Predictive Role of Preoperative Controlled Nutritional Status Score on Prolonged Mechanical Ventilation after Heart Valve Surgery

Background: Postoperative prolonged mechanical ventilation (MV) in patients with heart valve disease (HVD) is usually concomitant with poor prognosis. Its relationship with preoperative nutritional status still remains unclear. The present study intends to explore the influence of preoperative controlled nutritional status (CONUT) score on early postoperative outcomes and its predictive role in prolonged MV. Methods: HVD patients receiving cardiac surgeries in our department from January 2022 to December 2023 were retrospectively selected. CONUT score was calculated according to the level of serum albumin, total cholesterol and lymphocyte counts. When the CONUT score was greater than or equal to 3, patients were included in high CONUT group, and the other patients were included in low CONUT score group. Propensity score matching (PSM) was used to adjust baseline characteristics. Results: A total of 411 patients were included, of which 129 patients had the preoperative CONUT score greater than or equal to 3 points, accounting for 31.4%. After adjustment at a ratio of 1:2, 103 patients were included in high CONUT group while 206 patients were included in low CONUT group. The incidence of postoperative ventilator associated pneumonia (VAP) in high CONUT group was significantly higher than that in low CONUT group (p = 0.039). Length of ICU stay showed up a significant extension in high CONUT group compared with low CONUT group (p = 0.041). Significantly prolonged MV time could be observed in high CONUT group compared with low CONUT group (p = 0.022). The proportion of patients receiving MV over 48 h and 72 h in high CONUT group significantly increased (p = 0.020 and 0.009 respectively) except for MV over 24 h. MV time of all patients was found to be significantly correlated with CONUT score (r = 0.186, p = 0.001). The area under the curve (AUC) for CONUT predicting MV >48 h was 0.625 (p = 0.008), with sensitivity of 0.419 and specificity of 0.808. The AUC for CONUT predicting MV >72 h was 0.691 (p = 0.003), with sensitivity of 0.545 and specificity of 0.801. Conclusions: Preoperative CONUT score had an accurate predictive role of postoperative prolonged MV and early poor prognosis in HVD patients, which deserves much attention to improve clinical outcomes.