Quantitative Tissue‐Tracking Cardiac Magnetic Resonance (CMR) of Left Atrial Deformation and the Risk of Stroke in Patients With Atrial Fibrillation

BACKGROUND: Recent evidence suggests that left atrial (LA) dysfunction may be mechanistically contributing to cerebrovascular events in patients with atrial fibrillation (AF). We investigated the association between regional LA function and a prior history of stroke during sinus rhythm in patients referred for catheter ablation of AF. METHODS AND RESULTS: A total of 169 patients (59±10 years, 74% male, 29% persistent AF) with a history of AF in sinus rhythm at the time of pre‐ablation cardiac magnetic resonance (CMR) were analyzed. The LA volume, emptying fraction, strain (S), and strain rate (SR) were assessed by tissue‐tracking cardiac magnetic resonance. The patients with a history of stroke or transient ischemic attack (n=18) had greater LA volumes (V(max) and V(min); P=0.02 and P<0.001, respectively), lower LA total emptying fraction (P<0.001), lower LA maximum and pre‐atrial contraction strains (S(max) and S(preA); P<0.001 and P=0.01, respectively), and lower absolute values of LA SR during left ventricular (LV) systole and early diastole (SR(s) and SR(e); P=0.005 and 0.03, respectively) than those without stroke/transient ischemic attack (n=151). Multivariable analysis demonstrated that the LA reservoir function, including total emptying fraction, S(max), and SR(s), was associated with stroke/transient ischemic attack (odds ratio 0.94, 0.91, and 0.17; P=0.03, 0.02, and 0.04, respectively) after adjusting for the CHA(2)DS(2)‐VASc score and LA V(min). CONCLUSIONS: Depressed LA reservoir function assessed by tissue‐tracking cardiac magnetic resonance is significantly associated with a prior history of stroke/transient ischemic attack in patients with AF. Our findings suggest that assessment of LA reservoir function can improve the risk stratification of cerebrovascular events in AF patients.