Cardiac MRI Left Atrial Strain Associated With New‐Onset Atrial Fibrillation in Patients With ST‐Segment Elevation Myocardial Infarction.

Background: Left atrial (LA) strain is associated with structural remodeling of the LA. Whether there is an association between LA strain obtained by cardiac magnetic resonance imaging (MRI) and new‐onset atrial fibrillation (AF) after ST‐segment elevation myocardial infarction (STEMI) is unclear. Purpose: To investigate the relationship between LA strain and new‐onset AF after STEMI. Study Type: Retrospective. Population: Three hundred and seventy‐nine STEMI patients were enrolled, of which 26 had new‐onset AF. Field Strength/Sequence: 3.0 T, balanced turbo field echo sequence. Assessment: Patients were divided into w/o AF group and new‐onset AF group. Cardiac MRI images were analyzed using cardiovascular imaging software CVI 42 (Circle Cardiovascular Imaging, Canada). An automatic tracing algorithm was applied to obtain strain values. The reservoir strain, conduit strain, and booster strain were included in model 1, model 2, and model 3, respectively. Statistical Tests: Student's t‐test, Mann–Whiney U test, and chi‐square test were performed. Variables with a P ≤ 0.05 were incorporated into the logistic regression analysis. Area under curve of receiver operating characteristic was used to assess the ability of LA strain to identify new‐onset AF. Bayesian information criterion, Akaike information criterion, and C‐index were used to make comparisons between three models. P < 0.05 was considered statistically significant. Results: Three models were used to assess LA strain identification ability for new‐onset AF. After including multiple factors, right coronary artery (RCA), LVEF, and reservoir strain were still risk factors for new‐onset AF in model 1. In model 2, age, RCA, LVEF, and conduit strain were still risk factors for new‐onset AF. In model 3, RCA, LVEF, LVEDVi, and booster strain were still risk factors for new‐onset AF. Model 2 has a stronger identification ability than others. Data Conclusion: LA strain associated with new‐onset AF after STEMI. The model including conduit strain was the best‐fit one. Level of Evidence: 4 Technical Efficacy: Stage 3 [ABSTRACT FROM AUTHOR]