|Classification and external resources|
Contrast-induced nephropathy is defined as either a greater than 25% increase of serum creatinine or an absolute increase in serum creatinine of 0.5 mg/dL after percutaneous coronary intervention (PCI) using a contrast agent. Despite extensive speculation, the actual occurrence of contrast-induced nephropathy in other patient populations has not been demonstrated in the literature.
To minimize the risk for contrast-induced nephropathy, various actions can be taken if the patient has predisposing conditions. These have been reviewed in a meta-analysis. A separate meta-analysis addresses interventions for emergent patients with baseline insufficient kidney function.
Three factors have been associated with an increased risk of contrast-induced nephropathy: preexisting decreased kidney function (such as creatinine clearance < 60 mL/min [1.00 mL/s] - online calculator), preexisting diabetes mellitus, and reduced intravascular volume.
- Systolic blood pressure <80 mm Hg - 5 points
- Intraarterial balloon pump - 5 points
- Congestive heart failure (Class III-IV or history of pulmonary edema) - 5 points
- Age >75 y - 4 points
- Hematocrit level <39% for men and <35% for women - 3 points
- Diabetes mellitus- 3 points
- Contrast media volume - 1 point for each 100 mL
- Decreased kidney function:
- Serum creatinine level >1.5 g/dL - 4 points
- 2 for 40–60 mL/min/1.73 m2
- 4 for 20–40 mL/min/1.73 m2
- 6 for < 20 mL/min/1.73 m2
5 or less points
- Risk of CIN - 7.5
- Risk of Dialysis - 0.04%
- Risk of CIN - 14.0
- Risk of Dialysis - 0.12%
- Risk of CIN - 26.1*
- Risk of Dialysis - 1.09%
- Risk of CIN - 57.3
- Risk of Dialysis - 12.8%
Choice of contrast agent
The osmolality of the contrast agent was previously believed to be an important factor in contrast-induced nephropathy. Today it has become increasingly clear that other physicochemical properties play a greater role, such as viscosity. Attention should be paid to use contrast agents of low viscosity. Moreover, sufficient fluids should be supplied to limit fluid viscosity of urine. Modern iodinated contrast agents are non-ionic, the older ionic types caused more adverse effects and are not used much anymore.
N-acetylcysteine (NAC) 600 mg orally twice a day, on the day before and of the procedure if creatinine clearance is estimated to be less than 60 mL/min [1.00 mL/s]) may reduce nephropathy.[medical citation needed] Some authors believe the benefit is not overwhelming. A systematic review by Clinical Evidence concluded that NAC is "likely to be beneficial" but did not recommend a specific dose.
While there are currently no FDA-approved therapies for contrast-induced nephropathy, two therapies are currently being investigated. CorMedix, Inc. is currently in the latter part of phase II clinical trials with approved phase III Special Protocol Assessment for CRMD001 (unique formulation Deferiprone) to prevent contrast-induced acute kidney injury and to slow progression of chronic kidney disease. Dosing trials began in June 2010 in the sixty patient trial.
PLC Medical Systems, Inc. has begun a phase III clinical trial of RenalGuard Therapy to prevent contrast-induced nephropathy. The therapy utilizes the RenalGuard System, which measures the patient's urine output and infuses an equal volume of normal saline in real-time. The therapy involves connecting the patient to the RenalGuard System, then injecting a small dosage of furosemide to induce high urine rates. RenalGuard Therapy has already been studied in two Italian studies, both of which found the therapy to be superior to the current standard of care.
- Barrett BJ, Parfrey PS (2006). "Clinical practice. Preventing nephropathy induced by contrast medium". N. Engl. J. Med. 354 (4): 379–86. doi:10.1056/NEJMcp050801. PMID 16436769.
- Pannu N, Wiebe N, Tonelli M (2006). "Prophylaxis strategies for contrast-induced nephropathy". JAMA 295 (23): 2765–79. doi:10.1001/jama.295.23.2765. PMID 16788132.
- Sinert R, Doty CI (2007). "Evidence-based emergency medicine review. Prevention of contrast-induced nephropathy in the emergency department". Annals of Emergency Medicine 50 (3): 335–45, 345.e1–2. doi:10.1016/j.annemergmed.2007.01.023. PMID 17512638.
- McCullough PA, Wolyn R, Rocher LL, Levin RN, O'Neill WW (1997). "Acute renal failure after coronary intervention: incidence, risk factors, and relationship to mortality". Am J Med 103 (5): 368–75. doi:10.1016/S0002-9343(97)00150-2. PMID 9375704.
- Scanlon PJ, Faxon DP, Audet AM, Carabello B, Dehmer GJ, Eagle KA, Legako RD, Leon DF, Murray JA, Nissen SE, Pepine CJ, Watson RM, Ritchie JL, Gibbons RJ, Cheitlin MD, Gardner TJ, Garson A Jr, Russell RO Jr, Ryan TJ, Smith SC Jr (1999). "ACC/AHA guidelines for coronary angiography. A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on Coronary Angiography). Developed in collaboration with the Society for Cardiac Angiography and Interventions". J Am Coll Cardiol 33 (6): 1756–824. doi:10.1016/S0735-1097(99)00126-6. PMID 10334456.
- Mehran R, Aymong ED, Nikolsky E et al. (2004). "A simple risk score for prediction of contrast-induced nephropathy after percutaneous coronary intervention: development and initial validation". J. Am. Coll. Cardiol. 44 (7): 1393–9. doi:10.1016/j.jacc.2004.06.068. PMID 15464318.
- Bagshaw SM, Ghali WA (2005). "Theophylline for prevention of contrast-induced nephropathy: a systematic review and meta-analysis". Arch. Intern. Med. 165 (10): 1087–93. doi:10.1001/archinte.165.10.1087. PMID 15911721.
- Gleeson TG, Bulugahapitiya S (2004). "Contrast-induced nephropathy". AJR Am J Roentgenol 183 (6): 1673–89. doi:10.2214/ajr.183.6.01831673. PMID 15547209.
- Kellum J, Leblanc M, Venkataraman R (2006). "Renal failure (acute)". Clinical evidence (15): 1191–212. PMID 16973048.
- Sadat U, Usman A, Gillard JH, Boyle JR (2013). "Does ascorbic acid protect against contrast-induced acute kidney injury in patients undergoing coronary angiography: a systematic review with meta-analysis of randomized, controlled trials.". J Am Coll Cardiol 62 (23): 2167–75. doi:10.1016/j.jacc.2013.07.065. PMID 23994417.
- , CorMedix June 25, 2010 Press Release, "CorMedix Doses First Patient in Phase II Clinical Trial of CRMD-001"
- , ClinicalTrials.gov, "Deferiprone for the Prevention of Contrast-Induced Acute Kidney Injury"
- , ClinicalTrials.gov,"Evaluation of RenalGuard® System to Reduce the Incidence of Contrast Induced Nephropathy in At-Risk Patients (CIN-RG)"
- Marenzi, Giancarlo; Bartorelli,A (2012). "Prevention of Contrast Nephropathy by Furosemide With Matched Hydration". J Am Coll Cardiol Intv 5 (1): 90–97. doi:10.1016/j.jcin.2011.08.017. PMID 22230154.
- Briguori, Carlo (September 2011). "Renal Insufficiency After Contrast Media Administration Trial II (REMEDIAL II): RenalGuard System in high-risk patients for contrast-induced acute kidney injury.". Circulation 124 (11): 1260–9. doi:10.1161/CIRCULATIONAHA.111.030759. PMID 21844075.