Interstudy heterogeneity of definitions of diastolic dysfunction severely affects reported prevalence

The aim of this article is to examine how the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE) recommendations on the classification of diastolic dysfunction (DDF) are interpreted in the scientific community and to explore how variations in the DDF definition affect the reported prevalence.

A systematic review of studies citing the EACVI/ASE consensus document 'Recommendations for the evaluation of left ventricular diastolic function by echocardiography' was performed. The definition of DDF used in each study was recorded. Subsequently, several possible interpretations of the EACVI/ASE classification scheme were used to obtain DDF prevalence in a community-based sample (n = 714). In the systematic review, 60 studies were included. In 13 studies, no specification of DDF definition was presented, a one-level classification tree was used in 13, a two-level classification tree in 18, and in the remaining 16 studies, a DDF definition was presented but no grading of DDF was performed. In 17 studies, the DDF definition relied solely on early diastolic tissue velocity and/or left atrial size. In eight of these studies, a single parameter was used, in two studies the logical operator AND was used to combine two or more parameters, and the remaining seven studies used the logical operator OR. The resulting prevalence of DDF in the community-based sample varied from 12 to 84%, depending on the DDF definition used.

A substantial heterogeneity of definitions of DDF was evident among the studies reviewed, and the different definitions had a substantial impact on the reported prevalence of DDF.