[Platelet activation during thrombolysis and percutaneous transluminal coronary angioplasty in the acute phase of myocardial infarction].
To clarify the mechanism of recanalization and reocclusion in thrombolysis and percutaneous transluminal coronary angioplasty (PTCA), the plasma concentrations of beta-thromboglobulin (beta-TG), thromboxane B2 (TXB2) and platelet aggregation adenosine diphosphate (ADP) (2 microM/ml, collagen 2 micrograms/ml) were assessed in 11 normal subjects and in 19 patients with acute myocardial infarction whose infarct-related vessels were recanalized by thrombolysis and/or PTCA. In patients with acute myocardial infarction, the plasma concentrations of beta-TG and TXB2 were significantly higher than those in normal subjects (beta-TG: 128 +/- 132 ng/ml vs 38 +/- 17 ng/ml, TXB2: 131 +/- 154 pg/ml vs 36 +/- 18 pg/ml). Collagen-induced platelet aggregation decreased significantly in patients with acute myocardial infarction; whereas, ADP-induced platelet aggregation showed no significant difference. Infarct-related vessels recanalized by thrombolysis (seven patients: group 1) and PTCA (seven patients: group 2) were patent on the follow-up angiograms. Infarct-related vessels were reoccluded in five patients immediately after PTCA or during the follow-up angiography (group 3). Beta-TG and TXB2 did not change before and after recanalization in groups 1 and 2, but increased significantly after recanalization in group 3 (beta-TG: 155 +/- 185 ng/ml----269 +/- 233 ng/ml, TXB2: 104 +/- 87 pg/ml----169 +/- 91 pg/ml). Platelet aggregation did not differ significantly among the three groups. We concluded that platelets are not activated during thrombolysis and/or PTCA in cases without reocclusion, while platelets are markedly activated during PTCA in cases with reocclusion. Thus, it is suggested that platelet activation plays an important role in the mechanism of reocclusion.
Abe
S
S
First Department of Internal Medicine, Faculty of Medicine, Kagoshima University.
Maruyama
I
I
Arima
S
S
Yamaguchi
H
H
Okino
H
H
Hamasaki
S
S
Nomoto
K
K
Atsuchi
Y
Y
Tahara
M
M
Tanaka
H
H
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary; D003094:Collagen / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000628:therapy; D015539:Platelet Activation; D010974:Platelet Aggregation / Q000187:drug effects; D012008:Recurrence; D015912:Thrombolytic Therapy; D013929:Thromboxane B2 / Q000097:blood*; D001620:beta-Thromboglobulin / Q000378:metabolism
D001620:beta-Thromboglobulin; D013929:Thromboxane B2; D000244:Adenosine Diphosphate; D003094:Collagen