• pulmonary congestion
• acute heart failure
• b-lines
• lung ultrasoud
• LUS
• congestion
• diuretic therapy
• VExUS

Introduction:
Heart Failure (HF) is a major public health problem world-wide, and it is expected to increase in the next few decades. The vast majority of acute HF (AHF) episodes are characterized by increasing symptoms and signs of congestion with volume overload and/or fluid redistribution. Current Guidelines stress on the importance of relieving congestion before discharge, recommending anyway only daily assessment of signs and symptoms. Evaluation of pulmonary B-lines and other ultrasound markers of congestion has been recently emerged as a safe and rapid technique, capable to improve diagnostic accuracy and help clinicians in daily fluid management.

Methods: Fifty-eight patients (age 72±11 years, 35% women) admitted to a Cardiology Department with a diagnosis of acute heart failure (AHF) were enrolled. Patients underwent clinical evaluation (Clinical Score, including rhales, pathological S3 heart sound, pedal oedema and jugular vein distension; ranging 0-4) and radiologic evaluation with chest X-ray (CXR score, including enlargement and loss of definition of hilar structures, peribronchial and perivascular cuffing, cardiomegaly and pleural effusion; ranging 0-4). Routine blood tests including NT-proBNP and urine electrolytes were collected in all patients. An integrated multiorgan ultrasound exam including pulmonary B-lines, echocardiography and venous excess ultrasound (VExUS) was performed at admission (T0), between 24 and 48 hours from T0 (T1), and at discharge (T2). Follow-up data at 60 days were collected.

Results: The mean number of B-lines was 26±12 at T0 with a significant reduction already at T1 (17±11, p<0.01), whereas a significant reduction in the Clinical Score and in the VExUS score was observed only at discharge (T2). The number of B-lines was associated with the Clinical Score (T0: R=0.368, p=0.005; T1: R=0.519, p<0.001; T2: R=0.550, p<0.001), with the CXR score (T0: R=0.473, p<0.001; T2: R=0.582 p<0.00.1), and the VExUS score (T0: R=0.668, P<0.001; T2: R=0.462, p<0.001). The number of B-lines was also correlated to NT-proBNP values at admission (R=0.445, p=0.001) and at discharge (R=0.426, p=0.002).
ROC analysis found a value of ∆B-lines >10 (B-lines at T0 - B-lines at T2) as the cut-off to maximize specificity and sensitivity in predicting 60-day events (AUC 0.72, 95% I.C. 0.5-0.94, p<0.05). Patients with ∆B-lines > 10 group had a significantly higher chlorine and sodium urinary excretion at T1 (p<0,001; p<0,005), with a correlation between ∆B-lines > 10 with total diuresis from T0 (R=0.426, p=0.002) and total diuresis from T1 (R=0.344, p=0.026).

Conclusions: In patients hospitalized with AHF, B-lines quantification is related to standard congestion evaluation and monitoring based on clinical evaluation, CXR and NT-proBNP, showing, however, more dynamic changes in the assessment of decongestion. B-lines variations are also related with diuresis and chlorine urinary output, a recognized predictor of diuretic response. Our study confirms that persistent congestion is related to an increased risk of hospitalization and death. Further studies are needed to assess the impact of lung ultrasound to guide diuretic therapy during AHF hospitalization.