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).