Comparison of left atrial and right atrial mechanical function in the risk stratification of AF-related stroke
Y K Mao, J P Chen, Y Yang, M M Ma, Y H Wang, C Y JiangAbstract
Background
Left atrial (LA) mechanical dysfunction have been shown to be associated to strokes in atrial fibrillation(AF). However, the contribution of right atrium(RA) in the mechanism of strokes have been overlooked. Accordingly, we aimed to investigate and compare the association of LA and RA mechanics with AF-related stroke.
Methods
A total of 422 consecutive patients with AF (median age 64 years, 68% male, 46% persistent AF) who underwent echocardiography before catheter ablation were prospectively included. Speckle-tracking echocardiography was used to measure LA reservoir strain(LASr), RA reservoir strain(RASr)and mechanical dispersion (MD) of LA and RA were measured in all patients. Mechanical dispersion was defined as the standard deviation of the time to peak positive strain corrected by R-R interval.
Results
Patients with a history of stroke or transient ischemic attack (TIA) (n = 53) showed significantly lower LA and RA reservoir strain, and significantly higher LA MD than those without (n=369) (LASr,13.8±6.7% vs.18.2±9.9%, RASr,19.1±10.4% vs.24.3±12.5%, LA MD,10.6±3.6% vs 7.6±3.1%; P < 0.01).However, the RA MD was not significantly different between two groups. LA MD was independently associated with stroke/TIA in five multivariate models (Odds ratio, 1.29-1.34, respectively, P<0.01). In contrast, LASr, RASr and RA MD failed to be independent contributors for identifying strokes. LA MD> 7.77% identified patients with AF-related stroke with a sensitivity of 83% and a specificity of 52.6%,with an AUC of 0.73(P <0.01), which is significantly higher than LASr (AUC 0.63) and RASr (AUC 0.63)(P< 0.01).
Conclusions
Both left and right atrial mechanical function assessed with speckle tracking echocardiography were more severely impaired in AF patients with a prior stroke or TIA. However, only LA mechanical dispersion was independently associated with stroke/TIA in AF patients, superior to LASr and RA mechanical parameters.ROC curvesstrain analysis