Low-Density Lipoprotein Cholesterol and Mortality Risk in Elderly Patients Undergoing Valve Replacement Surgery: A Propensity Score Matching Analysis

BACKGROUND: The prognostic value of low-density lipoprotein cholesterol (LDL-C) in elderly patients is controversial. This study aimed to elucidate the relationship between the preoperative LDL-C and adverse outcomes in elderly patients undergoing valve replacement surgery (VRS). METHODS: A total of 2,552 aged patients (age ≥ 60 years) undergoing VRS were retrospectively recruited and divided into two groups according to LDL-C level on admission: low LDL-C (<70 mg/dL, n = 205) and high LDL-C groups (≥ 70 mg/dL, n = 2,347). The association between the preoperative LDL-C with in-hospital and one-year mortality was evaluated by propensity score matching analysis and multivariate analysis. RESULTS: The mean age was 65 ± 4 years and 1,263 (49.5%) were men. Patients in the low LDL-C group were significantly older (65.9 ± 4.6 vs. 64.9 ± 4.1, p = 0.002), with more male (65.4 vs. 48.1%, p < 0.001), higher alanine transaminase (ALT) (21 vs. 19, p = 0.001), lower serum albumin (35.3 ± 4.6 vs. 37.1 ± 4.1, p < 0.001), higher serum creatinine (92.2 ± 38.2 vs.84.6 ± 26.1, p = 0.006), lower lymphocyte count (1.7 ± 0.7 vs. 1.9 ± 0.6, p < 0.001), lower hemoglobin (121.9 ± 22.3 vs. 130.2 ± 16.5, p < 0.001), lower platelet count (171.3 ± 64.3 vs. 187.7 ± 58.7, p < 0.001), lower prognostic nutrition index (44 ± 6.2 vs. 46.7 ± 5.8, p < 0.001), and more severe tricuspid regurgitation (33.7 vs. 25.1%, p = 0.008). The rates of in-hospital death (11.2 vs. 3.7%, p < 0.001) and major adverse clinical events (17.6 vs. 9.6%, p < 0.001) were significantly higher in the low LDL-C group. The cumulative one-year death rate was significantly higher in the low LDL-C group (Log-Rank = 16.6, p < 0.001). After matching analysis and multivariate analysis, no association between LDL-C level and adverse outcomes was detected (all p > 0.05). CONCLUSION: Our study did not support the negative relationship between LDL-C level and mortality risk in elderly patients undergoing VRS.