Gadolinium contrast agents: their role in vascular and nonvascular diagnostic angiography and interventions

The use of gadolinium in patients with contrast allergy or renal failure requiring coronary angiography, coronary intervention, or vascular procedure

Coronary artery angiography remains an important procedure for the assessment of coronary arteries. It requires injection of iodinated contrast for the opacification of coronary arteries. Severe allergy to iodine contrast and renal insufficiency are two main problems with iodine-based contrast media. Gadolinium (Gd) has different chemical structure with no cross reactivity with iodine-based contrast media in patients with iodine allergy. The use of Gd is commonly used in contrast-enhanced magnetic resonance imaging for image enhancement, making it a potential alternative in patients in whom iodine is contraindicated. The aim of this manuscript is to review the available literature on the use of Gd in patients with contraindication to iodine contrast due to allergy or in patients with severe renal failure requiring coronary or vascular procedures.

Gadolinium-based coronary angiography in patients with contraindication for iodinated x-ray contrast medium: a word of caution

BACKGROUND

In coronary angiography, the use of contrast agents containing iodine still defines the gold standard. In patients with contraindications for iodine exposition, gadolinium has been considered to be a safe alternative to standard iodinated contrast medium for coronary angiography. The aim of the present study was to assess the safety and technical quality of gadolinium-based coronary angiography.

METHODS

Nineteen consecutive patients with contraindication to iodinated contrast medium underwent gadolinium-based coronary angiography. Contraindications included previous anaphylactic shock or severe allergic reaction to iodinated contrast medium (n = 13) or thyrotoxicosis (n = 6). Gadolinium was diluted 1:1 with sodium chloride before application. Patients were clinically observed for potential side effects, and renal function was assessed by determination of creatinine values and calculation of creatinine clearance in pre- and postprocedural blood samples. Image quality was evaluated by two independent observers, and classified into three different categories (grade 1, high diagnostic quality; grade 2, moderate diagnostic quality; and grade 3, poor quality).

RESULTS

During angiography, a mean of 32.6 +/- 10.9 mL (range 10-45 mL) gadolinium was used. No patient developed a significant impairment of renal function within 24 hours after the examination (mean creatinine value preprocedural: 1.12 +/- 0.15 mg/dL, postprocedural: 6 hours 1.15 +/- 0.18 mg/dL, 24 hours 1.13 +/- 0.16 mg/dL) (baseline vs. 6 hours P = 0.23, baseline vs. 24 hours P = 0.66, 6 hours vs. 24 hours P = 0.12) (mean creatinine clearance preprocedural: 73.8 +/- 18 mg/dL, postprocedural: 6 hours 71.7 +/- 16.8 mg/dL, 24 hours 73.2 +/- 17.8 mg/dL) (baseline vs. 6 hours P = 0.2, baseline vs. 24 hours P = 0.71, 6 hours vs. 24 hours P = 0.21). Four patients (21%) suffered severe complications due to gadolinium application, such as malignant cardiac arrhythmias (n = 3) and hemodynamic decompensation (n = 1). Image quality was generally reduced in comparison to iodine contrast coronary angiography, but was adequate for diagnostic purposes (13 patients [68.4%] had reasonably good picture contrast [grade 2.1 +/- 0.3]; in 6 patients [31.6%], image quality was satisfactory [grade 2.6 +/- 0.13]). Opacification of distal vessels as compared to proximal segments was remarkably reduced.

CONCLUSIONS

Gadolinium-based coronary angiography is a potential alternative technique in patients with allergy to iodinated contrast medium or thyrotoxicosis with reduced, but acceptable, image quality for diagnostic purposes. Nevertheless, possible life-threatening side effects and complications have to be considered.