Clinical Research
Atrial Fibrillation
Does the Left Atrial Appendage Morphology Correlate With the Risk of Stroke in Patients With Atrial Fibrillation?: Results From a Multicenter Study

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Objectives

This study investigated the left atrial appendage (LAA) by computed tomography (CT) and magnetic resonance imaging (MRI) to categorize different LAA morphologies and to correlate the morphology with the history of stroke/transient ischemic attack (TIA).

Background

LAA represents one of the major sources of cardiac thrombus formation responsible for TIA/stroke in patients with atrial fibrillation (AF).

Methods

We studied 932 patients with drug-refractory AF who were planning to undergo catheter ablation. All patients underwent cardiac CT or MRI of the LAA and were screened for history of TIA/stroke. Four different morphologies were used to categorize LAA: Cactus, Chicken Wing, Windsock, and Cauliflower.

Results

CT scans of 499 patients and MRI scans of 433 patients were analyzed (age 59 ± 10 years, 79% were male, and 14% had CHADS2 [Congestive heart failure, Hypertension, Age >75, Diabetes mellitus, and prior Stroke or transient ischemic attack] score ≥2). The distribution of different LAA morphologies was Cactus (278 [30%]), Chicken Wing (451 [48%]), Windsock (179 [19%]), and Cauliflower (24 [3%]). Of the 932 patients, 78 (8%) had a history of ischemic stroke or TIA. The prevalence of pre-procedure stroke/TIA in Cactus, Chicken Wing, Windsock, and Cauliflower morphologies was 12%, 4%, 10%, and 18%, respectively (p = 0.003). After controlling for CHADS2 score, gender, and AF types in a multivariable logistic model, Chicken Wing morphology was found to be 79% less likely to have a stroke/TIA history (odd ratio: 0.21, 95% confidence interval: 0.05 to 0.91, p = 0.036). In a separate multivariate model, we entered Chicken Wing as the reference group and assessed the likelihood of stroke in other groups in relation to reference. Compared with Chicken Wing, Cactus was 4.08 times (p = 0.046), Windsock was 4.5 times (p = 0.038), and Cauliflower was 8.0 times (p = 0.056) more likely to have had a stroke/TIA.

Conclusions

Patients with Chicken Wing LAA morphology are less likely to have an embolic event even after controlling for comorbidities and CHADS2 score. If confirmed, these results could have a relevant impact on the anticoagulation management of patients with a low-intermediate risk for stroke/TIA.

Key Words

CHADS2 score
left atrial appendage
stroke
stroke prevention
TIA

Abbreviations and Acronyms

AF
atrial fibrillation
CHADS2
Congestive heart failure, Hypertension, Age >75, Diabetes mellitus, and prior Stroke or transient ischemic attack
CHA2DS2-VaSc
Congestive heart failure, Hypertension, Age (>75 = 2 points, 65 to 74 = 1 point, <65 = 0 point, Diabetes mellitus, prior Stroke or transient ischemic attack, female gender
CI
confidence interval
CT
computed tomography
LA
left atrium
LAA
left atrial appendage
MRA
magnetic resonance angiography
MRI
magnetic resonance imaging
OR
odds ratio
3D
3-dimensional
TIA
transient ischemic attack

Cited by (0)

Dr. Di Biase is a consultant for Hansen Medical and Biosense Webster. Dr. Burkhardt is the chief medical advisor to Stereotaxis. Dr. Natale received speaker honorariums from Boston Scientific, Biosense Webster, St. Jude Medical, Medtronic, Biotronik, and Life Watch; and a research grant from St. Jude Medical. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose Drs. Di Biase and Santangeli are joint first authors.