Contrast induced nephrotoxicity (CIN) after coronary angiography or angioplasty (CA) has been shown to be related to mortality. The rate and predictors of CIN when preventive measures are applied are poorly documented.

All consecutive patients submitted to non-urgent CA in 2014 with low-osmolar contrast medium were stratified for CIN risk: patients with renal dysfunction (defined as eGFR<60mL/min) had interruption of diuretics and received a 250-500mL intravenous saline infusion before and after CA. Serum Creatinine (SCr) levels were measured before CA and daily thereafter up to 5 days after CA. CIN was defined as an absolute increase of 44µmol/L SCr or of 25% over baseline SCr level. Predictors of CIN and of recovery were determined by logistic regression. CIN patients had clinical follow-up for death or end-stage renal dysfunction.

SCr results were available in 958 patients, 72% male, 25% diabetics, median eGFR was 71mL/min before CA (interquartiles (IQ)=54; 89). Median amount of contrast was 129mL (IQ=90; 186). At 2-4 days, CIN was observed in 188(20%), driven by a 25% increase in SCr (n=185, 19%) whereas 81 (8.5%) had an increase of>44mmol/L in SCr. CIN rate was related to quartiles of eGFR before CA: 20% when eGFR<53, 14% for eGFR between 53 and 88 and 30% for eGFR>87ml/min. The amount of contrast medium was not a predictor of CIN. In patients without renal dysfunction, a lower SCr was a predictor of CIN. Conversely, in patients with renal dysfunction, older age and diabetes were associated with CIN (figure).

In contemporary routine practice, CIN occurs in 20%, driven by a relative 25% increase in SCr, and irrespective of the amount of contrast medium. In patients with renal dysfunction, older age and diabetes were associated with CIN.