A retrospective analysis of the frequency of heparin-induced thrombocytopenia in the intensive care unit at a tertiary care center in Riyadh, Saudi Arabia.

Am J Blood Res 2023;13(6):198-206 www.AJBlood.us /ISSN:2160-1992/AJBR0152876 Original Article A retrospective analysis of the frequency of heparin-induced thrombocytopenia in the intensive care unit at a tertiary care center in Riyadh, Saudi Arabia Ali H Mushtaq1,2, Abdulrahman W Rasheed2, Mouhamad G Jamil3, Khalid Maghrabi3, Osama Khoja3, Muhammad R Sajid1, Hani Tamim1, Mohammad Hijazi3, Tarek Owaidah1,3 Al Faisal University, Riyadh, Saudi Arabia; 2Department of Internal Medicine, Cleveland Clinic Foundation, Cleveland, Ohio, The United States of America; 3Department of Hematology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia 1 Received August 11, 2023; Accepted December 21, 2023; Epub December 25, 2023; Published December 30, 2023 Abstract: Background: Heparin-induced thrombocytopenia (HIT) is an extremely serious and potentially fatal condition that can develop in patients taking heparin-based medications, such as unfractionated heparin (UFH) or lowmolecular-weight heparin (LMWH). The incidence and risk factors for HIT in critically ill patients, however, are not well defined. Methods: We retrospectively collected data on HIT test results, route of heparin administration, age, sex, heparin type (UFH or LMWH), and date of illness from patients admitted to the intensive care unit (ICU) and regular nursing floor (non-ICU) at our hospital between January 2011 and December 2014. We screened patients for HIT using the 4T score and confirmed the diagnosis through laboratory testing (direct enzyme immunoassay immunoglobulin G [IgG] or a platelet-activating antibody). Results: We screened a total of 946 patients, 56 (5.9%) of whom were positive for HIT. Among 776 patients receiving UFH and 180 receiving LMWH, 2.8 and 6.6% developed HIT, respectively (P = 0.051). We then classified our patients into two groups: ICU, and non-ICU. In the non-ICU group (n = 317), 4 (2.7%) patients receiving LMWH and 25 (5.1%) receiving UFH were positive for HIT (P = 0.221). In the ICU group (n = 639), 1 (3.1%) patient receiving LMWH and 26 (9.1%) receiving UFH were positive for HIT (P = 0.249). The ICU group, therefore, had a higher cumulative incidence rate of HIT than the non-ICU group (8.5 vs. 4.5%). Conclusion: HIT was more common in ICU patients than non-ICU patients and in more patients receiving UFH than LMWH, although the differences were not statistically significant. Early diagnosis and appropriate treatment are essential to prevent adverse outcomes in patients with HIT. Keywords: Heparin-induced thrombocytopenia, heparin, intensive care unit, critical illness, low molecular weight heparin Introduction Heparin and its derivatives are widely used as anticoagulants for the prevention and treatment of various medical conditions. Among the most common applications of heparin are prophylaxis and treatment of deep venous thrombosis [1-4]. While hemorrhagic episodes are the prevailing adverse effects associated with heparin, some individuals are prone to developing thrombotic complications secondary to heparin-induced thrombocytopenia (HIT) [1]. HIT is a severe and potentially fatal immunologically mediated adverse drug reaction to heparin- based medications, unfractionated heparin (UFH), and low-molecular-weight heparin (LMWH). Medical professionals need to be more aware of the presence of HIT to ensure its detection, treatment, and prevention of its serious repercussions, especially considering relevant literature reports. HIT-related mortality is estimated to be 20-30% [5]. The morbidity and mortality of HIT are affected by the misdiagnosis of the condition, along with the misunderstanding of the course of the illness [1]. The incidence of HIT is significantly reduced in patients receiving LMWH (0.1-0.5%) than in https://doi.org/10.62347/GPME5540 Heparin-induced thrombocytopenia in intensive care unit There is a paucity of studies analyzing the frequency of HIT in Saudi Arabia, particularly in critically ill ICU patients. The present study, therefore, aimed to retrospectively evaluate and compare the risk of developing HIT in association with the use of UFH and LMWH, specifically in patients admitted to medical wards and ICUs. The present study was a retrospective analysis of data from a large tertiary care center in Riyadh, Saudi Arabia. Figure 1. Depicts the annual development of HIT from January 2011 to December 2014. those receiving UFH (0.5-1%) [2, 4-8]. Numerous patient and drug related factors influence the likelihood of someone developing HIT, although the factors most closely linked to an increased likelihood of developing HIT include the length of heparin therapy, type and dose of heparin used, underlying indications for heparin treatment, and patient sex [8-10]. HIT should be suspected in patients who have new complaints of new-onset thrombocytopenia, development of venous or arterial thromboses, or necrotic skin lesions at heparin injection sites after receiving prolonged LMWH treatment or starting heparin within the preceding 5-10 days [11, 12]. Thrombocytopenia affects 95% of all patients with HIT and is caused by platelet removal and consumption [13, 14]. HIT is a highly prothrombotic state, and as a result, 25-64% of individuals with HIT develop arterial or venous thromboses [2, 3, 5]. Thrombotic disorders can affect any part of the vasculature; however, venous thrombosis is most commonly observed and can cause gangrene, adrenal hemorrhage, skin necrosis, and/or pulmonary embolism [12, 15-17]. Diagnosing HIT can be challenging, especially in critically ill patients in the intensive care unit (ICU), where thrombocytopenia and thromboses are common for a variety of reasons [1822]. The overall incidence of HIT reported in ICU patients is estimated to be between 0.4-3% [23, 24]. In a German study of 12,528 medicalsurgical ICU patients, Selleng et al. [25] reported an incidence of HIT of 0.21%. Another large, randomized trial of 3,764 patients found the overall incidence of HIT to be 0.4% [6]. 199 Materials and methods We conducted a retrospective study of all patients who received heparin (UFH or LMWH) and were diagnosed with HIT between January 2011 and December 2014 at King Faisal Specialist Hospital and Research Center (KFSHRC), Riyadh, Saudi Arabia (Figure 1). The data we collected included the HIT test results, enzyme-linked immunosorbent assay (ELISA) confirmation test results, age, sex, ICU status, type of heparin (UFH or LMWH), and route of administration (Table 1). We obtained a total of 1190 patient records to include in our study based on the following inclusive and exclusive criteria. Inclusive criteria: Patients admitted to our hospital between January 2011 and December 2014 who received preventative or therapeutic doses of LMWH or UFH and underwent a HIT test due to clinical suspicion. Thrombocytopenia was defined as a >50% drop in platelet count from baseline or ≥2 consecutive platelet counts of <150,000 per mm3. Exclusive (...truncated)