Six-month follow-up of patients with in-hospital thrombocytopenia during heparin-based anticoagulation (from the Complications After Thrombocytopenia Caused by Heparin [CATCH] registry).

Thrombocytopenia is a predictor of adverse outcomes in patients with acute coronary syndromes and in critically ill patients. The Complications After Thrombocytopenia Caused by Heparin (CATCH) registry was designed to explore the incidence, management, and clinical consequences of in-hospital thrombocytopenia occurring during heparin-based anticoagulation in diverse clinical settings. We conducted a prospective observational study of 37 United States hospitals participating in the CATCH registry to assess the relation of in-hospital thrombocytopenia to long-term outcomes. A total of 2,104 patients at increased risk of developing in-hospital thrombocytopenia or thrombosis were identified, and the 6-month mortality and rehospitalization rates were determined. Thrombocytopenia was not a significant predictor of 6-month mortality. In an adjusted model for in-hospital death in this cohort, thrombocytopenia had an odds ratio of 3.59 (95% confidence interval 2.24 to 5.77). The postdischarge mortality rate at 6 months was 9.7%. No significant difference was observed in the long-term mortality between patients who developed thrombocytopenia and those who did not. Thrombocytopenia was a weak, but statistically significant, predictor of a composite of mortality and rehospitalization at 6 months (hazards ratio 0.80, 95% confidence interval 0.65 to 0.98, p = 0.03). In conclusion, the 6-month mortality rate among heparin-treated patients with thrombocytopenia is high, although the risk independently related to thrombocytopenia appears to be restricted to the acute hospital phase.