Younis, Ahmed

Introduction: Adults with repaired tetralogy of Fallot (TOF) have right atrial (RA) remodeling and dysfunction, and RA function can be measured using speckle-tracking echocardiography. There is limited data about the role of RA strain imaging in risk stratification in this population. Hypothesis: We hypothesized that RA reservoir strain could identify TOF patients at risk of developing atrial arrhythmia. We assessed the relationship between RA reservoir strain and atrial arrhythmias in adults with repaired TOF to test this hypothesis. Methods: Retrospective cohort study of adults with repaired TOF, and no prior history of atrial arrhythmias. Atrial arrhythmia was defined as atrial fibrillation, atrial flutter/atrial tachycardia, and categorized as new onset versus recurrent atrial arrhythmias. Results: We identified 426 patients (age 33±12 years; males 208 (49%)) that met the inclusion criteria. The mean RA reservoir, conduit, and booster strains were 34±11%, 20±9%, and 15±12%, respectively. Of 426 patients, 73 (17%) developed new-onset atrial arrhythmias (atrial flutter/tachycardia n=42; atrial fibrillation n=31); annual incidence 1.9%. RA reservoir strain was associated with new-onset atrial arrhythmias (adjusted HR 0.95, 95% CI 0.93-0.97) after multivariable adjustment. Of 73 patients with new-onset atrial arrhythmia, 41 (56%) had recurrent atrial arrhythmia (atrial flutter/tachycardia n=18; atrial fibrillation n=23); annual incidence 11.2%. Similarly, RA reservoir strain was associated with recurrent atrial arrhythmias (adjusted HR 0.92, 95% CI 0.88-0.96) after multivariable adjustment. Conclusions: RA strain indices can identify patients at risk for atrial arrhythmias, and this can, in turn, be used to guide the type/intensity of therapy in such patients.