 The course of patients with chronic heart failure is marked by periodic episodes of clinical decompensation that not only impair the quality of life and may be fatal but also consume substantial health care resources, primarily due to the costs of hospitalization. Heart failure management programs have been developed to reduce the frequency and severity of these clinical events, but their effectiveness may be limited by physicians difficulty in identifying patients at imminent risk. Reliable prediction of these events may afford physicians the opportunity to intervene aggressively and potentially minimize the need for hospitalization or the risk of a serious adverse outcome. 