Normal values of left atrial strain in 62–65 year old men and women from the general population

Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): South-Eastern Norway Regional Health Authority Background Left atrial (LA) function is divided in a reservoir, a conduit and a contractile phase. LA reservoir and contractile function can be quantified through echocardiographic speckle tracking strain analysis and provide prognostic information in cardiovascular disease. Normal values are still not fully established for all age groups. Purpose To provide normal values of LA reservoir (LASr) and contractile (LASct) strain in men and women in their sixties. Methods We included 3,706 men and women, all born in 1950, from the general population in a prospective observational study. Study inclusion and baseline examination including echocardiorgraphy took place between 2012 and 2015. The echocardiographic images were assessed for LA strain analysis, and only participants with sinus rhythm during echocardiography, good image quality without LA foreshortening, and frame rates > 40/second were included. We further defined a healthy group without cardiovascular, cerebrovascular, pulmonary or renal disease. Values of LASr and LASct are presented as median and interquartile range (IQR), and the lower limits of normality (LLN) for LASr and LASct were defined as the 2,5th percentile value in the healthy group. We used Mann Whitney U-test to compare groups. Results Of 3,229 participants with available LA strain analyses, median age was 63.9 years and 50.0% were women. Healthy individuals (n=758) had a median LASr of 35.5% (IQR 29.6%-42.2%), which was significantly higher than the LASr of 33.1% (IQR 27.9%-39.4%) in non-healthy individuals (p<0.001). LASct was similar between the healthy and non-healthy individuals. Men and women of the healthy group had similar measures of LASr and LASct. The LLN of LASr was 21.9%, whereas LASct had a LLN of 9.0%, both similar for males and females. Conclusion We present normal values and limits of normality of LASr and LASct, similar between men and women, in 758 healthy individuals aged 62–65. We found LASr to be significantly higher in healthy compared to non-healthy individuals, whereas LASct was similar between the groups.