Echocardiographic measures of atrial function may predict atrial fibrillation in stroke patients.

OBJECTIVE: In patients with a prior stroke or transient ischemic attack (TIA) and atrial fibrillation anticoagulant treatment is indicated. This study's purpose was to investigate if echocardiography can predict unknown AF in patients after stroke. DESIGN: Prospectively, 174 stroke/TIA patients without diagnosed AF underwent echocardiographic evaluation including tissue Doppler imaging (TDI) focusing on functional parameters of the left atrium and left ventricular diastolic function. AF screening was performed during 30 d. RESULTS: Fifteen patients (8.6%) were diagnosed with AF. Echocardiography in the AF group compared to those without AF, showed larger left atrial volume index (LAVI), (37.2 ± 6.7 vs. 31.6 ± 8.6 ml/m(2), p = 0.018), lower A' velocities in ventricular (5.9 ± 2.2 vs. 7.2 ± 1.6, p = 0.010) and atrial (4.8 ± 1.4 vs. 5.9 ± 1.4, p = 0.013) septa, higher LAVI/A' in ventricular septum (6.7 (5.0-8.7) vs. 4.2 (3.2-5.5), p = 0.001) and atrial septum (8.5 (5.9-11.0) vs. 5.1 (4.1-6.8), p = 0.003). Receiver operating characteristic analyses to detect AF was performed, area under the curve for LAVI was 0.71 (0.61-0.83), p = 0.008, and for LAVI/A' in ventricular septum 0.76 (0.59-0.93), p = 0.006 and atrial septum 0.78 (0.63-0.93), p = 0.002, respectively. CONCLUSIONS: LAVI and measures of atrial contraction as measured by TDI predict unknown AF in patients after an stroke/TIA and may be used to detect silent AF.

Thrombin generation in acute cardioembolic and non-cardioembolic ischemic stroke.

OBJECTIVE: Increased thrombin generation, as measured by the Calibrated Automated Thrombogram (CAT), has recently been reported to predict ischemic stroke, especially stroke with a cardioembolic source. However, there are few studies on thrombin generation using CAT in patients with manifest ischemic stroke, particularly in patients with cardioembolic stroke not yet on anticoagulation. MATERIALS AND METHODS: Therefore, a prospective cohort study of 205 stroke patients > 45 years of age was performed. They were recruited during their hospital stay or shortly thereafter. Inclusion criteria were ischemic stroke or TIA within two weeks and no atrial fibrillation (AF) in the history or at inclusion. Patients received a thumb ECG device in order to detect silent AF. Blood samples were collected at inclusion and after 1 month. Thrombin generation in plasma after addition of tissue factor was assessed in patients and in healthy controls. RESULTS: Mean age of patients was 72 ± 7 years and 43% were females. Peak thrombin concentrations were variable among stroke patients but overall significantly higher at both time points (p < 0.0001) compared to controls, and tended to be highest in patients in whom paroxysmal atrial fibrillation was subsequently documented. CONCLUSION: Thrombin generation in patients with acute cardioembolic and non-cardioembolic schemic stroke/TIA is variable but overall higher compared to healthy subjects. The long-term prognostic value of thrombin generation in patients with a recent ischemic stroke deserves further investigation.