Effects of calcific and inflammatory mechanisms on different aortic cusps in etiopathogenesis of degenerative aortic stenosis

Objectives: This study aimed to evaluate pathological differences in aortic valve cusps from patients undergoing aortic valve replacement due to aortic stenosis. Patients and methods: In this single-blind observational study, aortic valves from 20 patients (10 males, 10 females; mean age: 69±6.36 years; range, 62-84 years) were divided into left coronary, right coronary, and noncoronary cusps between January 2013 and December 2014. The cusps were stabilized in 10% formalin and sent to the pathology lab in a blinded manner. Sections 5 µm in thickness were prepared, stained with hematoxylin-eosin and Van Gieson, and analyzed for inflammation, fibrosis, and calcification using light microscopy. Comparisons were made between right, left, and noncoronary cusps. Results: Inflammation comparisons between right, left, and noncoronary cusps showed no statistically significant differences (p=0.199, p=0.789, and p=0.379, respectively). For fibrosis, left and right coronary cusps and right and noncoronary cusps were not significantly different (p=0.079 and p=0.880); however, the comparison between left coronary and noncoronary cusps was significant (p=0.046). Regarding calcification, left and right coronary cusps and right coronary and noncoronary cusps showed no significant difference (p=0.285 and p=0.180), while the comparison between left coronary and noncoronary cusps was statistically significant (p=0.011). Conclusion: While pathological differences between aortic valve cusps are rarely emphasized in the literature, this study identified significant fibrosis and calcification differences in left coronary and noncoronary cusps. These findings could contribute to a better understanding of calcific aortic stenosis and potentially guide new treatments.