Do stents interfere with the densitometric assessment of a coronary artery lesion?

This in vitro study was designed to assess the contribution of three currently investigated coronary stents to the densitometrlc measurement of a known stenosis contained within two different sized plexiglass phantoms. These studies were performed at two concentrations of the contrast agent iopamidol (50 and 100%). The calculated minimal luminal cross‐sectional area values in the control phanton ranged from 0–18% higher than the theoretical values. Insertion of a stainless steel stent (Wallstent™, Schneider, Zürich or Palmaz‐Schatz™, Johnson and Johnson, Warren, NJ) resulted in further minor increases (≤8%) in the calculated minimal luminal cross‐sectional area, except in the smaller phantom filled with 50% contrast medium. The Wiktor™ (tantalum) stent (Medtronic, Minneapolis, MN) had the largest impact of the three stents depending on the concentration of iopamidol (100% contrast medium: 9–13% values above control; 50% contrast medium; 23–56% higher). We conclude that although densitometry may overestimate the minimal luminal cross‐sectional area in stented vessels, this effect is usually minor with stainless steel stents. However, tantalum‐containing stents may result in serious overestimation of lesion area, particularly if contrast is diluted or the vessel Is not well filled.