A Case of Heparin-Induced Thrombocytopenia following Surgery for DeBakey Type I Acute Aortic Dissection / 日本心臓血管外科学会雑誌

ABSTRACT

A 73-year-old man underwent ascending aortic replacement and F-F crossover bypass for acute aortic dissection with right leg ischemia. He was treated postoperatively for acute renal failure due to myonephropathic metabolic syndrome (MNMS) with continuous hemodiafiltration. He suffered from acute graft occlusion and brain infarction on postoperative day (POD) 3. Although recovery of organ functions was observed, an unexpected decrease in platelet count occurred rapidly below 1.1×10⁴/μl on POD 6. We suspected heparin-induced thrombocytopenia (HIT) and all heparin administration was halted and argatroban was initiated at a dose of 0.2 μg/kg/min, with titration to achieve an activated partial thromboplastin time (APTT) of 1.5-3.0 times the initial value not to exceed 100 sec. The platelet factor 4-reactive HIT antibody was positive and definite diagnosed of HIT was made. Administration of warfarin started after the platelet count recovered to 10.0× 10⁴/μl on POD 36. Awareness of the clinical features and different presentations of HIT are essential for preventing severe complications associated with this disease.