Factor seven activating protease (FSAP) predicts response to intravenous thrombolysis in acute ischemic stroke

Prediction of recanalization after intravenous thrombolysis could be important to direct secondary reperfusion techniques. Factor seven activating protease (FSAP) has been described to have a relevant pathophysiological role in stroke.

The aim is to determine whether plasma FSAP levels are associated with recanalization after tissue plasminogen activator in acute stroke.

FSAP antigen, activity, and FSAP-inhibitor complexes were measured in 120 acute stroke patients admitted to Hospital Vall d'Hebron with arterial occlusions, before intravenous thrombolysis. Recanalization was assessed by transcranial Doppler 2 h after thrombolysis. Predictors of recanalization were determined by logistic regression analysis and the additional predictive value of FSAP over them was determined by integrated discrimination improvement index.

Complete recanalization was achieved in 31 patients. FSAP antigen levels were lower in patients achieving recanalization (8.2 (6.3-11.7) µg/mL vs. 9.8 (7.6-12.8) µg/mL; p = 0.046). After adjustment by age, sex, and National Institutes of Health Stroke Scale, Oxfordshire Community Stroke Project (odds ratio = 0.33 (0.13-0.82), p = 0.017) and FSAP antigen (odds ratio = 3.22 (1.22-8.47), p = 0.018) were independently associated with recanalization, and the addition of FSAP improved the model discrimination (integrated discrimination improvement = 5.5% (1.4-9.7), p = 0.009).

Our study showed that lower FSAP antigen plasma levels were associated with a higher chance of arterial recanalization after tissue plasminogen activator treatment, suggesting an involvement of FSAP in tissue plasminogen activator-induced clot lysis. FSAP antigen determination might be useful in predicting tissue plasminogen activator response in stroke patients.