Serum Alpha-1-microglobulin (A1M) as an independent predictor of calcific aortic valve stenosis and its diagnostic value.

RNA sequencing revealed a significant upregulation of the AMBP (alpha-1-microglobulin/bikunin precursor) expression in calcific aortic valve tissue. This study aimed to investigate the potential diagnostic value of serum A1M for aortic valve stenosis (AVS). Patients with AVS were consecutively enrolled, with age- and gender- matched controls. All participants were rigorously categorized into non-severe AVS, severe AVS and control groups based on transthoracic echocardiography. Serum A1M levels were measured via ELISA. We explored the relationship between serum A1M and AVS using logistic regression, smoothed curve fitting, threshold effect analysis, and subgroup analysis. A total of 234 (69.9 ± 8.36 years, 92 (39.3 %) males) patients were included, with 61 (26.0 %) in the non-severe AVS group, 89 (38.0 %) in the severe AVS group, and 84 (36.0 %) in control group. Serum A1M levels were significantly lower in AVS patients, particularly in those with severe AVS (Control: 22.00 ± 8.25 μg/mL, non-severe AVS: 14.72 ± 4.79 μg/mL, severe AVS: 10.11 ± 3.95 μg/mL, respectively, P < 0.001). Multivariate analysis identified serum A1M levels as independent predictor for AVS (adjusted OR = 0.761 [95 % CI: 0.715 to 0.811], P < 0.001). ROC analysis demonstrated that A1M exhibited good diagnostic value in diagnosing AVS (AUC = 0.867, 95 % CI: 0.818 to 0.917, P < 0.001) and assessing its severity (AUC = 0.771, 95 % CI: 0.695 to 0.847, P < 0.001). Serum A1M levels were significantly reduced in AVS patients and progressively decreased with disease severity. It served as an independent predictor and demonstrated strong diagnostic utility for both AVS presence and severity grading.