Emergency department observation of patients with acute heart failure prior to hospital admission: impact on short-term prognosis.

Objectives: To analyze whether short-term outcomes are affected when patients diagnosed with acute heart failure (AHF) spend time in an emergency department observation unit (EDOU) before hospital admission.

Material and methods: Baseline and emergency episode data were collected for patients diagnosed with AHF in the EDs of 15 Spanish hospitals. We analyzed crude and adjusted associations between EDOU stay and 30-day mortality (primary outcome) and in-hospital mortality and a prolonged hospital stay of more than 7 days (secondary outcomes).

Results: A total of 6597 patients with a median (interquartile range) age of 83 (76-88 years) were studied. Fifty-five percent were women. All were hospitalized for AHF (50% in internal medicine wards, 23% in cardiology, 11% in geriatrics, and 16 in other specialties. Of these patients, 3241 (49%) had had EDOU stays and 3350 (51%) had been admitted immediately, with no EDOU stay. Having an EDOU stay was associated with female sex, dementia or chronic obstructive pulmonary disease, long-term treatment with certain drugs for heart failure, greater baseline deterioration in function, and a higher degree of decompensation. Patients in the EDOU group were more often admitted to an internal medicine ward and had shorter stays; cardiology, geriatric, and intensive care admissions were less likely to have had an EDOU stay. Overall, 30-day mortality was 12.6% (13.7% in the EDOU group and 11.4% in the no-EDOU group; P = .004). In-hospital mortality was 10.4% overall (EDOU, 11.1% and no-EDOU, 9.6%; P = .044). Prolonged hospitalization occurred in 50.0% (EDOU, 48.7% and no-EDOU, 51.2%; P = .046). After adjusting for between-group differences, the EDOU stay was not associated with 30-day mortality (hazard ratio, 1.14; 95% CI, 0.99-1.31). Odds ratios for associations between EDOU stay and in-hospital mortality and prolonged hospital stay, respectively, were 1.09 (95% CI, 0.92-1.29) and 0.91 (95% CI, 0.82-1.01).

Conclusion: Although mortality higher in patients hospitalized for AHF who spend time in an EDO, the association seems to be accounted for by their worse baseline situation and the greater seriousness of the decompensation episode, not by time spent in the EDOU.