Thrombotic-fibrinolytic system balance and prognosis in unstable angina

The balance between thrombotic and fibrinolytic system is supposed to play an important role in the pathophysiology of unstable angina (UA). To assess whether an imbalance between thrombotic and fibrinolytic factors is responsible for different outcomes in UA, we assessed in 50 patients with severe UA plasma levels of thrombin-antithrombin III complex (TAT) and prothrombin fragment 1+2 (F1+2) as markers of thrombotic activation, and plasma levels of D-Dimer (DD) and Plasmin-antiplasmin complex (PAP), as markers of fibrinolyic activation. Samples were taken on admission and six hourly in the first 24 h and daily for 3 days. We assessed the mean values of each marker (TAT, F1+2, DD, PAP) through the whole study, and calculated the following ratios of the means: DD/TAT, DD/F1+2, PAP/TAT, PAP/F1+2. We also considered the number of samples with elevated levels of TAT, F1+2, PAP and DD for each pts throughout the study. Results: Twenty-seven pts (Gl) had a complicated in-hospital outcome, and 23 (G2) had a spontaneous waning of symptoms. No differences in the DD/TAT, DD/F1+2, PAP/TAT, PAP/F1+2 ratios were observed between Gl and G2 (respectively 2.76 vs 4.55, 12.8 vs 13, 135.8 vs 172.2 and 518.4 vs 490.2, all p=ns). However in Gl significantly more samples had elevated levels of TAT and F1+2 than in G2 (respectively 42 and 61 of 148 samples, vs 10 and 22/103 samples, p<0.01) whereas there was no difference in the number of samples with elevated levels of PAP and DD between Gl and G2. Conclusions: Our data show that there is not an overall imbalance between thrombotic and fibrinolytic factors as an underlying characteristic differentiating UA pts with different outcomes, but suggest that acute imbalance of these factors may suddendly develops in UA pts with complicated in-hospital course and possibly be the cause of the waxing of symptoms in these patients.