Atrial Appendage Morphology
284 patients in the cohort had a cardiac CT or cardiac MRI performed for
clinical indications. Three-dimensional structures of the left atrial
appendge (LAA) were constructed using the volume-rendered
post-processing technique. Standard measurements of LAA volume, os
circumference, and diameters were obtained. The morphology of the LAA
was also evaluated using multiplanar reconstruction. LAA morphologies
were classified by the reading radiologist and confirmed by the primary
investigator (SK). The LAA os was pre-determined to be the proximal
border of the LAA and all visualized lobes were included in the volumes.
LAA was reported as chicken wing (CW), cauliflower (CF), cactus (CS),
and windsock (WS) as previously described13. Given the
numbers and known stroke associations, we prespecified patients as CW
(n=136) or non-CW (148) for analysis. In addition to stratifying by GRS,
patients were stratified by the 4q25 variant of greatest significance to
AF (r2200733 (NC_000004.12:g.110789013C>T) given the known
association with left-right asymmetry. Patients were categorized at this
SNV as carriers (C; n=109) if they were heterozygous (CT) or homozygous
(TT). Patients with the CC genotype were classified as non-carriers (NC;
n=175).
Statistical
analysis
Continuous variables are expressed as mean ± SD and categorical
variables. Analysis was performed using Prism (version 6.0d, GraphPad
Software Inc, La Jolla, CA). Continuous variables were expressed as mean
± SD. The Student t test and Mann‐Whitney U test were used
for the comparison of continuous variables between groups. The
paired t test and Wilcoxon signed‐rank test were used for the
comparison of continuous variables between echocardiographic follow‐ups.
The χ 2 test and Fisher exact test were used
for noncontinuous variables. Bonferroni correction was used for multiple
correction where applicable. A 2‐sided P value <0.05
was considered statistically significant.