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.

Transcatheter aortic valve implantation using transfemoral/transsubclavian or transapical approach: 30-day follow-up of the initial 30 patients.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is a new method for the treatment of aortic stenosis (AS). AIM: To evaluate early results of TAVI using transfemoral/transsubclavian approach (TFA/TSA) or transapical approach (TAA) in patients with severe AS and high risk for surgical aortic valve replacement. METHODS: Between January 2009 and May 2010, 30 high-risk patients underwent TAVI. The primary treatment option was TFA, and TAA was used if contraindications to TFA were present; one patient underwent the procedure using TSA. Reasons for selecting TAA were as follows: small diameter (<7 mm) and/or severe calcification of the iliofemoral arteries, peripheral atherosclerosis, "porcelain" aorta and a horizontal course of the ascending aorta. Edwards-Sapien or CoreValve devices were used in all cases, and procedures were performed without the use of cardiopulmonary bypass in a cardiac catheterisation laboratory. RESULTS: Mean patient age was 82.46 ± 5.79 years, mean NYHA class was 3.23 ± 0.41, and predicted mean surgical mortality using logistic Euroscore was 29.18 ± 16.9% (22.72 ± 12.07% in the TFA/TSA group vs 34.6 ± 15.4% in the TAA group; p = 0.031). Eleven patients were treated using TAA. The valve was implanted successfully in 96% of patients. Inhospital mortality was 3.3%. Mean 30-day mortality was 6.6% in the entire cohort, 0% in the TFA/TSA group and 18% in the TAA group. There were no cases of periprocedural myocardial infarction (MI), cardiogenic shock, stroke/transient ischaemic attack, or need for cardiopulmonary resuscitation. One patient died suddenly three weeks after the procedure; except for this case, there were no major adverse cardiovascular events (MACCE: MI, cerebrovascular accident, re-do procedure) at 30-day follow-up. The TAVI was associated with a significant reduction in the mean maximal aortic gradient in both groups (from 99.6 ± 22.07 mm Hg to 21.83 ± 9.38 mm Hg post-procedure and to 23.25 ± 9.22 mm Hg at 30-day follow up), with no cases of severe aortic valve regurgitation. The NYHA class at 30 days improved from 3.23 ± 0.41 to 1.72 ± 0.52 (p = 0.03). CONCLUSIONS: Our results demonstrate lower 30-day complication rate and mortality in the TFA/TSA group. The availability of several techniques of valve implantation in the group of non-surgical patients with severe AS potentially broadens the patient population with indications for this treatment.