High spatial endothelial shear stress gradient independently predicts site of acute coronary plaque rupture and erosion.

AIMS

To investigate local haemodynamics in the setting of acute coronary plaque rupture and erosion.

METHODS AND RESULTS

Intracoronary optical coherence tomography performed in 37 patients with acute coronary syndromes caused by plaque rupture (n = 19) or plaque erosion (n = 18) was used for three-dimensional reconstruction and computational fluid dynamics simulation. Endothelial shear stress (ESS), spatial ESS gradient (ESSG), and oscillatory shear index (OSI) were compared between plaque rupture and erosion through mixed-effects logistic regression. Lipid, calcium, macrophages, layered plaque, and cholesterol crystals were also analysed. By multivariable analysis, only high ESSG [odds ratio (OR) 5.29, 95% confidence interval (CI) 2.57-10.89, P < 0.001], lipid (OR 12.98, 95% CI 6.57-25.67, P < 0.001), and layered plaque (OR 3.17, 95% CI 1.82-5.50, P < 0.001) were independently associated with plaque rupture. High ESSG (OR 13.28, 95% CI 6.88-25.64, P < 0.001), ESS (OR 2.70, 95% CI 1.34-5.42, P = 0.005), and OSI (OR 2.18, 95% CI 1.33-3.54, P = 0.002) independently associated with plaque erosion. ESSG was higher at rupture sites than erosion sites [median (interquartile range): 5.78 (2.47-21.15) vs. 2.62 (1.44-6.18) Pa/mm, P = 0.009], OSI was higher at erosion sites than rupture sites [1.04 × 10-2 (2.3 × 10-3-4.74 × 10-2) vs. 1.29 × 10-3 (9.39 × 10-5-3.0 × 10-2), P < 0.001], but ESS was similar (P = 0.29).

CONCLUSIONS

High ESSG is independently associated with plaque rupture while high ESSG, ESS, and OSI associate with plaque erosion. While ESSG is higher at rupture sites than erosion sites, OSI is higher at erosion sites and ESS was similar. These results suggest that ESSG and OSI may play critical roles in acute plaque rupture and erosion, respectively.