Aims:

Chronic kidney disease (CKD) is frequent in patients with severe aortic stenosis (AS). Previous studies revealed tubular N-acetyl-b-D-glucosamindase (NAG) and Kidney-injury-molecule-1 (KIM-1) as potential markers for the cardiorenal syndrome (CRS). The study aimed to investigate the prognostic impact of baseline NAG, KIM-1, and NT-proBNP in patients with severe AS undergoing TAVR, as well as the value of these biomarkers in different subtypes of severe AS. 

Methods and Results: 

Blood (NT-proBNP) and urine samples (NAG, KIM-1) were collected from 151 individuals with severe AS at admission and from 40 healthy controls. 

A follow-up (median follow-up time 31 months) was conducted regarding the endpoints of all-cause mortality, and the combined endpoint. 

Significantly elevated NAG and KIM-1 values were found in study population in comparison to healthy controls (each p < 0.001). NT-proBNP was significantly elevated in classical low-flow, low-gradient AS in comparison to other severe AS phenotypes (p < 0.01), opposite to NAG and KIM-1 (each p = n.s.). During follow-up, 40 patients (26.5%) died, and 58 patients (38.4%) reached the combined 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, KIM-1 and serum creatinine remained significant predictors for all-cause mortality in multivariate COX-regression analysis (each p < 0.05), unlike NT-proBNP and clinical parameters (each p = n.s.).  Further, NAG and serum creatinine were significant predictors for the combined endpoint (each p < 0.05).

Conclusion:

NT-proBNP, KIM-1 and NAG demonstrated a relevant potential in predicting the prognosis of patients with severe AS undergoing TAVR. Therefore, CRS may present a strong predictor of adverse long-term prognosis after TAVR.