Relationship between left atrial myopathy and atrial fibrillation in adults with coarctation of aorta

Background: Although patients with coarctation of aorta (COA) have clinical risk factors for atrial fibrillation (AF), there are limited data about AF prevalence, and role of left atrial (LA) indices for risk stratification in this population. We hypothesized that LA indices (LA reservoir strain and LA volume index) were associated with AF, and would identify patients at risk for AF progression.Methods: We analyzed electrocardiograms/Holters, and echocardiograms of adult COA patients at Mayo Clinic (2000-2018).Results: Of 776 patients, 726(94 %), 46(5.9 %) and 4(0.5 %) had no history of AF, paroxysmal AF, and persistent AF respectively; yielding AF prevalence of 6.4 %. LA reservoir strain (AUC 0.782 [0.751-0.808]) had more robust association with AF as compared to LA volume index (AUC difference -0.115, p < 0.001).Among 726 patients without prior AF, 25(3.4 %) had new-onset AF during follow-up. LA reservoir strain <25 % and LA volume index >34 ml/m(2) were independent predictors of new-onset AF (HR 1.81 [1.15-3.85], and HR 1.41 [1.03-4.78], respectively). Of 46 patients with paroxysmal AF, 22(48 %) had recurrent AF, and LA reservoir strain <25 % was an independent predictor of recurrent AF (HR 1.94 [1.41-4.17]). LV pressure overload and stiffness indices were associated with progressive LA dysfunction and new-onset AF.Conclusions: Collectively, these data suggest that LA strain can potentially be used for AF risk stratification. Further studies are required to determine whether LA strain can proactively identify patients that will respond favorably to different antiarrhythmic therapies, and whether interventions to reduce LV pressure overload will improve LA function and reduce AF progression.