HIT

Dr. Hill presented a case today of heparin induced thrombocytopenia (aka HIT). His PICO question looked at whether patients receiving therapeutic heparin compared to prophylactic, subcutaneous heparin had higher incidence of HIT. An article in CHEST 2007 looked to determine the overal incidence of HIT in a tertiary care center based on retrospective review. It found an overal incidence of 0.2% with 0.76% incidence receiving therapeutic heparin compared to less than 0.1% incidence receiving prophylactic dosing. Similarly, in a 2011 article in British Journal of Hematology found that full dose anticoagulation with unfractionated heparin had a RR 3.66 (CI 1.98-6.75) compared to prophylactic dosing.

Generally, the teaching points from the case presentation were:

  • thrombosis is the presenting finding in up to 25% of patients with HIT
  • venous and arterial thrombosis occurred in 61% and 14% respectively in one restrospective review in the American Journal of Medicine.
  • the 4T score is useful to establish pre-test probability
 4T scoring system as described in  CHEST 2013

4T scoring system as described in CHEST 2013

Additional review of HIT can be found in the CHEST review from 2012.


Dr. Deloughery (Hematology/Oncology) weighs in with a couple of more key articles on HIT:

1) This new review is good by two of the masters of HIT

2) IVIG article is based on two OHSU cases

3) Former resident along with Shatzel did a review of DOAC for HIT that is widely quoted

Also at OHSU cost of UFH = that of Lovenox