Background

Heart failure (HF) complicating acute coronary syndrome (ACS) is a herald of adverse outcomes. In this systematic review, we investigated the prevalence of lung ultrasound (LUS) findings and their prognostic utility among patients with ACS.

Methods

We searched the online databases PubMed, EMBASE, and Web of Science for studies (full-text articles, published in English) that used LUS in adult patients with ACS [ST-elevation myocardial infarction (STEMI), non-ST-elevation myocardial infarction (NSTEMI), and unstable angina].

Results

Of 462 studies screened, five prospective, observational investigations published between 2010 and 2021 including 1087 patients met our inclusion criteria. Two studies employed 28-zone imaging protocols whereas three used eight-zone protocols. The proportion of patients with a prior HF diagnosis was ≤ 5% in all studies. The prevalence of B-lines was examined prior to or within 12 hours after coronary angiogram and reporting varied between studies due to different imaging protocols or quantification methods. A higher number of B-lines on admission was associated with an increased risk for developing symptomatic HF during the baseline hospitalization and with a higher in-hospital mortality rate using either 8 or 28-zone protocols. A higher number of B-lines at baseline was also associated with an increased risk of subsequent HF hospitalization or all-cause death.

Conclusions

Pulmonary congestion by LUS performed on admission appears to be a common finding among patients hospitalized for ACS and is associated with adverse in-hospital and long-term outcomes. Further investigations using standardized LUS protocols are warranted and have the potential to improve risk stratification in ACS.