Increased neutrophil-to-lymphocyte ratio is associated with higher incidence of acute kidney injury and worse survival after transcatheter aortic valve implantation

Abstract

Background: Although considered a minimally invasive procedure, transcatheter aortic valve implantation (TAVI) generates an inflammatory response which is related to post-procedural complications including acute kidney injury (AKI). The aim of the present study was to analyze the association between simple, easily available post-operative morphological parameters of inflammatory status such as neutrophil-to-lymphocyte ratio (NLR) and AKI as well as post-discharge survival. Methods: The study group was comprised of 203 consecutive patients (102 females and 101 males, mean age 78 ± 6.9 years) who underwent TAVI between January 2013 and March 2017. Demographic and clinical data were collected. Baseline and subsequent post-procedural blood samples (at 8, 24, 48, 72 h and at discharge) were taken. Blood morphology (including NLR) and creatinine concentration were assessed. Long-term survival was also analyzed. Results: Seventy-four (36.5%) patients developed AKI. Baseline morphological parameters did not differ between subject with and without AKI. Those reflecting post-procedural inflammatory response, including leucocytes, neutrophils and NLR increased significantly following TAVI in both subgroups and the rise was more pronounced in AKI patients (p < 0.001). A comparison of Kaplan-Meier curves for patients with the lowest (NLR 1; below 25th percentile) and highest NLR (NLR 3; above 75th) revealed a significant difference in the log-rank test (p = 0.049). Estimated probability of 1-, 2-and 5-year survival were 100% vs. 79%, 94% vs. 77% and 75% vs. 46%, respectively in subgroup NLR 1 and NLR 3. Conclusions: Inflammatory response after TAVI, estimated by means of NLR, is more pronounced in patients with AKI. A higher value of NLR is associated with a lower probability of long-term survival after TAVI.