Safe Limits of Contrast Vary With Hydration Volume for Prevention of Contrast-Induced Nephropathy After Coronary Angiography Among Patients With a Relatively Low Risk of Contrast-Induced Nephropathy

Abstract

Background-Few studies have investigated the safe limits of contrast to prevent contrast-induced nephropathy (CIN) based on hydration data. We aimed to investigate the relative safe maximum contrast volume adjusted for hydration volume in a population with a relatively low risk of CIN. Methods and Results-The ratios of contrast volume-to-creatinine clearance (V/CrCl) and hydration volume to body weight (HV/W) were determined in patients undergoing cardiac catheterization. Receiver-operator characteristic curve analysis based on the maximum Youden index was used to identify the optimal cutoff for V/CrCl in all patients and in HV/W subgroups. Eighty-six of 3273 (2.6%) patients with mean CrCl 71.89±27.02 mL/min developed CIN. Receiver-operator characteristic curve analysis indicated that a V/CrCl ratio of 2.44 was a fair discriminator for CIN in all patients (sensitivity, 73.3%; specificity, 70.4%). After adjustment for other confounders, V/CrCl >2.44 continued to be significantly associated with CIN (adjusted odds ratio, 4.12; P<0.001) and the risk of death (adjusted hazard ratio, 2.62; P<0.001). The mean HV/W was 12.18±7.40. We divided the patients into 2 groups (HV/W ≤12 and >12 mL/kg). The best cutoff value for V/CrCl was 1.87 (sensitivity, 67.9%; specificity, 64.4%; adjusted odds ratio, 3.24; P=0.011) in the insufficient hydration subgroup (HV/W, ≤12 mL/kg; CIN, 1.32%) and 2.93 (sensitivity, 69.0%; specificity, 65.0%; adjusted odds ratio, 3.04; P=0.004) in the sufficient hydration subgroup (HV/W, >12 mL/kg; CIN, 5.00%). Conclusions-The V/CrCl ratio adjusted for HV/W may be a more reliable predictor of CIN and even long-term outcomes after cardiac catheterization. We also found a higher best cutoff value for V/CrCl to predict CIN in patients with a relatively sufficient hydration status, which may be beneficial during decision-making about contrast dose limits in relatively low-risk patients with different hydration statuses. (Circ Cardiovasc Interv. 2015;8:e001859.

Excessively High Hydration Volume May Not Be Associated With Decreased Risk of Contrast‐Induced Acute Kidney Injury After Percutaneous Coronary Intervention in Patients With Renal Insufficiency

“…Using data from the previous study,6 we included patients ≥18 years of age who agreed to stay in the hospital for 2 to 3 days after coronary angiography. Inclusion criteria were use of low‐osmolarity contrast agents and isotonic saline hydration administration.…”

“…The most effective methods for controlling risk of CI‐AKI have been reported to include preventive measures aimed at reducing risk of PCI‐induced renal complications. According to existing PCI guidelines, the key prophylaxes include identifying high‐risk patients, individually reducing the dose of the contrast medium, and providing adequate hydration with isotonic saline 3, 4, 5, 6, 7, 8. However, no well‐defined protocols currently exist regarding the optimal rate and duration of normal saline administration to prevent CI‐AKI in patients with renal insufficiency undergoing PCI 9, 10.…”

Balancing the Risks and Benefits of Using Emergency Diagnostic Radiocontrast Studies to Diagnose Life-Threatening Illness in Critically Ill Patients: A Decision Analysis

“…In addition, hypotension is known to increase the risk of CIN 1 , but its presence also increases the pre-test probability of a life-threatening illness which would increase the yield and possibly benefit of a radiocontrast study. While the benefit of using prophylactic measures against CIN after administering radiocontrast has not been well studied and documented, it is possible that some simple measures, such as aggressive intravenous hydration, possibly with sodium bicarbonate, both immediately before and after radiocontrast exposure may still have some benefit [3][4][5][6]16,17 , and thus should be initiated for critically ill patients who are at high risk of developing CIN.…”

“…CT pulmonary angiography, CT aortography, CT abdominal angiography), between 50 and 100 ml of radiocontrast would be needed. For patients with severe pre-existing risk impairment (eCrCl <20 ml/minute), the estimated risk of CIN would be twice as estimated by the CIN risk calculator because the volume of contrast needed (in ml) would exceed 2.5-3.0 times the value of eCrCl (in ml/minute) 3,[8][9][10][11] .…”

“…In practice, to balance the benefit and risk of a radiocontrast study for critically ill patients is challenging. Firstly, in critically ill patients presenting with symptoms of a life-threatening illness, opportunities to use prophylactic measures against CIN, including aggressive intravenous hydration, are limited [3][4][5][6] . Secondly, although renal impairment is the most established and important risk factor for CIN, other risk factors such as hypotension, diabetes mellitus, anaemia, and older age are also common in the critically ill 1,7 .…”