Hypothesis:

Cystatin C compared with creatinine is a better and earlier marker of contrast-induced nephropathy in high and intermedium risk cardiac catheterization patients.

Primary Objective:

Establish if Cystatin C is superior detecting contrast-induced nephropathy than creatinine in high and intermedium risk cardiac catheterization patients.

Contrast induced-nephropathy is a complication that is underestimated in clinical practice after cardiac catheterization. During the last 30 years, because of the increasing use of contrast medium for diagnostic and therapeutic procedures, this has become the third in-hospital cause of acute renal failure (12%). That's why, it is necessary to establish an earlier marker of renal dysfunction that can help us in the diagnosis and allow us to initiate the appropriate therapeutics, because depending on the severity of the renal damage, it can increase the cardiovascular risk and morbidity.

The risk of contrast medium nephropathy is still present even with the use of low osmolarity contrast media, and many patients increase their in-hospital days, costs and hemodialysis requirement.

Cystatin C is a non glucosylated protein produced in nucleated cells in a constant rate, and because of its low molecular weight it's filtered through the glomerular membrane without restriction and it's fully reabsorbed in the proximal tubule, that's why it's considered an excellent marker evaluating the glomerular filtration rate in patients with acute renal failure during the first 24-48 hours.

We propose that Cystatin C can be useful as an earlier and superior marker of contrast-induced nephropathy in high and intermedium cardiac catheterization patients.

Inclusion Criteria:

• Age over 20 years old
• Indication for coronariography and/or percutaneous coronary intervention
• Voluntary written consent for the realization of coronariography and/or percutaneous intervention and for the participation in this clinical trial
• A MEHRAN contrast-induced nephropathy score from six to fifteen.

Exclusion Criteria:

• N-Acetylcystein and Fenoldopam pre-medication
• Low risk patients according MEHRAN classification
• Cardiogenic and septic shock
• Acute renal failure by any other cause
• Patients with chronic kidney failure requiring any kind of dialysis
• Patients unable to complete follow-up
• Exposure to contrast media 48 hours prior to study
• Patients unable to give consent
• Receiving contrast media other than non-ionic

Patients over 20 years old with an indication for coronariography and/or percutaneous coronary intervention, and with a MEHRAN contrast-induced nephropathy score from six to fifteen.