Design and rationale for the Acute Congestive Heart Failure Urgent Care Evaluation: the ACUTE Study

Background — Heart failure is one of the leading reasons for emergency department (ED) visits and hospitalization. However, externally validated risk algorithms for acute prognostication of heart failure (HF) patients are not available. Thus, many low-risk patients are hospitalized and some high-risk patients are discharged home, which, in some cases, may lead to death.

Objectives — The first objective of the ACUTE study is to perform a prospective validation of the Emergency Heart failure Mortality Risk Grade (EHMRG), which is a risk score derived to predict 7-day mortality in the ED setting. The second objective is to independently validate the 30-day model extension of the risk score (EHMRG30-ST) in the same cohort.

Study Design — Patients with HF presenting to the ED will be recruited with a waiver of informed consent as a minimal risk study. The ED physician will calculate the EHMRG 7-day risk score, but treatment decisions will not be influenced by the predictive models. Follow-up will be obtained using probabilistic linkage with the Registered Persons Database of vital statistics, whereby deaths will be ascertained. We will examine mortality rates according to EHMRG and EHMRG30-ST algorithms. We will also compare physician-judged risk estimates, based on clinical judgement alone, with the EHMRG score.

Conclusion — The ACUTE study will determine if a retrospectively derived algorithm for simultaneous estimation of 7-day and 30-day mortality risk can accurately identify low and high risk patients with acute HF, and improve upon physician-judged risk estimation.