Background: There is conflicting evidence regarding the impact of preexisting renal dysfunction (RD) on mid-term outcomes after transcatheter aortic valve implantation (TAVI) in patients with symptomatic aortic stenosis (AS).
Methods and results: Forty-seven articles representing 32,131 patients with AS undergoing a TAVI procedure were included in this systematic review and meta-analysis. Pooled analyses were performed with both univariate and multivariate models, using a fixed or random effects method when appropriate. Compared with patients with normal renal function, mid-term mortality was significantly higher in patients with preexisting RD, as defined by the author (univariate hazard ratio [HR]: 1.69; 95% confidence interval [CI]: 1.50-1.90; multivariate HR: 1.47; 95% CI: 1.17-1.84), baseline estimated glomerular filtration rate (eGFR) (univariate HR: 1.65; 95% CI: 1.47-1.86; multivariate HR: 1.46; 95% CI: 1.24-1.71), and serum creatinine (univariate HR: 1.69; 95% CI: 1.48-1.92; multivariate HR: 1.65; 95% CI: 1.36-1.99). Advanced stage of chronic kidney disease (CKD stage 3-5) was strongly related to bleeding (univariate HR in CKD stage 3: 1.30, 95% CI: 1.13-1.49; in CKD stage 4: 1.30, 95% CI: 1.04-1.62), acute kidney injure (AKI) (univariate HR in CKD stage 3: 1.28, 95% CI: 1.03-1.59; in CKD stage 4: 2.27, 95% CI: 1.74-2.96), stroke (univariate HR in CKD stage 4: 3.37, 95% CI: 1.52-7.46), and mid-term mortality (univariate HR in CKD stage 3: 1.57, 95% CI: 1.26-1.95; in CKD stage 4: 2.77, 95% CI: 2.06-3.72; in CKD stage 5: 2.64, 95% CI: 1.91-3.65) compared with CKD stage 1+2. Patients with CKD stage 4 had a higher incidence of AKI (univariate HR: 1.70, 95% CI: 1.34-2.16) and all-cause death (univariate HR: 1.60, 95% CI: 1.28-1.99) compared with those with CKD stage 3. A per unit decrease in serum creatinine was also associated with a higher mortality at mid-term follow-up (univariate HR: 1.24, 95% CI: 1.18-1.30; multivariate HR: 1.19, 95% CI: 1.08-1.30).
Conclusions: Preexisting RD was associated with increased mid-term mortality after TAVI. Patients with CKD stage 4 had significantly higher incidences of peri-procedural complications and a poorer prognosis, a finding that should be factored into the clinical decision-making process regarding these patients.