title: Delayed-onset heparin-induced thrombocytopenia presenting with multiple arteriovenous thromboses: case report.
abstract: BACKGROUND
  Delayed-onset heparin-induced thrombocytopenia with thrombosis, albeit rare, is a severe side effect of heparin exposure. It can occur within one month after coronary artery bypass grafting (CABG) with manifestation of different thrombotic events.
  
  
  METHODS
  A 59-year-old man presented with weakness, malaise, bilateral lower limb pitting edema and a suspected diagnosis of deep vein thrombosis 18 days after CABG. Heparin infusion was administered as an anticoagulant. Clinical and paraclinical work-up revealed multiple thrombotic events (stroke, renal failure, deep vein thrombosis, large clots in heart chambers) and 48 x103/mul platelet count, whereupon heparin-induced thrombocytopenia was suspected. Heparin was discontinued immediately and an alternative anticoagulant agent was administered, as a result of which platelet count recovered. Heparin-induced thrombocytopenia, which causes thrombosis, is a serious side effect of heparin therapy. It is worthy of note that no case of delayed-onset heparin-induced thrombocytopenia with thrombosis associated with cardiopulmonary bypass surgery has thus far been reported in Iran.
  
  
  CONCLUSIONS
  Delayed-onset heparin-induced thrombocytopenia should be suspected in any patient presenting with arterial or venous thromboembolic disorders after recent heparin therapy, even though the heparin exposure dates back to more than a week prior to presentation; and it should be ruled-out before the initiation of heparin therapy.
authors.affiliation: Cardiovascular Surgery Department, Tehran Heart Center, Medical Sciences/University of Tehran, Iran. abbasomran2006@yahoo.com.
authors.forename: Abbas Salehi
authors.initials: AS
authors.lastname: Omran
authors.forename: Abbasali
authors.initials: A
authors.lastname: Karimi
authors.forename: Hossein
authors.initials: H
authors.lastname: Ahmadi
authors.forename: Parin
authors.initials: P
authors.lastname: Yazdanifard