Contrast medium dose-to-GFR ratio: a measure of systemic exposure to predict contrast-induced nephropathy after percutaneous coronary intervention.
BACKGROUND
The contrast medium (CM) dose-to-eGFR (estimated glomerular filtration rate) ratio has recently been advocated to express systemic exposure to CM in assessing the risk of contrast medium-induced nephropathy (CIN).


OBJECTIVE
To evaluate how CIN risk might vary with decreasing eGFR at fixed CM-dose/eGFR ratios and other CIN risk factors, and to find a relatively safe CM-dose/eGFR ratio.


METHODS
391 patients underwent primary coronary angioplasty for ST-segment elevation acute myocardial infarction. CM dose (grams iodine; g I), eGFR (ml/min), and preprocedural CIN risk factors were entered into a multiple logistic regression model. From the established statistical model, the probability of CIN (>or=44.2 micromol/l serum creatinine rise or oliguria/anuria) was calculated at various eGFR levels based on g-I/eGFR ratios of 1:2, 1:1, 2:1, and 3:1.


RESULTS
At a g-I/eGFR ratio <1 the risk of CIN was 3%, while it was 25% at a g-I/eGFR ratio >or=1. Independent predictors of CIN were CM dose, eGFR, left ventricular ejection fraction (LVEF) and cardiogenic shock (ROC area =0.87). An estimated CIN risk of 10% would for example occur at a g-I/eGFR ratio of 1.5:1 in patients with 50% LVEF without shock. At a 1:2, 1:1, 2:1, and 3:1 g-I/eGFR ratio with 50% LVEF without shock, the CIN risk was about 2, 6, 18, and 30%, respectively, over a wide range of eGFR values (30-90 ml/min). At a 1:1 g-I/eGFR ratio with 50% LVEF+shock, 25% LVEF without shock, or 25% LVEF+shock, the CIN risk was 20, 55, and 80%, respectively.


CONCLUSIONS
Relating CM dose to eGFR appears to be an attractive pharmacotoxic model to assess CIN risk. At fixed CM-dose/eGFR ratios, CIN risk increased marginally with decreasing eGFR. Limiting the CM dose in g I numerically to the eGFR value in ml/min or less may be relatively safe with regard to CIN, unless multiple risk factors are present.
Department of Radiology, Lasarettet Trelleborg, University of Lund, Trelleborg, Sweden.
U
U
Nyman
J
J
Björk
P
P
Aspelin
G
G
Marenzi
D058186:Acute Kidney Injury / Q000139:chemically induced; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary; D015415:Biomarkers / Q000097:blood; D003287:Contrast Media / Q000008:administration & dosage* / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009203:Myocardial Infarction / Q000628:therapy; D011237:Predictive Value of Tests; D012372:ROC Curve; D051437:Renal Insufficiency / Q000139:chemically induced*; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity
D015415:Biomarkers; D003287:Contrast Media; D003404:Creatinine