Abstract 120: Measures of Coagulation and Hemostatic Activation Outperform Left Atrial Structural Parameters in Identifying Embolic Stroke of Undetermined Source (ESUS) Patients Who May Benefit From Early Anticoagulation

Abstract

Introduction: The objective of this study was to evaluate left atrial (LA) echocardiographic parameters and a novel panel of serum biomarkers to identify ESUS patients who may benefit from early anticoagulation. Methods: We prospectively identified ESUS patients seen in the Emory Clinic from January 1, 2015 to June 30, 2017 who underwent prolonged cardiac monitoring with mobile cardiac outpatient telemetry (MCOT) and/or implantable loop recorder (ILR). In a subset of consecutive patients, 4 measures of coagulation and hemostatic activation (MOCHA) including d-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex and fibrin monomer were obtained ≥ 2 weeks after the index stroke and repeated if abnormal. We evaluated the ability of LA structural parameters to identify patients with atrial fibrillation (AF) on monitoring and the ability of abnormal MOCHA levels to identify patients who had the composite outcome of newly diagnosed AF, malignancy, or recurrent stroke. Results: During the study period, 92 ESUS patients (mean age 64 +/- 15 years, 54% female, 62% non-white, mean follow-up 1.4 +/- 0.8 years) underwent prolonged cardiac monitoring (65% MCOT, 62% ILR, 38% MCOT+ILR); 16 (17%) were found to have AF. Severe LA enlargement (vs normal) was associated with subsequent detection of AF (p=0.09) however LA diameter and LA volume index were not. Baseline characteristics of ESUS patients who underwent MOCHA testing (n=44) were similar to patients who did not except that those tested were younger (60 vs 67 years, p=0.04); over mean follow-up of 1.2 +/- 0.8 years, 18 (41%) patients had newly diagnosed AF, malignancy or recurrent stroke. ESUS patients with persistently abnormal (vs normal) MOCHA levels were significantly more likely to have newly diagnosed AF, malignancy or recurrent stroke (OR 11.3, 95% CI 2.5-50.1, p=0.001); elevated levels of ≥ 3 MOCHA markers had a 67% sensitivity and 81% specificity for identifying patients with the composite outcome. Conclusion: Abnormal MOCHA levels identified ESUS patients who were more likely to have newly diagnosed AF, malignancy or recurrent stroke over follow-up and may be more effective than LA structural abnormalities in identifying patients who could benefit from early anticoagulation.