Heart failure is one of the most common reasons for admission to acute care hospitals. A proportion of these admissions are probably low risk and could be managed in subacute care facilities, resulting in substantial cost savings. To investigate the proportion of low-risk hospital admissions for heart failure, all admissions for heart failure to Vanderbilt University Medical Center between July 1993 and June 1995 were identified (n = 743). One hundred twenty of these admissions were randomly selected, reviewed, and classified into a high-risk versus low-risk group on admission based on the severity of heart failure and the presence of life-threatening complications. Of the 120 admissions, 57 (48%) were classified as high risk based on the presence of moderate to severe heart failure for the first time or recurrent heart failure with a major complicating factor. Sixteen admissions (28%) were associated with adverse outcomes, including myocardial infarction in 5 (9%), intubation in 6 (11%), and death in 4 (7%). Sixty-three admissions (52%) were classified as low risk based on the presence of new-onset mild heart failure or mild to moderate recurrent heart failure with no complicating factors. Most of these admissions were for dyspnea without any life-threatening complication; 57 (91%) had no evidence of interstitial or alveolar pulmonary edema, and arterial oxygen saturation averaged 95 +/- 3%. Only 3 of these low risk admissions (5%) were associated with an adverse cardiovascular event. None of the patients died. These data suggest that over half of the patients admitted for heart failure to an acute care facility are low risk and probably could be managed in a subacute care setting, resulting in large cost savings.