Plasminogen Activator-Angioplasty Compatibility Trial - PACT


Reduced dose tPA + PTCA in acute MI


To evaluate the safety and efficacy of a reduced dose of the fibrinolytic agent tPA in combination with PTCA as the primary recanalization modality in acute MI.

Study Design

Study Design:

Patients Screened: N/A
Patients Enrolled: 606
NYHA Class: Not reported
Mean Follow Up: 1 year
Mean Patient Age: average 58 years
Female: 21%
Mean Ejection Fraction: No baseline assessment. See principal findings for predischarge data.

Patient Populations:

Presenting within 6 hours of onset and with ischemic symptoms >= 30 minutes and ST elevation >= 30 min and ST elevation >= 0.1mV in >= 2 limb leads or >= 0.2 mV in >= 2 contiguous leads


Age > 75 years, prior CVA or TIA, head trauma within 6 months, active bleeding or bleeding diasthesis, recent trauma or major surgery, prior bypass surgery, PTCA within 6 months, SBP >170 mmHg or DBP >110 mmHg, pregnant or lactating women

Primary Endpoints:

Predischarge ejection fraction

Secondary Endpoints:

Culprit artery patency on cath lab arrival, PTCA technical results, complication rates, time to restored patency following PTCA

Drug/Procedures Used:

Precatheterization thrombolysis (tPA 50-mg bolus) or placebo followed by immediate coronary ngiography. If TIMI grade 3 flow was present, a second bolus of tPA 50 mg was given. If TIMI grade 0–2 flow was present, angioplasty was performed.

Concomitant Medications:

Aspirin, heparin

Principal Findings:

Initial angiography showed that the tPA group had better TIMI grade 3 flow (32.8% vs. 14.8%) and patency (TIMI grade 2 or 3; 61% vs 34%, p=0.001). Rescue and primary PTCA restored TIMI-3 flow in closed arteries equally (77% vs 79%). There was no significant difference between the groups in predischarge ejection fraction (primary end point) but EF was higher in those with TIMI 3 flow on cath lab arrival (62.4%). The small group of patients (12%) who had PTCA performed <1 hour after the tPA bolus also had better ejection fractions (62.5% vs 57.3%). Mortality rates (30 day) were 3.6% and 3.3% in the rt-PA and placebo groups, respectively (p=0.81). There were no significant differences between the two groups in the incidence of stroke (both 0.7%) or major bleeding (12.9% vs 13.5%)


In acute ST elevation MI, a reduced dose thrombolytic regimen followed by primary PTCA results in improved early patency and preserved LV function.


J Am Coll Cardiol 1999; 34: 1954-62.

Clinical Topics: Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, Lipid Metabolism

Keywords: Thrombolytic Therapy, Stroke, Coronary Disease, Fibrinolytic Agents, Tissue Plasminogen Activator, Angioplasty, Balloon, Coronary

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