The prognostic impact of systemic immune-inflammatory index in patients with isolated mitral valve replacement and non-ischemic mitral regurgi̇tati̇on

Objective: Mitral regurgitation is one of the most common heart valve diseases. Severe mitral regurgitation is known to be associated with progressive left ventricular dysfunction and congestive heart failure. Therefore, in cases where medical treatment is insufficient, surgical treatment should be performed before left ventricular dysfunction develops. Mitral valve replacement still maintains its significance today in cases where valve repair is not appropriate. To be able to make inferences about the postoperative prognosis of patients who will undergo mitral valve replacement due to mitral regurgitation, simple and clear data are needed in the literature. Recently, the Systemic Immune-Inflammatory Index (SII) value, which has been shown to be associated with poor prognosis and mortality, has been foreseen to be a predictive marker in this regard. In our study, we aim to investigate the early-term prognostic effects of SII in patients who undergo isolated mitral valve replacement due to primary severe mitral regurgitation. Material-Method: 176 patients who underwent isolated mitral valve replacement at the Department of Cardiovascular Surgery of Necmettin Erbakan University Meram Medical Faculty between January 2015 and December 2021 were retrospectively included in the study. Patients under the age of 18, pregnant/breastfeeding women, those with secondary or acute mitral regurgitation, those who underwent surgery through mini-thoracotomy, those with a history of previous cardiac surgery, those who underwent combined cardiac surgery, those with active infection and malignancy, and those with chronic inflammatory and autoimmune diseases were excluded from the study. The patients were divided into three classes based on age group (18-49, 50-65, and >65 years), and two main groups based on the type of valve used (mechanical and bioprosthetic), which were further divided into subgroups based on three different valve brands. The platelet, lymphocyte and neutrophil counts, as well as the Systemic Immune-Inflammatory Index (SII), Neutrophil-to-Lymphocyte Ratio (NLR), and Platelet-to-Lymphocyte Ratio (PLR) values were calculated from the patients' preoperative and postoperative 1st- and 4th-day hemogram tests. The relationship between the results and the patients' early-term prognosis and mortality within 30 days after surgery were examined. Findings: The sample group of 176 patients consists of 123 women (%69,9) and 53 men (%30,1) and 9,1% (n=16) of all patients were recorded as exitus. Of the valve groups used, 85,8% (n=151) were mechanical valves and 14,2% (n=25) were bioprosthetic valves. A significant positive correlation was observed between age (p<0.001), preoperative SII (p=0.049), NLR (p=0.003) and postoperative 4th day SII (p=0.04), NLR (<0.001) values and 30-day mortality. It was also observed that the combinations of age + preoperative SII (p<0,001), age + preoperative NLR (p<0,001) and age + postoperative 4th day NLR (p=0,001) had significant predictive values for 30-day mortality determination. Conclusion: In patients who have undergone isolated mitral valve replacement, an opinion can be expressed about the early 30-day prognosis with the simple parameters of SII and NLR, which are measured preoperatively. The postoperative 4th day values also support this result, and there is a need for prospective and randomized studies with a larger patient population.