Combination of plaque burden, wall shear stress, and plaque phenotype has incremental value for prediction of coronary atherosclerotic plaque progression and vulnerability

- Coronary segments with large plaque burden and low WSS show greater plaque progression.
- Segments with PIT, large plaque burden and high WSS show increased plaque vulnerability.
- Incremental value of regional WSS in predicting plaque progression and vulnerability.
- WSS: wall shear stress; PIT: pathological intimal thickening.

AimsLarge plaque burden, certain phenotypes, and low wall shear stress (WSS) are associated with adverse outcomes and high WSS with development of plaque vulnerability. We aimed to investigate the incremental value of the combination of plaque burden, WSS and plaque phenotype for prediction of coronary atherosclerotic plaque progression and vulnerability.MethodsTwenty patients with CAD underwent baseline and 6-month follow-up coronary virtual histology-intravascular ultrasound (VH-IVUS) and computational fluid dynamics modeling for calculation of WSS. Low WSS was defined as <10 dynes/cm2 and high WSS as ≥25 dynes/cm2. Baseline plaque characteristics and WSS were related to plaque progression and vulnerability.ResultsIn 2249 VH-IVUS frames analyzed, coronary segments with both plaque burden >40% and low WSS had significantly greater change in plaque area at follow-up (+0.68 ± 1.05 mm2), compared to segments with plaque burden >40% without low WSS (−0.28 ± 1.32 mm2) or segments with low WSS and plaque burden ≤40% (+0.05 ± 0.71 mm2) (p = 0.047). Among plaque phenotypes, pathologic intimal thickening (PIT) had the greatest increase in necrotic core (NC) area (p = 0.06) and greatest decrease in fibro-fatty (FF) area (p < 0.0001). At follow-up, compared to segments with either plaque burden >60%, PIT, or high WSS, those with a combination of plaque burden >60%, PIT, and high WSS developed greater increase in NC area (p = 0.002), greater decrease in FF (p = 0.004) and fibrous areas (p < 0.0001), and higher frequency of expansive remodeling (p = 0.019).ConclusionCombination of plaque burden, WSS, and plaque phenotype has incremental value for prediction of coronary plaque progression and increased plaque vulnerability in patients with non-obstructive CAD.