Failure of current strategies in the prevention of thrombosis in patients with heparin-induced thrombocytopenia: A clinician's perspective

Heparin-induced thrombocytopenia (HIT), and heparin-induced thrombocytopeni a with thrombosis syndrome (MITTS), are immune-mediated complications of he parin therapy associated with significant morbidity and mortality. Although much has been learned about the pathophysiology of this syndrome, there ar e many difficult issues remaining for physicians involved in the daily care of the patient about the diagnosis, prevention, and treatment. To determin e whether the earliest detection of HIT and heparin cessation impacted outc ome, 116 consecutive patients at a single institution, with HIT diagnosed b y platelet aggregometry, mere divided into groups by time to heparin cessat ion basted on daily platelet counts. Thrombocytopenia was defined in two wa ys: as a 50% decline from baseline and an absolute platelet count of less t han 100 X 10(9)/L. The overall thrombosis rate was 39% and was predominantl y venous, The mortality rate of 27% was similar in patients with both HIT a nd MITTS. Despite heparin cessation at less than 48 h from the onset of thr ombocytopenia (mean 0.5 days), there were no differences in thrombosis or m ortality when compared to patients with later heparin cessation (mean 4.3 d ays). In summary, early detection of HIT with heparin cessation is insufficient t herapy for the management and treatment of MITTS, An alternative to this st rategy in the treatment of patients with HIT is indicated.