Risk factors for worsening renal function and their association with long-term mortality following transcatheter aortic valve implantation: data from the SWEDEHEART registry

BACKGROUND: The occurrence of persistent acute kidney injury (pAKI) following transcatheter aortic valve implantation (TAVI) has serious implications. METHODS: There were 1540 patients undergoing and surviving TAVI included in the nationwide SWEDEHEART registry between 2008 and 2015. Creatinine was measured at baseline and discharge, and those with baseline estimated glomerular filtration rate (eGFR) <15 mL/min/1.73 m(2) or dialysis were excluded. pAKI was defined by and encompassing theValve Academic Research Consortium-2 (VARC-2) criteria: increase in serum creatinine concentration ≥26.5 μmol/L or increase by ≥50% (1.5×), or start of in-hospital dialysis until hospital discharge. Logistic regression analysis was used to find baseline factors associated with pAKI. Adjusted Cox regression analysis was used to assess the association of pAKI with mortality. Median follow-up was 1.8 years (IQR 0.7–3.0). RESULTS: pAKI occurred in 6.1% (n=94) of the patients (71.3% male). These patients had higher creatinine level (117±50 vs 100±35 mmol/L, p<0.001), but similar baseline eGFR (59±21 vs 56±23 mL/min/1.73 m(2), p=0.18) and received higher contrast volume (129 mL ±89 vs 110 mL ±78, p=0.027). On multivariable logistic regression analysis, pAKI was predicted by eGFR (OR 0.88, 95% CI (0.79 to 0.98), p=0.019), male gender (OR 2.68, 95% CI (1.63 to 4.38), p<0.001) and apical access (OR 2.23, 95% CI (1.35 to 3.69), p=0.002), whereas contrast volume/10 mL (OR 1.02, 95% CI (1.00 to 1.05), p=0.052) did not reach statistical significance. Mortality at 1 year/end of follow-up was 10.4%/26.9%. pAKI was associated with a doubled risk of death (HR 2.04, 95% CI (1.49 to 2.81), p<0.001). CONCLUSION: Persistent AKI after TAVI occurs in 6.1% and is associated with a doubled long-term mortality. Special efforts to avoid AKI should be taken, especially among vulnerable patients.