Bedside Ultrasound-guided Volume Management and Discharge Timing for Patients With Heart Failure During Hospitalization: A Randomized Controlled Trial

Point-of-Care Ultrasound-Guided Volume Management During Hospitalization and Discharge Timing in Patients with Heart Failure: A Randomized Controlled Trial (POCUS-HF Study) Heart failure (HF) is a clinical syndrome caused by structural or functional abnormalities of the heart leading to inadequate perfusion of the body's organs and tissues^[1]^. It is characterized by recurrent episodes of acute decompensation requiring frequent hospitalizations and is a leading cause of hospitalization and mortality in the elderly^[2,3]^. Globally, approximately 64.34 million people are affected by HF, with about 3 million patients hospitalized annually. Approximately 25% to 30% of patients are readmitted within 30 to 90 days after discharge, and 50% are readmitted within 6 months^[4]^. The 5-year mortality rate is as high as 50%^[5]^. Recent epidemiological surveys indicate that the number of chronic HF patients in China has exceeded 8.9 million^[6]^. With an aging population and increasing chronic disease burden, the prevalence of HF continues to rise. As a significant global cause of morbidity and mortality, HF poses a major challenge to patients and healthcare systems in China, necessitating serious attention as a public health issue^[7-9]^. The high readmission rate not only increases healthcare costs and worsens prognosis but also highlights the inadequacy of current HF management strategies.

Congestion is a major reason for frequent hospitalizations in patients with acute decompensated HF and a key predictor of poor outcomes^[10,11]^, as well as an important treatment target. However, despite diuretic therapy, a significant proportion of acute HF patients still exhibit signs of congestion at discharge, which is associated with higher risks of readmission and mortality^[12,13]^. Studies show that 30-50% of acute HF patients have residual congestion at discharge, and these patients have higher rates of readmission and mortality within 1 year compared to those without congestion^[10]^. Research by Lala et al.^[14]^ similarly found that only 52% of HF patients were free of clinical congestion at discharge, yet 38% of these patients developed recurrent congestion requiring hospitalization within 60 days. Numerous clinical trials have observed that venous congestion, rather than low cardiac output, is the primary reason for HF hospitalizations^[15]^. Although current guidelines emphasize the importance of aggressive congestion management, these data suggest a lack of clear assessment strategies, leading to suboptimal volume management at discharge.

The gold standard for congestion assessment is invasive cardiac catheterization to measure right and left atrial pressures^[16]^. However, due to its invasive nature, time-consuming process, and associated risks, it is generally unsuitable for routine use in decompensated HF patients during hospitalization or pre-discharge assessment. Congestion assessment is a dynamic process involving various clinical and physiological parameters. However, guidelines do not clearly define the optimal method for assessing decongestion in HF, and current standards rely on improvements in clinical symptoms and signs as indicators of treatment efficacy and discharge readiness^[17]^. Yet, symptom and sign-based assessments can only detect moderate to severe congestion. Clinical findings such as dyspnea, orthopnea, systemic edema, elevated jugular venous pressure, and third heart sounds are important for identifying decompensated HF, but none of these signs can accurately assess the underlying hemodynamic changes causing congestion. Even patients without clinical signs of congestion may have subclinical volume overload^[4]^. Due to the dissociation between clinical manifestations and cardiac filling pressures, relying solely on clinical findings has low sensitivity and poor predictive value for identifying decompensated HF^[18]^. Therefore, for HF management, especially pre-discharge congestion assessment, combining clinical evaluation with other parameters (e.g., biomarkers, imaging) is essential to guide volume management during hospitalization and assess congestion before discharge, thereby reducing residual congestion at discharge and lowering readmission and mortality rates.

Point-of-care ultrasound (POCUS) is a non-invasive, portable, and easy-to-learn adjunct to physical examination. Inferior vena cava (IVC) imaging and lung ultrasound (LUS) can be easily performed at the bedside using portable devices. These methods provide reliable estimates of right atrial pressure and pulmonary congestion, respectively, and quickly reflect changes in volume status post-treatment. They are already widely used for fluid management in dialysis patients^[19,20]^, shock management in sepsis^[21,22]^, and HF prognosis assessment^[23-25]^. Previous studies have shown that IVC correlates well with right atrial pressure, offering high sensitivity and specificity, and outperforms physical examination in detecting elevated jugular venous pressure^[24]^. Persistently dilated IVC with low collapsibility index in HF patients at discharge predicts a higher risk of readmission. Pulmonary B-lines (ultrasound artifacts representing extravascular lung edema) correlate with the severity of pulmonary congestion. A systematic review of 13 studies found that HF patients with ≥15 B-lines at discharge had a fivefold higher risk of readmission or death^[26]^. Recently, the ESC Heart Failure Association consensus statement recommended using IVC imaging and LUS for pre-discharge assessment of residual congestion and discharge guidance. IVC diameter <2.1 mm with collapsibility >50% and fewer than 5 B-lines are proposed as key discharge criteria^[12]^. However, these recommendations are based on expert consensus and lack validation in large randomized controlled trials. A small pilot study (CAVAL US-AHF)^[4]^ demonstrated that IVC and LUS-guided HF therapy reduced subclinical congestion at discharge and improved short-term outcomes, suggesting that IVC combined with LUS is a valuable and novel approach for guiding HF treatment. However, this study had a small sample size (n=60) and focused on a Western population, where the average diuretic dose was 170 mg/day, compared to 40-60 mg/day in Chinese HF patients. Thus, the applicability of these findings to Chinese and Asian populations remains unclear. Additionally, the CAVAL US-AHF study^[4]^ used IVC and LUS only to guide decongestion therapy, not discharge timing. Further research is needed to explore the use of IVC combined with LUS for guiding discharge timing. Moreover, the IVC <2.1 mm threshold recommended by the ESC consensus is based on Western populations, and the optimal IVC value for Chinese and Asian HF patients at discharge remains unknown.

Therefore, we propose a randomized controlled trial (POCUS-HF study) to investigate the use of POCUS-assessed IVC and B-lines for guiding volume management during hospitalization in HF patients and to explore the relationship between IVC at discharge and HF risk, aiming to determine the optimal IVC threshold for discharge timing in Chinese and Asian HF patients and provide quantitative discharge criteria.