Contrast-induced nephropathy in patients undergoing primary percutaneous coronary intervention without acute left ventricular ejection fraction impairment

The prognostic relevance of direct contrast toxicity in patients treated with primary percutaneous coronary intervention remains unclear, owing to the confounding hemodynamic effect of acute left ventricular ejection fraction (LVEF) impairment on kidney function estimation. In the present study, 644 consecutive patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention were prospectively enrolled. Contrast-induced nephropathy (CIN) was defined as an increase in serum creatinine >25% or a decrease in the estimated glomerular filtration rate (eGFR) <25% from baseline in the first 72 hours. The primary end point of the study was major adverse cardiovascular events at 1 year (composite of death, myocardial infarction, target lesion revascularization, and bleeding). Among the global population, the interaction between the LVEF and eGFR at admission to define CIN was statistically significant (p <0.001). When only the 385 patients without acute LVEF impairment (i.e., those with LVEF ≥40%) were considered, 27 (7%) developed postprocedural CIN that was associated with increased major adverse cardiovascular events rate at 1 year of clinical follow-up (38% vs 9%; p <0.001). On adjusted Cox multivariate analysis, CIN was an independent predictor of worse outcomes, both when defined according to creatinine (hazard ratio 3.81, 95% confidence interval 1.71 to 8.48, p = 0.001) or eGFR (hazard ratio 3.77, 95% confidence interval 1.53 to 9.28, p = 0.004) variations. In conclusion, in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention, LVEF has a significant interaction with eGFR. When only patients without acute LVEF impairment were considered, CIN confirmed its negative prognostic effect on the 1-year clinical outcomes.