Dissimilarity in coagulation system in adults after fontan surgery based on thrombin generations.

Abstract

The Fontan procedure is the treatment of choice in congenital cardiac malformations defined as the single ventricle. Those patients are at high risk of thromboembolism, but the exact mechanism of this is poorly understood.The aim of this study was to evaluate an involvement of thrombin generations and microparticles in prothrombotic state in adults with Fontan circulation. Study included hospitalized patients after Fontan procedure and healthy volunteers. We assessed laboratory tests including thrombin generation by Calibrated Automated Thrombography in three variants (platelet poor plasma (impact of coagulation factors), platelet rich plasma (influence of platelets) and related with microparticles). The technique allows for a comprehensive evaluation of the coagulation system. The study groups consisted of 81 adult Fontan patients (41 females (50.6%); median age 22 interquartile range [20-27] years) and 54 control subjects. In patients with Fontan circulation higher values of endogenous thrombin potential and peak values were observed for both platelet poor plasma (+17% and +33%) and microparticles (+29% and 41%) compared to controls (all p < 0.05). Moreover, in Fontan group we found 64.9% shorter lag time and 70.4% time to peak for microparticles variant (both p < 0.001). Contrary, analysis in the platelet rich plasma showed 17.1% reduced endogenous thrombin potential in Fontan. Further, there were no differences in thrombin synthesis in platelet rich plasma in Fontan patients receiving aspirin or those with thrombocytopaenia (all p > 0.05). This study for the first time showed that thrombin generation associated with microparticles may be an important contributor to prothrombotic state in Fontan population.