Prognostic associations of left atrial strain with major adverse cardiovascular events and atrial fibrillation: Data from the Akershus cardiac examination (ACE) 1950 study

BACKGROUND: Left atrial (LA) reservoir (LASr), conduit (LAScd) and contractile (LASct) strain are known to reflect atrial remodeling and is prognostic in atrial fibrillation (AF) and heart failure. Evidence is scarce on prediction of major adverse cardiovascular events (MACE) in general populations. LA mechanical dispersion (LA MD) and stiffness index (LASI) are less studied strain-derived indices of AF and cardiovascular risk. METHODS: The Akershus Cardiac Examination 1950 Study included 3706 participants from the general population who underwent baseline echocardiography in 2012-2015. MACE (cardiovascular death, non-fatal stroke, non-fatal myocardial infarction or coronary intervention) and incident AF were recorded through 2022. Prognostic value of LA strain was assessed by Cox regression. RESULTS: In 3229 participants with baseline LA strain analysis, MACE was recorded in 242 (7.5%) and incident AF in 157 (5.0%) over a median 8.3 years (IQR 7.9-8.9) of follow-up. LASr, LAScd and LASI were associated with MACE in univariable analyses, and LASI remained independently associated with MACE after multivariable adjustment (HR per 1SD increment 1.12, 95% CI 1.04-1.21). LASr (HR per 1SD decrement 1.21, 95% CI 1.01-1.45), LASct (HR per 1SD decrement 1.26, 95% CI 1.04-1.52) and LA MD (HR per 1SD increment 1.23, 95% CI 1.03-1.48) were independently associated with incident AF after multivariable adjustment. Accounting for competing risk of all-cause death, LA MD remained independently associated with incident AF, whereas LASr and LASct did not. CONCLUSION: In a general population, LASI was independently associated with MACE, whereas LASr, LASct and LA MD were associated with incident AF.