Impact of Age on Aortic Valve Calcium Progression and Risk for Aortic Stenosis: Multi-Ethnic Study of Atherosclerosis

Background Aortic valve calcium (AVC) is strongly associated with the risk for severe aortic stenosis (AS). The prevalence of AVC increases with age, but the impact of age on the progression of AVC and its association with moderate-severe AS is unknown. Methods Our study included 6,810 participants (52.9% women) without overt cardiovascular disease between ages 45 and 84 from the Multi-Ethnic Study of Atherosclerosis. AVC was measured using non-contrast cardiac CT at Visit 1. Progression was calculated as the change in AVC divided by years between CT scans (2-10 years). Incident moderate-severe AS was adjudicated using medical chart review and echocardiogram data from Visit 6 (median follow-up of 16 years). The association between AVC and moderate-severe AS was assessed using multivariable adjusted Cox proportional hazards ratios. Results There were 5,899 participants with AVC =0 and 911 with AVC >0. There were 3,834 participants age <65 years and 2,979 age ≥65 years. The median AVC was 34.1 AU (IQR 13-1,113) for participants <65 versus 69.0 AU (IQR 23-2,453) for participants ≥65. Participants <65 and ≥65 years had no significant difference in median annualized AVC progression within the baseline AVC categories of 1-99 (10 versus 12 AU/year, p=0.303) and AVC ≥100 (50 versus 47 AU/year, p=0.846). AVC >0 was associated with a similar significantly higher risk of incident moderate-severe AS for both younger (HR 13.37; 95% CI 5.67-31.52) and older participants (HR 10.59, 95% CI 6.77-16.56). Conclusion AVC progression was significantly associated with baseline AVC burden and was similar for younger versus older persons after accounting for baseline AVC. The presence of AVC was significantly associated with a higher long-term risk for moderate-severe AS among both younger and older participants.