Automatic assessment of stent neointimal coverage by intravascular optical coherence tomography

This study aimed to validate automatic intravascular optical coherence tomography (IVOCT) analysis for the evaluation of neointimal coverage in response to stent implantation.

Fourteen stented segments in common iliac arteries, acquired from a total of seven adult male New Zealand White rabbits, were interrogated in vivo by IVOCT. Durable polymer everolimus-eluting stents (EES; Xience V, Abbott Vascular, Santa Clara, CA, USA) were used exclusively. Comparison with histology was made in a total of 63 pairs of images, where neointimal thickness over corresponding individual stent struts was assessed. A high correlation coefficient (R = 0.85, P < 0.001) was obtained by comparing automatic IVOCT analysis with histology. Moreover, Bland-Altman statistics showed good limits of agreement (LOAs) of ±45 µm, with an average difference of -10 µm. In addition, manual IVOCT assessment presented very similar results when compared with histology (R = 0.83, P < 0.001 and LOA = ±48 µm with an average difference of -8 µm). Therefore, a very high correlation value was found, comparing manual to automatic IVOCT measurements (R = 0.95, P < 0.001) together with good LOAs (±27 µm) and an average difference of -2 µm.

The results of the study suggest that automatic IVOCT analysis is a reliable and accurate tool able to speed up current IVOCT analysis procedures. This would potentially allow for a better integration of IVOCT in clinical practice and clinical studies assessing vascular response to stent implantation in a large series of patients.