Comparison of reperfusion regimens with or without tirofiban in ST-elevation acute myocardial infarction.
There is continued debate as to whether a combined reperfusion regimen with platelet glycoprotein IIb/IIIa inhibitors provides additional benefit in optimal myocardial reperfusion of patients with a ST-elevation acute myocardial infarction (AMI). In addition, the best angiographic method to evaluate optimal myocardial reperfusion is still controversial. Patients (n = 144) with a first AMI presenting <6 hours from onset of symptoms were randomized to receive a conjunctive strategy (n = 72) with low-dose alteplase (50 mg) and tirofiban (0.4 microg/kg/min/30 minute bolus; infusion of 0.1 microg/kg/minute), or tirofiban plus stenting percutaneous coronary intervention (PCI). Control patients (n = 72) received standard strategy with either full-dose alteplase (100 mg) or stenting PCI [correction]. All patients were submitted to coronary angiographic study at 90 minutes. The primary end point was Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow at 90 minutes. Secondary end points were TIMI myocardial perfusion (TMP) rates, a composite end point at 30 days (death, reinfarction, refractory ischemia, stroke, heart failure, revascularization procedures, or pulmonary edema), and bleeding or hematologic variables. The rate of TIMI 3 flow at 90 minutes for patients treated with alteplase alone was 42% compared with 64% for those who received low-dose alteplase and tirofiban. Standard stenting PCI achieved 81% of TIMI 3 flow compared with 92% when tirofiban was used. Significantly higher rates of TMP grade 3 were observed when tirofiban was used as the adjunctive treatment in both alteplase (66% vs 47%) and stenting PCI (73% vs 55%). Higher rates of the composite end point were observed in standard regimens compared with conjunctive regimens (hazard ratio 5.8, 95% confidence interval 1.27 to 26.6, p = 0.023). Regardless of reperfusion regimen, better outcomes were observed when a combination of TIMI 3 flow and TMP grade 3 was achieved. Beyond TIMI 3 flow rate, the TMP grade was an important determinant. The rates of major bleeding were similar (2.8%) for standard versus conjunctive regimens with tirofiban. Thus, tirofiban as a conjunctive therapy for lytic and stenting regimens not only improves TIMI 3 flow rates, but also the TMP3 rates, which are related to a better clinical outcome without an increase in the risk of major bleeding. This study supports the hypothesis that platelets play a key role not only in the atherothrombosis process, but also in the disturbances of microcirculation and tissue perfusion.
Martínez-Ríos
Marco A
MA
National Institute of Cardiology, Mexico City, Mexico. mtzrios@cardiologia.org.mx
Rosas
Martín
M
González
Héctor
H
Peña-Duque
Marco A
MA
Martínez-Sánchez
Carlos
C
Gaspar
Jorge
J
García
Héctor
H
Gaxiola
Efraín
E
Delgado
Luis
L
Carrillo
Jorge
J
Leyva
José-Luis
JL
Lupi
Eulo
E
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D003131:Combined Modality Therapy / Q000379:methods; D017023:Coronary Angiography; D003326:Coronary Circulation; D004562:Electrocardiography; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000628:therapy*; D015425:Myocardial Reperfusion / Q000379:methods*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors; D011446:Prospective Studies; D015607:Stents; D015912:Thrombolytic Therapy; D000077466:Tirofiban; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*; D014443:Tyrosine / Q000008:administration & dosage* / Q000031:analogs & derivatives*
D005343:Fibrinolytic Agents; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D014443:Tyrosine; D010959:Tissue Plasminogen Activator; D000077466:Tirofiban