Prediction of contrast-induced nephropathy after percutaneous coronary intervention: Role of contrast volume/body weight ratio

Abstract

Background : The use of contrast media has been closely related to contrast-induced nephropathy (CIN) in several studies. However, there is no firm description of the association. The volume of contrast media and patient characteristics may be important risk factors for CIN. Identifying and quantifying these risk factors may be useful in predicting risk of CIN.

Objective : To identify important risk factors of CIN after percutaneous coronary intervention (PCI).

Design : Prospective analytical study

Setting : King Chulalongkorn Memorial Hospital

Method : A total of 181 consecutive patients who underwent PCI were enrolled. Patient- and procedure-related factors including calculated volume/body weight (V/BW) ratio were recorded. CIN was defined as an increase in serum creatinine > 25% or > 0.5 mg/dl from pre-PCI value within 72 hours after PCI or diagnosed with CIN. Receiver-operator characteristics (ROC) methods were used to determine the optimal cutoff point of V/BW ratio. The V/BW ratio and other factors were tested for an association with CIN by multivariate logistic regression analysis.

Results : The incidence of CIN after PCI was 6.1%. The mean of V/BW ratio in patients developing CIN was 3.2 ± 2.0 ml/kg, and those who did not develop CIN was 2.0 ± 1.0 ml/kg (p-value = 0.001). The ROC curve analysis indicated that V/BW ratio of 2.6 ml/kg was a good discriminator for CIN with concordance statistic (C-statistic) of 0.73. Multivariate logistic regression analysis showed that V/BW ratio ≥ 2.6 ml/kg (OR = 8.184; p-value = 0.003), congestive heart failure (CHF) (OR = 6.465, p-value = 0.010) and creatinine clearance (CrCl) < 30 ml/min (OR = 6.141, p-value = 0.019) were associated with CIN after PCI.

Conclusions : The risk of CIN after PCI was associated with V/BW ratio ≥ 2.6 ml/kg, CrCl < 30 ml/min and CHF. The V/BW ratio ≥ 2.6 ml/kg may be a useful predictor in estimating optimal volume of contrast media for individual patient.