Baseline Characteristics
In total, 1313 eligible patients were screened for inclusion based on
the criteria mentioned above. Among the excluded subjects, those with
uninterpretable echocardiograms stood out as the most notable group. Due
to the inherent limitations of clinical research and the challenges
associated with speckled tracking strain analysis on clinical
echocardiograms, meticulous care was taken to ensure accurate tracking
of the LA chamber walls. Consequently, approximately 22% of the
echocardiograms were deemed uninterpretable and subsequently excluded
from the final cohort of the analytic sample (Figure 1). The criteria
for defining echocardiograms as uninterpretable included foreshortening
of the LA chamber view, inadequate visibility of one or more walls of
the LA chamber for endocardial tracing, and echocardiograms with a wall
tracking score of 1 where more than one endocardial wall did not show
appropriate tracking despite its adequate gross visibility.
Among the 656 total stroke patients utilized in the study sample, 349
patients were classified as NCE and 307 as ESUS. Among the NCE patients,
208 had large artery atherosclerosis, 87 had small vessel disease, and
54 had other determined or undetermined etiology. The clinical
characteristics of the NCE cohort and ESUS cohort were largely similar,
except for a few notable differences. The NCE cohort had a higher
percentage of males (61.3% vs. 48.5%, p = 0.001) and a higher mean
systolic blood pressure in mm Hg (152.2 + 29.5 vs. 144.6 + 26.5, p =
0.001). Conversely, the NCE cohort had a lower percentage of individuals
with a history of congestive heart failure (0.6% vs. 4.2%, p = 0.003)
and a lower median NIHSS (National Institutes of Health Stroke Scale)
score (7 vs. 10, p < 0.001) compared to the ESUS cohort (Table
1).
On echocardiography analysis, compared to NCE, patients with ESUS had a
significantly lower LA reservoir strain (32.0 ± 16.1 vs. 36.7 ± 17.9, p
< 0.001), LA contractile strain (15.5 ± 9.6 vs. 17.4 ± 10.7, p
= 0.018), and LA conduit strain (16.5 ± 10.7 vs. 19.3 ± 11.5, p = 0.001)
(Table 1).