Tissue factor-induced thrombin generation in the fasting and postprandial state among elderly survivors of myocardial...

Tissue factor (TF)-induced thrombin generation (TG) ex vivo has been suggested to be an important method to assess thrombotic risk. No studies have investigated the impact of postprandial lipemia on TF-induced TG. Since myocardial infarction (MI) is associated with elevated postprandial levels of triglycerides, we hypothesized a differential impact of postprandial lipemia on coagulation activation in MI-patients and healthy controls.

Elderly survivors of acute MI (n=44) and healthy age-and sex matched controls (n=43) underwent a fat tolerance test (1 gram per kg body weight) to assess coagulation activation during postprandial lipemia.

The incremental area under the curve (AUCi) for serum triglycerides was higher in MI-patients than in healthy age-and sex matched controls (5.64±0.52 mmol/L*h and 3.94±0.39 mmol/L*h, p=0.012) during the postprandial phase. Subsequent endogenous activation of coagulation, assessed by FVIIa and thrombin generation (F1+2), was similar among groups and not related to levels of triglycerides during the postprandial phase. Healthy individuals had a gradual decline in TF-induced thrombin generation ex vivo, assessed by endogenous thrombin potential (ETP) (AUCi=-542.4±71.4 nM*min*h, p<0.001), whereas MI-patients retained their ETP (AUCi=127.4±89.0 nM*min*h, p=0.47) in plasma during the postprandial phase (p for group difference=0.005).

MI-patients had elevated postprandial lipemia and retained their ability for TF-induced TG in plasma ex vivo in the postprandial phase, whereas the capacity gradually decreased in healthy individuals. Further studies are warranted to reveal underlying mechanism(s) and clinical implications.