Provided are methods for evaluating the risk of an adverse clinical outcome in a subject, deciding whether to discharge or continue treating a subject (e.g., treatment on an inpatient basis), or to initiate or terminate treatment, selecting a subject for participation in a clinical study, and selecting a therapeutic treatment for a subject that include determining a level of ST2 in a biological sample from the subject and determining a level of galectin-3 in a biological sample from the subject. Kits are also provided that include an antibody that specifically binds to ST2 and an antibody that specifically binds to galectin-3.