Affiliations: Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
Correspondence:
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Corresponding author: Hao-Ming Hsiao, Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan. E-mail:hmhsiao@ntu.edu.tw
Abstract: Rupture-prone plaques in the coronary arteries, called
``vulnerable plaques'', are recognized as the key factor in acute myocardial
infarction. Vulnerable plaques have a thin fibrous cap over a large fatty
core and are highly susceptible to rupture. In general, this type of plaque
rupture is mainly associated with stress concentrated on the fibrous cap.
Fibrous cap stresses are counted among the most important factors in the
plaque rupture process and must be taken into consideration when assessing
the plaque vulnerability leading to heart attacks. The objective of this
paper was to investigate the effects of nitinol stent deployment on the
morphological changes of vulnerable plaques and then to propose a new stent
design concept for effectively reducing fibrous cap stresses and the
associated rupture risk. The deployment of a self-expanding nitinol stent
was modeled, and the resulting stress distribution on the fibrous cap was
investigated. The fibrous cap stresses were more uniformly distributed and
the maximum stress was reduced by 13% when the crown number of the stent
was increased. This study demonstrates an excellent approach to stent design
that could effectively reduce the risk of a vulnerable plaque rupturing and
causing a heart attack.
Keywords: Heart attack, vulnerable plaque, fibrous cap stresses, nitinol stent, finite element analysis
