preprocedural bioimpedance vectorial analysis of fluid status and prediction of contrastinduced acute kidney injury objectives the aim of this study was to evaluate the relationship between preprocedural fluid status assessed by bioimpedance vector analysis biva and development of contrastinduced acute kidney injury ciakibackground accurate fluid management in patients undergoing angiographic procedures is of critical importance in limiting the risk of ciaki therefore establishing periprocedural fluid volume related to increased risk of ciaki development is essentialmethods we evaluated the fluid status by biva of 900 consecutive patients with stable coronary artery disease cad immediately before coronary angiography measuring the resistanceheight rh ratio and impedanceheight zh vector ciaki was defined as an increase in serum creatinine 05 mgdl above baseline within 3 days after contrast administration iodixanolresults ciaki occurred in 54 patients 60 preprocedural rh ratios were significantly higher in patients with ciaki than without ciaki 395 71 ohmm vs 352 58 ohmm p 0001 for women 303 59 ohmm vs 279 45 ohmm p 0009 for men indicating lower fluid volume in the patients with ciaki when patients were stratified according to rh ratio there was an almost 3fold higher risk in patients with higher values odds ratio or 29 95 confidence interval ci 15 to 55 p 0002 the optimal receiveroperating characteristic curve analysis threshold values of rh ratio for predicting ciaki were 380 ohmm for women and 315 ohmm for men rh ratio above these thresholds was found to be a significant and independent predictor of ciaki or 31 95 ci 18 to 55 p 0001conclusions lower fluid status evaluated by biva immediately before contrast medium administration resulted in a significant and independent predictor of ciaki in patients with stable cad this simple noninvasive analysis should be tested in guiding tailored volume repletion