7th Dutch Bio-Medical Engineering Conference

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14:00
15 mins

Temporal and Spatial Changes in Wall Shear Stress During Atherosclerotic Plaque Progression in Mice
Ruoyu Xing, Astrid Moerman, Yanto Ridwan, Anton van der Steen, Frank Gijsen, Kim van der Heiden

Session: Cardiovascular diseases
Session starts: Friday 25 January, 13:00
Presentation starts: 14:00
Room: Lecture room 558

Ruoyu Xing ()
Astrid Moerman ()
Yanto Ridwan ()
Anton van der Steen ()
Frank Gijsen ()
Kim van der Heiden ()

Abstract:
ABSTRACT Wall shear stress (WSS) is involved in atherosclerotic plaque initiation, yet its role in plaque progression remains unclear. We aimed to study (i) the temporal and spatial changes in WSS over a growing plaque and (ii) the correlation between WSS and plaque composition, using animal-specific data in an atherosclerotic mouse model. Tapered casts were placed around the right common carotid arteries (RCCA) of ApoE-/- mice (n=7). At 5, 7 and 9 weeks after cast placement, RCCA geometry was reconstructed using contrast-enhanced micro-CT. Lumen narrowing was observed in all mice, indicating the progression of a lumen intruding plaque. Next, we determined the flow rate in the RCCA of each mouse using Doppler Ultrasound and computed WSS at all time points. Over time, as the plaque developed and further intruded into the lumen, absolute WSS significantly decreased (see figure). Finally at week 9, plaque composition was histologically characterized. The proximal part of the plaque was small and eccentric, exposed to relatively lower WSS. Close to the cast a larger and concentric plaque was present, exposed to relatively higher WSS. Lower WSS was significantly correlated to the accumulation of macrophages in the eccentric plaque. When pooling data of all animals, correlation between WSS and plaque composition was weak and no longer statistically significant [1]. In conclusion, our data showed that in our mouse model absolute WSS strikingly decreased during disease progression, which was significantly correlated to plaque area and macrophage content. Besides, our study demonstrates the necessity to analyze individual animals and plaques when studying correlations between WSS and plaque composition. [1] Xing et al., Royal Society, 2018, 5(3)