Importance of reperfusion on thromboxane A2 metabolite excretion after thrombolysis.
Fibrinolytic therapy is a major advance in the treatment of coronary artery disease. A marked elevation in plasma and urinary metabolites of thromboxane A2 (TXA2) after administration of thrombolytic therapy has been observed and has been related to a direct effect of thrombolytic drugs on platelets. To test this hypothesis we evaluated the 11-dehydro-thromboxane B2 (11-d-TXB2) level, as an index of platelet activation, in 20 healthy subjects and in 30 patients with acute myocardial infarction (AMI). Patients with infarction received streptokinase (n = 8), recombinant tissue-type plasminogen activator (rt-PA) (n = 8), or thrombolytic therapy preceded by acetylsalicylic acid (n = 7) or were treated without thrombolytic therapy (n = 7). The urinary 11-d-TXB2 level in healthy control subjects was 327 +/- 126 pg/mg creatinine. A significant increase was observed in patients with AMI with no difference between those who received no thrombolytic therapy (673 +/- 283 pg/mg creatinine in the first 12 hours) and those who received streptokinase (833 +/- 613 pg/mg creatinine) or rt-PA (836 +/- 653 pg/mg creatinine). Patients pretreated with acetylsalicylic acid had urinary 11-d-TXB2 values ranging between 361 and 155 pg/mg creatinine. A significant difference in 11-d-TXB2 values was observed only when patients who were reperfused were separated from those who remained occluded according to angiographic criteria (1085 +/- 498 vs 391 +/- 227 pg/mg creatinine in the first 12 hours, p less than 0.001). We conclude that reperfusion and not thrombolytic agents per se appears to be the factor that induces platelet activation and consequently facilitates reocclusion.
Rebuzzi
A G
AG
Institute of Cardiology and Pharmacology, Catholic University of the Sacred Heart, Roma, Italy.
Natale
A
A
Bianchi
C
C
Albanese
S
S
Lanza
G A
GA
Coppola
E
E
Ciabattoni
G
G
D001241:Aspirin / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000188:drug therapy*; D015425:Myocardial Reperfusion; D015539:Platelet Activation / Q000502:physiology*; D013300:Streptokinase / Q000627:therapeutic use; D015912:Thrombolytic Therapy; D013928:Thromboxane A2 / Q000378:metabolism*; D013929:Thromboxane B2 / Q000031:analogs & derivatives* / Q000652:urine; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use
D013929:Thromboxane B2; D013928:Thromboxane A2; C049235:11-dehydro-thromboxane B2; D013300:Streptokinase; D010959:Tissue Plasminogen Activator; D001241:Aspirin