Acute kidney injury after aortic valve replacement in a nationally representative cohort in the USA

Background: Randomized trials have consistently shown lower rates of acute kidney injury (AKI) with transcatheter aortic valve replacement (TAVR) compared with surgical aortic valve replacement (SAVR). Comparative rates of AKI for TAVR versus SAVR, and predictors and prognostic implications of AKI after aortic valve replacement (AVR) have not been well studied in nationally representative real-world data. Objectives: First, to compare rates of AKI and dialysis requiring AKI in TAVR versus SAVR. Second, to determine predictors of AKI and prognostic implications of AKI in patients undergoing TAVR or SAVR. Methods: We used the 2011-14 National Inpatient Sample to identify all patients undergoing isolated TAVR or SAVR using validated international classification of diseases, ninth revision ICD-9 codes. Rates of AKI and AKI requiring dialysis (AKI-D) were compared between the two groups using a propensity-matched design. Predictors of AKI and prognostic impact of AKI on in-hospital outcomes were ascertained using multivariate logistic regression. Results: A total of 8004 unweighted TAVR procedures and 29 355 unweighted SAVR procedures representative of 39 898 TAVR and 143 608 SAVR procedures nationwide were included in the analysis. Mean age of all patients undergoing AVR was 70.9 years and 42.3% were females. In a propensity-matched cohort of 4889 pairs of TAVR and SAVR procedures, TAVR was associated with significantly lower rates of AKI [odds ratio (OR) 0.73, 95% confidence interval (CI) 0.66-0.80, P < 0.001] and AKI-D (OR 0.69, 95% CI 0.50-0.96, P = 0.03) compared with SAVR. AKI was associated with significantly higher rates of in-hospital mortality for TAVR (OR 7.16, 95% CI 5.52-9.29, P < 0.001) as well as SAVR (OR 9.43, 95% CI 7.71-11.55, P < 0.001). Conclusions: In a large propensity-matched cohort of TAVR and SAVR procedures, TAVR was associated with significantly lower rates of AKI and AKI-D compared with SAVR. AKI and AKI-D are predictors of poor in-hospital outcomes in TAVR as well as SAVR.