## 2 Materials and Methods
### Measurements  
First, 158 cardiac patients were pre-enrolled on a rolling \"first come, first served\" criterion if they were admitted to the Arad County Emergency Clinical Hospital from the Emergency Department (ED) due to hypertensive urgencies or episodes of acute decompensated HF. All measurements were conducted using validated and calibrated devices to ensure consistency across all data points. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were recorded at ED triage. Echocardiography was conducted as soon as possible after admission to the hospital (within the first 1 to 2 h after arrival) to assess the patient's baseline cardiac condition. Ejection fraction (EF), left atrial diameter (LAD), left ventricle diameter (LVD), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and interventricular septum thickness (IVSWd) were measured because these metrics are crucial indicators of cardiac health. Thus, EF is considered a key indicator of cardiac performance. Enlarged LAD indicates chronic pressure overload and atrial fibrillation. LVD and LVEDV are associated with ventricular hypertrophy/dilatation and increased preload. Elevated LVESV reflectsworsening heart failure. Increased IVSd is a sign of hypertension-related hypertrophic changes [6; 7; 11]. Blood samples (50 mL) were collected within the same time frame to capture the effects of acute hypertensive crises or acute decompensation episodes [25]. The key hematological indices measured included erythrocyte sedimentation ratio (ESR), C-reactive protein (CRP), absolute leukocyte count (ALC), absolute neutrophil count (ANC), platelet-related parameters (RDW-CV, RDW-SD), and hemoglobin. ADMA and NT-proBNP were used, respectively, as biomarkers for endothelial dysfunction and cardiac stress [25; 26]. Indices of renal function included serum creatinine, glomerular filtration rate (GFR), serum urea, serum uric acid, serum sodium, and serum potassium. The cardiometabolic parameters measured were total cholesterol, LDL, HDL, triglycerides, random glucose, and glycated hemoglobin (HbA1c), while liver function was evaluated using aspartate transaminase (AST) and alanine transaminase (ALT). Additional blood samples (20 mL) were collected at discharge to determine serum creatinine, potassium, and sodium levels. Measuring these parameters at both admission and discharge is critical for patients hospitalized due to hypertensive crises or acute decompensation episodes. This monitoring helps to determine kidney function, detect electrolyte imbalances, and evaluate treatment effectiveness, thereby preventing complications such as arrhythmia and worsening HF [26]. Biochemical analyses were run at the Arad County Emergency Clinical Hospital, except for ADMA and TRAIL measurements, which were conducted at the \"Vasile Goldis\" Western University of Arad. All analyses were conducted in triplicate, and only the mean values were considered. For ELISA analysis, 20 mL of the initial blood samples were incubated at 25 \({}^{\circ}\)C for 2 h in test tubes, followed by centrifugation at 1000\(\times\)\(g\) for 15 min. The resulting serum was stored at \(-\)20 \({}^{\circ}\)C until analysis. After defrosting, half of the serum was used to assess ADMA levels, and the other half was used to determine TRAIL concentrations. ADMA was measured using the Human ADMA ELISA Kit (Cusabio, Wuhan, China), as detailed in our previous work [26]. TRAIL was quantified using the human TRAILIC PicoKineTM ELISA kit (Boster Bio, Pleasanton, CA, USA) and a microplate reader, Stat Fax 4200 (Awareness Technology, Palm City, FL, USA) [27]. To accurately quantify ADMA and TRAIL, standard curves were generated by plotting the log\({}_{10}\)-transformed concentrations against the corresponding optical densities of the positive controls. The ELISA calibration curves demonstrated coefficients of determination (R\({}^{2}\)) above 0.97.