Sr Dir, Pharmacoepidemiology Regeneron Pharmaceuticals, Inc., United States
Background: Aortic stenosis (AS) is one of the most common valvular heart diseases in the US and aortic valve replacement (AVR) is the only current treatment option. Currently, there are no published studies exploring the national population-based prevalence estimates of AS or AVR.
Objectives: Describe the overall, age- and sex-specific annual and 5-year prevalence of AS between 2017 – 2021 and the proportion of AS patients who received AVR annually.
Methods: A cross-sectional, descriptive study was conducted using the Optum Clinformatics® Data Mart, which includes a 25% subset of the Medicare Advantage population. AS was defined as >1 inpatient or >2 outpatient ICD-9 and ICD-10 AS codes at any point in a patient’s claims record. To estimate annual prevalence, patients needed to meet the AS definition criteria in that specific year or prior years and had 28 days minimum enrollment in that given year. Prevalence estimates were age and sex standardized to the 2020 US Census population. The AS cohort was used as the denominator to determine the proportion of AS patients that received AVR. Linear regression was applied to model the annual trend of AS prevalence over the study period.
Results: The 5-year age- and sex-standardized AS prevalence (n=498,064) was 1.01%, with the peak annual prevalence occurring in 2017 (1.11%). The mean AS diagnosis age was 74.0 years (standard deviation [SD] 10.2) and the mean age at initial AVR was 75.4 years (SD: 9.5). The 5-year sex-standardized prevalence was lowest among those aged 18-44 years (0.04%) and increased with age, peaking at age >85 years (12.53%). The 5-year age-standardized prevalence was nearly equal between sexes (female: 0.96%; male: 1.06%). On average, there was a 0.03% decrease in sex- and age-standardized AS prevalence with each year increment (slope = -0.03%; 95% CI: -0.04%- -0.01%). Yet, sans age and sex standardization there was a 0.5% increase in the prevalence (slope= 0.05%; 95% CI: 0.04%-0.07%), indicating that age and sex likely influence AS prevalence estimates and should be considered in future estimates. In 2021, 4.02% (n=12,124) of AS patients underwent AVR. From 2017-2021, the occurrence of transcatheter AVR increased by 1.7-fold (2017: 1.63%, 2021: 2.91%), surpassing surgical AVR by 2.2-fold in 2021.
Conclusions: To date, we report the most recent US AS prevalence estimates. Our overall prevalence estimate is nearly double published ones from a decade ago, but our age- and sex-specific estimates align with prior ones. Our results indicate that 1 out of 8 Americans aged >85 years have AS and further supports the specific role that age plays in changes to AS prevalence trends. Given the rising number of elderly Americans, it is likely that the prevalence of AS may continue to rise and possibly in turn, the number of AVRs performed.
