Unraveling Acute Cardiorenal Syndrome: Predictors and Consequences in Acute Heart Failure

<b>Introduction:</b> Acute cardiorenal syndrome (ACRS) is a common complication of acute heart failure (AHF), leading to worse outcomes and therapeutic challenges. This study aimed to identify clinical parameters associated with ACRS and evaluate its impact on prognosis in hospitalized AHF patients. <b>Methods:</b> This prospective observational study included patients hospitalized for AHF at the Venizelio Cardiology Department from February to November 2023. Demographic characteristics, comorbidities, medications, laboratory and echocardiographic parameters, hospital stay, and in-hospital mortality were recorded. Patients with incomplete data or end-stage chronic kidney disease (CKD) were excluded. Survivors were followed for six months to assess renal function changes, readmissions, initiation of renal replacement therapy (RRT), and mortality. ACRS was defined as a serum creatinine increase of ≥0.3 mg/dL or ≥1.5 times baseline. <b>Results:</b> Among 218 hospitalized AHF patients, 112 (51.3%) developed ACRS. These patients were older, had higher CKD prevalence, worse New York Heart Association (NYHA) functional class, lower hemoglobin, and higher N-terminal Pro-B-type Natriuretic peptide (NT-proBNP) levels. Multivariate analysis identified CKD stage (OR 2.30, 95% CI 1.64-3.23, <i>p</i> < 0.001) and creatinine change on admission (OR 3.53, 95% CI 2.02-6.18, <i>p</i> < 0.001) as independent predictors of ACRS. ACRS was associated with higher in-hospital mortality, longer hospital stays, increased vasoactive medication use, worsening renal function, and higher six-month all-cause readmission and mortality rates. <b>Conclusions:</b> ACRS is a frequent and severe complication in AHF. CKD stage and creatinine on admission are key predictors. Early recognition for risk stratification and individualized management are crucial to improving outcomes in this high-risk population.