Relationship between residual atheroma burden and neointimal growth in patients undergoing stenting: Analysis of the atherectomy before MULTI-LINK improves lumen gain and clinical outcomes trial intravascular ultrasound substudy

Objectives The objective of this study was to examine the relationship between quantitative volumetric and cross-sectional measures of residual atheroma burden and neointimal growth after coronary stenting. Background Previous intravascular ultrasound (IVUS) studies have demonstrated a correlation between residual atheroma burden and neointimal growth after coronary stenting. However, postmortem studies contradict this finding. Methods The study population included 34 patients who underwent IVUS six to eight months after stent placement, including 26 patients who underwent IVUS immediately after stent placement and at six to eight months follow-up. Using manual planimetry, the lumen cross-sectional area (LA), stent cross-sectional area (SA) and external elastic membrane cross-sectional area (EEM) were measured at 1-mm intervals after the procedure and at follow-up. Percent neointimal area (NA) and atheroma area (AA) were calculated as: percent neointimal AREA = ([SA − LA]/SA) × 100; percent AA = ([EEM − SA]/EEM) × 100 in the entire cross section and in individual quadrants. Postinterventional atheroma volume and neointimal volume at follow-up were calculated using Simpsons’s rule. Results In pooled analyses using all cross sections and cross-sectional quadrants, there was a weak correlation between percent AA and NA (r = 0.11 and 0.12, respectively). Analysis in individual patients demonstrated no significant relationship between total or quadrant measurements of percent AA and NA (p = 0.47 and 0.4, respectively). No relationship between atheroma volume postintervention and neointimal volume at follow-up was observed (r = 0.1, P = 0.62). Conclusions This study failed to demonstrate a clinically significant relationship between quantitative volumetric and cross-sectional measures of residual atheroma burden and subsequent neointimal growth.