226 Fibrinolytic parameters are not risk factors for developing restenosis after recanalisation procedures in peripheral arteries

POSTER PRESENTATIONS: Fibrinolysis in vascular disease

83

I

224 Elevated PAl-1 and F1.2 levels in children with Escherichia coil O157-H7 related hemolytic uremic syndrome *CHANDLER WL, **HABEEB RL, **WATK1NSSL, and **TARR P1 *Depts. of Laboratory Medicine and **Pediatrics, Children's Hospital and Regional Medical Center, University of Washington, Seattle, WA, USA Approximately 10% of children infected with Escherichia coli O157:H7 develop the hemolytic uremic syndrome (HUS), a microangiopathic hemolytic anemia. To study the prothrombotic changes that occur in this disease, we obtained citrated blood samples from 18 children (mean 4 years old, range 1 to 8 years) with E. coli O157:H7 infection. Overall, 6 o f the 18 children (33%) developed clinical HUS (hemolytic anemia, thrombocytopenia and renal impairment). Compared to children that did not develop HUS, children with H U S had evidence o f coagulation activation (F1.2 1.3±0.4 vs 6.0±3.8 nmol/L, P = 0.0005), suppression o f fibrinolysis (PAI-1 activity 3±3 vs 21±12 U/mL, P = 0.0001) and increased thrombus formation (D-dimer 0.9_+0.4 vs 18.3± 17.6 Iag/mL, P = 0.003). Overall, the level of D-dimer was positively correlated with both F1.2 (r 2 = 0.53) and PAI-1 activity

(r z = 0.73). The strongest correlation though was between D-dimer and the product o f F1.2 x PAI-1 activity (r 2 = 0.96). While elevated Ddimer levels indicate fibrinolysis is occurring, high PAl- 1 activity correlated with high D-dimers suggests that reduced fibrinolytic activation favors more rapid thrombus accretion, which in turn leads to a greater volume of clot to lyse and thus elevated D-dimers. W e conclude that children with E. coli O157:H7 associated H U S have both an activated coagulation system and a suppressed fibrinolytic system which in turn leads to increased microthrombi and elevated D-dimers.

/

225 Stress and fibrinolysis: blood parameters in relation to body parameters ERIKSSON E, GRANATH-ERIKSSON L, JOHANSSON S, SODERBERG R, and HOLMDAHL L Dept. of Surgery, Sahlgrenska University Hospital/Ostra. G6teborg University, G6teborg, Sweden

82+ 11 m m Hg. The fibrinolytic parameters were as follows: t-PA Ag 6.3 (5.5) ng/ml, PAI-1 act 4 (11) IU/ml, t-PA-PAI complex 110 (94) pmol/L, u P A act 0.5 (0.2) ng/ml, u P A Ag 0.7 (0.2) ng/ml and PAI-2 Ag 1 (1) ng/ml. Values are median(IQR).

The purpose of the study was to investigate if stress as assessed in a physiotherapeutic body examination (PBE) correlates with fibrinolytic parameters measured in blood.

Muscular tension correlated with PAI-I act, t-PA Ag and t-PA-PAI complex. Spearmans r = 0.49-0.56, p= 0.020 - 0.007, respectively. Individuals with a high muscular tension (n= 14) had higher levels o f fibrinolytic parameters compared with individuals with lower muscular tension (n= 13).

Tventyseven unemployed men and w o m e n were examined with PBE in order to assess bodily stress. The examination assesses muscle tension, posture, respiration and body function in 3-5 graded scales. Blood samples were collected in test tubes with a) citrate for analysis of u P A activity(act) and antigen(Ag) and PAI-2 Ag, b) Stabilyte for analysis of t-PA act and Ag) t-PA-PAI complex and PAI-1 act, c) serum for analysis of other stress parameters. Blood pressure and BMI were also measured. Results. The study consisted of 19 m e n and 8 women. Their age (mean -l- SD) was 49+6 years old. BMI was 25±3 and blood pressure 135± 18 /

Blood parameter t-PA Ag ng/ml PAI-I act IU/ml t-PA-PAI pmol/L

High tension 9.3 (4.7) 10.7 (18.1) 146 (75)

I Low tension 4.6 (1.9) 3.0 (1.7) 84 (76)

p value 0.013 0.028 0.035

Conclusion. Stress assessed as muscular tension correlates with fibrinolytic blood parameters. This observation indicates that fibrinolytic parameters m a y be utilised as a diagnostic tool for bodily stress.

/

226 Fibrinolytic parameters are not risk factors for developing restenosis after recanalisation

procedures in peripheral arteries KOZAK M Department of Angiology, University Clinical Centre Ljubljana, Ljubljana, Slovenia Restenosis of a peripheral artery after percutaneous transluminal angioplasty (PTA) occurs in about 20 to 30 % of treated patients in the first year after the procedure. It appears probably due to endothelial proliferation and due to superimposed thrombosis. The aim of the study was to assess the role of fibrinolytic system as an opponent of thrombotic process in development of restenosis. In 166 consecutive patients successfully treated for atherosclerotic stenosis or occlusion of lower limb arteries with PTA we measured tPA activity after venous occlusion, tPA antigen, PAl antigen and activity, flbrinogen, plasminogen and euglobulin clot lysis time (ECLT) three months after the procedure. The patients have been followed for one year. We assessed the status of the treated vessel by ultrasound measuring of perfusion pressures and by calculating ankle-brachial index. Restenosis, confirmed by at least 15% index lowering in comparison to immediate postprocedure values, was detected in 45 patients (27%). The values of fibrinolytic parameters are shown in table 1.

Tab 1. Fibrinolytic parameters in patients with or without restenosis. Parameter F brino~en(8/1)(x ± SD) ECLT(~n)(M) i c~2-antiplasmin(%)(x ± SD) Plasminogen(%)(x + SD) t-PA a[g(n~/ml) (M) t-PA ac VO (IE/ml) (M) PAl-1 ag (ng/ml) (M) PAl ac ng/nd) (M)

Wi~outrestenosis 5,1±1,4 270 0,9±0,12 0,97 ± 0,15 12,1 7218 15,4 9,0

With~stenosis 4,8±1,3 2~ 0,89±0,~ 0,98 ± 0,18 12,1 8582 12,4 6,5

P 0,25 0,75 0,41 0,69 0,78 0.52 0,33 0,17

ag - antigen, ac - activity, VO - venous occlusion, M - median, SD - standard deviation The comparison of fibrinolytic parameters among patients with or without restenosis showed no difference. We concluded that endogenous fibrinolysis estimated by the mentioned parameters does not influence the development of important restenosis or reocclusion after PTA in low-extremity arteries.