Abstract: Objective To investigate the association of preoperative lymphocyte-to-monocyte ratio (LMR) with short- and long-term prognosis in patients with acute type A aortic dissection (ATAAD). Methods A total of 100 patients with ATAAD who underwent surgical treatment in our hospital from January 2021 to January 2024 were enrolled as subjects. Peripheral blood lymphocytes and monocytes were measured before surgery, and LMR was calculated. Death during hospitalization after surgery was recorded, and the patients were followed up for 1 year after surgery to record deaths. Univariate and multivariate logistic regression analyses were used to investigate the risk factors for short- and long-term mortality in patients, and the receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC) were used to assess the efficacy of preoperative LMR in predicting the short- and long-term prognosis of patients with ATAAD. Results Among the 100 patients, 26 (26.00%) died within 30 days after surgery, and 42 (42.00%) died within 1 year after surgery. The univariate and multivariate logistic regression analyses showed that white blood cell count (odds ratio [OR]=1.881, 95% confidence interval [CI]: 1.121-3.156, P<0.05), lymphocyte count (LYM) (OR=0.415, 95%CI: 0.235-0.734, P<0.05), and LMR (OR=0.398, 95%CI: 0.231-0.687, P<0.05) on admission were independent influencing factors for death within 30 days after surgery in ATAAD patients, and LYM (OR=0.394, 95%CI: 0.268-0.578, P<0.05) and LMR (OR=0.296, 95%CI: 0.186-0.471, P<0.05) on admission were independent influencing factors for death within 1 year after surgery in ATAAD patients. The ROC curve analysis showed that LYM and LMR on admission had an AUC of 0.713 and 0.745, respectively, in predicting death within 30 days after surgery in ATAAD patients, with an optimal prediction threshold of 1.045×10⁹/L and 1.8, respectively, a sensitivity of 73.08% and 88.46%, respectively, and a specificity of 60.81% and 52.70%, respectively; LYM and LMR on admission had an AUC of 0.813 and 0.886, respectively, in predicting death within 1 year after surgery in ATAAD patients, with an optimal prediction threshold of 0.675×10⁹/L and 1.525, respectively, a sensitivity of 57.14% and 85.71%, respectively, and a specificity of 94.83% and 77.59%, respectively. Conclusion Preoperative LMR is an independent influencing factor for both short- and long-term prognoses in ATAAD patients and can be used as a predictive indicator for short- and long-term mortality.

Key words: Acute type A aortic dissection, Lymphocyte-to-monocyte ratio, Prognosis, Association