[Anaemia and heart failure with preserved ejection fraction in adult patients with cardiorenal syndrome: a cross-sectional study]

The study addres the issue of anemia in patients with acute decompensated heart failure and chronik kidney disease, affering a valuable contribution due to its multicenter desing and the clinical relevance of the topic. Hawever, it is presents sinificant methodological limitations, sucha sa, the absence of a clearly stated hypotesis, the exclution of the sugrups with mid-range ejection fraction, limited justification of the multivariable models, and the dichotomization of hemoglobin, which may have compromised the sensibility of the analysis. Moreover, key clinical variables sucha s comorbidities, volume status, or inflamatory markers were not included. From a clinical and epidemiological prespective, the estudy confirms the high prevalence of anemia in this setting, particularly in patients with renal dysfunction and preserved ejection fraction, where it exceeds 40% and is associated with a worse prognosis. Hemoglobin may act as a mediator between the decline in renal function and functional capacity. A better understanding of these mechanisms requires more robust statistical models and more precise clinical characterization to guide more effective interventions.