Letter regarding the article ‘Clinical profiles and prognostic impact of residual intravascular and tissue congestion in acute heart failure’

We read with great interest the article by Ceelen et al.1 investigating the clinical profiles and prognostic impact of residual intravascular and tissue congestion in acute decompensated heart failure (ADHF). This post hoc analysis of the PROTECT and RELAX-AHF-2 trials provides valuable insights into the heterogeneity of residual congestion (RC) phenotypes and their differential associations with diuretic response and clinical outcomes. The authors elegantly demonstrated that intravascular RC was the most prevalent phenotype at discharge (45%), associated with better diuretic responses and shorter hospital stays compared with tissue or combined RC, yet still carrying increased 180-day mortality risk [hazard ratio (HR) 1.69]. Meanwhile, tissue and combined RC phenotypes exhibited poorer diuretic responses despite higher diuretic doses, with even greater mortality risk (HR 2.07 and 2.18, respectively). These findings support the concept of a two-compartment congestion model and highlight the clinical importance of phenotype-specific assessment. However, several methodological considerations merit discussion. First, the reliance on clinical examination (jugular venous pressure for intravascular, rales/peripheral oedema for tissue congestion) has inherent limitations. Previous studies have shown that rales exhibit sensitivity of only 13–70% for pulmonary congestion, and jugular venous pressure assessment demonstrates substantial interobserver variability in routine clinical practice.2 Lung ultrasound and biomarkers such as bioactive adrenomedullin (bio-ADM) and cancer antigen-125 may offer more objective and reproducible assessments of congestion compartments.3 Indeed, Ceelen et al.'s own data showed elevated bio-ADM in patients with intravascular RC, suggesting biomarkers could enhance phenotype identification.