Severe Aortic Stenosis: Secular Trends of Incidence and Outcomes

Quick Takes

  • The current analysis aimed to assess population-based secular trends in incidence, treatment, and outcomes in patients with severe aortic stenosis (AS).
  • Over a span of 20 years, the incidence of severe AS remained stable (52 per 100,000 patient-years). There was a slight decrease in incidence among women, with stable incidence among men over the study period.
  • There was a significant increase in aortic valve replacement (AVR) volumes with reduced time to treatment. Early AVR was associated with significant survival benefit; however, short-term (3-month = 8%) and long-term (3-year = 36%) mortality remained stable. Undertreatment of AS remained prevalent (40%).

Study Questions:

What is the change in incidence, clinical presentation, treatment, and outcome for quantitatively defined severe aortic stenosis (AS) over the last 20 years in a population-based community?

Methods:

All adult residents in Olmsted County, MN diagnosed over 20 years (1997–2016) with incident severe AS (first diagnosis) based on quantitatively defined measures (aortic valve area ≤1 cm2, aortic valve area index ≤0.6 cm2/m2, mean gradient ≥40 mm Hg, peak velocity ≥4 m/s, Doppler velocity index ≤0.25) were counted to define trends in incidence, presentation, treatment, and outcome.

Results:

Incident severe AS was diagnosed in 1,069 community residents. The incidence rate was 52.5 [49.4–55.8] per 100,000 patient-years, slightly higher in males versus females, and was almost unchanged after age and sex adjustment for the US population 53.8 [50.6–57.0] per 100,000 residents/year. Over 20 years, severe AS incidence remained stable (p = 0.2) but absolute burden of incident cases markedly increased (p = 0.0004) due to population growth. Incidence trend differed by sex, stable in men (incidence rate ratio, 0.99; p = 0.7) but declining in women (incidence rate ratio, 0.93; p = 0.02). Over the study, AS clinical characteristics remained remarkably stable and aortic valve replacement (AVR) performance grew and was more prompt (from 1.3 [0.1–3.3] years in 1997–2000 to 0.5 [0.2–2.1] years in 2013–2016; p = 0.001) but undertreatment remained prominent (>40%). Early AVR was associated with survival benefit (adjusted hazard ratio, 0.55; [0.42–0.71]; p < 0.0001). Despite these improvements, overall mortality (3-month 8% and 3-year 36%) was swift, considerable, and unabated (all p ≥ 0.4) throughout the study.

Conclusions:

Over 20 years, the population incidence of severe AS remained stable with increased absolute case burden related to population growth. Despite stable severe AS presentation, AVR performance grew notably, but while declining, undertreatment remained substantial and disease lethality did not yet decline. These population-based findings have important implications for improving AS management pathways.

Perspective:

The current analysis aimed to assess population-based secular trends in incidence, treatment, and outcomes in patients with severe AS. Notable findings include: 1) Over a span of 20 years, incidence of severe AS remained stable (52 per 100,000 patient-years). There was a slight decrease in incidence among women, with stable incidence among men over the study period; 2) There was a significant increase in AVR volumes with reduced time to treatments; 3) Early AVR was associated with significant survival benefit; and 4) Despite increasing intervention, short-term (3 month = 8%) and long-term (3 year = 36%) mortality remained stable and undertreatment remained prevalent (40%). Study findings highlight the need for identifying ways to get patients with severe AS appropriate treatment without delay.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Aortic Surgery, Cardiac Surgery and VHD, Interventions and Structural Heart Disease

Keywords: Aortic Valve Stenosis, Transcatheter Aortic Valve Replacement


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