Upstream high-dose tirofiban does not reduce myocardial infarct size in patients undergoing primary percutaneous coronary intervention: a magnetic resonance imaging pilot study.
BACKGROUND
Primary percutaneous coronary intervention (PCI) is more effective than fibrinolytic therapy for ST-segment elevation myocardial infarction (STEMI), but initial treatment delay to intervention is the main limitation of this strategy.


OBJECTIVE
Upstream use of high-dose tirofiban could reduce myocardial infarct size, using analysis of contrast-enhanced magnetic resonance imaging (CE-MRI).


METHODS
Patients with STEMI within 12 hours after symptom onset were randomized to a facilitated PCI group (n = 19) or to a primary PCI group (n = 20). The primary endpoint was myocardial infarct size evaluated by the volume of delayed hyperenhancement on CE-MRI at 1 month after index procedure.


RESULTS
The baseline clinical characteristics were not significantly different between the 2 groups. Although the incidence of pre-PCI thrombolysis in myocardial infarction (TIMI) flow grade 2 to 3 was significantly higher in the facilitated PCI group than in the primary PCI group (47.4% vs 15.0%, P = 0.03), the achievement of myocardial blush grade 2 to 3 or ST-segment resolution at 30 minutes after procedure was not significantly different between the facilitated PCI and the primary PCI group (36.8% vs 40%, P = 0.84 and 31.6% vs 20%, P = 0.41, respectively). Infarct size on CE-MRI was similar in the facilitated PCI group and the conventional primary PCI group (22.1% +/- 11.7% vs 25.2% +/- 13.2%, P = 0.44). At 6 months, the left ventricular ejection fraction (LVEF) on echocardiography was 52.6% +/- 10.4% in the facilitated PCI group and 50.9% +/- 9.8% in the primary PCI group (P = 0.68).


CONCLUSIONS
Despite the improvement of initial TIMI flow grade, the upstream use of high-dose tirofiban did not reduce myocardial infarct size measured by CE-MRI.
Song
Young Bin
YB
Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Hahn
Joo-Yong
JY
Gwon
Hyeon-Cheol
HC
Kim
Jun Hyung
JH
Lee
Sang Yeub
SY
Choe
Yeon Hyeon
YH
Choi
Seung-Hyuk
SH
Choi
Jin-Ho
JH
Lee
Sang Hoon
SH
D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation; D003287:Contrast Media; D017023:Coronary Angiography; D003326:Coronary Circulation; D004452:Echocardiography; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D009206:Myocardium / Q000473:pathology*; D010865:Pilot Projects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015607:Stents; D013318:Stroke Volume; D013997:Time Factors; D000077466:Tirofiban; D016896:Treatment Outcome; D014443:Tyrosine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D016277:Ventricular Function, Left
D003287:Contrast Media; D010975:Platelet Aggregation Inhibitors; D014443:Tyrosine; D000077466:Tirofiban; D019786:Gadolinium DTPA