CI-AKI, or contrast-induced acute kidney injury, is defined as a 25% or 0.5 mg/dl increase in creatinine within 48-120 hours of intravenous contrast exposure. It is the third leading cause of hospital-acquired acute kidney injury. Risk factors include higher contrast volumes, pre-existing kidney dysfunction, and diabetes. Prevention strategies include intravenous hydration with isotonic saline before and after the procedure, minimizing contrast volume, and potentially forced diuresis or coronary sinus aspiration of contrast. The risk of CI-AKI in CTO procedures is relatively low if contrast volume is kept under 400 ml without other risk factors like CKD or diabetes. Most cases of CI-AKI are
5. Definition
CI-AKI is defined as a 25% or 0.5 mg/dl increase in creatinine
from baseline
or an increase in cystatin C >10%
within 48 to 120 hours of intravenous contrast exposure
6. CI-AKI
Important complication of use of radiocontrast agents, representing
the third leading cause of hospital-acquired acute kidney injury
CI-AKI typically manifests within 1-3 days of CM administration, peaks
within 3–5 days and resolves within 10– 21 days.
In rare occasions sustained or permanent kidney injury occurs
warranting the use of dialysis.
To monitor for CI-AKI, it is recommended that serum creatinine follow-
up should be obtained at not less than 24 h or more than 72 h
following contrast exposure.
7. It is believed to be due to renal artery vasoconstriction induced by
contrast media, which leads to renal medullary hypoxia.
Other mechanisms include delayed intrarenal transit of the contrast
agent as a result of vasoconstriction leading to oxidative stress
damage
Direct tubular damage due to receptor-mediated tubular
reabsorption of filtered contrast
CI-AKI
11. General measures
Administration of the lowest possible dose of
contrast medium, use of low or iso-osmolar contrast
agents
Maintenance of hemodynamic stability throughout
the procedure to ensure adequate renal perfusion.
14. Cigarroa et al reported an empiric formula for
calculating the maximal acceptable contrast dose
(MACD):
5 ml x body weight (kilograms)/serum creatinine
(milligrams per deciliter)
The use of contrast beyond the MACD was later
correlated to an increased risk of CI-AKI
15. A ratio of <3.7 for the volume of contrast media to creatinine
clearance has also been proposed as a stricter limit.
• Laskey WK et al J Am Coll Cardiol 2007;50:584e590.
16. During CTO, patients who underwent PCI receiving 400 ml of
contrast have an almost 2-fold higher incidence of CI-AKI
compared with those receiving <400 ml of contrast.
However, in the absence of coexistent CKD and diabetes mellitus,
the incidence of CI-AKI remains low, even after high volumes of
contrast media ( 5.4% ).
From: Antonis N. Pavlidis et Al. Am J Cardiol 2015;115:844e851)
The estimated average amount of contrast load in CTO procedures
is 350 ml compared with uncomplicated PCI procedures where it
has been reported in the range of 150 to 200 ml.
18. The majority of CIN patients (53.6%; 15/28)
recovered their baseline renal function within
three months, even those who were in the high-
risk categories (50%; 7/14).
The risk of developing CIN in CTO PCI is
relatively low and the Mehran scoring system is
a good predictor for CIN in CTO PCI
Lin et al. Eurointervention 9:1173-1180 2014
22. Intravenous 0.9% sodium chloride has been
shown to be more effective than 0.45%sodium
chloride or oral hydration in prevention of CI-AKI
23. The most widely used approach is the
administration of
intravenous 0.9% sodium chloride at a rate of
1 ml/kg/hour for 24 hours
beginning 12 hours before administration of
the contrast medium
to achieve a urine output of >150 ml/hour.
24. Patients with moderate-to-severe left
ventricular dysfunction:
cautious hydration with isotonic 0.45% saline
and close monitoring of urine output aiming to
maintain a euvolemic state.
26. Intra CTO technical tips
From: Antonis N. Pavlidis et Al. Am J Cardiol 2015;115:844e851)
27. Forced diuresis (RenalGuard System):
Treatment protocol for the RenalGuard System. Source: Reproduced with
permission from PLC Medical Systems.
28. The physiological benefits include a more
rapid transit of contrast through the kidneys
and reduced oxygen consumption in the
medulla of the kidney.
The study showed a 3-fold reduction in CI-
AKI,which was also associated with a lower
incidence of postprocedural major adverse
clinical events
Marenzi G et al.: the MYTHOS trial. JACC Cardiovasc Interv 2012;5:90e97.
29.
30. The CI-AKICOR System
Comprises an 11Fr coronary sinus aspiration
catheter that is inserted through the jugular
vein. On activation,it exerts a vacuum effect
and removes contrast from the coronary
sinus.
Stephen J. Duffy, MD, PhD
31. Follow-up:
Repeat contrast administration within a short period of time
should be avoided in patients who have undergone complex CTO
recanalization procedures.
From: Antonis N. Pavlidis et Al. Am J Cardiol 2015;115:844e851)
32. CONCLUSION
Nearly one-third of the in-hospital mortality risk post PCI is
attributable to AKI; avoiding nine cases of AKI post PCI could
potentially save one life.
Although the use of a high contrast dose at time of
PCI significantly increases the risk of AKI, contrast dosing is
only a minor contributor to the overall burden of AKI.
Judith Kooiman et al. Circ Cardiovasc Interv. 2015;8:e002212
33. CONCLUSION
In patients with moderate-to-severe CKD the 2014 ESC EACTS guidelines
recommend:
<350 mL
or <4 mL/kg
or total contrast volume/GFR <3.4.
Short-term, high-dose statin therapy should be considered:
Rosuvastatin 40/20 mg or atorvastatin 80 mg or simvastatin 80 mg.
Consensus document from the EuroCTO Club: Eurointervention May 2012
34. CONCLUSION
In patients with normal e GFR keep dye load to less than 400 ml; however,
up to 500-600 ml can be tolerated
Consensus document from the EuroCTO Club: Eurointervention May 2012
In CTO procedures use of retrogradely positioned wires as markers
(rather than using contrast injections) and IVUS may all help to reduce dye
load.
