Intracoronary thrombus and platelet glycoprotein IIb/IIIa receptor blockade with tirofiban in unstable angina or non-Q-wave myocardial infarction. Angiographic results from the PRISM-PLUS trial (Platelet receptor inhibition for ischemic syndrome management in patients limited by unstable signs and symptoms). PRISM-PLUS Investigators.
BACKGROUND
The present study describes the effects of tirofiban, a nonpeptide platelet glycoprotein (GP) IIb/IIIa receptor blocker, on the characteristics of culprit lesions in patients with unstable angina (UA) or non-Q-wave myocardial infarction (NQWMI).


RESULTS
Of 1915 patients enrolled in PRISM-PLUS, 1491 had a readable film obtained a median of 65 hours after randomization. A core laboratory examined the culprit lesions for intracoronary thrombus burden (primary end point) and for TIMI flow grade distribution and severity of the obstruction and of underlying coronary artery disease (secondary end points). The combination of tirofiban plus heparin compared with heparin alone significantly reduced the intracoronary thrombus burden of the culprit lesions (OR=0.77, P=0.022), improved the perfusion grade (OR=0.65, P=0.002), and decreased the severity of the obstruction (P=0.037), but it did not influence the severity of the underlying plaque. Persistence of a thrombus in 45% of patients was associated with a 2.4-fold increase in the odds of death at 30 days (P=0.005) and a 2-fold increase in the odds of myocardial infarction (P=0.002).


CONCLUSIONS
The addition of tirofiban to heparin reduced the thrombus burden of the culprit lesion and improved distal perfusion in patients with UA or NQWMI, which supports the clinical benefit observed with the combination treatment.
Zhao
X Q
XQ
University of Washington School of Medicine, Seattle, Washington, USA. xueqiao@u.washington.edu
Théroux
P
P
Snapinn
S M
SM
Sax
F L
FL
D000368:Aged; D000789:Angina, Unstable / Q000150:complications / Q000188:drug therapy*; D000925:Anticoagulants / Q000008:administration & dosage / Q000627:therapeutic use; D001161:Arteriosclerosis / Q000150:complications* / Q000000981:diagnostic imaging; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000150:complications* / Q000000981:diagnostic imaging; D003326:Coronary Circulation / Q000187:drug effects; D003328:Coronary Thrombosis / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000209:etiology; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004562:Electrocardiography; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D006493:Heparin / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000209:etiology; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*; D000077466:Tirofiban; D016896:Treatment Outcome; D014443:Tyrosine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use
D000925:Anticoagulants; D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D014443:Tyrosine; D006493:Heparin; D000077466:Tirofiban