Prognostic factors for patients with heparin-induced thrombocytopenia: a systematic review

Int J Clin Pharm. 2021 Jun;43(3):449-460. doi: 10.1007/s11096-020-01166-2. Epub 2020 Oct 12.


Background Little is known with regards to the prognostic factors for patients with suspected or diagnosed Heparin-Induced Thromobocytopenia (HIT). The role of patient and therapy characteristics may play a role in predicting the outcome. Aim of the review To investigate the role of patient and therapy characteristics as potential prognostic factors for HIT-related complications (haemorrhagic and thromboembolic events), and mortality. Method The present systematic review was conducted according to the PRISMA statement. In September 2020, the main online databases were accessed: Pubmed, EMBASE, Scopus, Google Scholar. All the clinical trials concerning the management of patients with suspected or confirmed HIT were eligible. Studies evaluating the use of oral anticoagulants (e.g. vitamin K antagonists, Apixaban) were not considered, along with those comparing the use of heparin. For pairwise correlation, the Pearson Product-Moment Correlation Coefficient (r) was used. The final effect was evaluated according to the Cauchy-Schwarz inequality.Results Data from 33 clinical studies (4338 patients) were retrieved. The overall mean age was 62.3 ± 6.6 years old. Patients with HIT-related thromboembolism at the moment of diagnosis were associated with greater rate of haemorrhages (P > 0.0001), thromboembolism (P > 0.0001) and mortality (P = 0.001). Patients with more comorbidities at diagnosis were associated with a greater risk of haemorrhages (P = 0.07), thromboembolism (P = 0.002) and mortality (P = 0.002). Patients with longer duration of the therapy were associated with lower rate of mortality (P = 0.04). ConclusionsPatient comorbidities, presence of HIT-related thromboembolism on admission and shorter anticoagulant therapy were found to be negative prognostic factors. Thrombocythemia on admission, patients age and gender did not influence the overall outcome.

Keywords: HIT; Heparin-induced thrombocytopenia; Prognostic factors; Systematic review.

Publication types

  • Review
  • Systematic Review

MeSH terms

  • Aged
  • Anticoagulants / adverse effects
  • Heparin / adverse effects
  • Humans
  • Middle Aged
  • Prognosis
  • Thrombocytopenia* / chemically induced
  • Thrombocytopenia* / diagnosis
  • Thrombocytopenia* / epidemiology
  • Thromboembolism*


  • Anticoagulants
  • Heparin