Regression graph of TEG R-time and TMA versus anti-FXa for blood samples treated with heparin. The best-fit regression curve of R-time and TMA against anti-FXa calculated for citrated blood samples to which a range of unfractionated heparin had been added (n = 38). For the R-time, a significant relationship was observed (particularly at low concentrations of anti-FXa < 0.4 U/mL), and a general increase in R-time is noted. For the TMA, a significant relationship is demonstrated over the whole range of anti-FXa. Inset: Typical TEG showing the R-time, the TMA, the MA value, and the clot lysis index, or LY30.