Factors Affecting Rate of Progression of Aortic Stenosis and Its Impact on Outcomes

Abstract

The rate of aortic stenosis (AS) progression in patients with moderate AS is unclear. This study examined the risk factors of progression from moderate to severe AS and its impact on clinical outcomes. A total of 954 patients with moderate AS (valve area >1.0 and ≤1.5 cm²) and follow-up echocardiograms were included. AS progressed to severe (valve area <1.0 cm¹) in 589 patients (61.7%) over a median follow-up of 2.46 (interquartile range [IQR] 1.29 to 3.91) years. Of those who progressed to severe AS, patients were subdivided into Slow (n = 294, over 3.91 [IQR 3.11 to 5.10] years) versus Fast (n = 295, over 1.29 [IQR 0.85 to 1.85] years) Progressors, according to the median time between the 2 echocardiograms. The correlates of fast AS progression and its impact on cumulative survival and freedom from valve intervention were evaluated. On multivariate analysis, age, thickened left ventricle posterior wall, severe renal impairment, and aortic valve area were significantly associated with fast AS progression. Over a median follow-up of 6.34 (IQR 4.05 to 9.55) years, 228 patients (38.7%) died. Despite similar aortic valve intervention rates, Fast Progressors had worse 5-year survival (61.2% vs 81.9%, log-rank p <0.001) and event-free (valve intervention and all-cause mortality) survival rates (16.2% vs 55.9%, log-rank p <0.001). On multivariable Cox analysis, shorter progression to severe AS (in years) was independently associated with increased risk of all-cause mortality (hazard ratio 1.26, 95% confidence interval 1.16 to 1.37, p <0.001), or combined aortic valve intervention and death (hazard ratio 1.46, 95% confidence interval 1.38 to 1.55, p <0.001). In conclusion, fast progression from moderate to severe AS is associated with worse outcomes.