Risk of Worsening Renal Function Following Repeated Exposures to Contrast Media During Percutaneous Coronary Interventions

BACKGROUND: Multiple contrast media exposures are common, but their cumulative effect on renal function is unknown. We aimed to investigate the renal consequences of repeated exposures to contrast media with coronary interventions. METHODS AND RESULTS: We studied 2942 patients who underwent between 1 and 9 procedures. The primary end point was a persistent creatinine increase of ≥50% above baseline at ≥90 days after the last procedure. The effect of cumulative contrast media dose was assessed using Cox models, with cumulative exposure as a time‐dependent variable, and propensity score matching. The primary end point occurred in 190 patients (6.5%), with 6.1%, 6.8%, and 6.2% of patients with 1, 2 or 3, and ≥4 procedures, respectively (P=0.75). In the multivariable Cox model, baseline renal function, diabetes, anemia, acute coronary syndrome, and heart failure were independent predictors of the primary end point (all P≤0.01), whereas cumulative contrast dose was not (hazard ratio [HR], 1.29 [95% CI, 0.89–1.88] for the fourth contrast quartile [>509 mL] versus first contrast quartile [<233 mL]). Propensity score matching yielded 384 patient pairs with similar characteristics and either 1 or 2 to 9 contrast exposures (median cumulative dose, 160 and 480 mL, respectively). Despite large differences in the cumulative contrast exposure, there were similar rates of the primary end points (7.3% versus 6.3%, respectively; HR, 0.76 [95% CI, 0.44–1.32]). CONCLUSIONS: In patients with multiple exposures to contrast media, worsening of renal function over time is associated with known risk factors for the progression of kidney disease but not with cumulative contrast volume.