Dynamic coronary fibrinolysis evaluation in patients with myocardial infarction and unstable angina by specific plasma fibrin degradation product determination.

It has been shown that myocardial infarction (MI) is caused by thrombotic occlusion of a coronary artery. A thrombotic process is also involved in the flow obstruction associated with peripheral embolization in unstable angina (UA). In UA, a local fibrinolytic process should occur, but biological evidence has never been reported. Therefore, we measured sequential changes in plasma fibrin degradation products (FDP) in patients with stable and unstable angina pectoris without MI and compared the levels to those in patients with MI. FDP determination was carried out by ELISA using a D neo monoclonal antibody allowing low amounts of FDP to be reliably and precisely detected. Our results show an early increase in FDP in UA indicating a thrombolytic process. In patients who presented only one episode of chest pain, a prompt decrease of FDP was noted whereas in patients with recurrent chest pain, the levels of FDP remained high. On the contrary, during the first 3 days of uncomplicated MI, FDP levels were not significantly different from those of normal control suggesting an absence of clot dissolution. This study underlines the important function of fibrinolysis in the spontaneous evolution of acute coronary syndrome.