Effect of Systemic Immune-Inflammation Index on Prognosis in Non-Functional Mitral Regurgitation Patients Undergoing Isolated Mitral Valve Replacement.

Objective: To investigate the effect of preoperative and postoperative systemic immune-inflammation index (SII) values on early prognosis in patients with nonfunctional mitral regurgitation etiology undergoing isolated mitral valve replacement (MVR).

Methods: A total of 176 patients with isolated MVR performed from 2015 to 2021 were retrospectively investigated. The platelet, lymphocyte, and neutrophil counts were measured, and SII, neutrophil/lymphocyte ratio (NLR), and platelet/lymphocyte ratio (PLR) values were calculated preoperatively and on the first and fourth days postoperatively. The correlations with postoperative 30-day early-term prognosis and mortality were investigated.

Results: Mean age of the patients was 55.4 years, 69.9% were female, and 30.1% were male. At 30-day follow-up, 9% (n = 16) of patients died. There were significant positive correlations observed between age (P < 0.001), preoperative NLR (P = 0.003), preoperative SII (P = 0.02), and postoperative fourth day NLR (P < 0.001) values with 30-day mortality. Receiver operating characteristic analysis identified that age + preoperative SII (P < 0.001), age + preoperative NLR (P < 0.001), and age + postoperative fourth day NLR (P = 0.001) combinations were significant predictive factors for 30-day mortality. There was a significant positive correlation between postoperative fourth day SII value with intensive care unit (ICU) admission duration (P < 0.001, Ρ = 0.308).

Conclusion: For non-functional, isolated MVR patients, preoperative and postoperative fourth day SII and NLR values were found to provide an idea about 30-day prognosis. Additionally, patients with high postoperative fourth day SII values were observed to have longer ICU stays.