Intra- and postoperative fibrinolysis in patients undergoing cardiopulmonary bypass surgery

Area of Science:

• Cardiovascular Surgery
• Hemostasis and Thrombosis
• Biochemistry

Background:

• Cardiopulmonary bypass (CPB) is a critical procedure in cardiac surgery.
• The impact of CPB on the body's blood clotting and clot-dissolving systems (fibrinolysis) requires thorough understanding.
• Previous research indicates potential alterations in fibrinolytic activity during CPB.

Purpose of the Study:

• To investigate the influence of cardiopulmonary bypass (CPB) on the fibrinolytic system.
• To quantify changes in key fibrinolytic markers during and after CPB in patients undergoing cardiac surgery.
• To elucidate the dynamic interplay between CPB and the mechanisms of clot formation and breakdown.

Main Methods:

• Prospective study involving 100 patients with valvular heart disease or atrial septal defects undergoing CPB.
• Measurement of euglobulin fibrinolytic activity (EFA), tissue type plasminogen activator (t-PA) activity, plasminogen activator inhibitor 1 (PAI-1) activity, plasminogen, alpha 2-antiplasmin (alpha 2-AP), fibrinogen degradation products (FDP), and D-dimer.
• Serial blood sampling and analysis performed preoperatively, intraoperatively, and postoperatively.

Main Results:

• Significant intraoperative increases in EFA and t-PA activity, alongside decreases in plasminogen and alpha 2-AP.
• Postoperative decrease in t-PA activity, contrasted by a marked increase in PAI-1 activity.
• Elevated intraoperative and postoperative levels of FDP and D-dimer, indicating increased clot breakdown.

Conclusions:

• CPB surgery triggers significant activation of the fibrinolytic system during the procedure.
• A subsequent 'fibrinolytic shutdown' is observed postoperatively, characterized by reduced clot-dissolving capacity.
• These dynamic changes in fibrinolysis during and after CPB highlight its complex impact on hemostasis.