The prevalence of aortic stenosis (AS) according to age in the following population-based series from the USA or Europe: Lindroos et al. (Finland)14, in which AS was defined as an aortic valve area of < 1.2 cm2; Stewart et al. (Cardiovascular Health Study, USA)9, in which AS was defined as a peak aortic jet velocity of > 2.5 m per sec; Nkomo et al. (USA)12, in which AS was defined as an aortic valve area of < 1.5 cm2; Eveborn et al. (Tromsø Study, Norway)13, in which AS defined was as a mean gradient of ≥ 15 mmHg; Danielsen et al. (AGES-Reykjavik Study, Iceland)15, in which AS was defined as an indexed aortic valve area of ≤ 0.6 cm2 per m2.