Thoracic Aortic Plaque Enhances Hypercoagulability in Patients With Nonrheumatic Atrial Fibrillation

Abstract

trial fibrillation (AF) is associated with higher thromboembolic risk, possibly because of the hypercoagulable state. 1,2 Elevated levels of hemostatic markers have been shown in patients with nonrheumatic AF. [2][3][4][5][6] During AF, stagnation of blood flow in the left atrial appendage (LAA) could contribute to the hypercoagulable state and clot formation in the fibrillating atria. Hemostatic markers could be therefore used for stratification of patients at high risk vs low risk for thromboembolism as demonstrated in previous studies. [1][2][3][4][5][6] Aortic atheroma is recognized as an important marker of stroke and peripheral embolism in patients with AF. 7-9 The SPAF-III investigators reported that complex aortic plaque emerged as a risk factor of thromboembolism in patients with nonrheumatic AF, and warfarin was effective in reducing stroke in patients with AF and complex aortic plaque. 10 Complex aortic plaques with ulcerated or mobile plaques and superimposed thrombi would activate hemostatic markers. The Framingham Offspring Study raised the possibility that the increases in hemostatic factors in patients with AF were mainly caused by the confounding effect of traditional risk factors and coexistent cardiovascular diseases rather than by AF itself. 2 We recently reported that patients with nonrheumatic AF had elevated levels of D-dimer when complicated with spontaneous echocardiographic contrast (SEC) in the descending thoracic aorta. 11Because AF and aortic atherosclerosis might contribute synergistically to increased levels of hemostatic markers, and could be associated with increased risk of thromboembolism, we determined the relationship between plasma levels of hemostatic markers and atherosclerosis in the descending thoracic aorta assessed by transesophageal echocardiography (TEE) in patients with nonrheumatic AF and in those in sinus rhythm (SR). Methods Study PatientsEchocardiographic and hematologic studies were performed in 106 consecutive patients (79 men, 27 women; mean age of 67±11 years) referred to a university hospital for cardiovascular assessment for stroke risk or identification of the cardiogenic source of recent embolism. Patients who received anticoagulant therapy were not included in the present study. Of these 106 patients, AF was documented electrocardiographically in 60 patients (AF group) but not in the remaining 46 patients (SR group). The study protocol was approved by the institutional ethics committee and written informed consent was given by all patients. Underlying heart diseases included the following: ischemic heart disease (n=8), hypertrophic cardiomyopathy (n=4), dilated cardiomyopathy (n=5), sick sinus syndrome (n=3), atrial septal defect (n=5), post pericarditis (n=6), and miscellaneous diseases (n=20). No apparent underlying diseases were identified in 55 patients. Baseline clinical characteristics, including body mass index, diabetes mellitus, hyperlipidemia, smoking, previous cerebral or peripheral embolic event and the use of oral antiplatelet medication at...

Plasma Brain Natriuretic Peptide Levels Indicating Thromboembolism in Very Elderly Patients With Non-Valvular Atrial Fibrillation

“…42,43,45 In the present study, a significant positive correlation was found between plasma D-dimer and BNP levels. Therefore, we suggest that a high plasma BNP level might indicate a hypercoagulate state in very elderly patients who have non-valvular AF without overt heart failure.…”

Relation of left atrial blood stasis to clinical risk factors in atrial fibrillation

“…Indeed, we have shown in the present study that the severity of aortic atherosclerosis was associated with an increase in the risk level. Aortic atherosclerosis might be associated with a hypercoagulable state in patients with AF, resulting in a high prevalence of cerebral infarction [15].…”

Transesophageal Echocardiographic Findings Are Independent and Relevant Predictors of Ischemic Stroke in Patients with Nonvalvular Atrial Fibrillation

“…The existence of complex aortic plaques is considered to be a marker of atherosclerosis, and is known to enhance hypercoagulability in patients with NVAF 15. Therefore, the development of an accurate ischemic stroke risk stratification scheme that would include certain types of laboratory data such as TEE risk markers that directly reflect a prothrombotic condition of the LA is warranted 16,17…”

“…Thus, further studies are warranted to evaluate the correlation between LVEF and LAD, and the presence of TEE risk. The addition of hemostatic markers, such as D-dimer levels, to the criteria for stroke risk stratification should also be considered 15,18,19…”