Aim of the study. To identify the clinical, laboratory, hemodynamic, and anamnestic factors associated with in-hospital mortality in patients with a history of COVID-19 undergoing surgical correction of valvular heart disease, considering infection severity, timing of infection (pre- or postoperative), renal dysfunction, protein status, tissue injury biomarkers, and respiratory failure.

Materials and methods. This retrospective, single-center study included 100 patients who experienced COVID-19 either before or after surgical correction of valvular heart disease at the National M. Amosov Institute of Cardiovascular Surgery affiliated to National Academy of Medical Sciences of Ukraine (Kyiv, Ukraine), between 2021 and 2024. Patients were stratified by in-hospital outcome (survival vs. death). Comparative analyses was performed across clinical, laboratory, hemodynamic, and operative parameters, with particular attention to the timing (pre- or postoperative) and severity of COVID-19 infection. Statistical analysis was carried out Student’s t-test and chi-square tests; significance was set at p < 0.05.

Results. Seventeen clinical and biochemical indicators demonstrated significant differences between survivors and non-survivors. The key predictors included older age (65.05 ± 2.11 vs 54.71 ± 1.62 years; p = 0.001), longer hospitalization (29.7 ± 4.46 vs 18.73 ± 1.31 days; p < 0.001), reduced glomerular filtration rate (pre- and postoperatively; p < 0.05), hypoproteinemia (p < 0.01), elevated tissue injury markers (LDH, CK-MB, AST; p < 0.05), and markers of respiratory and metabolic failure. In addition, the severity of COVID-19 significantly influenced mortality: 85 % in the severe group, 6.38 % in the mild group, and 0 % in the moderate group (χ2 = 66.51; p < 0.01). The timing of infection was also critical: mortality was highest (59.3 %) among patients who contracted COVID-19 postoperatively, compared to only 4.35 % among those infected preoperatively (χ2 = 36.64; p < 0.01).

Conclusions. The primary determinants of in-hospital mortality after valve surgery in post-COVID-19 patients include advanced age, renal dysfunction, reduced protein reserves, tissue damage biomarkers, respiratory failure, as well as the timing and severity of COVID-19 infection. These factors should guide perioperative risk stratification and support the rationale for delaying surgery in high-risk post-COVID-19 cases.