The clinical association of left atrial appendage thrombus on CTA with functional outcome

Left atrial appendage (LAA) thrombus is associated with atrial fibrillation (AF) and can be a marker of atrial cardiomyopathy. We determined the association between computed tomography angiography (CTA) identified LAA thrombus in patients presenting with acute ischaemic stroke or transient ischaemic attack (TIA), and 3-month outcome.

We undertook a dual-centre, retrospective cohort study from New Zealand and Australia. All consecutive patients presenting with acute ischaemic stroke or TIA during the inclusion period who underwent acute stroke imaging were included. We analysed the association with CTA-LAA thrombus and 3-month outcome on modified Rankin Scale using multivariable logistic regression models adjusted for known predictors of outcome.

Of the 1435 patients included, 1304 (90.9%) had acute ischaemic stroke and 131 (9.1%) had TIA. 582 (41%) had confirmed intracranial medium or large vessel occlusion (MLVO), and 565 (40%) received reperfusion therapies. CTA-LAA thrombus was identified in 58 (4.0%) patients, and these patients were older (median age 85 (IQR 75-88) vs 73 (63-81), p < 0.01), more likely to be female (62% vs 40%, p < 0.01), had higher rates of AF (79% vs 29%, p < 0.01), heart failure (29% vs 9%, p < 0.01), MLVO (53% vs 40%, p = 0.05), and mortality at 3-months (28% vs 11%, p < 0.01). Adjusting for known predictors of poor outcome, LAA thrombus was independently associated with increased 3-month mRS score (OR: 2.02, 95% CI: 1.20-3.40, p < 0.01).

CTA-LAA thrombus detected during the acute stroke imaging protocol in patients with ischemic stroke or TIA is a predictor of worse outcome.