Optimal Coronary Flow After PCI for Myocardial Infarction - a Pilot Study

Optimal Coronary Flow After PCI for Myocardial Infarction - a Pilot Study

In this study the investigators test the hypothesis that alteplase given intra coronary after PCI reduce infarct size in patients with ST-elevation myocardial infarction(STEMI) and impaired microvascular function defined as a value of index of microvascular resistance (IMR) >30.

After coronary stenting, index of microvascular resistance (IMR) will be measured invasively. Patients with IMR >30 will be randomised to 20 mg alteplase or placebo (NaCl) administered in the culprit vessel through a microcatheter. Magnet resonance imaging (MRI) of the myocardium will be performed early (2-6 days) and late (3 months) to estimate the primary endpoint (infarct size).

10 non-randomised patients, with IMR <30, will undergo the same follow-up as the randomised patients.

Clinical events for all randomised and non-randomised patients will be collected from Swedish national registries and by telephone at 3 and 12 months.

Criteria for randomization:

1. IMR measured in culprit vessel > 30

Criteria for IMR measurement:

Inclusion Criteria:

1. Oral and signed informed consent
2. Males and females 18 - 85 years of age
3. Diagnosis of ST-elevation myocardial infarction (STEMI) including occlusion of culprit vessel on angiography
4. Onset of continuous symptoms within 12 hours
5. Have undergone PCI of culprit vessel
6. Subjects are willing to comply with scheduled visits and tests and are able and willing to provide informed consent

Exclusion Criteria:

1. Previously known ejection fraction <30%

2. Previous PCI in the culprit vessel

3. Chronic total occlusion in major vessel

4. Any history of bleeding diathesis, known coagulopathy, or will refuse blood transfusions

5. Recent history or known platelet count <100.000 cells/mm3 or Hbg < 10 g/dL

6. Known reduced kidney function with estimated glomerular filtration rate (GFR) <30 ml/min/1.73m2.

7. Previous hemorrhagic stroke

8. Ongoing oral anticoagulation treatment

9. Severe asthma requiring daily treatment

10. Any mechanical complication (e.g. ventricular septal defect, papillary muscle rupture, cardiac tamponade)

11. Atrioventricular block grade III

12. Known inability to undergo MRI investigation

    Permanent pacemaker

    • Pronounced claustrophobia

13. Known intolerance to study drug

14. Known intolerance to adenosine

15. Pregnancy

16. Participation in another investigational drug study

17. Previous randomization in the OPTIMAL-PCI trial