinical scenarios. Practice patterns did not correlate with provider experience or case volume. Management of anticoagulation in the congenital cardiac catheterization lab varies from operator to operator. Our study may provide some initial insight and context for discussion regarding anticoagulation in a field of increasingly heterogeneous interventional techniques and patient substrates. Future studies would be helpful to better define "best practices" for peri-procedural thromboprophylaxis in patients with congenital heart disease.

Monitoring the harm associated with use of anticoagulants in pediatric populations through trigger-based automated adverse-event detection

BACKGROUND

The safety profile of anticoagulants, which are being used with increasing frequency in pediatric populations, is not well studied. Automatic triggers built into electronic health record systems (EHR) have been shown to be an effective way to monitor for and identify medication errors. Anticoagulant-associated adverse events were examined through the use of an anticoagulant trigger panel.

METHODS

In a retrospective, five-year (September 2007-September 2012) observational study, four automated triggers were used to detect anticoagulant-related adverse events: activated partial thromboplastin time (aPTT) > 100 seconds in patients on an unfractionated heparin (UFH) infusion, International Normalized Ratio (INR) > 4, anti-factor Xa (anti-FXa) >1.5U/mL for patients on enoxaparin, and the documented use of protamine.

RESULTS

For the 1,664 triggers evaluated, 12 were associated with the aPTT trigger, only 1 of which was preventable. Receiver operator characteristic curve analysis indicated that increasing the aPTT trigger > 140 seconds would optimize sensitivity and specificity. The INR trigger identified four outpatients with adverse events. No adverse events were associated with the anti-FXa trigger. The protamine trigger identified 12 adverse events and was associated with more severe events. Minimal overlap was found with protamine and aPTT triggers.

CONCLUSION

Laboratory- and medication-based triggers can be effective monitoring tools for anticoagulants. For patients receiving a UFH infusion, an aPTT cutoff value of > 140 seconds is more precise. We also found that protamine use as a trigger adds value to a trigger-based anticoagulant monitoring system. Continued improvement in the logic algorithms associated with the EHR-based trigger tool will allow expanded use of this tool in a clinical manner.

Adherence to Anticoagulant Therapy in Pediatric Patients Hospitalized With Pulmonary Embolism or Deep Vein Thrombosis

Objectives:

The American College of Chest Physicians recommends anticoagulant therapy for at least 3 months in children hospitalized for venous thromboembolism. The objectives of the study were to evaluate the medication utilization patterns and predictors of adherence to anticoagulant therapy in pediatric population.

Methods:

Texas Medicaid medical and prescription claims from September 1, 2007 to December 12, 2012 were extracted for children (<18 years) hospitalized for pulmonary embolism (PE) or deep vein thrombosis (DVT). The index date was defined as the date of the first prescription of an anticoagulant given within 14 days of discharge. Proportion of days covered (≥80% vs <80%) was used to assess adherence to anticoagulants while controlling for demographics, cause of hospitalization, history of nonsteroidal anti-inflammatory drug use, anticoagulant use, malignancy, drug type, and Charlson comorbidity index (CCI).

Key Findings:

The patients (n = 60) had a mean (± standard deviation [SD]) age of 14.2 (±4.8) years, were primarily female (56.7%), African American (55.0%), enoxaparin users (58.3%), and had a mean (±SD) CCI of 18.3 (±37.7). The mean (±SD) adherence rates for warfarin and enoxaparin were 85.5% (±22.7%) and 78.7% (±27.8%), respectively. Overall, 66.7% were adherent (≥80%) to anticoagulant therapy. Logistic regression showed that increasing age was significantly associated with adherence to anticoagulant therapy, after controlling for other covariates (odds ratio = 1.5, 95% confidence interval = 1.13-1.85).

Conclusion:

Nearly one-third of the pediatric patients on anticoagulant therapy after discharge from PE or DVT were still nonadherent. Further research is needed to highlight the factors responsible for nonadherence in pediatric patients.

Beta (β)-antithrombin activity in children and adults: implications for heparin therapy in infants and children

BACKGROUND

Antithrombin, a hemostatic protein and naturally occurring anticoagulant, is a major thrombin inhibitor. The capacity of antithrombin to inhibit thrombin is known to increase a 1000-fold whilst in the presence of unfractionated heparin. β-antithrombin is an isoform of antithrombin with a high affinity for unfractionated heparin. This study aimed to determine the differences in the anticoagulant activity of the β-antithrombin isoform in children compared with adults.

METHODS

Plasma samples were obtained from 105 healthy individuals from the following age groups: neonates (day 1 and day 3), 28 days to 1 year, 1-5 years, 6-10 years, 11-16 years and adults. The method utilized to measure the activity of β-antithrombin in plasma is a modified version of the total antithrombin assay routinely used in diagnostic laboratories. The modified version of this assay allows for the specific quantification of the β-antithrombin glycoform anticoagulant activity alone, as the β-antithrombin molecule is activated under a high salt concentration, which in turn does not allow activation of other antithrombin isoforms.

CONCLUSIONS

This study demonstrated that there are no age-specific differences in the activity of β-antithrombin. However, considering that the total AT activity is significantly reduced in neonates, our results suggest that in this population β-antithrombin activity is a major contributor to the overall activity of AT.