Atrial Cardiopathy and the Risk of Ischemic Stroke in the CHS (Cardiovascular Health Study)

Embolic stroke of undetermined source correlates to atrial fibrosis without atrial fibrillation

Objective

To examine the hypothesis that atrial fibrosis and associated atrial cardiopathy may be in the causal pathway of cardioembolic stroke independently of atrial fibrillation (AF) by comparing atrial fibrosis burden between patients with embolic stroke of undetermined source (ESUS), patients with AF, and healthy controls.

Methods

We used late-gadolinium-enhancement MRI to compare atrial fibrosis in 10 patients with ESUS against 10 controls (no stroke, no AF) and 10 patients with AF. Fibrosis was compared between groups, controlling for stroke risk factors.

Results

Mean age was 51 ± 15 years, and 43% of participants were female. Patients with ESUS had more atrial fibrosis than controls (16.8 ± 5.7% vs 10.6 ± 5.7%, p = 0.019) and similar fibrosis compared to patients with AF (17.8 ± 4.8%, p = 0.65). Odds ratios of ESUS per quartile of fibrosis were 3.22 (95% CI [CI] 1.11–9.32, p = 0.031, unadjusted) and 3.17 (95% CI 1.05–9.52, p = 0.041, CHA2DVASc score adjusted). Patients with >12% fibrosis had a higher percentage of ESUS (77.8% vs 27.3%, p = 0.02), and patients with >20% fibrosis had the highest proportion of ESUS (4 of 5).

Conclusions

Patients with ESUS exhibit similar atrial fibrosis compared to patients with AF and more fibrosis than healthy controls. Fibrosis is associated with ESUS after controlling for stroke risk factors, supporting the hypothesis that fibrosis is in the causal pathway of cardioembolic stroke independently of AF. Prospective studies are needed to assess the role of anticoagulation in primary and secondary stroke prevention in patients with high atrial fibrosis.

Association between excessive supraventricular ectopy and subclinical cerebrovascular disease: a population-based study

BACKGROUND AND PURPOSE

The association between an increased supraventricular ectopic beat (SVEB) and subclinical cerebrovascular disease remains unclear. Given the emerging concept that an increased SVEB is a marker of atrial cardiomyopathy or atherosclerosis burden, we sought to determine whether excessive supraventricular ectopic activity (ESVEA) is associated with a higher burden of subclinical cerebrovascular disease in the middle-aged to older cohort with neither apparent stroke nor atrial fibrillation.

METHODS

We conducted a cross-sectional population-based study of 462 men (mean age, 68.1 years) who underwent 24-h Holter electrocardiography and brain magnetic resonance imaging. ESVEA was defined as the presence of >10 SVEBs/h. Subclinical cerebrovascular diseases were defined as silent brain infarct (SBI), white matter hyperintensity (WMH) and intracranial atherosclerotic stenosis (ICAS). The association of ESVEA with the presence of subclinical cerebrovascular diseases was adjusted for potential confounding covariates.

RESULTS

A total of 88 (19.0%) participants had ESVEA and 81 (17.5%), 91 (19.7%) and 109 (23.6%) had SBI, WMH and ICAS, respectively. In multivariable-adjusted Poisson regression with robust error variance, ESVEA was associated with the presence of WMH (relative risk, 1.58; 95% confidence interval, 1.06-2.36) and ICAS (relative risk, 1.49; 95% confidence interval, 1.02-2.18), but not with that of SBI (relative risk, 1.32; 95% confidence interval, 0.86-2.01). These associations were consistent when the graded distributions of subclinical cerebrovascular diseases were applied as outcomes in ordinal logistic regression.

CONCLUSIONS

The ESVEA was independently associated with higher burdens of WMH and ICAS. This suggests that increased SVEBs might improve risk stratification of individuals at high risk of subclinical cerebrovascular disease and consequently apparent ischaemic stroke.

Prognostic value of global left atrial peak strain in patients with acute ischemic stroke and no evidence of atrial fibrillation

Prognostic stratification of acute ischemic stroke (AIS) patients without atrial fibrillation (AF) remains a challenge. Two-dimensional speckle tracking echocardiography (2D-STE) has recently been introduced for dynamic evaluation of left atrial function. However only few data are actually available regarding the application of 2D-STE in AIS patients. The aim of our study was to assess the prognostic role of global left atrial peak strain (GLAPS), measured by 2D-STE, in AIS patients without AF history. Eighty-five AIS patients (mean age 74.1 ± 12.1 years, 49 males) with normal sinus rhythm on ECG and without AF history were enrolled in the prospective study. All patients underwent a complete echocardiographic study with 2D-STE. At 1 year follow-up, we evaluated the occurrence of a composite endpoint of all-cause mortality plus cardiovascular re-hospitalizations. GLAPS was markedly reduced in AIS patients (15.71 ± 4.70%), without any statistically significant difference between the stroke subtypes. At 1-year follow-up, 14 deaths and 17 hospital readmissions were detected in AIS subjects. On a multivariate Cox model, variables independently associated with the occurrence of the composite endpoint were the "Rankin in" Scale (HR 1.69, p = 0.001), GFR (HR 0.98, p = 0.03) and the GLAPS value (HR 0.78, p < 0.0001). A GLAPS value ≤ 15.5% predicted the composite endpoint with sensitivity of 100% and specificity of 80%. A GLAPS value ≤ 15.5% reflects a more advanced atrial cardiomyopathy and might provide a reliable and useful prognostic risk stratification of AIS patients without AF history.