PURPOSE: The complications of heparin-induced thrombocytopenia include thrombosis and death. The purpose of the study was to determine whether early heparin cessation can prevent these outcomes. SUBJECTS AND METHODS: We performed a retrospective analysis of consecutive patients with heparin-induced thrombocytopenia diagnosed by platelet aggregometry. Demographic, clinical, and laboratory findings were compared in patients by whether heparin treatment was stopped early (less than or equal to 48 hours) or late (>48 hours) after the onset of thrombocytopenia, as well as between patients with and without thrombosis. Thrombocytopenia was defined as a 50% decline in baseline platelet counts or an absolute platelet count <100,000/mm(3). RESULTS: Of the 113 patients, 38% developed thrombosis and 27% died. One-half of patients had thrombosis diagnosed >24 hours after heparin cessation. No difference in thrombosis or mortality was found in the 40 patients with early heparin cessation [mean (+/-SD) time of cessation 0.7 +/- 0.6 days] compared with the 73 patients with late heparin cessation (5 +/- 3 days). Thrombosis >24 hours after heparin cessation occurred in 61% of the patients in the early group and in 40% of the late group (P = 0.17). In a multivariate analysis, only a lower nadir of the platelet count (percent of baseline) was associated with thrombosis. Neither thrombosis nor the time to heparin cessation were associated with mortality. CONCLUSIONS: Early heparin cessation was not effective in reducing morbid events in patients with heparin-induced thrombocytopenia. Treatment strategies other than heparin cessation alone should be considered in patients with this condition. Am I Med. 1999;106:629-635. (C) 1999 by Excerpta Medica, Inc.