Over-testing for heparin induced thrombocytopenia in hospitalized patients

Research output: Contribution to journalArticle

Abstract

Heparin induced thrombocytopenia (HIT) is a pro-thrombotic and potentially fatal complication of heparin therapy. Its diagnosis rests on high clinical probability and the laboratory demonstration of anti-PF4/heparin antibodies. The high prevalence of thrombocytopenia in hospitalized patients and the high sensitivity but low specificity of immunoassays for HIT antibodies can lead to over-testing and over-diagnosis. We conducted a study to review HIT screening practices in a tertiary care setting. We reviewed 63 consecutive patients undergoing testing for anti-PF4/heparin antibodies over 3 months. Pre-test probability for HIT was calculated using the 4T score. Sixty three patients underwent testing for anti-PF4/heparin antibodies. Twenty one had been admitted for cardiovascular surgery, 5 for other surgery and 35 for non-surgical indications. Twenty nine patients (46 %) had low pre- test probability, twenty three (36.5 %) had intermediate probability, and eleven (17.4 %) had high pre-test probability of having HIT. Anti-PF4/heparin ELISA was positive in 8 of 63 patients. SRA was ordered for 16 patients and was positive in 5. Only five patients were diagnosed and treated for HIT. Over-testing for HIT is highly prevalent in a tertiary care setting. This increases cost and exposes patients to expensive anti-coagulation with its attendant risk of hemorrhage. The 4Ts score has been shown to have high sensitivity and may be used to rule out HIT in most situations, although its utility depends on subjective analysis. Consistently applying this in practice could minimize over-testing and facilitate safer, cost-effective care.

Original languageEnglish (US)
Pages (from-to)12-16
Number of pages5
JournalJournal of Thrombosis and Thrombolysis
Volume40
Issue number1
DOIs
StatePublished - Jul 1 2015
Externally publishedYes

Fingerprint

Thrombocytopenia
Heparin
Antibodies
Tertiary Healthcare
Costs and Cost Analysis
Immunoassay
Enzyme-Linked Immunosorbent Assay
Hemorrhage
Sensitivity and Specificity

Keywords

  • 4T score
  • Anti-Heparin/PF4 ELISA
  • Heparin induced thrombocytopenia
  • Pre-test probability
  • Screening test
  • Thrombocytopenia

ASJC Scopus subject areas

  • Hematology
  • Cardiology and Cardiovascular Medicine

Cite this

Over-testing for heparin induced thrombocytopenia in hospitalized patients. / Chaturvedi, Shruti; Kohli, Ruhail; McCrae, Keith.

In: Journal of Thrombosis and Thrombolysis, Vol. 40, No. 1, 01.07.2015, p. 12-16.

Research output: Contribution to journalArticle

@article{892b15cbcfd94d45ac17afcd1f431d68,
title = "Over-testing for heparin induced thrombocytopenia in hospitalized patients",
abstract = "Heparin induced thrombocytopenia (HIT) is a pro-thrombotic and potentially fatal complication of heparin therapy. Its diagnosis rests on high clinical probability and the laboratory demonstration of anti-PF4/heparin antibodies. The high prevalence of thrombocytopenia in hospitalized patients and the high sensitivity but low specificity of immunoassays for HIT antibodies can lead to over-testing and over-diagnosis. We conducted a study to review HIT screening practices in a tertiary care setting. We reviewed 63 consecutive patients undergoing testing for anti-PF4/heparin antibodies over 3 months. Pre-test probability for HIT was calculated using the 4T score. Sixty three patients underwent testing for anti-PF4/heparin antibodies. Twenty one had been admitted for cardiovascular surgery, 5 for other surgery and 35 for non-surgical indications. Twenty nine patients (46 {\%}) had low pre- test probability, twenty three (36.5 {\%}) had intermediate probability, and eleven (17.4 {\%}) had high pre-test probability of having HIT. Anti-PF4/heparin ELISA was positive in 8 of 63 patients. SRA was ordered for 16 patients and was positive in 5. Only five patients were diagnosed and treated for HIT. Over-testing for HIT is highly prevalent in a tertiary care setting. This increases cost and exposes patients to expensive anti-coagulation with its attendant risk of hemorrhage. The 4Ts score has been shown to have high sensitivity and may be used to rule out HIT in most situations, although its utility depends on subjective analysis. Consistently applying this in practice could minimize over-testing and facilitate safer, cost-effective care.",
keywords = "4T score, Anti-Heparin/PF4 ELISA, Heparin induced thrombocytopenia, Pre-test probability, Screening test, Thrombocytopenia",
author = "Shruti Chaturvedi and Ruhail Kohli and Keith McCrae",
year = "2015",
month = "7",
day = "1",
doi = "10.1007/s11239-014-1123-0",
language = "English (US)",
volume = "40",
pages = "12--16",
journal = "Journal of Thrombosis and Thrombolysis",
issn = "0929-5305",
publisher = "Springer Netherlands",
number = "1",

}

TY - JOUR

T1 - Over-testing for heparin induced thrombocytopenia in hospitalized patients

AU - Chaturvedi, Shruti

AU - Kohli, Ruhail

AU - McCrae, Keith

PY - 2015/7/1

Y1 - 2015/7/1

N2 - Heparin induced thrombocytopenia (HIT) is a pro-thrombotic and potentially fatal complication of heparin therapy. Its diagnosis rests on high clinical probability and the laboratory demonstration of anti-PF4/heparin antibodies. The high prevalence of thrombocytopenia in hospitalized patients and the high sensitivity but low specificity of immunoassays for HIT antibodies can lead to over-testing and over-diagnosis. We conducted a study to review HIT screening practices in a tertiary care setting. We reviewed 63 consecutive patients undergoing testing for anti-PF4/heparin antibodies over 3 months. Pre-test probability for HIT was calculated using the 4T score. Sixty three patients underwent testing for anti-PF4/heparin antibodies. Twenty one had been admitted for cardiovascular surgery, 5 for other surgery and 35 for non-surgical indications. Twenty nine patients (46 %) had low pre- test probability, twenty three (36.5 %) had intermediate probability, and eleven (17.4 %) had high pre-test probability of having HIT. Anti-PF4/heparin ELISA was positive in 8 of 63 patients. SRA was ordered for 16 patients and was positive in 5. Only five patients were diagnosed and treated for HIT. Over-testing for HIT is highly prevalent in a tertiary care setting. This increases cost and exposes patients to expensive anti-coagulation with its attendant risk of hemorrhage. The 4Ts score has been shown to have high sensitivity and may be used to rule out HIT in most situations, although its utility depends on subjective analysis. Consistently applying this in practice could minimize over-testing and facilitate safer, cost-effective care.

AB - Heparin induced thrombocytopenia (HIT) is a pro-thrombotic and potentially fatal complication of heparin therapy. Its diagnosis rests on high clinical probability and the laboratory demonstration of anti-PF4/heparin antibodies. The high prevalence of thrombocytopenia in hospitalized patients and the high sensitivity but low specificity of immunoassays for HIT antibodies can lead to over-testing and over-diagnosis. We conducted a study to review HIT screening practices in a tertiary care setting. We reviewed 63 consecutive patients undergoing testing for anti-PF4/heparin antibodies over 3 months. Pre-test probability for HIT was calculated using the 4T score. Sixty three patients underwent testing for anti-PF4/heparin antibodies. Twenty one had been admitted for cardiovascular surgery, 5 for other surgery and 35 for non-surgical indications. Twenty nine patients (46 %) had low pre- test probability, twenty three (36.5 %) had intermediate probability, and eleven (17.4 %) had high pre-test probability of having HIT. Anti-PF4/heparin ELISA was positive in 8 of 63 patients. SRA was ordered for 16 patients and was positive in 5. Only five patients were diagnosed and treated for HIT. Over-testing for HIT is highly prevalent in a tertiary care setting. This increases cost and exposes patients to expensive anti-coagulation with its attendant risk of hemorrhage. The 4Ts score has been shown to have high sensitivity and may be used to rule out HIT in most situations, although its utility depends on subjective analysis. Consistently applying this in practice could minimize over-testing and facilitate safer, cost-effective care.

KW - 4T score

KW - Anti-Heparin/PF4 ELISA

KW - Heparin induced thrombocytopenia

KW - Pre-test probability

KW - Screening test

KW - Thrombocytopenia

UR - http://www.scopus.com/inward/record.url?scp=84948716397&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84948716397&partnerID=8YFLogxK

U2 - 10.1007/s11239-014-1123-0

DO - 10.1007/s11239-014-1123-0

M3 - Article

C2 - 25127902

AN - SCOPUS:84948716397

VL - 40

SP - 12

EP - 16

JO - Journal of Thrombosis and Thrombolysis

JF - Journal of Thrombosis and Thrombolysis

SN - 0929-5305

IS - 1

ER -