Abstract TMP59: Low Value Of Inherited Thrombophilia Testing Among Patients With Stroke Or Transient Ischemic Attack: A Single-institution Study

Abstract

Background/Purpose: Inherited thrombophilia testing in the acute inpatient setting is controversial and expensive, and in many cases does not change clinical management. We sought to determine the value of inpatient inherited thrombophilia testing for patients who presented with an isolated acute ischemic stroke or transient ischemic attack (TIA) without concurrent venous thromboembolism. Methods: We retrospectively analyzed a database comprising patients who were admitted for acute ischemic stroke or TIA in 2019 at Thomas Jefferson University Hospitals in Philadelphia, PA and had inherited thrombophilia testing performed during the hospital admission. Charts were reviewed to determine stroke risk factors, test results, and clinical management. Results: The study included 102 patients (median age 49.0 years, 53.9% female) who presented with acute ischemic stroke or TIA (including branch and central retinal artery occlusions) and underwent inpatient testing for factor V Leiden, prothrombin G20210A variant, hyperhomocysteinemia, PAI-1 elevation, and deficiencies of protein C and S and antithrombin. 406 tests were ordered, among which 14.0% resulted abnormal, and 41.2% of patients had at least one abnormal test. Patients without stroke risk factors were more likely to have an abnormal result (60.0% vs 35.1%, P = .028). However, 40% of abnormal tests were borderline positive antigen or activity assays that likely represented false positives. Considering only definitively positive results, there was no significant difference in the likelihood of a positive test in patients with vs without stroke risk factors (32.0% vs 26.0%, P = .557) or those under vs over age 50 years (30.2% vs 24.5%, P = .519). No patients with an abnormal result had their clinical management changed as a result. Charges for the tests totaled $182,994 USD. Conclusions: Inpatient inherited thrombophilia testing immediately following isolated acute arterial ischemic stroke or TIA was associated with high rates of false positive results and was expensive. Positive results did not change clinical management in a single case.