Abstract WP264: Relationship between Left Atrial Volume and Ischemic Stroke Subtype

Abstract

Introduction: Embolic strokes of undetermined source (ESUS) are thought to mostly arise from occult cardiac sources or large-artery atherosclerotic lesions. Atrial cardiopathy in the absence of atrial fibrillation (AF) has been proposed as one potential cardiac source of ESUS. Methods: We compared left atrial volume across ischemic stroke subtypes in the Cornell Acute Stroke Academic Registry (CAESAR). All patients with acute ischemic stroke at our hospital have been prospectively registered in CAESAR since 2011. Stroke subtype was determined by a panel of neurologists per the TOAST classification and consensus ESUS definition using all data available during the index hospitalization. The left atrial volume index (LAVI) was pulled directly from our hospital’s echocardiographic image management system (Xcelera, Philips Healthcare). We used t-tests and analysis of variance (ANOVA) for unadjusted comparisons and multiple logistic regression for demographic-adjusted comparisons. Results: Among 2,116 patients registered in CAESAR from 2011-2016, the 1,577 with LAVI data were younger (mean age, 71.3 vs 73.4 years), had less severe strokes (mean NIHSS score, 7.5 vs 10.1), less often had AF (20.8% vs 25.3%), and more often had diabetes (26.8% vs 19.3%). LAVI varied significantly across stroke subtypes ( P <0.001) from 49.5 (±31.6) mL/m 2 in cardioembolic strokes to 29.4 (±10.3) mL/m 2 in small-vessel strokes. Patients with cryptogenic stroke had significantly larger LAVI (35.0 ±14.6 mL/m 2 ) than those with small- or large-vessel strokes (30.5 ±10.6 mL/m 2 ) ( P < 0.001). The association between LAVI and cryptogenic stroke (compared to small- or large-vessel stroke) persisted after adjustment for demographics (OR per mL/m 2 , 1.03; 95% CI, 1.02-1.04). Results were similar when comparing ESUS versus non-cardioembolic strokes. Conclusions: We found significantly larger left atria among patients with cryptogenic stroke vs non-cardioembolic stroke. At the same time, there was significant overlap in left atrial size between cryptogenic and non-cardioembolic stroke patients, highlighting that not all cryptogenic strokes are cardioembolic.