The effect of glycoprotein IIb/IIIa receptor inhibitor on the microcirculation in patients undergoing high-risk coronary stenting; a prospective, randomized study.
OBJECTIVE
We evaluated the effect of the glycoprotein IIb/IIIa inhibitor, tirofiban, on the microcirculation measured by Doppler coronary flow reserve (CFR) in patients undergoing high-risk coronary stenting.


BACKGROUND
The mechanisms by which glycoprotein IIb/IIIa inhibitors benefit patients undergoing high-risk angioplasty are not fully understood. This may be due to prevention of distal embolization of the coronary clot at the site of angioplasty.


METHODS
Thirty two consecutive patients with acute coronary syndrome within 72 hours or with high-risk angiographic features were randomized into 2 groups. Group A (n = 17) received tirofiban (10 microg/kg bolus followed 0.15 microg/kg/min). Group B (n = 15) received placebo bolus and infusion. Coronary flow reserve was measured by Doppler wire technique at baseline, post balloon angioplasty and post-stenting. Platelet aggregation was measured at baseline, 10 minutes, 6 hours and 12 hours post bolus.


RESULTS
There was no significant difference in CFR between the groups at baseline and after balloon angioplasty. Post-stenting CFR, however, was significantly higher in the group pretreated with tirofiban (2.94 vs. 2.25, p = 0.014). The inhibition of platelet aggregation was 94% at 10 minutes, 97% at 6 hours and 94% at 12 hours in the tirofiban group.


CONCLUSIONS
In patients undergoing high-risk coronary stenting, tirofiban protects and improves the microcirculation measured by Doppler wire technique. This may be due to prevention of distal embolization of clot by tirofiban and explain the clinical benefit.
Wong
Philip
P
Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
Harding
Scott
S
Inglessis
Ignacio
I
Choi
C Joon
CJ
Walters
Darren
D
Chang
Yuchiao
Y
Gimelli
Giogio
G
Jang
Ik-Kyung
IK
D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D003326:Coronary Circulation; D003327:Coronary Disease / Q000150:complications / Q000188:drug therapy / Q000601:surgery; D004617:Embolism / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000187:drug effects*; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*; D015607:Stents / Q000009:adverse effects*; D013997:Time Factors; D000077466:Tirofiban; D014443:Tyrosine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*
D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D014443:Tyrosine; D000077466:Tirofiban