HIT
with Thrombosis
10% of hospitalized patients are on
heparin therapy
Incidence of HIT with thrombosis:
1% of patients on unfractionated
heparin for >5 days develop HIT – in 4-7 days or 1 – 3 days
Antibodies against PF4 causes
thrombocytopenia (ab-ag complex binds via Fc) and microvascular thrombi
Drop in platelet count after heparin
injection
Features:
Diagnosis:
However:
Drop in platelet count after heparin
injection occurs in 30% of patients but is immediate, benign, and limited drop