Prevalence and prognostic importance of lung ultrasound findings in acute coronary syndrome: A systematic review.

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.