Table 1.

B-lines and Heart Failure vs. outcomes.

First Author Year of Publication Country	Objectives	Methods				Results
		Design	Participants	Instruments, Procedure	Outcomes
Platz E et al. 2019 [47] (EEUU)	To assess the prevalence, changes in, and prognostic importance of B-lines	Prospective, observational study	N = 349	4-zone LUS was performed at discharge. B-lines were quantified off-line, blinded to clinical findings and outcomes.	Risk of HF hospitalization or all-cause death	The OR ratio for each B-line was 1.82 (95% CI 1.14 to 2.88; p = 0.011) after adjusting for important clinical variables.
Kobalava Zh D et al. 2019 [49] (Russia)	To assess the prognostic significance of B-lines number at discharge.	Observational descriptive	N = 162	B lines at hospital discharge	Probability of 12-month all-cause death and probability of HF readmission.	At discharge normal LUS profile was observed in 48.2% of patients. Sum of B-lines ≥ 5 was associated with higher probability of 12-month all-cause death ([HR] 2.86, 95% CI 1.15–7.13, p = 0.024); and B-lines ≥ 15 B-lines with higher probability of HF readmission (HR 2.83, 95% CI 1.41–5.67, p = 0.003).
Marini et al., 2020 [55] (Italy)	To evaluate the usefulness of LUS + physical examination (PE) in the management of out-patients with acute decompensated heart failure (ADHF).	Randomized, multicenter, and unblinded study	N = 244	PE + LUS’ group vs. ‘PE only’ group.	Hospitalization rate for ADHF at 90-day follow-up.	The hospitalization was significantly reduced in ‘PE + LUS’ group with a reduction of risk for hospitalization by 56% (p = 0.01). There were no differences in mortality between the two groups.
Araiza-Garaigordobil et al., 2020 [56] (Mexico)	LUS during follow-up of patients with HF may reduce the rate of adverse events compared with usual care.	Randomized, single-center, blinded, and controlled trial CLUSTER-HF study	N = 126	LUS vs. usual care	Urgent visits, rehospitalization for worsening HF, and death from any cause during a 6-month period.	LUS-guided treatment was associated with a 45% risk reduction for hospitalization (HR 0.55, 95% CI 0.31–0.98, p = 0.044), and reduction in urgent visits (HR 0.28, 95% CI 0.13–0.62, p = 0.001). No significant differences in death were found.
Rivas-Lasarte M et al., 2019 [62] (Spain)	To evaluate relationship between results LUS-guided follow-up protocol and reduction NT-proBNP.	Randomized, single-blind clinical trial.	N = 123	A standard follow-up (n = 62, control group) or a LUS-guided follow-up (n = 61, LUS group)	urgent visit, hospitalization and death, at 14, 30, 90 and 180 days after discharge	Reduction the number of decompensations and improved walking capacity, but N-terminal pro-B-type natriuretic peptide reduction were not achieved.
Conangla et al., 2020 [43] (Spain)	LUS improved diagnostic accuracy in HF suspicion.	Prospective study of LUS in ambulatory patients > 50 years old	N = 223	LUS was performed on 2 anterior (A), 2 lateral (L), and 2 posterior (P) areas per hemithorax. An area was positive when ≥3 B-lines were observed.	Two diagnostic criteria were used: for LUS-C1, 2 positive areas of 4 (A-L) on each hemithorax; and for LUS-C2, 2 positive areas of 6 (A-L-P) on each hemithorax.	LUS was accurate enough to rule-in HF in a primary care setting irrespective NT-proBNP availability.
Domingo M, et al. 2021 [50] (Spain)	The prognostic value of LUS.	Observational, prospective, single-center cohort study	N = 577	LUS was performed in situ. The sum of B-lines across all lung zones and the quartiles of this addition were used for the analyses.	The main clinical outcomes were a composite of all-cause death or hospitalization for HF and mortality from any cause during mean follow-up of 31 ± 7 months.	The mean number of B-lines was 5 ± 6. Having ≥ 8 B-lines doubled the risk of the composite primary event (p < 0.001) and increased the risk of death from any cause by 2.6-fold (p < 0.001) with a 3% to 4% increased risk for each 1-line addition irrespective NT-proBNP level.
Wang Y et al., 2021 [51] (Brasil)	Prognostic value of lung ultrasound assessed by B-lines	A Systematic Review and Meta-Analysis	Nine studies involving N = 1212	HF out-patients	Outcomes of all-cause mortality or HF hospitalization	B-lines > 15 and >30 at discharge were significantly associated with increased risk of combined outcomes
Rueda-Camino JA et al. 2021 [52] (Spain)	To determine the diagnostic accuracy of bedside LUS prognostic tool for HF suspicion	Prospective cohort study		B lines: two groups were formed: less than 15 B-lines (unexposed) and ≥15 B-lines (exposed).	Risk of readmission and mortality with 3-month follow-up	Patients with ≥15 B-lines are 2.5 times more likely to be readmitted (HR: 2.39; 95%CI: 1.12–5.12; p = 0.024), without differences in terms of mortality.
Zisis G et al., 2022 [60] (Australia)	To evaluate the efficacy a nurse-led, LUICA-guided disease management program (DMP)	RISK-HF randomized controlled trial	N = 404	Patients at high risk for 30-day readmission and/or death to LUS-guided DMP or usual care.	LUS was performed at discharge and at least twice in the first month of follow-up	Handheld ultrasound at and after hospital discharge improves fluid status but does not reduce heart failure readmission.
Maestro-Benedicto, A et al., 2022 [45] (Spain)	contemporary HF risk scores can be improved upon by the inclusion of the number of B-lines detected by LUS	Randomized, single-center, simple blind trial	N = 123	LUS at discharge contemporary HF risk scores at 15 days, 1, 3 and 6 months after the hospitalization	predict death, urgent visit, or HF readmission at 6-month	Adding the results of LUS evaluated at discharge improved the predictive value of most of the contemporary HF risk scores in the 1-month score and 1-year.
Mhanna M et al., 2022 [57] (EEUU)	A point-of-care lung ultrasound (LUS) is a useful tool to detect subclinical pulmonary edema.	Systematic review and meta-analysis	N = 493	LUS plus PE-guided therapy vs. managed with PE-guided therapy alone	HF hospitalization, all-cause mortality, urgent visits for HF worsening, acute kidney injury (AKI), and hypokalemia rates.	Out-patient LUS-guided diuretic therapy of pulmonary congestion reduces urgent visits for worsening symptoms of HF. No significant difference in HF hospitalization rate. Similarly, there was no significant difference in all-cause mortality, and hypokalemia.
Rattarasan I et al., 2022 [48] (Thailand)	Evaluate the prognostic value of B-lines for prediction of rehospitalization and death	Prospective cohort	N = 126	B-lines and the size of the inferior vena cava. Two groups were formed: B-lines (<12) vs. B-lines (≥12)	Prediction of readmission hospitalization and death within 6 months	The mean number of B-lines at discharge was 9 ± 9, and the presence ≥ 12 B-lines before discharge was an independent predictor of events at 6 months
Dubon-Peralta E et al. 2022 [54] (Spain)	assessment of pulmonary congestion in patients with heart failure	A systematic review	14 articles	evaluate the prognostic significance of the presence of B lines detected by LUS	Optimization of treatment by monitoring the dynamic changes	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.
Arvig MD et al., 2022 [46] (Denmark)	investigate if treatment guided by serial LUS compared to standard monitoring	Systematic search	24 studies N = 2040	serial LUS of the inferior vena cava-collapsibility index (IVC-CI) and B-lines on LUS	mortality, readmissions	A single ultrasound measurement can influence prognostic outcomes, but it remains uncertain if repeated scans can have the same impact.
Yan Li et al., 2022 [58] (China)	to evaluate the usefulness of LUS-guided treatment vs. usual care in reducing the major adverse cardiac event (MACE) rate	systematic review and meta-analysis of randomized controlled trials	10 studies N = 1203	LUS-guided treatment vs. usual care a, LUS-guided treatment	MACEs, all-cause mortality, and HF-related rehospitalization, during mean follow-up of 4.7 months	The meta-regression analysis showed a significant correlation between MACEs and the change in B-line count (p < 0.05). LUS-guided treatment was associated with a significantly lower risk of MACEs.
Platz E et al., 2023 [59] (EEUU)	PARADISE-MI Assess the trajectory of pulmonary congestion using lung ultrasound (LUS)	Prospective cohort study	N = 152	LUS underwent 8-zone LUS and echocardiography at baseline (±2 days of randomization) and after 8 months.	Patients with acute myocardial Left ventricular ejection fraction, pulmonary congestion or both	The proportion of patients without pulmonary congestion at follow-up was significantly higher in those with fewer B-lines at baseline
Cohen et al., 2023 [44] (EEUU)	Association between numbers of B-lines on LUS.	Prospective study of adults	200 patients at discharge	Number of B-lines. By an 8-zone LUS exam to evaluate for the presence of B-lines	Risk of 30-day readmission in patients hospitalized for acute decompensated HF.	The presence of B-lines at discharge was associated with a significantly increased risk of 30-day readmission. Compared with patients with 0–1 positive zones, patients with 2–3 positive lung zones was 1.25 times higher (95% CI: 1.08–1.45), and with 4–8 positive lung zones was 1.50 times higher (95% CI: 1.23–1.82).
Goldsmith AJ et al., 2023 [61] (EEUU)	BLUSHED-AHF study: to explore whether LUS early targeted intervention vs. leads improves pulmonary congestion	Multicenter, randomized, pilot trial	N = 130	LUS-guided protocol	Number of B-lines at 6 h or in 30 days	LUS conferred no benefit compared with usual care in reducing the number of B-lines at 6 h or in 30 days, but a significantly greater reduction in the number of B-lines was observed in LUS-guided patients during the first 48 h.