Abstract 559: Left Atrial Enlargement In Primary Cryptogenic Strokes Without Atrial Fibrillation

The relationship between left atrial enlargement (LAE) and primary cryptogenic stroke (PCS) remains a mystery. Previous literature found the severity of LAE to be an independent risk factor in cases of PCS, recurrent ischemic strokes, and paroxysmal atrial fibrillation. Our study seeks to further characterize potential risk factors for patients with PCS in the absence of atrial fibrillation. Our multi-center retrospective study constructed a database of 646 patients identified with a diagnosis of cerebral infarction over a three year period. Detailed chart review excluded all patients with known etiologies for PCS including: atrial fibrillation, atrial flutter, prior stroke, systolic heart failure, carotid artery stenosis, thromboembolic disease, previous anticoagulation, or an active cancer diagnosis. Diagnosis of LAE utilized a composite of criteria for transthoracic echocardiogram (TTE) measurements including left atrial diameter (LAD) and left atrial volume index (LAVI). All study criteria were met by 154 patients (24%) for analysis, where baseline characteristics included: 79 (51%) male, 104 (67.5%) Caucasian, 108 (70%) diagnosis of hypertension, 80 (52%) previous or current tobacco users, and 47 (31%) diagnosis of diabetes. Our preliminary analysis found 74 (48%) of patients met at least one criteria for LAE. The mean LAD for patients with and without LAE was 4.1cm and 3.4 cm, respectively (SD .87 vs .55, p<.0001). The mean LAVI for patients with and without LAE was 29.68 mL/m 2 and 18.44 mL/m 2 , respectively (SD 7.37 vs 5.13, p<.0001). Our findings support the significance of LAE as a risk factor for cases of PCS. Multiple risk factors were identified in our study population that reflect the importance of preventative counseling for patients with hypertension, hyperlipidemia, histories of tobacco use, and diabetes. Further research may elucidate whether LAE alone or in the setting of comorbidities warrant universal screening practices or prophylactic therapies to prevent cases of PCS.