Abstract TP101: Reduced Left Atrial Strain In Embolic Stroke Of Undetermined Source Is Associated With Atrial Fibrillation Detected On Mobile Cardiac Monitoring

Recent studies have failed to reveal benefit of anticoagulation over antiplatelet therapy in the prevention of recurrent stroke in Embolic Stroke of Undetermined Source (ESUS) patients. This is attributed to significant heterogeneity in underlying mechanisms of ESUS. Atrial fibrillation (AF) is a potential cause of ESUS, and evaluating left atrial (LA) function by measuring LA strain by speckle tracking echocardiography (STE) is an emerging technique to assess LA biomechanics. Our study investigates the relationship between LA strain and AF detection in ESUS patients. We included hospitalized patients with ESUS subtype who underwent STE. LA function by assessing three phases of LA strain (reservoir, conduit and contractile) were retrospectively quantified and evaluated. Several patients were discharged with mobile cardiac telemetry that was retrospectively reviewed for AF detection. Descriptive statistical methods and both unadjusted and adjusted regression models were used. Among 325 ESUS patients, mean age was 66.5±15.0, 49% were male, 49% had outpatient cardiac monitoring, and 25% had AF detected. LA reservoir (25.17±13.4 vs 32.43±18.13), LA contractile (11.95±9.66 vs 16.67±10.94) and LA conduit (13.08±6.47 vs 17.20±12.21) strains were significantly lower in patients with AF detected compared to patients without AF detected. In the unadjusted binary logistic regression analysis, patients with AF detected had significantly lower LA reservoir (OR 0.967, 95% CI 0.941-0.994), LA contractile (OR 0.957, 95% CI 0.918-0.997) and LA conduit (OR 0.961, 95% CI 0.925-0.998) strains. This significance was lost after adjusting for age. Our study demonstrates that reduced LA strain is associated with subsequent detection of AF in ESUS patients. We believe that routine LA strain measurement can aid clinicians in identifying ESUS patients with high AF prevalence and thereby appropriately target patients for anticoagulation therapy to prevent subsequent strokes.