Heparin induced thrombocytopenia and hemodialysis-single centre experince

ABSTRACT

BACKGROUND AND AIMS: Heparin-induced thrombocytopenia (HIT) is a potentially fatal adverse reaction after administration of unfractionated or fractionated heparin, which underlies the generation of antibodies to the heparin complex and platelet factor 4 (PF4). It occurs in 5% of patients treated with unfractionated heparin and 0.5-1.5% fractionated heparin. The aim of the study is to determine the incidence and outcome of hemodialysis patients with HIT over 4-years period. METHOD: This retrospective study analyzed patients who were tested for evidence of positive anti-heparin antibody in the period from 2015 to 2020 in Zvezdara University Medical Center. The diagnosis was confirmed by the 4T clinical scoring system, a positive antiheparin-PF4 ELISA test and a positive platelet aggregation test with heparin. RESULTS: During observation period, total of 64 tests were performed, out of which 23 patients were positive. Out of them, 14 patients were on HD, 7 patients (geriatric, surgery and cardiology departments) received therapy due to peripheral thrombosis, AIM or arrhythmia and 2 patients during 2020 due to SARS-CoV-2 bilateral pneumonia. All patients treated at nephrology, started hemodialysis (HD) with unfractionated heparin, while others were treated with LMWH. 4T scoring showed that 64% of patients had a moderate risk of developing HIT, while high risk was assessed in 36% of patients. Thrombotic complications in the form of deep venous thrombosis had 53% of patients and pulmonary thromboembolism had 17,5 % of patients. The greatest decrease in Tr was the most commonly observed between 10th and 14th day (61% of patients) and 39% from 4th to 10th day from start of heparin administration. In addition to heparin withdrawal and treatment with alternative nonheparin anticoagulation (fondaparinoux), 7 patients needed plasma treatment. 11 patients on HD were transferred to peritoneal dialysis (PD), and 3 patients recovered renal function. Overall mortality was 52%, and it was below 30% in hemodialysis patients. CONCLUSION: HIT should be considered in patients at risk. It is necessary to abolish heparin treatment and use alternative method (PD) or alternative anticoagulation. Hemodialysis patients have better prognosis than other comparable patients.