Right ventricular echocardiographic parameters associated with prothrombotic abnormalities in normotensive patients with acute pulmonary embolism

Abstract

Background: In acute pulmonary embolism (PE) right ventricular (RV) pressure overload negatively affects prognosis. Recently we have shown that RV dilatation is associated with a prothrombotic state in PE. We investigated which RV echocardiographic parameters best indicate prothrombotic alterations in acute PE.

Methods: In 121 normotensive, noncancer PE patients, markers of RV dilatation and dysfunction were evaluated on admission using transthoracic echocardiography, along with prothrombotic state markers, i.e. increased endogenous thrombin generation (ETP), low fibrin clot permeability (K_s, a measure of clot density), and prolonged clot lysis time (CLT).

Results: RV parasternal long axis (RVOT PLAX) >30 mm was associated with ETP (OR 3.86; 95% CI 1.55-9.62; p = 0.004) and CLT (OR 4.08; 95% CI 1.58-10.54; p = 0.004) in the top quartiles, but not with K_s. RV short parasternal axis (RVOT PSAX) >27 mm showed similar associations with higher ETP (OR 3.54; 95% CI 1.50-8.37; p = 0.004) and prolonged CLT (OR 2.78; 95% CI 1.17-6.62; p = 0.021). RV basal diameter >41 mm solely predicted prolonged CLT (OR 2.93; 95% CI 1.23-6.99; p = 0.016). The right atrium area, pulmonary trunk diameter, and tricuspid regurgitation maximum velocity were not related to prothrombotic markers, except for tricuspid annular plane systolic excursion weakly associated with ETP. Multivariable analysis showed that RVOT PSAX is independently associated with prolonged CLT (OR 1.16; 95% CI 1.04-1.30; p = 0.007), low K_s (OR 1.21; 95% CI 1.02-1.44; p = 0.029), and higher ETP (OR 1.14; 95% CI 1.03-1.26; p = 0.009).

Conclusions: Among RV echocardiographic parameters, the RVOT dilatation measured in PSAX best predicts prothrombotic alterations in PE patients.

Keywords: Echocardiography; Fibrin clot; Lysis; Prothrombotic state; Pulmonary embolism; Right ventricle.