Plasma levels of haemostatic factors in patients with pulmonary embolism on admission and seven months later

Introduction: With the exception of D-dimer, not much is known about the plasma levels of haemostatic factors during acute venous thromboembolism (VTE) compared to their basic levels in a stable phase. The goal of this study was to examine how plasma levels of factor V, VIII, XIIIa, von Willebrand factor antigen (vWF:Ag), fibrinogen, thrombomodulin evolve from the point of diagnosis of acute VTE to the end of standard treatment period.

Methods: Sixty-three consecutive patients (mean 57, range 18-86 years, 33 females) with acute pulmonary embolism (PE) were included. Laboratory samples were collected upon arrival (acute phase) and seven months later (stable phase). Fifteen similar aged individuals served as controls.

Results: Plasma levels of factor XIIIa (87.5% vs 117.7%, P < .001) and soluble thrombomodulin (36.6 vs 47.5 ng/L, P < .001) were lower, whereas plasma levels of vWF:Ag (2.66 vs 2.01 IU/mL, P < .001) and fibrinogen (4.3 vs 3.9 g/L, P < .05) were higher on admission compared to the stable phase. In the stable phase, vWF:Ag (2.01 vs 1.43 IU/mL, P < .01) and soluble thrombomodulin (47.5 vs 38.0 ng/mL, P < .05), but not FXIIIa levels, were higher in PE patients compared to healthy controls.

Conclusion: This study confirms the concept of FXIIIa consumption during acute phase of VTE by showing its intraindividual normalization during the follow-up. vWF:Ag, known to be associated with the risk of VTE, was constantly elevated in the majority of the patients. Soluble thrombomodulin levels were lower in acute phase compared to stable phase, a finding which significance needs to be evaluated in the future.