Scherer et al proposed the dynamic ultrasound congestion score (DUCS), which combines lung ultrasound (LUS) and the modified venous excess ultrasound (mVExUS), both established methods for hemodynamic assessment using point-of-care ultrasound (POCUS). The authors conducted an observational study demonstrating an association between POCUS parameters, such as ΔDUCS, and clinically important outcomes in patients with acute decompensated heart failure (ADHF), including in-hospital mortality, 30-day mortality, and hospital readmission. These findings are consistent with the growing interest in POCUS-guided management.1, 2 Although further validation is required, this study provides important insights into the role of POCUS in hemodynamic assessment. In this letter, I discuss several physiological concepts that may help clinicians appropriately interpret the results of this study. First, the combination of LUS and mVExUS is physiologically reasonable. LUS assesses pulmonary congestion, which results from elevated left ventricular end-diastolic pressure (LVEDP), a surrogate of left ventricular preload.3 In contrast, mVExUS reflects systemic venous congestion, characterized by a reduced pressure gradient driving venous return between mean systemic filling pressure and central venous pressure.4 Both elevated LVEDP and venous congestion are associated with poor outcomes in patients with ADHF. In addition, mVExUS alone may be insufficient to assess left ventricular failure, as it does not directly reflect LVEDP.5 Second, it is important to understand the factors that influence DUCS. Not only left ventricular function, but also hepatic, pulmonary, and right ventricular function should be considered. During the acquisition of mVExUS, right heart failure may result in a high mVExUS score, and cirrhosis or portal vein hypertension may cause abnormal waveforms in the hepatic and portal veins.6 In LUS, B-lines may also be observed in pulmonary conditions, such as acute respiratory distress syndrome, interstitial lung disease, and pneumonia.7 If a high DUCS reflects these factors rather than ADHF, DUCS-guided therapy may lead to inappropriate or potentially harmful diuretic strategies and worsening hemodynamics. Although the baseline characteristics, including comorbidities and right ventricular function, are described in this study, the results of DUCS should be interpreted in the context of these complex conditions in clinical practice. In summary, the practical use of POCUS in the management of ADHF should be grounded in physiological hemodynamic assessment. While the strength of POCUS lies in its convenience and clinical applicability, physiological principles should always guide its interpretation. I appreciate the opportunity to comment on this article. Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.
Yohei Masuda (Wed,) studied this question.