Prognostic value of N-Acetylglucosaminidase and Kidney-injury-molecule-1 in TAVI patients with severe aortic stenosis

Aim: Cardiorenal syndrome (CRS) is common in severe aortic stenosis (AS). Previous studies revealed N-Acetylglucosaminidase (NAG) and Kidney-injury-molecule-1 (KIM-1) as potential markers for CRS. The study aimed to investigate the prognostic capability of NAG, KIM-1, NT-proBNP in severe AS before TAVI.

Materials & methods: Plasma and urine samples were collected from 151 participants before TAVI. Long-term follow-up (median follow-up time 31 months) was conducted to assess all-cause mortality and a composite endpoint of mortality and congestive heart failure.

Results: NT-proBNP was significantly elevated in classical low-flow, low-gradient AS compared to other severe AS phenotypes (p < 0.01), unlike NAG and KIM-1 (each p = n.s.). During follow-up, 40 patients (26.5%) died, and 58 patients (38.4%) reached the composite endpoint. Elevated baseline levels of NAG and KIM-1 were associated with increased risk of all-cause mortality in Kaplan-Meier analysis, like NT-proBNP (each p<0.05). NAG and STS-Score were revealed as significant predictors for all-cause mortality in multivariable COX-regression analysis (each p<0.05), unlike NT-proBNP, KIM-1, eGFR, and clinical parameters (each p=n.s.).

Conclusion: Baseline NAG and, to a lesser degree, KIM-1 and NT-proBNP provide significant predictive value for all-cause mortality in patients with severe AS before TAVI.