The contrast media iohexol causes vasoconstriction of the proximal left anterior descending coronary artery: implications for appropriate stent sizing

Area of Science:

• Cardiology
• Radiology
• Medical Imaging

Background:

• Accurate reference vessel sizing is critical for percutaneous coronary interventions.
• The impact of contrast agents on coronary vessel dimensions is not fully understood.
• Iohexol is a commonly used non-ionic contrast agent in cardiac imaging.

Purpose of the Study:

• To evaluate the effect of iohexol on proximal reference vessel diameter.
• To assess the vasoconstrictive potential of iohexol in patients with left anterior descending artery disease.

Main Methods:

• Quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) were used.
• Measurements were taken in 15 patients with atherosclerotic proximal left anterior descending disease.
• The effect of intracoronary iohexol injection on vessel diameter was analyzed.

Main Results:

• Intravascular ultrasound showed a mean proximal reference vessel diameter of 4.65 mm.
• Iohexol injection caused a significant decrease in IVUS-measured diameter (4.65 to 4.47 mm, P = .002).
• Mean vasoconstriction was 0.18 mm, with a range of -0.04 to 0.5 mm.

Conclusions:

• Iohexol induces significant vasoconstriction in the proximal left anterior descending artery.
• This vasoconstriction can impact reference vessel size measurements.
• Caution is advised when interpreting vessel dimensions after iohexol administration in diseased arteries.