Abstract 19214: Echocardiographic Diagnosis of Chiari's Network and Arterial Embolic Events

Background: The clinical significance of Chiari’s network identified by echocardiogram is not yet established. A few authors have hypothesized that Chiari’s network may be associated with a patent foramen ovale, atrial septal aneurysm and paradoxical embolism. We set out to better understand the relationships of arterial embolic events and echocardiographic diagnosis of Chiari’s network in our adult population. Methods: We reviewed unique subject-adult transesophageal echocardiograms (TEE) performed at UIHC between November 2010 and March 2015 (n=3,703); we identified subjects with transesophageal echocardiographic diagnosis of Chiari’s network. Chiari’s network was observed in 6.2% of all TEE studies (n=229); males represented 59.8% with mean age of 61.5±16.3 years and mean left ventricular ejection fraction 53.8% ± 13.6%. Retrospective chart review was then performed to evaluate clinical variables encompassing a median [IQR] follow up of 8 months [2-19]. Results: Patent foramen ovale and atrial septal aneurysm were present in 22.3% and 11.4% subjects respectively. Approximately one half of patients (n=115, 50.2%) experienced at least one systemic embolic event by the end of the follow up period. Of these, 84 (36.7%) and 30 (13.1%) patients suffered stroke and transient ischemic events respectively. The all-cause mortality rate was high at 13.5%. Atrial tachyarrhythmia was present in 59 subjects (25.8%). The rate of systemic embolic events was higher in those without atrial tachyarrhythmia compared to those with atrial tachyarrhythmia (58.2% vs. 27.1%, p=0.000; OR (95% CI),0.267 (0.139-0.511). Antithrombotic therapy was prescribed in 79% of all subjects, 86.4% of patients with atrial tachyarrhythmia and 95.5% of patients with systemic embolic events. Conclusions: Patients with Chiari’s network have a high incidence of atrial tachyarrhythmia and systemic embolic events, primarily embolic stroke and transient ischemic events. Systemic embolic events occurred at significantly higher rates in subjects with Chiari’s network and no atrial tachyarrhythmia than those with atrial tachyarrhythmia. Future studies are warranted to further elucidate the risk of thromboembolic events in patients with Chiari’s network.