Heparin-induced thrombocytopenia (HIT): Identification and treatment pathways

Abstract

Heparin-induced thrombocytopenia (HIT) is a major health problem, especially in cardiac surgery theaters, cardiac catheterization labs, and intensive care units. Some patients with HIT develop serious thrombotic complications like limb ischemia and gangrene, while others may not develop such complications and have only mild thrombocytopenia. Current laboratory diagnostic tools incur significant time delays before confirming HIT, therefore upon clinical suspicion, treatment of HIT should start immediately while awaiting laboratory results. This is a review of the types, phases, pathophysiology, clinical presentation and diagnosis of HIT, and its current management strategies.

Expert consensus on the diagnosis and treatment of thrombocytopenia in adult critical care patients in China

“…The anticoagulation treatment target is APTT elongation of 1.5 to 3.0 times the baseline level (≤ 100 s). After dose adjustment, APTT is monitored every 4 h and then every day once the target has been met for at least 2consecutive times [102]. After the condition is stabilized, the patient may be switched to oral anticoagulants once the platelet count is ≥100 × 109 L or has returned to baseline level.…”

<p>Current Perspectives on Diagnostic Assays and Anti-PF4 Antibodies for the Diagnosis of Heparin-Induced Thrombocytopenia</p>

“…24 With advanced techniques of detection and early intervention, the mortality rate can be reduced to <2%. 24 In the following sections, we discuss in detail newer investigations related to HIT diagnosis.…”

Heparin-induced Thrombocytopenia: Pathophysiology, Diagnosis and Management

“…Its typical presentation includes mild thrombocytopenia (rarely below 100.000/mm 3 ) within the first two days of treatment. It is a self-limited direct effect of heparin and normalization of platelet count occurring spontaneously without discontinuation of therapy [10].…”

“…Physicians have to take into consideration that incorrect or missing information of the 4T factors can lead to false scores and, consequently, bad decision making and incorrect therapeutic approach in patients with HIT. Although informative and useful in clinical practice, the 4Ts scoring system has limitations in the intensive care unit (ICU) patients and in the management of patients undergoing cardiac surgery [10].…”

“…In patients who are categorized as having intermediate or high-risk for HIT based on their score (>=4), heparin should be discontinued, and alternative anticoagulant medication has to be started. HIT antibodies have a high affinity for LMWH, and for this reason, LMWH has to be excluded from the available therapeutic options for these patients [10].…”