Age-related changes in aortic valve with emphasis on the relation between pressure loading and thickened leaflets of the aortic valves

Background The information of the prevalence of TAV and its relation to aortic stenosis in a large-scale human population is limited. Methods An echocardiographic study was performed prospectively in 2850 subjects to determine the relationship between age and the thickened aortic valves (TAV). Another simulated study was designed to test the hypothesis that the noncoronary leaflet may have a greater diastolic loading than the right or left coronary leaflet. Results The prevalence of TAV in this population was 14.4% (410/2850). It was 0% in the <39 years old; however, the prevalence of TAV increased progressively with age: it was 10.0% in the middle age group, 17.0% in the elderly group, and 53.7% in the octogenarian group (Chi-square test for linear trend, χ2=67.10, p<0.001). A greater frequency of TAV was noted at noncoronary leaflet (57.0%) than at either right (22.3%) or left (20.6%) coronary leaflet (χ2=5.99, df=2, p<0.001). The prevalence of aortic stenosis (AS) tended to increase with age (Chi-square test for linear trend, χ2=37.85, p<0.001). The simulated study demonstrated that the sinus of Valsalva without a coronary leaflet had a higher pressure loading than that with a coronary leaflet. Conclusion This study demonstrates that the prevalences of TAV and AS increase progressively with age. A greater frequency of TAV is found at the noncoronary leaflet than at either the right or left coronary leaflet. The simulated study supports our hypothesis that the noncoronary leaflet may bear a greater pressure loading than either the left or right coronary leaflet.