Left Atrial Enlargement on Non-Gated CT Is Associated with Large Vessel Occlusion in Acute Ischaemic Stroke

<b><i>Background:</i></b> Recent reports have suggested that atrial fibrillation (AF) is more prevalent in the large vessel occlusion (LVO) subgroup of acute ischaemic stroke patients. Given the association between left atrial enlargement (LAE) and AF, we sought to evaluate the feasibility of assessing LAE on non-gated CT and its association with LVO in the hyperacute stroke setting. <b><i>Methods:</i></b> We analysed our prospectively collected database that included all stroke patients referred for consideration of endovascular treatment between April 14, 2020, and May 21, 2020. During this period, a CT chest was included in our regional stroke protocol to aid triage of patients suspected for COVID-19 from which cardiac measurements were obtained. Patients were dichotomized into LVO and no-LVO groups, and LA measurements were trichotomized into normal, borderline, and enlarged. Univariate analyses were performed between groups. <b><i>Results:</i></b> Of the included 38 patients, 21 were categorized as LVO and 17 as no LVO. There was a statistically significant association between LAE and LVO (<i>p</i> = 0.028). No significant difference was demonstrated between groups for the baseline AF and other clinical characteristics, except for baseline NIHSS (<i>p</i> = 0.0005). There was excellent inter- and intra-rater reliability (ICC = 0.969) for LA measurements. <b><i>Conclusion:</i></b> Our study provides preliminary data to suggest LAE is more prevalent in the LVO stroke subgroup at presentation and can be reliably assessed on non-gated CT in the hyperacute setting. These findings have potential implications for stratifying secondary management and may prompt a more rigorous pursuit of occult AF or other cardiac causes of stroke.

Cardiac Remodeling and Diastolic Dysfunction in Paroxysmal Atrial Fibrillation

Background: Atrial fibrillation (AF) leads to the development of cardiac remodeling/diastolic dysfunction and vice versa. We intended to determine whether cardiac remodeling/diastolic dysfunction is present at early stages of AF. Methods: We studied 175 patients with paroxysmal AF, compared with 175 matched control subjects, who had available echocardiography data to investigate the association between echocardiographic variables and AF from the STANISLAS cohort. Results: In this study (mean age 55 years; 70.3% male), patients with paroxysmal AF had greater left ventricular mass compared to matched controls (p < 0.05). Patients with paroxysmal AF were also likely to have larger left atrial volume and a higher peak tricuspid regurgitation velocity, leading to higher prevalence (though <10% in the AF group) of diastolic dysfunction (all-p < 0.05). Multivariable conditional logistic regression models showed that paroxysmal AF was significantly associated with increased left ventricular mass and left atrial enlargement (all-p < 0.001), but not with e’ and deceleration time of E wave (all-p > 0.1). Conclusions: Left ventricular mass and left atrial enlargement rather than diastolic dysfunction (as evaluated by echocardiography) were associated with paroxysmal AF irrespective of body mass index, blood pressure and renal function. These findings suggest that cardiac remodeling may occur very early in the natural history of AF.

Anticoagulation Therapy Reduces Recurrent Stroke in Embolic Stroke of Undetermined Source Patients With Elevated Coagulation Markers or Severe Left Atrial Enlargement

Background: The objective of this study was to evaluate if anticoagulation therapy reduces recurrent stroke in embolic stroke of undetermined source (ESUS) patients with left atrial enlargement (LAE) or abnormal markers of coagulation and hemostatic activity (MOCHA) compared to antiplatelet therapy.Methods: ESUS patients from January 1, 2017, to June 30, 2019, underwent outpatient cardiac monitoring and the MOCHA profile (serum d-dimer, prothrombin fragment 1.2, thrombin–antithrombin complex, and fibrin monomer). Anticoagulation was offered to patients with abnormal MOCHA (≥2 elevated markers) or left atrial volume index 40 mL/m2. Patients were evaluated for recurrent stroke or major hemorrhage at routine clinical follow-up. We compared this patient cohort (cohort 2) to a historical cohort (cohort 1) who underwent the same protocol but remained on antiplatelet therapy.Results: Baseline characteristics in cohort 2 (n = 196; mean age = 63 ± 16 years, 59% female, 49% non-White) were similar to cohort 1 (n = 42) except that cohort 2 had less diabetes (43 vs. 24%, p = 0.01) and more tobacco use (26 vs. 43%, p = 0.04). Overall, 45 patients (23%) in cohort 2 initiated anticoagulation based on abnormal MOCHA or LAE. During mean follow-up of 13 ± 10 months, cohort 2 had significantly lower recurrent stroke rates than cohort 1 (14 vs. 3%, p = 0.009) with no major hemorrhages.Conclusions: Anticoagulation therapy in a subgroup of ESUS patients with abnormal MOCHA or severe LAE may be associated with a reduced rate of recurrent stroke compared to antiplatelet therapy. A prospective, randomized study is warranted to validate these results.