Abstract
AIMS: This study aimed to investigate the functional correlate, clinical relevance, and prognostic implications of novel left ventricular (LV) deformations in patients with atrial fibrillation (AF). METHODS AND RESULTS: LV deformational indices, including peak global longitudinal strain (GLS), systolic strain rates (SRs), and early diastolic strain rates (SRe) were measured in a large-scale AF population. We related such measures to key clinical heart failure (HF) markers, conventional echocardiographic ventricular parameters, and clinical outcomes. Among 1483 subjects with newly diagnosed AF (mean age, 71.6 ± 12.4 years; 55.5% male), worsened GLS (mean, - 12.6 ± 3.9%) and strain rates (SRs and SRe: mean, - 0.86 ± 0.27 and 1.25 ± 0.41 1/s, respectively) by our three-beat measures were independently correlated with higher C-reactive protein, N-terminal pro-B-type natriuretic peptide, higher E/e', more impaired LV ejection fraction (LVEF < 50%), lower estimated glomerular filtration rate, permanent AF, and prevalent HF (all P < 0.05). LV deformations by three-beat analysis well correlated with the respective results of traditional methods. Abnormal GLS (>- 14.7%) was common in our cohort (67.8%) despite an averaged preserved LVEF (58.4 ± 14.2%), with worse GLS and SRe being associated with higher composite HF re-admissions/death during the 2.9 year follow-up (inter-quartile range, 1.6-4.1 years) in multivariate models incorporating key LV indices (LVEF, LV mass index, and E/e') (all P < 0.001). Sensitivity analysis by excluding those with regional wall motion abnormality showed broadly similar findings. An improved risk reclassification was observed when GLS and SRe were separately added to the LVEF. Comparison of the AF cohort with a fully matched independent non-AF cohort at the same baseline LVEF level showed a substantially lower GLS [- 13.2 ± 3.8% (AF) vs. 18.1 ± 3.2% (non-AF)] and higher clinical events rate (hazard ratio, 1.41 [95% confidence interval, 1.14-1.75]; log-rank P = 0.002) in the AF cohort. CONCLUSIONS: Impaired LV function defined by myocardial deformation was common in patients with AF and provides independent prognostic values over conventional measures with improved risk prediction. Our data highlight the need for implementing cardiac deformations in daily practice for patients with AF.