Neutrophil extracellular traps-related markers in chronic limb threatening ischemia - a relation with progression and prognosis

Background

Neutrophil extracellular traps (NETs) formation is involved in atherothrombosis, though little is known about this phenomenon in peripheral artery disease (PAD). We investigated whether NETs-associated markers are related with the PAD severity and long-term outcomes after endovascular treatment and if they affect fibrin properties and thrombin generation.

Patients and methods

We studied 85 patients with chronic limb threatening ischemia (CLTI) and restenosis within one year after endovascular treatment and 47 age-sex-matched PAD controls without restenosis. NETs-associated markers, i.e. circulating citrullinated histone H3 (H3cit), myeloperoxidase (MPO), protein arginine deaminase 4 (PAD4), cell-free DNA (cfDNA) along with DNAse-I, together with fibrin clot permeability (Ks), clot lysis time (CLT), thrombin generation and fibrinolysis markers were determined. During follow-up a composite endpoint including re-intervention, amputation and death was assessed.

Results

Compared with the control group, patients with CLTI and restenosis had higher H3cit (59.8 %), MPO (58.4 %) and cfDNA (35.3 %; all p < 0.01). Rutherford class positively correlated with H3cit, MPO, PAD4 and cfDNA in the restenosis group and with H3cit in controls (all p < 0.05). In the restenosis group Ks negatively correlated with H3cit and cfDNA while CLT positively correlated solely with H3cit (all p < 0.05). At a median follow-up of 66 months, 56 patients who died (65.9 %) had higher H3cit, MPO and cfDNA concentrations than survivors (all p < 0.05). On multivariable analysis H3cit, ETP, α2-antiplasmin and Ks were independent predictors of combined re-intervention, amputation and death.

Conclusion

Higher levels of NETs-associated markers in relation to prothrombotic fibrin clot properties characterize endovascularly treated PAD patients at risk of 1-year restenosis and worse long-term outcomes.