Impact of kidney function on mortality after transcatheter valve implantation in patients with severe aortic valvular stenosis

AIMS: Transcatheter aortic valve implantation (TAVI) is an accepted alternative for patients with severe aortic valve stenosis who cannot undergo surgery. Acute kidney injury (AKI) is a serious complication in any invasive cardiovascular intervention. The objectives of the study were to determine (i) the influence of kidney function before TAVI and (ii) the impact of changes in kidney function after TAVI, including acute kidney injury (AKI), on mortality.

METHODS AND RESULTS: A total of 540 patients undergoing TAVI were included. Patients were divided into three groups according to glomerular filtration rate (GFR) before TAVI (A: normal renal function i.e. GFR ≥60ml/min; B: impaired renal function i.e. GFR 30-59ml/min; C: severe impaired renal function i.e. GFR <30ml/min). Multivariate analysis showed a significant impact of GFR on mortality (p<0.0008). Subgroup analysis showed significant differences between the groups in 30-day (A: 5.4%, B: 9.0%, C: 25.0%) and 12-month mortality (A: 15.0%, B: 32.0%, C: 49%). Patients who had an increase in GFR after TAVI by more than 22% (p=0.0068) had an improved survival rate, whereas a decrease in GFR by more than 15% was associated with an increased mortality rate (p=0.0051). AKI occurred in 30 patients (5.6%), of which 22 patients (73.3%) died within 12months.

CONCLUSION: Outcome is significantly related to pre-procedural kidney function. In addition, changes in kidney function after TAVI have a significant impact on mortality. Due to a very poor prognosis in patients with AKI, any effort to prevent this serious complication after TAVI needs to be taken.