P1510
INCIDENCE AND OUTCOME HEMODIALYSIS PATIENCE WITH HEPARIN INDUCED THROMBOCYTOPENIA - FOUR YEAR EXPERIENCE ZVEZDARA UNIVERSITY MEDICAL CENTER

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.

Our retrospective study analyzed patients who were tested for evidence of positive anti-heparin antibody in the period from 2015 to 2019 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.

During observation period, total of 54 tests were performed on HIT suspected patients, out of which 21 patients were positive. Out of them, 14 patients were on HD, and other 7 (geriatric, surgery and cardiology departments) received therapy due to peripheral thrombosis, AIM or arrhythmia. 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 50% of patients, pulmonary thromboembolism had 11% of patients. The greatest decrease in Tr was most commonly observed between 10^th and 14^th day (61% of patients) and 39% from 4^th to 10^th day from start of heparin administration. In addition to heparin withdrawal and treatment with alternative nonheparin anticoagulation (fondaparinoux), 5 patients needed plasma treatment. 11 patients on HD were transferred to peritoneal dialysis (PD), and 2 patients recovered renal function. Overall mortality was 52%, while in nephrology patients was below 30%.

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.