Dynamic changes and prognostic value of pulmonary congestion by lung ultrasound in acute and chronic heart failure: a systematic review

Abstract

Aims: Pulmonary congestion is an important finding in patients with heart failure (HF) that can be quantified by lung ultrasound (LUS). We conducted a systematic review to describe dynamic changes in LUS findings of pulmonary congestion (B-lines) in HF and to examine the prognostic utility of B-lines in HF.

Methods and results: We searched online databases for studies conducted in patients with chronic or acute HF that used LUS to assess dynamic changes or the prognostic value of pulmonary congestion. We included studies in adult populations, published in English, and conducted in ≥25 patients. Of 1327 identified studies, 13 (25-290 patients) met the inclusion criteria: six reported on dynamic changes in LUS findings (438 patients) and seven on the prognostic value of B-lines in HF (953 patients). In acute HF, B-line number changed within as few as 3 h of HF treatment. In acute HF, ≥15 B-lines on 28-zone LUS at discharge identified patients at a more than five-fold risk for HF readmission or death. Similarly, in ambulatory patients with chronic HF, ≥3 B-lines on five- or eight-zone LUS marked those at a nearly four-fold risk for 6-month HF hospitalization or death.

Conclusions: Lung ultrasound findings change rapidly in response to HF therapy. This technique may represent a useful and non-invasive method to track dynamic changes in pulmonary congestion. Furthermore, residual congestion at the time of discharge in acute HF or in ambulatory patients with chronic HF may identify those at high risk for adverse events.

Keywords: Congestion; Heart failure; Lung ultrasound; Prognosis; Systematic review.

Figure 1

Literature search results. AHF, acute heart failure; BNP, B-type natriuretic peptide; HF, heart failure; LUS, lung ultrasound.

Figure 2

Examples of lung ultrasound scanning protocols and images in chronic heart failure (HF). (A) In the eight-zone method, ≥3 B-lines identified patients at nearly four-fold risk of 6-month HF hospitalization or death. (B) In the 28-zone method, in patients with acute HF ≥15 B-lines at the time of hospital discharge identified patients at more than five-fold risk for HF readmission or death. (C) Lung ultrasound image without B-lines. (D) Lung ultrasound image with several B-lines.

Figure 3

Unadjusted hazard ratios (HRs) for heart failure (HF) hospitalization or death with B-lines at hospital discharge in acute HF and chronic HF (n = 597). Cut-offs are >15 B-lines (28 zones) in acute HF pre-discharge from the hospital, and ≥3 B-lines (five to eight zones) in chronic HF (ambulatory) patients. The x-axis is on a logarithmic scale. CI, confidence interval.