Overdiagnosis of Heparin-Induced Thrombocytopenia in Surgical ICU Patients

Berry, Cherisse; Tcherniantchouk, Oxana; Ley, Eric J.; Salim, Ali; Mirocha, James; Martin-Stone, Sylvia; Stolpner, Dennis; Margulies, Daniel R.

doi:10.1016/j.jamcollsurg.2011.04.002

Cited by 54 publications

(51 citation statements)

References 46 publications

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“…9 High negative predictive values ranging from 91.4% to 100% have been reported in subsequent studies carried out in medical-surgical ICU patients and cardiothoracic surgical patients. [8][9][10]15,[22][23][24][25][26] In the present study, a high negative predictive value of 4Ts score, 87.5%, was obtained for HIT, similarly to the previous studies mentioned above. This value was still lower than the values ranging from 91.4% to 100% in previous reports.…”

Section: Discussionsupporting

confidence: 91%

“…30 The positive predictive value of the 4Ts score was as low as 15.4%, a value less than the previously reported range from 21.4% to 100%. [8][9][10]15,[22][23][24][25][26] The false-positive rate of the 4Ts score (percentage of "4T high score" patients in the non-HIT patients) was 11.8%, a value comparable to those previously reported (0-15.3%). [8][9][10]15,[22][23][24][25][26] In contrast, the false-negative rate of the 4Ts scores (percentage of "4T low score" patients in HIT patients) was 54.5% (6/11), a value considerably higher than those previously reported (0-25%).…”

Section: Discussionsupporting

confidence: 86%

“…[8][9][10]15,[22][23][24][25][26] The false-positive rate of the 4Ts score (percentage of "4T high score" patients in the non-HIT patients) was 11.8%, a value comparable to those previously reported (0-15.3%). [8][9][10]15,[22][23][24][25][26] In contrast, the false-negative rate of the 4Ts scores (percentage of "4T low score" patients in HIT patients) was 54.5% (6/11), a value considerably higher than those previously reported (0-25%). [8][9][10]15,[22][23][24][25][26] These findings suggested that many individuals might develop HIT even with a low 4Ts score.…”

Section: Discussionsupporting

confidence: 86%

“…[8][9][10]15,[22][23][24][25][26] In contrast, the false-negative rate of the 4Ts scores (percentage of "4T low score" patients in HIT patients) was 54.5% (6/11), a value considerably higher than those previously reported (0-25%). [8][9][10]15,[22][23][24][25][26] These findings suggested that many individuals might develop HIT even with a low 4Ts score.…”

Section: Discussioncontrasting

confidence: 62%

“…13,14 Although the 4Ts score has an advantage in that it eliminates HIT without carrying out an HIT antibody test due to its high negative predictive values, 7 some patients are reported to develop HIT even with a low 4Ts score. 15 Some patients with positivity for anti-PF4/heparin antibodies proven by ELISA have been reported to be negative for platelet activation when tested using a functional assay, indicating that they do not develop clinical HIT. 5 We have experienced the discrepancy between the 4Ts score and PF4/heparin Ab, especially in critically ill patients.…”

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confidence: 99%

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Relationship between the 4Ts scoring system and the antiplatelet factor 4/heparin antibodies test in critically ill patients

Matsumura

Nakada

Oda

2013

Acute Medicine & Surgery

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Aim: Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction and potentially progresses to fatal thrombosis. The 4Ts scoring system has been reported as a clinical pretest for HIT. However, its usefulness in critically ill patients has not yet been thoroughly examined. Thus, we evaluated the clinical usefulness of the 4Ts score in the diagnosis of HIT in critically ill patients. Methods:One hundred and four critically ill patients who were admitted to our intensive care unit and who underwent the antiplatelet factor 4/heparin complex antibodies (PF4/heparin Ab) test with suspected HIT were enrolled in the study. The primary endpoint variable was the 4Ts score. The secondary endpoint variables were laboratory data, length of stay, and mortality, compared between thePF4/ heparin Ab positive and negative groups.Results: There was no significant difference in the 4Ts scores between the PF4/heparin Ab positive and negative groups. The positive predictive value (HIT patients/4T high score patients) was 15.4% (2/13), the negative predictive value (non-HIT patients/4T low score patients) was 87.5% (42/48), and the false-negative rate for the 4Ts score (4T low score patients/HIT patients) was as high as 54.5% (6/11). The PF4/heparin Ab positive patients had longer stay in intensive care compared to the PF4/heparin Ab negative patients (P = 0.035). Conclusions:The present study showed the discrepancy between the 4Ts score and PF4/heparin Ab. When HIT is suspected in critically ill patients, an immediate HIT antibody test and initiation of therapeutic management of HIT are required regardless of the 4Ts score.

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Section: Discussionsupporting

confidence: 91%

Section: Discussionsupporting

confidence: 86%

Section: Discussionsupporting

confidence: 86%

Section: Discussioncontrasting

confidence: 62%

mentioning

confidence: 99%

See 3 more Smart Citations

Relationship between the 4Ts scoring system and the antiplatelet factor 4/heparin antibodies test in critically ill patients

Matsumura

Nakada

Oda

2013

Acute Medicine & Surgery

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Heparin‐induced thrombocytopenia in lower extremity free tissue transfers

et al. 2023

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BackgroundHeparin‐induced thrombocytopenia (HIT) an immunologically mediated reaction to heparin products, can lead to severe thrombocytopenia and potentially life‐threatening thrombotic events. In microsurgery, a missed or delayed diagnosis of HIT can cause complications requiring revision operations, flap loss, or limb loss. Surgeons must remain vigilant for this uncommon yet potentially devastating condition and keep abreast of management strategies.MethodsCPT and ICD‐10 codes in electronic medical records were used to collect demographic information, clinical courses, and outcomes for patients with a HIT diagnosis who underwent lower extremity free tissue transfer in one institution.ResultsThe authors' institution performed 415 lower extremity free flaps in 411 patients during the 10‐year study period. Flap salvage rate was 71% for compromised lower extremity flaps without HIT, and 25% in those with HIT. Four patients (four flaps) met study inclusion criteria during the study period. Three of the four flaps failed and were later debrided; one was rescued after a takeback for anastomosis revision. Two patients successfully underwent a delayed second free flap procedure after recovery, and one was salvaged with a pedicled muscle flap.ConclusionsSurgeons should monitor for HIT by establishing coagulation panel and platelet count baselines and trending these values in the early post‐operative period for patients treated with heparin products. The 4T score can be used to screen for HIT with high clinical suspicion. Arterial thrombosis or poor flap perfusion despite sound microvascular technique could suggest HIT. Surgical and medical management including strict heparin avoidance can prevent adverse events for these patients.

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Over-testing for heparin induced thrombocytopenia in hospitalized patients

Chaturvedi

Kohli

McCrae

2014

J Thromb Thrombolysis

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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.

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Overdiagnosis of Heparin-Induced Thrombocytopenia in Surgical ICU Patients

Cited by 54 publications

References 46 publications

Relationship between the 4Ts scoring system and the antiplatelet factor 4/heparin antibodies test in critically ill patients

Relationship between the 4Ts scoring system and the antiplatelet factor 4/heparin antibodies test in critically ill patients

Heparin‐induced thrombocytopenia in lower extremity free tissue transfers

Over-testing for heparin induced thrombocytopenia in hospitalized patients

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