[Thrombomodulin: physiology and clinical applications (excluding systemic diseases)]

Correlation between left atrial size, prothrombotic state and markers of endothelial dysfunction in patients with lone chronic nonrheumatic atrial fibrillation

Atrial fibrillation is associated with a prothrombotic state and endothelial dysfunction. To understand whether the prothrombotic state was correlated with endothelial dysfunction and whether the latter was related to atrial dimension (endocardial damage), we studied systemic hemocoagulative activity and markers of endothelial dysfunction in 45 patients with chronic nonrheumatic atrial fibrillation and in 35 controls. We assessed fibrinogen, antithrombin III, protein C, markers of platelet activation (platelet factor 4 and beta-thromboglobulin) as markers of fibrinolysis, and D-dimer, tissue plasminogen activator, plasminogen activator inhibitor, von Willebrand's factor and soluble thrombomodulin as endothelial dysfunction. Plasma fibrinogen (P<0. 005), platelet factor 4 (P<0.001), thromboglobulin (P<0.001), D-dimer (P<0.03), tissue plasminogen activator (P<0.006), plasminogen activator inhibitor (P<0.04) and both von Willebrand's factor (P<0.0001) and soluble thrombomodulin (P<0.03) were significantly higher in the patients than in the controls. Positive significant linear correlations were found between fibrinogen and markers of endothelial dysfunction and left atrial volume and fibrinogen or markers of endothelial dysfunction. These findings confirm that chronic nonrheumatic atrial fibrillation is associated with a prothrombotic state but also suggest that there is a correlation between endothelial dysfunction, coagulation factors and left atrial dimension.

[Pulmonary involvement in systemic scleroderma. Part II. Isolated pulmonary arterial hypertension, bronchopulmonary cancer, alveolar hemorrhage]

INTRODUCTION

Pulmonary interstitial fibrosis is the most frequent cause of lung disease in systemic sclerosis. However, other pulmonary complications exist, including lung cancer, alveolar hemorrhage, and in particular isolated pulmonary arterial hypertension, which is still considered the bête noire as regards this disease.

CURRENT KNOWLEDGE AND KEY POINTS

The prevalence of pulmonary arterial hypertension has been reported to range from 5 to 60% in cases of systemic sclerosis; isolated pulmonary arterial hypertension has been principally observed in subjects with a ten-year history of limited forms of the disease. As the patient remains asymptomatic for a long period, with nonspecific respiratory clinical manifestations, the diagnosis is made at a much later stage in the course of the disease. The diagnostic method of choice is echocardiography-doppler, which should be performed during the preliminary investigation, and at follow-up. The prognosis is poor, and patient survival rate at 2 years after onset of symptoms amounts to 40%. To date, no curative therapy for pulmonary arterial hypertension has yet been found.

FUTURE PROSPECTS AND PROJECTS

A knowledge of the mechanisms involved in the development of isolated pulmonary arterial hypertension is essential to the determination of new and relevant therapeutic strategies. Vasodilatory treatment, notably calcium channel blockers, prostacyclin and analogs such as iloprost, may be effective at an early stage of the disease before the appearance of permanent vascular damage.