A computerized scoring system to improve assessment of heparin‐induced thrombocytopenia risk

Gallo, Tyler; Curry, Steven C.; Padilla-Jones, Angela; Heise, C. William; Ramos, Kenneth S.; Woosley, Raymond L.; Raschke, Robert

doi:10.1111/jth.14359

Cited by 11 publications

(14 citation statements)

References 23 publications

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“…A HIT‐CR score was calculated every time a platelet count resulted in the EHR for inpatients receiving heparin products. The HIT‐CR score is based on the first two components of the 4Ts score including degree of thrombocytopenia and timing of the platelet count fall 10 . For thrombocytopenia, scores of 0, 1 and 2 are assigned to platelet count decreases from baseline of <30%, 30%–49% and ≥50%, respectively, with the baseline defined as the highest count recorded from <24 h before heparin initiation up to the time of the scoring.…”

Section: Methodsmentioning

confidence: 99%

Clinical decision support to reduce unnecessary diagnostic testing for heparin‐induced thrombocytopenia

et al. 2023

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SummaryAppropriate evaluation of heparin‐induced thrombocytopaenia (HIT) is imperative because of the potentially life‐threatening complications. However, overtesting and overdiagnosis of HIT are common. Our goal was to evaluate the impact of clinical decision support (CDS) based on the HIT computerized‐risk (HIT‐CR) score, designed to reduce unnecessary diagnostic testing. This retrospective observational study evaluated CDS that presented a platelet count versus time graph and 4Ts score calculator to clinicians who initiated a HIT immunoassay order in patients with predicted low risk (HIT‐CR score 0–2). The primary outcome was the proportion of immunoassay orders initiated but cancelled after firing of the CDS advisory. Chart reviews were conducted to assess anticoagulation usage, 4Ts scores and the proportion of patients who had HIT. In a 20‐week period, 319 CDS advisories were presented to users who initiated potentially unnecessary HIT diagnostic testing. The diagnostic test order was discontinued in 80 (25%) patients. Heparin products were continued in 139 (44%) patients, and alternative anticoagulation was not given to 264 (83%). The negative predictive value of the advisory was 98.8% (95% CI: 97.2–99.5). HIT‐CR score‐based CDS can reduce unnecessary diagnostic testing for HIT in patients with a low pretest probability of HIT.

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Section: Methodsmentioning

confidence: 99%

Clinical decision support to reduce unnecessary diagnostic testing for heparin‐induced thrombocytopenia

et al. 2023

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“…A maximal HIT‐CR score of 4 indicates that the 4Ts score is also at least 4, a threshold at which diagnostic testing would likely be recommended. Our previous study showed good agreement between HIT‐CR and 4Ts scores (κ = 0·69), and our statistical analysis indicated that the optimal mathematically derived cut‐off for a positive HIT‐CR score was a score of 3· 10 Using a cut‐off of 4 would improve the PPV at the cost of decreasing NPV. Whether this trade‐off would improve the clinical utility of HIT‐CR was uncertain as precise values for PPV and NPV were unknown.…”

Section: Introductionmentioning

confidence: 57%

“…The HIT computerised risk (HIT-CR) score is an automated short version of the 4Ts score that incorporates those elements of the 4Ts score stored as discrete data in most electronic health records. 10 The HIT-CR score assigns 0-2 points based on the degree of thrombocytopenia and 0-2 points based on the timing of onset of thrombocytopenia, for a total score of 0-4 points. A maximal HIT-CR score of 4 indicates that the 4Ts score is also at least 4, a threshold at which diagnostic testing would likely be recommended.…”

Section: Introductionmentioning

confidence: 99%

“…In a previous study, we described such a clinical decision‐support (CDS) tool. The HIT computerised risk (HIT‐CR) score is an automated short version of the 4Ts score that incorporates those elements of the 4Ts score stored as discrete data in most electronic health records 10 . The HIT‐CR score assigns 0–2 points based on the degree of thrombocytopenia and 0–2 points based on the timing of onset of thrombocytopenia, for a total score of 0–4 points.…”

Section: Introductionmentioning

confidence: 99%

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Computerised risk scores to guide recognition and diagnosis in patients with possible heparin‐induced thrombocytopenia

2020

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The heparin-induced thrombocytopenia computerised risk (HIT-CR) score is designed to aid in the diagnosis of HIT. We sought to evaluate its potential clinical utility. In this retrospective cohort study, we collected HIT-CR scores on all inpatients receiving heparin over a 4-month period and performed chart reviews on the subset who independently underwent clinical diagnostic testing for HIT to identify patients with HIT. In all, 34 342 patients received heparin, 1744 had high-risk HIT-CR scores of ≥3 and 220 had the maximal risk score of 4. Only 6% of high-risk and 10% of maximal-risk patients underwent testing for HIT. Conversely, among all 317 patients who underwent independent testing for HIT, 67% had low-risk HIT-CR scores (<3). Among patients independently tested, the positive predictive value (PPV) was 6Á6% [95% confidence interval (CI) 4Á9-8Á8%] and the negative predictive value (NPV) was 99Á5% (95% CI 97Á1-99Á9%) at a HIT-CR score cutoff of 3, and the PPV was 22Á7% (95% CI 12Á7-37Á4%) and NPV was 99Á0% (95% CI 97Á6-99Á6%) at a cutoff of 4. This study suggests clinicians fail to test most high-risk patients and unnecessarily test many low-risk patients for HIT. A reasonable approach to clinical application of HIT-CR scores would be recommending no testing for patients with a score of <3 and recommend testing for patients with a score of 4.

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“… 14 , 15 HIT causes a potentially life-threatening hypercoagulable state with up to 50% of patients developing thromboembolic complications associated with a mortality rate of up to 30%. 12 , 16 , 17 The diagnosis of HIT usually requires a combination of both clinical features, laboratory testing with 4 T score and laboratory evaluation with heparin antibodies (PF4) and serotonin release assays (SRAs) being used. Treatment revolves around cessation of heparin products and use of alternative anticoagulation with parental direct thrombin inhibitors are used effectively to manage these cases until the platelet count rises back in approximately 3–7 days but it can take up to several weeks in refractory cases.…”

Section: Discussionmentioning

confidence: 99%

A case report and literature review on Argatroban refractory Heparin-Induced Thrombocytopenia

Deen¹,

Jha²,

Mustafa³

2022

Journal of Community Hospital Internal Medicine Perspectives

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Heparin-induced thrombocytopenia (HIT) is characterized by low platelets and thrombosis after exposure to Heparin products. It is classically characterized by a rapid and significant drop in platelets and life-threatening thrombosis. Thrombosis can occur up to 50% of the cases if left untreated. It requires immediate discontinuation of all heparin products and switching to a non-heparin anticoagulant to prevent further thrombosis. Here we present a case of a 56-year-old male who presented to the Emergency Department with sudden onset of severe left leg pain. Duplex study showed arterial thrombosis in the common iliac and distal iliac arteries. He received TPA at once and underwent thrombectomy while his platelet continued to drop. He used Low Molecular Weight Heparin (enoxaparin) for bridging after his tonsil surgery a week prior to this hospital admission. His HIT assay was found to be positive and despite the Argatroban therapy his clinical condition continued to worsen while his platelet count continued to drop. Given the refractory nature of the thrombosis and thrombocytopenia; Intravenous immunoglobulin (IVIG) therapy was introduced. The patient showed a great response and his platelet count improved to 150,000/ μ . He was discharged on warfarin with a closer follow-up. Few case reports have described the treatment of such refractory cases using intravenous immunoglobulin (IVIG), resulting in stabilized platelet counts, reduced platelet activation, and reduced thrombotic complications, the exact mechanism of which is unknown. It is thought that IVIG inhibits platelet activation by binding as platelet receptors, which would otherwise bind with heparin–platelet factor 4 complexes and HIT antibodies.

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A computerized scoring system to improve assessment of heparin‐induced thrombocytopenia risk

Cited by 11 publications

References 23 publications

Clinical decision support to reduce unnecessary diagnostic testing for heparin‐induced thrombocytopenia

Clinical decision support to reduce unnecessary diagnostic testing for heparin‐induced thrombocytopenia

Computerised risk scores to guide recognition and diagnosis in patients with possible heparin‐induced thrombocytopenia

A case report and literature review on Argatroban refractory Heparin-Induced Thrombocytopenia

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