Predictors of increased mortality in untreated moderate aortic stenosis

Abstract

Abstract Background The natural history of native valvular moderate aortic stenosis (AS) is poorly understood. Purpose To examine the prognosis of patients with native valvular moderate AS, and identify high risk-features associated with increased mortality. Methods Natural language processing of electronic health records in the claims-linked Optum® database (2011–2018) from over 200 hospitals and 7000 clinics in the United States identified severity of AS (mild/moderate/severe) from echocardiograms and physician notes of patients more than 65 years old. Our cohort included 30,204 patients (3594 with mild, 9938 with moderate, and 16672 with severe AS). We used competing risk Kaplan-Meier analysis to compare 5-year mortality (obtained from the Social Security Death Masterfile) between the different AS severity groups adjusted for demographics and comorbidities, censoring for aortic valve replacement. The relationship between AS severity and survival was examined during median 1049 days (interquartile range: 597 to 1652 days) of follow-up. We performed Fine-Gray modeling to examine risk factors associated with long-term mortality in patients with moderate AS. Results A higher proportion of comorbidities like atrial fibrillation, diabetes, and coronary artery disease were observed with increasing severity of AS (Figure 1). After adjustment, compared with mild AS (5-year mortality: 31.6%), patients with untreated moderate (5-year mortality: 40.0%, HR 1.34, 95% CI 1.25 – 1.44) and untreated severe AS (5-year mortality: 51.1%, HR 1.88, 95% CI 1.75– 2.01) have increasing risk of long-term mortality (Figure 2). Significant predictors of 5-year mortality in patients with moderate AS include older age (HR 1.38, 95% CI 1.29 –1.47), male sex (HR 1.21, 95% CI 1.15 – 1.27), heart failure (HR 1.37, 95% CI 1.29 – 1.44), coronary artery disease (HR 1.20, 95% CI 1.13 – 1.27), and atrial fibrillation (HR 1.08, 95% CI 1.02 – 1.14). In a subcohort of 5189 patients for whom left ventricular ejection fraction (LVEF) information was available, reduced LVEF was associated with worse long-term mortality (LVEF<40%: HR 1.17, 95% CI 1.05 –1.31; LVEF 40–50%: HR 1.08, 95% CI 0.97 –1.20). Conclusion Our findings suggest that moderate AS is associated with poor long-term survival with higher risk associated with LVEF <40%, and comorbidities including heart failure, coronary artery disease and atrial fibrillation. Whether patients with moderate AS, particularly with high-risk features, benefit from treatment remains unknown. Funding Acknowledgement Type of funding sources: None. Baseline CharacteristicsAdjusted KM curves with Competing Risk