Evaluation of hemodynamic and biomarker changes in patients undergoing surgical aortic valve replacement

Background: Aortic stenosis (AS) is a systemic disease characterized by valvular obstruction, ventricular remodeling, and perioperative vulnerability to oxygen supply-demand imbalance. This study evaluated perioperative metabolic and biomarker dynamics and early postoperative outcomes in patients undergoing surgical aortic valve replacement (AVR). Patients and Methods: A prospective observational study was conducted on 60 consecutive adults with severe AS who underwent surgical AVR at a single center. Demographics, anthropometric data, intraoperative variables, complications, and preand postoperative hemodynamic and laboratory parameters were evaluated. Postoperatively, the following were assessed at 6 and 24 hours: mean arterial pressure (MAP), arterial oxygen saturation (SaO2), partial pressure of oxygen (PaO2), pH, partial pressure of carbon dioxide (PaCO2), hemoglobin (Hb), lactate, and creatine kinase-MB isoenzyme (CK-MB). Continuous data are presented as mean ± standard deviation (SD) or median (interquartile range, IQR). Paired t-tests were used to compare values between 6 and 24 hours. Results: The mean age was 69.9 ± 7.3 years; 58.3% were male. Mean anesthesia and operation times were 151.5 ± 21.8 and 126.8 ± 20.6 minutes, respectively; mean cardiopulmonary bypass (CPB) and cross-clamp times were 78.3 ± 17.6 and 58.5 ± 16.7 minutes. Nearly half of the patients (46.7%) had no postoperative complications; others experienced bleeding (16.7%), arrhythmias requiring therapy (6.7%), permanent pacemaker implantation (8.3%), re-exploration (6.7%), infection (8.3%), respiratory failure (3.3%), or renal failure (3.3%). From 6 to 24 hours postoperatively, lactate decreased (2.34 ± 0.96 → 1.87 ± 0.98 mmol/L; p = 0.006) and CK-MB declined (52.5 ± 34.2 → 39.0 ± 30.8 U/L; p = 0.001), while Hb increased (103.5 ± 10.1 → 120.1 ± 22.9 g/L; p < 0.001). pH decreased modestly (7.396 ± 0.057 → 7.365 ± 0.065; p = 0.015). MAP, SaO2, PaO2, and PaCO2 showed no significant changes. The median hospital stay was 7 days (IQR 6-8). Conclusions: In patients undergoing surgical AVR for AS, early postoperative trends demonstrated an improving metabolic profile (lower lactate) and biomarker normalization (CK-MB) with stable oxygenation, alongside low-to-moderate complication rates and a consistent 7-day median stay. Integrating perioperative oxygen-balance markers and cardiac biomarkers with imaging and left ventricular hypertrophy (LVH) assessment may refine timing and risk stratification for intervention. Prospective studies with standardized imaging and longer follow-up are warranted to link early metabolic recovery with ventricular remodeling and clinical outcomes.