Screening frequency, incidence and pattern of heparin-induced thrombocytopenia syndrome at a large tertiary institution.
Increasing awareness and availability of tests for anti-PF4/heparin complex antibodies has raised concerns about indiscriminate testing and inappropriate diagnosis of heparin-induced thrombocytopenia. A retrospective review of HITS testing at a large tertiary centre was performed to determine test patterns and incidence of HITS. Records of anti-PF4 tests over 4 years were reviewed. Positive results were matched against patient medical records and records of heparin utilisation for the diagnosis of HITS. Total of 33,308 patients (9.89 % of admissions) were exposed to at least 1 day of unfractionated heparin (UFH) or low molecular weight heparin (LMWH). Of 346 anti-PF4 antibody assays performed, 52 (15 %) were positive. Seventeen patients (4.9 % of total) were determined to have HITS. Of these, 13 cases (76 %) were patients who were initiated on haemodialysis via central venous catheters. Five patients (29 %) subsequently experienced thrombosis. The rate of HITS in patients given UFH was 0.33 %. HITS occurred in only one patient given LMWH. Of 1337 patients with chronic renal failure initiated on long term haemodialysis, the incidence of HITS was 0.97 %. Despite increased awareness of HITS, testing frequency remains conservative. An overwhelming majority of HITS cases were diagnosed among patients initiated on haemodialysis.
Department of Haematology, Singapore General Hospital, 20 College Road, Singapore, 169856, Singapore. mya.hae.tha@singhealth.com.sg.
Hae Tha
HT
Mya
Department of Haematology, Singapore General Hospital, 20 College Road, Singapore, 169856, Singapore.
Hui Ming
HM
Tay
Department of Renal Medicine, Singapore General Hospital, Singapore, Singapore.
Shien Wen
SW
Gan
Department of Haematology, Singapore General Hospital, 20 College Road, Singapore, 169856, Singapore.
Shilpa
S
Surendran
Department of Pharmacy, Singapore General Hospital, Singapore, Singapore.
Shu Hui
SH
Yeang
Department of Renal Medicine, Singapore General Hospital, Singapore, Singapore.
Cynthia Ciwei
CC
Lim
Department of Renal Medicine, Singapore General Hospital, Singapore, Singapore.
HuiLin
H
Choong
Department of Haematology, Singapore General Hospital, 20 College Road, Singapore, 169856, Singapore.
Lai Heng
LH
Lee
Department of Haematology, Singapore General Hospital, 20 College Road, Singapore, 169856, Singapore.
Heng Joo
HJ
Ng
D000906:Antibodies / Q000032:analysis; D006493:Heparin / Q000009:adverse effects*; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects; D006801:Humans; D015994:Incidence; D008499:Medical Records; D010978:Platelet Factor 4 / Q000276:immunology; D006435:Renal Dialysis / Q000009:adverse effects; D012189:Retrospective Studies; D062606:Tertiary Care Centers; D013921:Thrombocytopenia / Q000139:chemically induced / Q000175:diagnosis / Q000209:etiology*
D000906:Antibodies; D006495:Heparin, Low-Molecular-Weight; D010978:Platelet Factor 4; D006493:Heparin
Heparin; Heparin-induced thrombocytopenia; Incidence