Prognostic value of B lines detected with lung ultrasound in acute heart failure. A systematic review

Abstract

Pulmonary ultrasound is a simple diagnostic tool with immediate results for the assessment of pulmonary congestion in patients with heart failure (HF), allowing optimization of treatment by monitoring the dynamic changes identified. We aimed to evaluate the prognostic significance of the presence of B lines detected by lung ultrasound during hospitalization for heart failure. A search was conducted for scientific articles in PubMed, Embase, Google Scholar, and Cochrane databases including clinical trials, reviews, systematic reviews, and original articles that were related to the prognostic value of lung ultrasound in patients with HF in the last 5 years from 2016 to 2021. Studies including individuals aged ≥18 years evaluating the prognostic value of lung ultrasound in HF were included. Fourteen articles met inclusion criteria for analysis (three reviews, three systematic reviews with meta-analysis, six prospective studies, and two retrospective studies). The presence of more than 30-40 B lines at admission were considered a risk factor for readmission or mortality as was persistent pulmonary congestion with the presence of ≥15 B-lines. The presence of pulmonary congestion detected by lung ultrasound in acute heart failure has prognostic significance in terms of mortality and hospital readmission. Clinical trials are needed to evaluate whether diuretic therapy guided by lung ultrasound and the presence of B lines can reduce readmission and mortality in these patients.

New International Guidelines and Consensus on the Use of Lung Ultrasound

“…Experience with LUS in assessing COVID‐19 patients shows, however, that the alterations visualized in the posterior areas are the most significant 101 . Assessing each intercostal space along its entire length is time‐consuming, so reasonably simplified protocols have been suggested for COVID‐19 patients as well, such as 18 28–55,57–151 and 14 scan protocols 24,101 . Lately one interesting study on the correlation between LUS and laboratory results also described a protocol of 12 scans (quick COVID‐19 severity index [qCSI]), 6 for each half of the chest (upper and lower areas of the anterior, lateral and posterior surfaces, respectively), for assessing the presence of B‐line and/or consolidation 152 .…”

“…Despite the widespread use of vertical artifacts for identification and monitoring of different pleuro‐pulmonary pathophysiological conditions, 91 , 127 , 128 we currently do not fully understand the origin of this acoustic information. 39 …”

“…125,126 In the last consensus (2012) the vertical artifacts, commonly referred as "B lines," were originally defined as discrete laser-like vertical hyperechoic reverberation artifacts which arise from the pleural line, extend to the bottom of the screen without fading and move synchronously with lung sliding. 56 Despite the widespread use of vertical artifacts for identification and monitoring of different pleuropulmonary pathophysiological conditions, 91,127,128 we currently do not fully understand the origin of this acoustic information. 39 Furthermore, vertical artifacts appearance differs greatly, depending on the subpleural pathophysiological lung status, 36,38 on the US pulse center frequency and bandwidth, and on the shape of the probe (which influences the angle of incidence).…”

Lung ultrasound-guided treatment for heart failure: An updated meta-analysis and trial sequential analysis

“…Several recently published RCTs have demonstrated that LUS-guided treatment reduces HF-related rehospitalization in patients with HF compared with usual care ( 6 – 10 ), while more recent systematic reviews, including three with individual patient data, have published meta-analyses contradicting this finding and showing no effect ( 11 – 14 ). Based on these considerations, we believed that it would be helpful to validate the new findings by performing an up-to-date meta-analysis in an attempt to improve the precision of the estimates, reduce variability, and increase generalizability ( 39 ). As expected, the addition of the recently published RCT data, which increased the total number of participants, substantially increased the precision of the estimates.…”

Objective structured clinical examination in basic thoracic ultrasound: a European study of validity evidence

“…Basic thoracic ultrasound is a versatile and functional point-of-care ultrasound examination that may be useful in the diagnosis and management of a broad range of respiratory conditions, including pneumothorax, pleural effusion, cardiogenic pulmonary oedema, and pneumonia [1][2][3][4]. More comprehensive thoracic ultrasound examination can be performed by respiratory physicians, often needing more time and experience but potentially providing information on, for example, lymph node status and pleural pathologies.…”