Effect of middle cerebral artery territory ischemic stroke on QT interval.

BACKGROUND: Prolonged QT interval associates with increased risk for sudden cardiac death after acute ischemic stroke. However, pathophysiology of prolonged QT interval after stroke is poorly elucidated. In this study, we investigated whether QT interval dynamics is different in patients with right and left middle cerebral artery (MCA) territory stroke. METHOD: Electrocardiogram (ECG) intervals were compared between baseline (retrieved retrospectively from medical records) and admission (acquired at the acute hospital admission) in 33 patients (65 ± 9.5 years) with right or left MCA territory ischemic stroke. Head computed tomography (CT), cardiac ultrasound, and cardiac CT scans were undertaken. RESULTS: Stroke was located in the right MCA territory in 21 (64%) and in the left MCA territory in 12 (36%) patients. Patients with right and left MCA stroke were similar with respect to time interval between baseline and admission ECG recordings, positive history of heart disease, and left ventricular dimensions. Increase in heart rate-corrected QT interval (QTc) from baseline to admission was demonstrated to occur more often in patients with right (16 of 21; 76%) than in patients with left (3 of 12; 25%; P < .01) MCA stroke. ΔQTc between baseline and admission was significantly longer in patients with right (23 ± 23 milliseconds) than in patients with left (-11 ± 19 milliseconds; P < .0001) MCA stroke. Percent ΔQTc between baseline and admission was longer in patients with right (5.5% ± 5.5%) than in patients with left (-2.6% ± 4.7%; P < .001) MCA stroke. CONCLUSIONS: Right MCA ischemic stroke results in prolongation of QT interval. Findings indicate cerebral asymmetry in brain-heart interaction during acute ischemic stroke.

Morphological features of the left atrial appendage in consecutive coronary computed tomography angiography patients with and without atrial fibrillation.

The majority of intracardiac thrombi form in the left atrial appendage (LAA). Enlargement of this structure, together with certain morphological features, may indicate a predisposition to the formation of thrombi and subsequent cardioembolic stroke. Thus far, studies on LAA morphology have largely focused on those patients with atrial fibrillation (AF). Taking a different approach, we investigated the variation in LAA morphology in a consecutive patient population with and without AF. We evaluated 808 consecutive patients (529 females; mean age 52.5±9.9 years) who underwent coronary artery computed tomography angiography (CCTA), the majority of whom (749) had no history of AF. We assessed the length, lobe number, and morphological classification of their LAAs. Demographic data and medical histories were collated from medical records and then correlated with LAA morphology. The proportions of each of the four morphological classes of LAA for the overall vs. non-AF population were: WindSock, 62.3/61.5%; Cactus, 18.6/18.8%; ChickenWing, 10.0/10.0%; and CauliFlower, 9.2/9.6%. Age (p<0.001; r = 0.156) and female gender (p<0.001) were both found to be associated with an increased body surface area (BSA)-related LAA length. Male patients were more likely to manifest multi-lobed (p = 0.003) LAAs, and overweight patients with a greater number of multi-lobed LAA morphological classes (p = 0.010). No associations with morphological LAA features could be found for patients with diabetes, hypertension, or dyslipidemia. Nor did the size of the left atrium exhibit any correlation with BSA-related LAA length. In the overall and non-AF populations, aging and female gender were associated with longer BSA-indexed LAAs.

vWF correlates with visceral and pericardial adipose tissue in patients with a recent stroke of suspected cardiogenic etiology.

AIMS: A chronically elevated level of von Willebrand factor (vWF) is a common finding in patients with cardiovascular diseases. Obesity is a well-recognized risk factor for thrombotic cardiovascular complications including ischemic stroke, and it has been linked with increased plasma vWF. We evaluated whether elevated plasma levels of vWF associate with areas of visceral (VAT), pericardial (PAT), and subcutaneous adipose tissue (SAT) compartments in patients with acute/subacute stroke. METHODS AND RESULTS: A total of 69 patients with stroke of suspected cardiogenic etiology were examined. The plasma level of vWF antigen (vWF-ag) was measured both in the acute phase and in the chronic phase three months after stroke. The areas of VAT and/or PAT were assessed with computed tomography. As expected, in stroke patients, the levels of plasma vWF-ag were significantly higher than in the national reference population both in the acute and in the chronic phase. The level of vWF-ag in the chronic phase correlated with the amounts of VAT and PAT, but not with subcutaneous adipose tissue. CONCLUSIONS: These results agree with previous observations of the chronic inflammation/prothrombotic tendency in patients with cerebrovascular disease. Future studies should seek to clarify the role of visceral type adipose tissue in the pathophysiology of ischemic stroke.

Soluble Urokinase-type Plasminogen Activator Receptor Predicts All-cause 5-Year Mortality in Ischemic Stroke and TIA.

AIM: We evaluated soluble urokinase-type plasminogen activator receptor (suPAR) levels in different stroke subtypes and assessed their prognostic value regarding 5-year outcomes. MATERIALS AND METHODS: The study included 117 stroke patients (81 males; mean=age 61±11 years) with suspected cardioembolic stroke whose plasma suPAR concentration was assessed. Altogether, 20 (17.1%) patients suffered from stroke as a result of cardioembolism, 12 (10.3%) from large-artery atherosclerosis, 9 (7.7%) from small-vessel disease, 11 (9.4%) from both large-artery and cardioembolic etiology, and 65 (55.6%) had cryptogenic stroke. The mean follow-up period was 5 years. RESULTS: suPAR concentration was higher in patients who suffered from stroke/transient ischemic attack due to large-artery atherosclerosis (3.2±0.9 ng/ml) compared to small-vessel disease (2.0±0.5 ng/ml, p<0.001). An elevated plasma suPAR concentration was associated with all-cause mortality during the follow-up period (p=0.003). CONCLUSION: Elevated plasma suPAR concentrations predicted all-cause mortality during the 5-year follow-up after ischemic stroke. suPAR was not able to differentiate patients with cardioembolic stroke from those with other stroke types.

Cardiac CT Differentiates Left Atrial Appendage Thrombi from Circulatory Stasis in Acute Stroke Patients.

BACKGROUND/AIM: The left atrial appendage (LAA) is the most typical origin for a cardioembolic thrombusins' stroke etiology. Although transesophageal echocardiography (TEE) is widely used, this technique encounters difficulties in differentiating solid thrombus from circulatory stasis/spontaneous echo contrast (SEC). We assessed whether cardiac computed tomography (cCT) could more accurately detect LAA thrombi. MATERIALS AND METHODS: A total of 102 patients with suspected acute cardioembolic stroke/ transient ischemic attack (TIA) without chronic atrial fibrillation underwent arterial and venous phase cCT and TEE. TEE and cCT were consensus read to define LAA thrombus, while TEE alone was used to determine SEC. The LAA/aorta Houndsfield unit (HU) ratio was measured in both phases independently and blinded to prior visual readings. The optimal LAA/aorta HU ratio cut-off value for differentiating thrombi and SEC was estimated. RESULTS: TEE indicated 10 SECs and three thrombi. Consensus reading of cCT and TEE indicated that all thrombi detected in TEE were false-positive but revealed three actual thrombi missed in TEE. The LAA/aorta HU ratio correlated significantly with the presence of SEC both in arterial (p=0.019) and venous phases (p=0.024) and with the presence of thrombi in both phases (p<0.001). The best trade-off values for LAA/aorta HU ratio for the detection of thrombi was <0.245 in both phases. SEC was characterized with HU ratios of >0.245 and <0.577 in the arterial phase and>0.245 and <0.824 in the venous phase. Values of sensitivity, specificity, positive and negative predictive value and accuracy for detection of thrombi were 100% for cCT in both phases. CONCLUSION: cCT is more accurate than TEE in the detection of LAA thrombi, especially when combined with the measurement of LAA/aorta HU ratio.

Left atrial appendage morphology in patients with suspected cardiogenic stroke without known atrial fibrillation.

The left atrial appendage (LAA) is the typical origin for intracardiac thrombus formation. Whether LAA morphology is associated with increased stroke/TIA risk is controversial and, if it does, which morphological type most predisposes to thrombus formation. We assessed LAA morphology in stroke patients with cryptogenic or suspected cardiogenic etiology and in age- and gender-matched healthy controls. LAA morphology and volume were analyzed by cardiac computed tomography in 111 patients (74 males; mean age 60 ± 11 years) with acute ischemic stroke of cryptogenic or suspected cardiogenic etiology other than known atrial fibrillation (AF). A subgroup of 40 patients was compared to an age- and gender-matched control group of 40 healthy individuals (21 males in each; mean age 54 ± 9 years). LAA was classified into four morphology types (Cactus, ChickenWing, WindSock, CauliFlower) modified with a quantitative qualifier. The proportions of LAA morphology types in the main stroke group, matched stroke subgroup, and control group were as follows: Cactus (9.0%, 5.0%, 20.0%), ChickenWing (23.4%, 37.5%, 10.0%), WindSock (47.7%, 35.0%, 67.5%), and CauliFlower (19.8%, 22.5%, 2.5%). The distribution of morphology types differed significantly (P<0.001) between the matched stroke subgroup and control group. The proportion of single-lobed LAA was significantly higher (P<0.001) in the matched stroke subgroup (55%) than the control group (6%). LAA volumes were significantly larger (P<0.001) in both stroke study groups compared to controls patients. To conclude, LAA morphology differed significantly between stroke patients and controls, and single-lobed LAAs were overrepresented and LAA volume was larger in patients with acute ischemic stroke of cryptogenic or suspected cardiogenic etiology.

Increased visceral adipose tissue as a potential risk factor in patients with embolic stroke of undetermined source (ESUS).

PURPOSE: The etiology of an ischemic stroke remains undetermined in 20-35% of cases and many patients do not have any of the conventional risk factors. Increased visceral adipose tissue (VAT) is a suggested new risk factor for both carotid artery atherosclerosis (CAA) and atrial fibrillation (AF), but its role in the remaining stroke population is unknown. We assessed the amount of VAT in patients with embolic stroke of undetermined source (ESUS) after excluding major-risk cardioembolic sources, occlusive atherosclerosis, and lacunar stroke. METHODS: Altogether 58 patients (mean age 57.7 ± 10.2 years, 44 men) with ischemic stroke of unknown etiology but without CAA, known AF or small vessel disease underwent computed tomography angiography and assessment of VAT. For comparison VAT values from three different reference populations were used. Conventional risk factors (smoking, hypertension, diabetes, increased total and LDL-cholesterol, decreased HDL-cholesterol) were also registered. RESULTS: Mean VAT area was significantly higher in stroke patients (205 ± 103 cm2 for men and 168 ± 99 cm2 for women) compared to all reference populations (P < 0.01). 50% of male and 57% of female patients had an increased VAT area. In male patients, VAT was significantly higher despite similar body mass index (BMI). Increased VAT was more common than any of the conventional risk factors. CONCLUSION: Increased VAT was found in over half of our patients with ESUS suggesting it may have a role in the pathogenesis of thromboembolism in this selected group of patients.

Acute phase IL-10 plasma concentration associates with the high risk sources of cardiogenic stroke.

BACKGROUND: Etiological assessment of stroke is essential for accurate treatment decisions and for secondary prevention of recurrence. There is evidence that interleukin-10 (IL-10) associates with ischemic stroke. The aim of this prospective study was to assess the levels of IL-10 in ischemic stroke with unknown or suspected cardiogenic etiology, and evaluate the correlation between IL-10 plasma concentration and the number of diagnosed high risk sources for cardioembolism. METHODS: A total of 141 patients (97 males; mean age 61±11 years) with acute ischemic stroke with unknown etiology or suspected cardiogenic etiology other than known atrial fibrillation (AF) underwent imaging investigations to assess high risk sources for cardioembolic stroke established by the European Association of Echocardiography (EAE). IL-10 was measured on admission to the hospital and on a three month follow-up visit. RESULTS: Acute phase IL-10 concentration was higher in patients with EAE high risk sources, and correlated with their number (p<0.01). In patients with no risk sources (n = 104), the mean IL-10 concentration was 2.7±3.1 ng/L (range 0.3-16.3 ng/L), with one risk source (n = 26) 3.7±5.5 ng/L (0.3-23.6 ng/L), with two risk sources (n = 10) 7.0±10.0 ng/L (1.29-34.8 ng/L) and with three risk sources (n = 1) 37.2 ng/L. IL-10 level was not significantly associated with cerebral infarct volume, presence of previous or recent myocardial infarction, carotid/vertebral artery atherosclerosis, paroxysmal AF registered on 24-hour ECG Holter monitoring or given intravenous thrombolytic treatment. CONCLUSION: IL-10 plasma concentration correlates independently with the number of EAE cardioembolic risk sources in patients with acute stroke. IL-10 may have potential to improve differential diagnostics of stroke with unknown etiology.

Determinants of left atrial appendage volume in stroke patients without chronic atrial fibrillation.

BACKGROUND: Left atrial appendage (LAA) volume has been shown to be increased in patients with acute cryptogenic stroke. Atrial fibrillation (AF) is a well-recognized risk factor but it is not the only one associated with LAA enlargement. The aim of the study was to clarify the multifactorial etiology of LAA enlargement in cardiogenic stroke/TIA patients without AF. METHODS: Altogether 149 patients with suspected cardioembolic stroke/TIA (47 females; mean age 61 years) underwent cardiac CT. Diagnosed AF on admittance was an exclusion criteria but 24-hour Holter ambulatory ECG revealed paroxysmal AF (PAF) in 20 patients. Body surface area adjusted LAA volume was evaluated. Eighteen different variables were registered including general characteristics, definite and potential causal risk factors for ischemic stroke/TIA, clinical echoparameters and CT based cardiac volumetric and adipose tissue measurements. A stepwise linear regression analysis was performed to achieve a model adjusted for the number of predictors of LAA volume increase. RESULTS: In linear regression analysis, the best model accounted for 30% of the variability in LAA volume, including PAF (19%) and enlarged left atrial volume (6%), enlarged left ventricle end-systolic diameter (3%) and decreased pericardial adipose tissue (2%). No multi-colinearity between variables was observed. In addition to PAF, no other definitive or potential causal risk factors could account for the LAA volume in these patients. CONCLUSIONS: LAA volume increase seems to be poorly associated with currently known stroke/TIA risk factors, except for AF. Targeting more comprehensive ECG monitoring for stroke patients with increased LAA volume should be considered.

Morphological and volumetric analysis of left atrial appendage and left atrium: cardiac computed tomography-based reproducibility assessment.

OBJECTIVES: Left atrial appendage (LAA) dilatation and morphology may influence an individual's risk for intracardiac thrombi and ischemic stroke. LAA size and morphology can be evaluated using cardiac computed tomography (cCT). The present study evaluated the reproducibility of LAA volume and morphology assessments. METHODS: A total of 149 patients (47 females; mean age 60.9±10.6 years) with suspected cardioembolic stroke/transient ischemic attack underwent cCT. Image quality was rated based on four categories. Ten patients were selected from each image quality category (N = 40) for volumetric reproducibility analysis by two individual readers. LAA and left atrium (LA) volume were measured in both two-chamber (2CV) and transversal view (TV) orientation. Intertechnique reproducibility was assessed between 2CV and TV (200 measurement pairs). LAA morphology (A = Cactus, B = ChickenWing, C = WindSock, D = CauliFlower), LAA opening height, number of LAA lobes, trabeculation, and orientation of the LAA tip was analysed in all study subjects by three individual readers (447 interobserver measurement pairs). The reproducibility of volume measurements was assessed by intra-class correlation (ICC) and the reproducibility of LAA morphology assessments by Cohen's kappa. RESULTS: The intra-observer and interobserver reproducibility of LAA and LA volume measurements was excellent (ICCs>0.9). The LAA (ICC = 0.954) and LA (ICC = 0.945) volume measurements were comparable between 2CV and TV. Morphological classification (ĸ = 0.24) and assessments of LAA opening height (ĸ = 0.1), number of LAA lobes (ĸ = 0.16), trabeculation (ĸ = 0.15), and orientation of the LAA tip (ĸ = 0.37) was only slightly to fairly reproducible. CONCLUSIONS: LA and LAA volume measurements on cCT provide excellent reproducibility, whereas visual assessment of LAA morphological features is challenging and results in unsatisfactory agreement between readers.

Low plasma uric acid level in Parkinson's disease.

Earlier studies suggest that low plasma uric acid level is a risk factor for Parkinson's disease (PD), and that uric acid associates with iron-binding proteins. We therefore decided to examine plasma uric acid levels and markers of peripheral iron metabolism in PD patients and healthy controls. For the study, 40 patients with PD and 29 controls underwent clinical screening, laboratory testing, and body mass index (BMI) measurement. The average consumption of different foodstuffs and dairy products was estimated. Plasma uric acid level was significantly lower in the patients than in the controls. There were no significant differences in the levels of plasma iron parameters, but plasma uric acid correlated strongly with serum ferritin both in the patient and the control group. The BMI was slightly lower in the patients compared with the controls despite equal daily calorie consumption. Plasma uric acid level is low in patients with PD, which may have implications for both the disease pathogenesis and treatment recommendations.

Administration of nonionic iodinated contrast medium does not influence the outcome of patients with ischemic brain infarction.

Some reports indicate that exposure to iodinated contrast medium (CM) could worsen the outcome of patients with brain infarction. In this prospective study, we compared the outcome of 77 patients receiving and 128 not receiving nonionic iodinated CM. Stroke severity was assessed by the Scandinavian Prognostic Stroke Score, and outcome by the Rankin Scale. All radiological studies using intravenous or intra-arterial CM were registered. Two nonionic iodinated CM (iopamidol and iohexol) were used. Exposure to CM did not influence case fatality, ability to live at home, ability to walk, disability and stroke severity. Initial stroke severity and arterial hypertension were independent determinants of poor neurological recovery or death. Large infarct, age, male gender, and baseline stroke severity were independent determinants of major disability or death. CM enhancement on CT did not show any harmful effect on stroke severity or outcome. As a conclusion, intravascular administration of nonionic iodinated CM did not influence stroke severity or outcome of our patients.