Abstract
We reevaluate the predictive accuracy of intravascular ultrasound (IVUS)-derived per
cent plaque area stenosis (PAS) in significant coronary lesions (CLs) with or without
proximal and distal reference vessel area adjustment. IVUS is valuable in defining
moderate CL severity (30 to 70%) in left main (LM) or non-left main (NLM) coronaries
using minimum luminal area (MLA) of ≤5.9 and ≤4 mm2, respectively. Despite a strong correlation with severe CLs, PAS (≥ 70% for NLM and
≥67% for LM) remains underutilized because of confusion about an appropriate reference
standard. We studied 120 patients with symptomatic moderate CLs (74 NLM, 46 LM) who
underwent IVUS. In-lesion and adjusted PAS were derived by subtracting MLA from in-lesion
and proximal or distal reference's external elastic membrane (EEM) area, respectively,
divided by corresponding EEM area multiplied by 100. In-lesion PAS was correlated
with MLA cutoffs of ≤5.9 and ≤7.5 mm2 for LM and ≤4 mm2 for NLM. Adjusted PAS strongly correlated with in-lesion PAS irrespective of reference
segment (proximal reference, r = 0.879, p < 0.001; distal reference, r = 0.833, p < 0.001; mean proximal and distal reference, r = 0.896, p < 0.001). Considering MLA of ≤4 mm2 (for NLM) and ≤5.9 mm2 (for LM), in-lesion PAS of ≥70 and ≥67%, respectively, explained the majority of
severe CLs but the sensitive LM MLA cutoff of ≤7.5 mm2 showed higher predictive accuracy. Based on results, both in-lesion PAS and adjusted
PAS can be used interchangeably and correlate strongly with MLA.
Keywords
intracoronary vascular ultrasound - per cent plaque area stenosis - coronary artery
disease - minimum luminal area
