Malignant Left Atrial Appendage Morphology: Current Classification vs H-L System

Abstract

Introduction: In previous studies the risk of stroke recurrence has been associated with the left atrial appendage (LAA) morphology (non-chicken wing (NCW)), knowing those with a greater risk as malignant LAA. Recently, a simpler morphological classification has been suggested with two categories: Low-risk (LAA-L) and High-risk (LAA-H); which could be easier to apply and may correlate better with the risk of embolic stroke.

Methods: Retrospective analysis from a registry of patients with recurrent cardioembolic strokes despite appropriate anticoagulant therapy, in which LAA morphology was studied with cardiac CT scan. LAA morphology was classified according to the four current categories and H-L morphology by the same cardiologist. Other variables associated with a high risk of stroke were also assessed, such as CHA₂DS₂-VASc score and left atrial (LA) size.

Results: Twenty-six cases were included in the analysis. We identified 22 (84.6%) chicken wing (CW), 1 (3.8%) windsock and 3 (11.5%) cactus by the current classification system, while 15 (57.7%) were classified as LAA-H and 11 (42.3%) as LAA-L by the new system. Half of the 22 cases with CW morphology were considered LAA-H, whereas all NCW were also classified as LAA-H. LA diameter and area were significantly higher in cases with LAA-H morphology (p=0.03 and 0.014), and also in those CW and LAA-H, compared to those CW with LAA-L (p=0.035).

Conclusions: With this new classification system more than half of the cases of our malignant LAAs were classified as high-risk morphology. This morphology was also associated with an increased LA size.

Keywords: Cardioembolic stroke; Classification system; Malignant left atrial appendage; Morphology; Thromboembolism.