Prediction of atherosclerotic plaque life – Perceptions from fatigue analysis

Cardiovascular diseases are the leading causes of morbidity and mortality globally. Heart disease and stroke contribute to most fatalities in which atherosclerotic plaque disruption is the underlying pathology. The pulsatile blood flow in the arteries generates mechanical stresses that affect the rupture of the atherosclerotic plaque. Fatigue failure being the accumulation of the damage due to repeated loading that occurs when the stresses are much lower than those needed to rupture the plaque with normal loading. Therefore, fracture mechanics concepts were used to investigate the impact of morphology and blood pressure on the plaque life. Incremental fatigue crack propagation simulations were performed on idealized geometries based on the maximum circumferential stress criteria by using a finite element solver. XFEM, which extends the standard finite element formulation by introducing additional enrichment functions was used to model the fatigue crack growth simulations. Paris’ Law was used to determine the fatigue crack growth rate. Cracks extended radially and fatigue crack growth rate increased with increase in pulse pressure. Further validation studies on the 3D printed arteries are necessary for better understanding the factors contributing to plaque rupture. The results could help in assessing the atherosclerotic plaque life under the fatigue environment of the cardiovascular system.