Does contrast agent injection during trans-catheter aortic valve implantation negatively affect kidney function?

BACKGROUND Trans-catheter aortic valve implantation (TAVI) has recently emerged as an alternative to conventional surgery in high-risk surgical patients with haemodynamically significant aortic valve stenosis. However, patients referred for TAVI are usually elderly individuals (> 80 years) who frequently also suffer from renal impairment. Trans-catheter valve therapies require extensive use of contrast injections with a risk of nephrotoxicity. AIM To evaluate post-TAVI renal function and to determine whether the exposure to contrast injections might cause reduced kidney function and contrast-induced nephropathy. METHODS From January 2009 to September 2010, TAVI was performed in 39 patients (26 women and 13 men). The mean age of the patients was 81.43 ± 7.39 years, and the mean volume of contrast material administered was 187.95 ± 91.34 mL. Serum creatinine and glomerular filtration rate (GFR, acc. to the MDRD formula) were estimated in all patients prior to and 1, 2, and 5-8 days after TAVI. RESULTS Two female patients died on postoperative day 1. Other patients did not show clinically significant reduction in renal function following the procedure (mean creatinine concentration 104.46 vs 99.77 vs 94.56 vs 93.64 mmol/L, NS and mean GFR 52.37 vs 56.63 vs 60.18 vs 61.34 mL/min/1.73 m², NS). CONCLUSIONS 1. The TAVI procedure, which includes contrast injection does not seem to cause a clinically significant decrease of renal function. 2. None of our elderly patients with severe aortic valve stenosis, multiple co-morbidities, and pre- TAVI renal compromise developed contrast-induced nephropathy.