Atherosclerosis of the thoracic aorta: from risk stratification to treatment

Thoracic Aortic Plaque Enhances Hypercoagulability in Patients With Nonrheumatic Atrial Fibrillation

BACKGROUND

Patients with atrial fibrillation (AF) are at risk for thromboembolism, and coexistent cardiovascular diseases could affect their prothrombotic profiles. The relationship between plasma hemostatic markers and aortic atherosclerosis was determined in patients with AF or in sinus rhythm (SR).

METHODS AND RESULTS

Sixty patients with nonrheumatic AF and 46 patients in SR who underwent transesophageal echocardiography and did not receive anticoagulant therapy constituted the study group. Markers for platelet activity (platelet factor 4 and beta-thromboglobulin), thrombotic status (thrombin-antithrombin III complex and prothrombin fragment 1+2 (F1+2)) and fibrinolytic status (plasmin-alpha2-plasmin inhibitor complex (PIC) and D-dimer) were determined. Levels of F1+2, PIC and D-dimer were higher in AF patients with severe atheroma than in those without severe atheroma (p<0.05). In patients in SR, hemostatic markers were not significantly increased even if they had severe aortic atherosclerosis. AF (Odds ratio (OR) 4.06, p=0.04) and age>or=75 years (OR 3.98, p=0.02) were independently predictive of elevated D-dimer levels and severe atheroma was predictive of elevated F1+2 levels (OR 5.52, p=0.04).

CONCLUSIONS

Elderly patients with AF and severe aortic atherosclerosis might be in a prothrombotic state, and could benefit from intensive antithrombotic therapy.

3-D numerical simulation of blood flow through models of the human aorta

A Spiral Computerized Tomography (CT) scan of the aorta were obtained from a single subject and three model variations were examined. Computational fluid dynamics modeling of all three models showed variations in the velocity contours along the aortic arch with differences in the boundary layer growth and recirculation regions. Further down-stream, all three models showed very similar velocity profiles during maximum velocity with differences occurring in the decelerating part of the pulse. Flow patterns obtained from transient 3-D computational fluid dynamics are influenced by different reconstruction methods and the pulsatility of the flow. Caution is required when analyzing models based on CT scans.

Transesophageal Echocardiographic Identification of Normal and Stenosed Posterior Intercostal Arteries

We describe our experience in using transesophageal echocardiography to identify both right and left posterior intercostal arteries and assessing them for stenosis.