Fibrinolysis(1996) 10 Suppl 2, 145-147 © Pearson Professional Ltd 1996 Analysis of activation markers of coagulation, fibrinolysis and inflammation in unstable angina by probit transformation L.M. Biasucci 1, M.P.M. de Maat 2, A. Meo', W. van der Greef 1, F. Summaria 1, G. Quaranta 1, G. Liuzzo 1, C. Kluft 2, A. Maseri I 'Cardiology, Catholic University, Rome, Italy. 2Gaubius laboratory, TNO-PG, Leiden, The Netherlands. Summary In order to investigate the role of the hemostatic, fibrinolytic and inflammatory system in unstable angina, we assessed the levels of thrombin-antithrombin III (TAT), Prothrombin Fragment 1+2 (F1+2), plasmin-antiplasmin (PAP) and D-Dimer (DD) and of C-reactive protein (CRP) in 51 patients admitted to our CCU with severe unstable angina. Thirty-one pts had a complicated in hospital course (G1), levels of CRP and PAP were significantly higher in this group than in patients with non complicated in-hospital course (G2). Using the probit transformation we assessed the following cut-off point between G1 and G2:2.5 IJg/I for TAT, 0.9 nmol/ml for F1+2, 13 IJg/I for DD, 500 IJg/I for PAP, and 3.5 mg/I for CRP. Our study provides further evidence of the importance of markers of inflammation and fibrinolysis in unstable angina, and demonstrates the utility of data analysis by probit transformation. INTRODUCTION A major role of coronary thrombosis in the pathogenesis of unstable angina (UA) has been demonstrated by post- mortem, angiographic, angioscopic and biochemical studies. ~3 The waxing and waning of symptoms over a period of up to 2 months 4 and the very common multilayered appearance of coronary thrombi at post- mortem examination 5 indicate a recurrent episodic activation of the hemostatic system. More recently, a role for inflammation, and in particular for the acute phase reaction proteins has been claimed. 6 A possible prognostic value of markers of the clotting, fibrinolytic and inflammatory system has also been described. 68 In order to assess the role of each of these systems in the pathogenesis and in the prognosis of unstable angina, we studied levels of prothrombin fragment 1+2 (Fl+2),and thrombin- antithrombin III complexes (TAT), as markers of activation of the coagulation system, and levels of plasmin- antiplasmin complexes (PAP) and of D-Dimer as markers This study is supported by the Netherlands Programme for Research on Ageing - NESTOR (funded by the Ministry of Education, Cultural Affairs and Science and the Ministry of Health, Welfare and Sports). Correspondence to: L.M. Biasucci, Institute of cardiology, Catholic university, 00168 Largo F. Vito, Rome, Italy. Tel. +39-6-30154187; Fax. +39-6-63055535. of activation of the fibrinolytic system. C-reactive protein (CRP), a prototypic acute phase reactant, was measured as a marker of inflammation. In order to obtain reliable and easy-to-interpret analysis, and objective cut-off points able to differentiate between patients with different characteristics, the statistical analysis was carried out by means of the probit transformation. 9'~° MATERIALS AND METHODS We studied 51 patients (41 males, mean age 56 years old, range 44-79) admitted to our CCU with diagnosis of severe unstable angina (Class IIIB of Braunwald's classification). 4 All patients were taking aspirin and i.v. nitrates, plus calcium antagonists and/or beta-blocking agents, as clinically requested. In all patients a peripheral venous blood sample was always withdrawn, at entry, through a clean venipuncture with minimal venostasis using a 19 G needle, part of the blood was immediately transferred into precooled tubes containing citrate, theophilline, adenosine and dypiridamole (CTAD tubes, Becton and Dickinson, France). The tubes were centrifuged at 2000 g and at 4°C for 20 minutes. Plasma aliquots of 500 ~tl were pipetted in appropriate tubes, snap frozen and stored at -80°C within 1 hour from venipuncture, according to the method previously described by our group and by others. ~1-~3 The 145