Left Atrial Expansion Index for Ischemic Stroke Prediction in Patients with Atrial Fibrillation

The efficacy of the left atrial (LA) expansion index (LAEI) to predict cerebral ischemic events in patients with atrial fibrillation (AF) is unknown.

We enrolled 177 patients with AF (88 with paroxysmal AF and 89 with persistent AF) and a baseline CHA₂DS₂-VASc score (at enrollment) of 3.6 ± 2.3. Comprehensive echocardiography was performed at enrollment. The LAEI was calculated as (Vol_max - Vol_min) × 100%/Vol_min, where Vol_max and Vol_min denoted maximal and minimal LA volumes, respectively. The study endpoint was ischemic stroke. Stroke subtypes were classified into cardioembolic stroke (CE), non-CE with determined mechanism (NCE), embolic stroke of undetermined source (ESUS), or transient ischemic attack (TIA).

Over a mean 9.9-year follow-up period, 44 (24.9%) of the patients reached the endpoint (24 with CE, 4 with NCE, 6 with ESUS, and 10 with TIA). The LAEI was lower in the stroke group than in the non-stroke group. Stroke incidence in the lowest LAEI quartile was much higher than that in the other LAEI quartiles; the 10-year cumulative stroke risk was 15.9% (14/88) and 33.7% (30/89) in the patients with paroxysmal and persistent AF, respectively. An LAEI of < 35% predicted the presence of stroke with 77% sensitivity and 78% specificity. In multivariable analysis, the LAEI was independently associated with ischemic stroke (hazard ratio 0.952 per 1% increase, 95% confidence interval 0.932-0.971, p < 0.0001).

The LAEI is a useful predictor of ischemic stroke in patients with AF.