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

Coronary CTA to Investigate Predictive Value of Left Atrial Appendage for Cardiogenic Stroke in Patients with Nonvalvular Atrial Fibrillation

PURPOSE

To investigate the predictive value of changes in LAA size and function for cardiogenic stroke (CS) in patients with NVAF by coronary CTA examination. Materials and Method. 179 patients with NVAF were selected and grouped according to the outbreak of acute ischemic stroke and TIA within 2 years after coronary CTA examination. Those who met the criteria for CS were selected as cases (87 patients), and those neither stroke nor TIA as controls (92 patients). LAA size of selected patients was measured and data postprocessing was performed. The differences of baseline data and LAA parameters between groups were analyzed. The impacts of BMI, hyperlipidemia, the duration of AF, the LAAOA Index, and the LAAEF on CS were assessed by binary logistic regression. The predictive abilities of LAAOA Index, LAAEF, and the combined predictor were assessed by ROC curves.

RESULTS

Proportions of BMI ≥ 25, prevalence of hyperlipidemia, duration of AF, and LAAODmax, LAAODmin, LAAOA, LAAVmax, and LAAVmin with their correction index were greater in cases than controls. The LAAEF was lower in cases than that in controls. The binary logistic regression model showed an increase in LAAOA Index (P = 0.005) and a decrease in LAAEF (P < 0.001) were independent risk factors for CS. ROC curve analysis showed that the optimal cutoff values of LAAOA Index and LAAEF to predict CS were 3.16 cm²/m² and 38.71%, with AUC value of 0.712 and 0.734, respectively. The LAAOA Index-LAAEF combined predictor (AUC value = 0.786) was likely superior to either LAAOA Index or LAAEF.

CONCLUSIONS

Coronary CTA can provide additional valuable parameters, as a by-product of coronary artery assessment without additional radiation dose, for the risk assessment of CS in patients with NVAF. Coronary CTA may make up for the limitation of single indicator of CHA₂DS₂-VASc in guiding anticoagulation program, to reduce the incidence of embolism and bleeding events.

The left atrial appendage morphology and gender differences by multi-detector computed tomography in an Egyptian population

Background

The left atrial appendage (LAA) is the main source of thromboembolism in patients with non-valvular atrial fibrillation. Unique LAA morphologies have been associated with the risk of thromboembolism. This study investigates the LAA anatomy in the Egyptian population using cardiac multi-detector computed tomography (MDCT).

Results

We included 252 consecutive patients presenting for coronary computed tomography angiography in 2 tertiary centers in Egypt in the period from January to July 2017. Patients with atrial fibrillation, valvular affection, or left ventricular dysfunction were excluded. Two and three-dimensional cardiac MDCT images were assessed for LAA morphology, volume, length, and orifice position. The distribution of LAA morphologies was windsock (32.5%), chicken wing (25.4%), cauliflower (22.6%), and cactus (19.4%). Differences in the LAA dimensions in the 4 morphological variants were described. Females were less likely to have a chicken wing LAA morphology compared to males (7.9% vs 34.7%, p value < 0.01), and had a larger LAA volume, smaller LAA length, and a higher prevalence of high LAA orifice position.

Conclusions

The most common LAA morphology in our study population is windsock, which may represent the Egyptian population or patients in sinus rhythm. Females were less likely to have a chicken wing LAA morphology, and had a larger LAA volume, smaller length, and higher incidence of high orifice position. Clinical correlation into the translation of these differences into thromboembolic risk is required.

Age-related changes in morphology of left atrial appendage in patients with atrial fibrillation

The purpose of this study was to evaluate the relationship between age and frequency of left atrial appendage (LAA) morphology in patients with atrial fibrillation (AF) compared with sinus rhythm (SR). We enrolled 145 AF patients, and 199 SR patients for the control group without any cardiovascular disease. LAA volume index (LAAVi) and morphology were assessed by electrocardiogram-gated computed tomography angiography. LAA morphology was classified into "chicken wing" or "non-chicken wing" according to the previously described classification. There was no significant trend in frequency of non-chicken wing morphology among ages in the SR group (p = 0.36 for trend), whereas the frequency was negatively related to age in the AF group (p = 0.002 for trend). In multivariable logistic regression, age > 65 (odds ratio [OR] 0.42, p = 0.002) and duration of AF (OR 0.53, p = 0.010) and LAAVi (OR 0.62, p = 0.017) were independent factors of non-chicken wing LAA morphology in the AF group. LAA morphology is affected by age, especially in patients with AF. When we utilize non-chicken wing LAA morphology as a stroke risk factor in patients with AF, we should pay attention to their age.

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.

Characteristics of Anatomy and Function of the Left Atrial Appendage and Their Relationships in Patients with Cardioembolic Stroke: A 3-Dimensional Transesophageal Echocardiography Study

BACKGROUND

Increasing attention is being paid to the left atrial appendage (LAA) in the context of risk stratification in cardioembolic stroke (CES) and the requirement for meticulous planning of percutaneous closure device implantation. However, detailed systematic assessment of the LAA remains limited.

METHODS

This study evaluated the anatomy and function of LAA using 3-dimensional transesophageal echocardiography (3D-TEE) on 194 consecutive patients older than 50 years old hospitalized exclusively for CES. Patients were stratified into 3 groups on the basis of cardiac rhythm: (1) chronic atrial fibrillation (AF), n = 53; (2) paroxysmal AF, n = 26; and (3) no detected AF, n = 115.

RESULTS

Significant differences between the groups were observed for anatomical (orifice area [OA], depth, diastolic volume) and functional parameters (ejection fraction [EF], flow velocity [FV]), as measured by 3D-TEE. The anatomical parameters were consistently the greatest, and functional parameters were the poorest, in the group with chronic AF. There were significant inverse correlations between them (r = -.33, P = .0003 for depth and EF; r = -.27, P = .0020 for depth and FV; r = -.22, P = .016 for OA and EF; and r = -.38, P < .0001 for OA and FV).

CONCLUSIONS

LAA morphology and function were strongly affected by cardiac rhythm disturbances. Patients with chronic AF had the greatest LAA dimensions, areas, and volumes as well as the lowest LAA functions. An inverse correlation was observed between LAA size and function.

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.