Although the burden of aortic stenosis (AS) on our health care system is expected to rise, little is known regarding its epidemiology at the population level. Our primary objective was to evaluate trends in AS hospitalization, treatment and outcomes.

We performed a population-based observational study including 37,970 patients newly hospitalized with AS from 2004 and 2013 in Ontario, Canada. We calculated age- and sex-standardized rate of AS hospitalization through direct standardization. The independent association between year of the hospitalization, and 30-day and 1-year mortality rate was evaluated using logistic regression models to account for temporal changes in patient characteristics.

The overall age- and sex-standardized AS hospitalization rate increased slightly from 36 per 100,000 in 2004 to 39 per 100,000 in 2013. A substantial increase was seen in patients ≥85years, where hospitalization rates increased 29% from 400 to 516 per 100,000 from 2004 to 2013 (P<.001). In this study period, 36.2% of patients received aortic valve interventions within 30days of hospitalization. Among treated patients, an improving mortality trend was observed in which the adjusted odds ratio (OR) was significantly lower in 2013 as compared to 2004 (OR 0.55 for 30-day mortality, 0.74 for 1-year morality). In contrast, no significant temporal change in mortality was seen among patients without aortic valve intervention.

AS hospitalizations in the elderly increased significantly beyond that was expected from population growth. Many AS patients did not receive aortic valve intervention after hospitalization. Mortality among the treated patients improved significantly over time.