Platelet function and fibrinolytic agents: two sides of a coin?
Fibrinolytic therapy is the established treatment for the management of patients with ST elevation acute myocardial infarction (AMI). Present fibrinolytic regimens have a number of shortcomings, including the failure to produce early and sustained reperfusion, as well as failure to prevent reocclusion in at least some patients. Platelets play an important role in coronary thrombosis responsible for AMI. The effect of coronary fibrinolysis on platelets has been extensively debated in the literature with evidence of both platelet activation and inhibition. Among fibrinolytic agents, tissue plasminogen activator (t-PA) is considered to be the mainstay in the treatment of coronary artery disease. The native t-PA molecule has been modified in an attempt to achieve improved lytic characteristics with less risk of bleeding. The result is a group of mutant t-PA variants considered third-generation plasminogen activators. TNK-t-PA is one bioengineered variant of t-PA. Another third-generation plasminogen activator is reteplase (r-PA). Like TNK-t-PA, it is a variant of t-PA that has been developed to establish a more rapid, complete, and stable coronary artery patency, thus promising reduced mortality. Both r-PA and TNK-t-PA are effective when given as bolus therapy. This feature may facilitate more rapid treatment as well as decrease overall costs of treatment. New fibrinolytic regimens include potent antiplatelet agents that may improve sustained reperfusion. This review summarizes the latest and often confusing data on the interaction between fibrinolytic therapy and platelets in certain in vitro, animal and clinical scenarios.
Callahan
K P
KP
Sinai Center for Thrombosis Research, Baltimore, MD 21215, USA.
Malinin
A I
AI
Gurbel
P A
PA
Alexander
J H
JH
Granger
C B
CB
Serebruany
V L
VL
D000818:Animals; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D005343:Fibrinolytic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D009203:Myocardial Infarction / Q000188:drug therapy*; D010960:Plasminogen Activators / Q000009:adverse effects* / Q000627:therapeutic use; D015539:Platelet Activation / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects; D011994:Recombinant Proteins / Q000009:adverse effects / Q000627:therapeutic use; D013300:Streptokinase / Q000009:adverse effects / Q000627:therapeutic use; D000077785:Tenecteplase; D015912:Thrombolytic Therapy / Q000009:adverse effects*; D010959:Tissue Plasminogen Activator / Q000009:adverse effects / Q000627:therapeutic use
D005343:Fibrinolytic Agents; D011994:Recombinant Proteins; C087896:reteplase; D013300:Streptokinase; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator; D000077785:Tenecteplase