Impact of New eGFR Equations on Risk Assessment In Patients Undergoing Transcatheter Aortic Valve Implantation

Background: Recently, the Chronic Kidney Disease-Epidemiology Collaboration working group has published new formulas for race-independent estimation of glomerular filtration rate (GFR). We investigated the old and new eGFR equations in patients transcatheter aortic valve implantation (TAVI).

Methods: We conducted a retrospective analysis based on the data from a prospective registry of patients who underwent TAVI from January 2008 to May 2019. The primary endpoint was 30-day mortality after TAVI, and the secondary endpoints included one- and three-year mortality.

Results: In total, 1792 patients undergoing TAVI were included in the present analysis. The thirty-day mortality was 4.6 % (95 % CI 3.8-5.7 %), and the one- and three-year mortality were 17.5 % (95 % CI 15.7-19.4 %) and 34.4 % (95 % CI 32.0-37.0 %). After the application of the new eGFR formula, 12.0 % of patients were reclassified within the GFR category in CKD, while 13.2 % of patients were reclassified within the GFR categories of the EuroSCORE II. Hazard ratios for 30-day, one-year, and three-year mortality increased after introduction of the new creatine-based eq. (1.51, 1.52, 1.49 vs. 1.87, 1.79, 1.74, respectively). Compared to the old equation, the new eGFR <60 ml/min/1.73 m² had a better discrimination ability for the 30-day mortality (Harell's C: 0.563 (95 % CI 0.518-0.608) vs, 0.583 (95 % CI 0.546-0.636); delta Harell's C, 0.031 ± 0.022, p < 0.001). Similar findings were consistently observed in the cystatin creatinine-based equations.

Conclusions: The application of the new race-independent estimators of GFR results in the reassessment of renal function in a significant proportion of TAVI patients and may influence the risk stratification of this population.