title: Incidence, risk factors and prognosis of acute kidney injury after transcatheter aortic valve implantation.
abstract: OBJECTIVE
  Transcatheter aortic valve implantation (TAVI) poses a significant risk of acute kidney injury (AKI). Little is known of the impact of TAVI and AKI on long-term kidney function and health cost. We explored the predictive factors and prognostic implications of AKI following TAVI.
  
  
  METHODS
  Single-centre retrospective analysis of 52 elderly patients undergoing TAVI was conducted. The primary endpoint was renal outcome which included the incidence of AKI and 12-month renal function after TAVI. Secondary endpoints were mortality, the length of hospital stay (LOS) and cost.
  
  
  RESULTS
  AKI occurred in 15/52 (28.8%) patients (mean age 84 ± 6) and three patients (6%) required dialysis. Patients with AKI (AKI+) had greater comorbidity (diabetes and cerebrovascular disease) and a trend towards reduced estimated glomerular filtration rate (eGFR) at baseline compared with those without AKI (56.6 vs AKI-: 65.7 mL/min per 1.73 m(2) , P = 0.07). Following TAVI, AKI- patients experienced an immediate improvement in eGFR, which remained significantly higher at all time points compared with AKI+ patients (70.4 vs 46.9 at 6 months and 73.7 vs 53.0 at 12 months, P < 0.001). Cumulative mortality for AKI+versus AKI- group was 26.7% and 2.7% (P = 0.006). LOS doubled (P < 0.001) and average hospitalization cost per patient was 1.5 times higher in the AKI+ group (P < 0.001). Independent predictors of AKI were peri-procedural blood transfusion (OR: 2.4, 95% CI: 2.0-3.1), trans-apical approach (OR: 9.3, 95% CI: 4.3-23.7) and hypertension (OR: 6.4, 95% CI: 2.9-17.3).
  
  
  CONCLUSIONS
  AKI developed in 28.8% of patients after TAVI and was associated with procedural technique and transfusion requirement, and an increased LOS and mortality. However, most patients achieved a significant and sustained improvement in eGFR.
authors.affiliation: Department of Nephrology and Transplantation, Royal Perth Hospital Interventional Cardiology & High Risk Aortic Stenosis State Service WA, Royal Perth Hospital, Perth, Western Australia, Australia.
authors.forename: Wai Y
authors.initials: WY
authors.lastname: Kong
authors.forename: Gerald
authors.initials: G
authors.lastname: Yong
authors.forename: Ashley
authors.initials: A
authors.lastname: Irish
mesh_terms: D058186:Acute Kidney Injury / Q000191:economics / Q000453:epidemiology* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000191:economics / Q000601:surgery*; D006328:Cardiac Catheterization / Q000009:adverse effects* / Q000401:mortality; D016009:Chi-Square Distribution; D015897:Comorbidity; D005260:Female; D005919:Glomerular Filtration Rate; D017048:Health Care Costs; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000191:economics / Q000379:methods / Q000401:mortality; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D015994:Incidence; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000503:physiopathology; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D006435:Renal Dialysis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D065227:Transfusion Reaction; D016896:Treatment Outcome; D014904:Western Australia / Q000453:epidemiology