Post PCI Contrast Induced Nephropathy

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Post PCI Contrast Induced Nephropathy

• Brandon M. Williams M.D.
• A.M. Report 9/9/08

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Acute Renal Failure Post Cath/PCI

• Renal atheroemboli
• Hemodynamic instability with decreased renal
  perfusion
• Contrast induced nephropathy

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Renal Atheroemboli

• Other signs of embolization (blue toes, livedo
  reticularis, Hollenhorst plaques, abdominal pain)
• Transient eosinophilia and hypocomplementemia
• Renal failure which persists greater than 7 days

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Evidence of Renal Atheroemboli
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Renal Hypoperfusion

• Oliguria/anuria
• Postischemic acute tubular necrosis (increasing
  Cr, normal to reduced uop, granular casts, FeNa gt
  1

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Contrast Induced Nephropathy (CIN)

• Definition new-onset or an exacerbation of
  renal dysfunction after contrast administration
  in the absence of other causes
• Cr Increase of gt25 or absolute increase of
  gt0.5mg/dl

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CIN Timeline

• Symptoms initially seen 24-48 hours after
  exposure
• Cr peaks at 5-7 days
• Normalizes usually within 7-10 days

Mehran, 2007
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CIN Incidence

• 3rd most common hospital acquired renal failure
• gt5 of patients with cath experience transient
  increase Cr gt 1.0 from baseline

Up to Date Complications of diagnostic cardiac
catheterization
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Outcomes of CIN

• Prognosis of patients with CIN significantly
  worse than those without
• Case control study 1600 pts with contrast,
  mortality rate with CIN (n183) 5.5 times of
  matched controls (n174)
• Increased risk of mortality if require
  hemodialysis
• Increase in cost of 10,345 for hospital stay

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CIN and Coronary Procedures

• Higher mortality than other types of CIN
• 3 primary PCI for ACS (Marenzi et al 2004)
• McCullough et al. 1997
• 1800 pts with coronary interventions with
  contrast
• - ARF 14, dialysis 0.8
• - In house mortality for those to HD 36 (1
  for those without HD)
• - 2 yr survival 19 in those needing HD

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Patient CIN Risk Factors

• RENAL INSUFFICIENCY
• DIABETES MELLITUS WITH CRI
• Volume depletion
• Age gt 75
• Hypotension
• CHF
• Other renal toxins
• Renal transplant
• Hypoalbuminemia

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Procedure CIN Risk Factors

• Multiple studies in 72 hour period
• Intra-arterial injection site
• High volume of contrast
• High osmolality of contrast
• 1st generation ionic monomers, 14-18K
  mosmol/kg
• 2nd generation nonionic monomers, 500-850
  mosmol/kg
• 3rd generation nonionic dimers, 290
  mosmol/kg

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Pathogenesis of CIN

• In animal models, some evidence of ATN but
  mechanism is not fully understood.
• Theories
• Renal vasoconstriction
• Cytotoxic effect of contrast agent

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Renal Vasoconstriction

• Contrast induced release of endothelin (?
  importance) and adenosine
• High osmolality of contrast can cause a reduction
  of medullary blood flow secondary to increased
  viscosity of the blood flowing through the vasa
  recta (usually low viscosity)

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Vasa Recta
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Direct Tubular Injury

• Direct cytotoxic effects
• Oxygen free radicals

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McCullough et al.
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Prevention

• Contrast low or iso-osmolar (similar results)
  Omnipaque (iohexol) 844mOsm/kg
• Hold nephrotoxic drugs (NSAIDs, calcineurin
  inhibitors, diuretics, aminoglycosides,
  metformin)
• Hydration NS better than ½ NS, ?sodium
  bicarbonate, ascorbic acid, and N-acetylcysteine
• Continue statin
• Hemofiltration (Cr 3-4) 6hr before and 12-18hr
  post
• ? IV antioxidants, renal vasodilators, forced
  hydration

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McCullough et al.
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At UNC

• Hydration NS at 1mL/kg/hr for 12 hours prior to
  cath
• Acetylcystein 600-1200mg po BID x 4 doses (2
  doses the day prior and 2 the day of)
• Na Bicarb 150mEq in 1L D5W at 3mL/kg/hour(max
  110kg) x 1 hour on call to procedure, then
  1mL/kg/hour (max 110kg) x 6 hours

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References

• Marenzi et al. Contrast-induced nephropathy in
  patients undergoing primary angioplasty for acute
  myocardial infarction. J Am Coll Cardiol, 44,
  2004. pp 1780-1785
• McCullough et al. Contrast-Induced Acute Kidney
  Injury. J Am Coll Cardiol, 51, 2008, 1419-1428
• Mehran. Contrast-Induced Nephropathy Remains a
  Serious complication of PCI. J Interven Cardiol
  20. 2007 236-240
• Plueger et al. Role of adenosine in contrast
  media-induced acute renal failure in diabetes
  mellitus. Mayo Clin Proc 2000, Dec 70 (12)
  1275-83
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