Incidence trends and management of severe aortic valve stenosis in the community over 20 years of practice

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Severe aortic-stenosis (AS) is the guideline-based indication for aortic-valve-replacement (AVR) performance, which has markedly increased with transcatheter approaches, suggesting possible increasing AS incidence. However, reported secular trends of AS incidence remain contradictory, uncertain and lacking quantitative Doppler-Echocardiographic ascertainment. Thus, population-based trends in presentation, treatment and outcome are unknown. Methods All adults residents our County (MN,USA) diagnosed with incident (first-diagnosis) severe AS based on quantitative Doppler-Echocardiography (aortic-valve-area≤1cm2, aortic-valve-area-index≤0.6cm2/m2, mean-gradient≥40mmHg, peak-velocity≥4m/s, Doppler-velocity-index≤0.25) between 1997–2016, were accounted for and trends for incidence, presentation, treatment and outcome analysed. Results Incident severe-AS was diagnosed in 1069 community-residents over 20-years. Incidence-rate was 52.5[49.4–55.8] per 100.000 patient/year, slightly higher in male vs. female and was almost unchanged after age and sex adjustment for the US population 53.8[50.6–57.0] per-100000 residents/year. Over 20-years severe AS-incidence remained stable (p = 0.20) 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 = 0.72) but declining in women: (incidence-rate-ratio 0.93, p = 0.024). AS clinical-presentation, age, symptoms, comorbidity, ventricular size/function, valve-area-index, low-flow or low-ejection-fraction AS, remained stable. Over the study 20 years, AVR performance grew (1997–2001 to 2012–2016, at 3-month:14% to 21%, p = 0.02; at 1-year 19% to 33%,p<0.0001), and was more prompt (from 1.3[0.11–3.3]years in 1997–2001 to 0.48[0.15–2.11]years in 2013–2016, p = 0.001) but severe AS undertreatment remained prominent (>40%). Early-AVR (within 3-months) was associated with survival benefit (adjusted-hazard-ratio 0.55[0.42–0.71], p<0.0001) stable throughout the 20-years. Despite these improvements, overall mortality, 8.3% within 3-months, 17.8% within 1-year, 36% within 3-years, was swift, considerable and unabated (all p≥0.44) throughout the 20-year study. Conclusion Over 20 years, the population incidence of severe-AS remained stable with increased absolute case-burden purely related to population growth. Despite stable severe-AS presentation, AVR performance grew notably, but while declining, undertreatment remained substantial and disease-lethality did not decline. These findings have important population-health management implications.