Cardiologic prophylaxis for Contrast Induced Nephropathy (CARCIN-trial)

In preoperatieve screening for transcatheter aortic valve implantion (TAVI),
contrast enhanced computed tomography angiography (CTA) is performed as
standard imaging technique with administration of contrast agent. In patients
with an impaired kidney function defined as a the administration of contrast
agents is associated with contrast induced nephropathy (CIN). To prevent CIN,
patients with impaired kidney function get in-hospital CIN prophylaxis,
consisting of 24 hour hydration with saline. In patients with aortic stenosis
or heart failure however, the administration of excessive amounts of fluid can
result in hypervolemia resulting in pulmonary oedema. Recent studies in general
patients show that a 1 hour hydration protocol with sodium bicarbonate is
non-inferior to the widely used 24 hour saline protocol.

The TAVI population is characterized by a high age with a decreased renal
function due to ageing without a nephropathy.

Assess if CIN prophylaxis for CTA and a TAVI procedure with a 1 -hour sodium
bicarbonate protocol is non-inferior in terms of decline in eGFR and serum
creatinine level to the 24 hour saline protocol. in pre-operative screening for
TAVI and actual procedure.

The study is designed as a single center open label prospective randomized
controlled non-inferiority trial.
Arm 1: 24 hour NaCl 0.9%, 1 ml/kg/hour
Arm 2: 1 hour Sodiumbicarbonate 1.4%, 3 ml/kg/hour

This study will provide us insight in the effectiveness of the saline arm and
the bicarbonate as CIN-prophylaxis in the TAVI-patient group. This is of
significant importance since this is an increasing patient group in an ageing
population and advances in the absolute number of TAVI procedures performed
worldwide. Benefits of a shorter and low-volume hydration protocol are an
assumed decreased risk of pulmonary oedema and reduction in admission time.

Patients will be asked to collect two urine samples. An extra blood sample will
be taken 2-5 days after contrast administration. This blood sample can be taken
at the AMC or arranged by the patients general practitioner, according to
patients preference. Current guidelines already advice to follow-up renal
function by means of a blood sample. Furthermore a self-reported level of
dyspnea will be asked at five timepoints. Patients randomized in the saline arm
will receive standard care. Patients randomized in the bicarbonate arm will get
the short 1-hour hydration prophylaxis. There is no difference in admission
time for the TAVI procedure. Patients in the saline arm will be admitted one
day and night at the timepoint of the CTA whereas patients admitted in the
bicarbonate arm will not. There is no difference in admission prior to the TAVI
procedure.

Patients will probably have advantage of the accurate monitoring of kidney
function.