Progression in the severity of aortic stenosis according to race among those with advanced chronic kidney disease

There is a higher prevalence of aortic stenosis (AS) in patients with advanced chronic kidney disease (CKD) and European ancestry. However, studies comparing AS progression in white and black patients in an advanced CKD population do not exist.

Advanced CKD (stage IV-V) patients who were referred to the UNC Cardiorenal Clinic for pre-operative kidney transplant evaluation, and diagnosed with either AS (mild, moderate, or severe) or a left ventricular outflow tract velocity ≥2 m/s at any point between 2006-2016 were eligible for inclusion. Serial transthoracic echocardiograms over the 10-year period determined AS progression. All echocardiograms acquired after renal transplantation or aortic valve replacement were excluded. The rates of change of three indices of AS severity [mean gradient, aortic valve area (AVA), and aortic valve velocity] were compared between white and black patients. Mixed effects linear models with repeated measures were used to estimate the overall and race-stratified yearly rate of progression for each index, adjusted for age, sex, smoking status, dialysis, and baseline cholesterol.

Of 1,283 patients, 140 (34% white, 66% black) developed or had baseline AS. Initially, 81% had no AS, 13% had mild, and 6% had moderate. White patients were more likely to be male and less likely to be on hemodialysis compared to black patients. No differences in AS severity (P=0.55) or age (60 vs. 58 years, P=0.34) were seen at baseline. In white vs. black patients, mean gradient increased at 1.90 (95% CI: 0.79, 3.01) mmHg/year vs. 1.46 (95% CI, 0.79, 2.14) mmHg/year, P=0.20, AVA decreased at -0.10 (95% CI: -0.15, -0.05) m²/year vs. -0.08 (95% CI: -0.11, -0.05) m²/year, P=0.13, and transvalvular velocity increased at 0.11 (95% CI: 0.04, 0.18) m/s/year vs. 0.07 (95% CI: 0.03, 0.11) m/s/year, P=0.09.

Compared to black patients, white patients in an advanced CKD cohort may have exhibited more rapid progression of AS. Ours is the first study to analyze racial differences in such a population. A study with a larger sample size is needed to confirm our findings.