Quantification of pleural effusions on thoracic ultrasound in acute heart failure

Abstract

Background: Although pleural effusions are common among patients with acute heart failure, the relevance of pleural effusion size assessed on thoracic ultrasound has not been investigated systematically. Methods: In this prospective observational study, we included patients hospitalised for acute heart failure and performed a thoracic ultrasound early after admission (thoracic ultrasound 1) and at discharge (thoracic ultrasound 2) independently of routine clinical management. A semiquantitative score was applied offline blinded to clinical findings to categorise and monitor pleural effusion size. Results: Among 188 patients (median age 72 years, 62% men, 78% white, median left ventricular ejection fraction 38%), pleural effusions on thoracic ultrasound 1 were present in 66% of patients and decreased in size during the hospitalisation in 75% based on the pleural effusion score ( P<0.0001). Higher values of the pleural effusion score were associated with higher pleural effusion volumes on computed tomography ( P<0.001), higher NT-pro brain natriuretic peptide values ( P=0.001) and a greater number of B-lines on lung ultrasound ( P=0.004). Nevertheless, 47% of patients were discharged with persistent pleural effusions, 19% with large effusions. However, higher values of the pleural effusion score on thoracic ultrasound 2 did not identify patients at increased risk of 90-day heart failure rehospitalisations or death (adjusted hazard ratio (HR) 1.05, 95% confidence interval (CI) 0.92–1.19; P=0.46) whereas seven or more B-lines on lung ultrasound at discharge were independently associated with adverse events (adjusted HR 2.43, 95% CI 1.11–5.37; P=0.027). Conclusion: Among patients with acute heart failure, pleural effusions are associated with other clinical, imaging and laboratory markers of congestion and improve with heart failure therapy. The prognostic relevance of persistent pleural effusions at discharge should be investigated in larger studies.

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

“…There was an association between effusion size and number of B‐lines ( p = 0.004) and signs of vascular congestion on the first radiograph ( p = 0.013) as well as higher scores on the X‐ray scale ( p < 0.001). High pre‐discharge lung ultrasound pleural effusion scale scores (47% residual effusion present) were not associated with increased readmission or death at 90 days (adjusted HR 10 5.95% CI 0.92–1.19; p = 046) while a finding of ≥7 B‐lines at discharge was independently associated (adjusted HR 2.43, 95% CI 1.11–5.37; p = 0.027) 16 …”

“…In addition, they were more likely to have chronic oxygen therapy. Right‐sided pleural effusion tended to be higher (4 [IQR 3–4] vs. 3 [IQR 1–4]) 16 . There was an association between effusion size and number of B‐lines ( p = 0.004) and signs of vascular congestion on the first radiograph ( p = 0.013) as well as higher scores on the X‐ray scale ( p < 0.001).…”

“…In addition, each study uses different visualization protocols of the B lines, varying between eight and 28 zones. In 2012, a council of experts recommended the use of the 8‐zone protocol for the assessment of interstitial syndrome 16 …”

“…We should also consider that in our research we have not included other echographic parameters that are also assessed in acute heart failure such as the measurement and collapsibility of the inferior vena cava. Studies in the field of acute heart failure with bedside ultrasound evaluation of the vena cava show that patients with plethoric vena cava (greater than 21 mm) and who do not collapse on inspiration have a higher readmission and mortality rate 16 . This parameter can be very important in assessing the degree of pulmonary hypertension and presence of right congestion in patients with acute HF.…”

Sex differences in congestive markers in patients hospitalized for acute heart failure

“…If clinically indicated, patients underwent an upright CXR examination on admission. These CXRs were analysed by radiologists for the presence of vascular congestion, interstitial oedema, and alveolar oedema 5 . Only CXR examinations performed within 1 day of admission based on date change were included in this analysis.…”