Hereditary Thrombophilia Testing Among Hospitalized Patients: Is It Warranted?

Background

Hereditary thrombophilias (HTs) are a group of inherited disorders that predispose the carrier to venous thromboembolism (VTE). It is estimated that 7% of the population has some form of HT. Although testing for HT has become routine for many hospitalized patients, knowing when to order the tests and how to interpret the results remains challenging. In the United States, there are no clear guidelines regarding testing for HT. We conducted a study to evaluate the utilization of HT testing among hospitalized patients to examine its impact on immediate management decisions and overall cost burden. In addition, we discuss the common reasons for healthcare providers to order these tests and review the data behind these reasons in the literature.

Methodology

A retrospective analysis of 2,402 patients who underwent HT testing between February 1, 2016, and January 31, 2018, was conducted. Eligible patients had at least one HT test ordered during hospitalization. The primary outcome was to determine the incidence of positive actionable tests. A positive actionable test was defined as a positive result that changed the anticoagulation intensity, type, or duration. Patients with a history of previous VTE, ongoing medical conditions requiring life-long anticoagulation, or unprovoked VTE were considered non-actionable.

Results

Among the 2,402 patients, 954 patients met the inclusion criteria with a mean age of 54 years. A total of 397 (41.6%) tests were ordered for acute VTE, while the rest were for non-VTE conditions, such as stroke, pregnancy complications, peripheral artery diseases, and others. Only 89 positive tests were actionable (14% of the positive tests, and 9.3% of the total ordered tests). There was a statistically significant association between increasing age and having both a positive test result (p = 0.006) and an actionable test (p = 0.046). The total cost of ordering these tests was estimated to be $566,585.

Conclusions

HT testing in the inpatient setting did not alter management in many cases and was associated with increased healthcare costs. The decision to order these tests should be individualized based on the clinical scenario.

Current Practice and Clinical Utility of Thrombophilia Testing in Hospitalized Patients with Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Testing for thrombophilic disorders is often performed in patients after cryptogenic ischemic stroke in an attempt to identify a hematologic explanation for the event. However, the role of commonly tested thrombophilias in ischemic stroke is poorly defined. There is limited evidence to quantify how these disorders affect ischemic stroke risk and testing practices are highly variable.

METHODS

Retrospective evaluation of thrombophilia testing practices and clinical outcomes was performed in hospitalized patients with acute ischemic stroke (n = 1898) at a large academic hospital over a two-year period. Variables assessed included testing components, timing of testing, number of abnormal results, and frequency of change in clinical management prompted by abnormal results. A provider survey was also performed to assess perceptions of current testing practices and provider understanding of testing indications.

RESULTS

Thrombophilia testing was performed in 190 (10%) patients admitted for acute ischemic stroke. Of those tested, 137 (72.1%) had at least one abnormal result, but this decreased to 37.4% when elevated factor VIII activity was excluded. An abnormal result prompted initiation of anticoagulation in only 4 patients (2%). The provider survey indicated that all providers (100%) were selecting thrombophilia tests using a pre-existing order set and were interested in additional education on testing indications and interpretation. Comparison to similar studies at other institutions revealed significant variation in testing practices, and a small proportion of patients in which testing prompted a change in management (1-8%).

CONCLUSIONS

Thrombophilia testing is frequently obtained in hospitalized patients with acute ischemic stroke, yet testing only changed management in 2% of patients. Efforts to improve provider education and the stewardship of testing are needed to ensure appropriate evaluation and treatment of patients with acute ischemic stroke.

Systems-based hematology: highlighting successes and next steps

Systems-based hematology is dedicated to improving care delivery for patients with blood disorders. First defined by the American Society of Hematology in 2015, the idea of a systems-based hematologist arose from evolving pressures in the health care system and increasing recognition of opportunities to optimize the quality and cost effectiveness of hematologic care. In this review, we begin with a proposed framework to formalize the discussion of the range of initiatives within systems-based hematology. Classification by 2 criteria, project scope and method of intervention, facilitates comparison between initiatives and supports dialogue for future efforts. Next, we present published examples of successful systems-based initiatives in the field of hematology, including efforts to improve stewardship in the diagnosis and management of complex hematologic disorders (eg, heparin-induced thrombocytopenia and thrombophilias), the development of programs to promote appropriate use of hematologic therapies (eg, blood products, inferior vena cava filters, and anticoagulation), changes in care delivery infrastructure to improve access to hematologic expertise (eg, electronic consultation and disorder-specific care pathways), and others. The range of projects illustrates the broad potential for interventions and highlights different metrics used to quantify improvements in care delivery. We conclude with a discussion about future directions for the field of systems-based hematology, including extension to malignant disorders and the need to define, expand, and support career pathways.

Thrombophilia evaluation in pulmonary embolism

PURPOSE OF REVIEW

Patients with pulmonary embolism commonly undergo thrombophilia evaluation for a variety of reasons including risk stratification for recurrent venous thromboembolism (VTE) and treatment planning. However, the utility of thrombophilia testing in many clinical scenarios remains unclear. This review evaluates current recommendations for thrombophilia testing described in consensus VTE guidelines, recent literature on the clinical application of these recommendations, novel genetic assessments for hereditary thrombophilias, and studies evaluating use of direct oral anticoagulants (DOACs) in VTE patients with thrombophilias.

RECENT FINDINGS

Current VTE guidelines advise limited use of thrombophilia testing, recognizing that testing may be misinterpreted and frequently does not lead to a change in management. Testing and test results are not necessarily benign, are frequently misinterpreted, and can lead to increased anxiety in both patients and clinicians. Recent studies have offered innovative techniques to better align clinical practice with these recommendations as well as expanded genomic assessments to improve the scope and predictive value of thrombophilia testing. There is also emerging literature on the appropriateness of direct oral anticoagulant therapy for VTE patients with hereditary thrombophilias or antiphospholipid syndrome.

SUMMARY

Thrombophilia testing in its current form does not significantly impact clinical management or improve outcomes for most VTE patients. Therefore, it should be employed judiciously and only in patients for whom it is likely to alter clinical management. Novel expanded genomic thrombophilia testing approaches and additional studies evaluating optimal anticoagulant treatment in various thrombophilia subpopulations will make thrombophilia testing more useful for patients moving forward.

Limited impact of clinician education on reducing inappropriate PF4 testing for heparin-induced thrombocytopenia

A high frequency of PF4-ELISA testing in patients suspected to have heparin-induced thrombocytopenia (HIT) despite low 4T scores has been observed in multiple medical centers. Education of clinicians has been suggested to reduce inappropriate testing. We determined trends of PF4-ELISA testing in our institution after the introduction of a HIT education program for clinicians. A HIT Program was developed that included ongoing education, individual feedback, and continuous clinical audit of PF4-ELISA utilization. To assess the impact of education on PF4-ELISA testing trends, we conducted a prospective cohort review of all adult patients who had a PF4-ELISA ordered over a 3 month period (the last quarter of the academic year). 72 PF4-ELISA tests were ordered during the study period. Prospectively calculated 4T scores by investigators revealed 60 low-risk (83.3%), 9 intermediate-risk (12.5%), and 3 high-risk (4.16%). We observed divergent 4T scores with the ordering clinician calculating a higher 4T score compared to the Hematology Quality Improvement (QI) team. The majority of PF4-ELISA testing was ordered by the intensive care units (ICUs) (n = 32, 44.44%). Our study revealed that the frequency of calculation of 4T scores remains poor with the majority inappropriately performed in the ICU setting, with ordering clinicians calculating higher 4T scores than the Hematology QI team. This suggests that clinician education alone is insufficient. Introducing mandatory 4T score calculation prior to PF4-ELISA testing may not be helpful as ordering clinicians can bypass the restriction through inaccurate 4T score calculation.

Analyzing the impact of systems-based hematologist in the healthcare system at an academic medical center

Over the next decade, there is a predicted shortage of nonmalignant hematologist to maintain the workforce in the United States. To address this, the American Society of Hematology described the creation of the healthcare systems-based hematologist (SBH). The role of SBH has the potential to provide high-value, cost-conscious care to the healthcare system. In 2011, an Anticoagulation and Bleeding Management Medical Directorship position for a SBH was created at our healthcare system. We described our 6-year experience as SBH at a 750-bed tertiary academic medical center to improve clinical outcomes while reducing costs. Via four different initiatives, we were able to provide high-value, cost-conscious care as SBH by reducing cost of heparin-induced thrombocytopenia management, optimizing blood product utilization using goal-directed algorithms, reducing inappropriate thrombophilia testing and improving inferior vena cava filter retrieval rates. To ensure continuing success as a SBH, business plans need to include education, enforcement, monitoring, feedback, validation of safety and outcomes and a shared vision among leadership.