Objectives To determine the impact of risk stratification using the MEESSI-AHF (Multiple Estimation of risk based on the Emergency department Spanish Score In patients with acute heart failure) scale to guide disposition decision-making on the outcomes of ED patients with acute heart failure (AHF), and assess the adherence of emergency physicians to risk stratification recommendations.

Methods This was a prospective quasi-experimental study (before/after design) conducted in eight Spanish EDs which consecutively enrolled adult patients with AHF. In the pre-implementation stage, the admit/discharge decision was performed entirely based on emergency physician judgement. During the post-implementation phase, emergency physicians were advised to ‘discharge’ patients classified by the MEESSI-AHF scale as low risk and ‘admit’ patients classified as increased risk. Nonetheless, the final decision was left to treating emergency physicians. The primary outcome was 30-day all-cause mortality. Secondary outcomes were days alive and out of hospital, in-hospital mortality and 30-day post-discharge combined adverse event (ED revisit, hospitalisation or death).

Results The pre-implementation and post-implementation cohorts included 1589 and 1575 patients, respectively (median age 85 years, 56% females) with similar characteristics, and 30-day all-cause mortality was 9.4% and 9.7%, respectively (post-implementation HR=1.03, 95% CI=0.82 to 1.29). There were no differences in secondary outcomes or in the percentage of patients entirely managed in the ED without hospitalisation (direct discharge from the ED, 23.5% vs 24.4%, OR=1.05, 95% CI=0.89 to 1.24). Adjusted models did not change these results. Emergency physicians followed the MEESSI-AHF-based recommendation on patient disposition in 70.9% of cases (recommendation over-ruling: 29.1%). Physicians were more likely to over-rule the recommendation when ‘discharge’ was recommended (56.4%; main reason: need for hospitalisation for a second diagnosis) than when ‘admit’ was recommended (12.8%; main reason: no appreciation of severity of AHF decompensation by emergency physician), with an OR for over-ruling the ‘discharge’ compared with the ‘admit’ recommendation of 8.78 (95% CI=6.84 to 11.3).

Conclusions Implementing the MEESSI-AHF risk stratification tool in the ED to guide disposition decision-making did not improve patient outcomes.