Prognostic value of chronic kidney disease after transcatheter aortic valve implantation

Abstract

Objectives: This study sought to assess the influence of chronic kidney disease (CKD) classification on clinical outcomes in patients undergoing transcatheter aortic valve implantation (TAVI).

Background: The prognostic value of impaired renal function according to CKD classification has not been thoroughly investigated in very elderly TAVI cohorts.

Methods: Data from 642 consecutive patients who underwent TAVI were prospectively collected. Clinical outcomes were compared in enrolled patients, divided into CKD stage 1+2, CKD stage 3a, CKD stage 3b, and CKD stage 4 on the basis of estimated glomerular filtration rate ≥60, 45 to 59, 30 to 44, and 15 to 29 ml/min/1.73 m(2), respectively.

Results: Among the study patients (mean age: 83.5 ± 6.5 years, logistic European System for Cardiac Operative Risk Evaluation score 20.0% [range: 13.6% to 28.8%]), 34% were categorized as CKD stage 1+2 (n = 218), 28.3% as CKD stage 3a (n = 182), 28.2% as CKD stage 3b (n = 181), and 9.5% as CKD stage 4 (n = 61). Thirty-day and cumulative 1-year mortality rates increased significantly across the 4 groups (6.9% vs. 8.8% vs. 13.3% vs. 26.2%, p = 0.002, and 17.2% vs. 23.4% vs. 29.2% vs. 47.8%, p < 0.001, respectively). After adjustment for considerable influential confounders in a Cox multivariate regression model, CKD stage 4 was associated with increased risk for 30-day mortality (hazard ratio: 3.04; 95% confidence interval [CI]: 1.43 to 6.49; p = 0.004), and CKD stages 3b and 4 were related to increased cumulative 1-year mortality (hazard ratios: 1.71 and 2.91; 95% CI: 1.09 to 2.68 and 1.73 to 4.90; p = 0.020 and p < 0.001, respectively) compared with CKD stage 1+2 as the referent.

Conclusions: Classification of CKD stages before TAVI allows risk stratification for early and midterm clinical outcomes. TAVI for patients with CKD stage 4 is still considered challenging because of high mortality rates after the procedure.

Keywords: AKI; CI; CKD; EuroSCORE; European System for Cardiac Operative Risk Evaluation; HR; MDRD; Modification of Diet in Renal Disease; SAVR; TAVI; acute kidney injury; chronic kidney disease; confidence interval; eGFR; estimated glomerular filtration rate; hazard ratio; prognosis; surgical aortic valve replacement; transcatheter aortic valve implantation.