Angiography is used to take pictures of the coronary arteries. This technique uses contrast material (intravenous contrast dye) that is injected directly into the coronaries. This is the same contrast dye used in many CT-scans. Blood vessels filled with contrast appear darker than the heart and lungs during an x-ray.
Is Intravenous (IV) Contrast Dye Safe?
Most people have no problem with IV contrast dye. Unfortunately, in some people the dye causes allergic reactions and can harm the kidneys. These risks are considered by your doctor before recommending you have a coronary angiogram.
Are My Kidneys at Increased Risk?
If you have chronic kidney disease or diabetes, you are at increased risk of further kidney injury from contrast dye.
What Happens if my Kidneys are Injured by Contrast Dye?
In most cases, kidney function returns to normal. If this does not happen, kidney function may worsen, then stabilize at a new level or progress to complete failure. If your kidneys fail, you¡¯ll require dialysis, which requires a machine to filter your blood. This may occur several times per week. Most dialysis takes place in a hospital or out-patient dialysis center.
The chance that contrast induced kidney injury leads to dialysis is less than 1% (higher if you have chronic kidney problems or need an emergency cardiac procedure).
What Can be Done to Protect my Kidneys?
A blood test of your kidney function is often done before and after angiography. Your doctor may ask you to drink more fluids on the day before or after the angiogram. You may also be instructed to stop certain medications prior to the procedure. Finally, you may be asked to take certain new medications to protect your kidneys prior to the angiogram.
Source:
McCullough PA. Contrast-Induced Acute Kidney Injury. JACC 519(15) 2008.