Improvement in renal functions with transcatheter aortic valve implantation

In recent years, emerging transcatheter aortic valve implantation (TAVI) has become an alternative for surgery. However, with advanced age, several co-morbid factors together with contrast agent usage can cause deterioration in renal function and increase in the risk of acute kidney injury (AKI) with poor prognosis in patients with AKI. Therefore, many patients cannot benefit from this treatment. In this study, we aim to examine the effects of TAVI on renal functions.

Seventy patients, mean age of 77.6 years, underwent TAVI between July 2011 and December 2012. Estimated glomerular filtration rate (eGFR) was calculated by using the Cockcroft and Gault Formula. Patients were monitored for 48 h for urine output. Stage 1 AKI, according to the VARC-2 AKIN system, developed in only five (7.1%) of the patients after the procedure. There was a statistically significant increase between the mean 1(st) month eGFRs before (68.2 vs. 61.0, P < 0.01) and after (68.2 vs. 63.6, P < 0.05) the TAVI in the cohort. After TAVI (48.5 mL/min, P < 0.01) and the 1(st) month (52.1 mL/min, P < 0.01), the eGFR of the 36 (51.4%) patients diagnosed with chronic kidney disease before the procedure showed a statistically significant increase in renal functions. The hospital mortality rate was higher in the group which developed AKI (P < 0.01). First month eGFR showed a more statistically significant increase than pre-TAVI eGFR (62.8 and 69.8, P < 0.05, respectively) in AKI developing patients and this difference - though statistically not significant - continued into the sixth month.

In this study, we showed that the treatment of aortic stenosis through TAVI allows improvement of renal functions, and that AKI rates will be lower with careful patient selection, proper pre-procedural hydration, and careful use of contrast agent.