An Automated Microfluidic System for Haemostasis Assessment in Cirrhosis With Thrombocytopenia

ABSTRACT Background & Aims Conventional laboratory tests do not capture platelet–vessel wall interactions (primary haemostasis) occurring in vivo, limiting guidance before invasive procedures. This is relevant in patients with thrombocytopenia, hallmark of advanced cirrhosis. Microfluidic assays may overcome these limitations. The Total Thrombus Analysis System (T‐TAS) is a flow chamber that can be adapted for thrombocytopenic samples when equipped with the HD‐CHIP. The CirTAS study aimed to assess T‐TAS reproducibility and the ability to identify a disease‐severity gradient in patients with cirrhosis and thrombocytopenia. Methods Eighty‐one patients with cirrhosis and thrombocytopenia were enrolled (20 Child–Pugh A, 41 B/C and 20 B/C with bacterial infection). T‐TAS measurements were performed using the HD‐CHIP. Reproducibility was assessed by intraclass correlation coefficients. Thromboelastometry (ROTEM) parameters were analysed in parallel. Multivariable and piecewise regression analyses were performed to test factors influencing T‐TAS parameters. Results T‐TAS showed high reproducibility, with intraclass correlation coefficients ≈0.90 for all parameters ( p < 0.001), even in platelet counts < 50 × 10 9 /L. Thrombus formation under flow declined with worsening clinical status and presence of bacterial infection ( p < 0.05). Alongside, ROTEM showed a trend towards hypocoagulability with increasing disease severity and correlated with T‐TAS parameters. Platelet count and factor VIII (FVIII) were independent determinants of the most representative T‐TAS parameters. Exploratory analyses detected a trend towards a stronger platelet count‐T‐TAS association at 30–50 × 10 9 /L. Conclusions T‐TAS is reproducible in thrombocytopenic cirrhosis and is associated with reduced thrombus formation alongside disease progression and bacterial infection. Platelet count and FVIII are the main determinants of thrombus formation assessed by T‐TAS.