Microvascular Recovery With Ultrasound in Myocardial Infarction (MRUSMI) Post PCI Trial

Effect of Diagnostic Echocardiogram on Microvascular Recovery Following Acute STEMI

The investigators propose to test the effectiveness of a technique that uses a modified commercially available ultrasound system used for cardiac imaging, and a commercially available ultrasound contrast agent (microbubbles) to break up the blood clots that cause heart attacks. The ultrasound and microbubbles will be applied as soon as possible to patients presenting to the emergency department, after an EKG confirms that a heart attack is ongoing. Patients who provide emergent consent will be randomized to either conventional therapy for a heart attack, or conventional therapy and ultrasound with microbubbles. The ultrasound will be applied both before and after emergent heart catheterization, in order to break up the blood clots that are not only in the artery supplying the heart muscle, but also in the small branches (capillaries) that are fed by this artery. Following the randomized treatment, patients will be followed for the development of any complications (recurrent heart attack, heart failure, or need for defibrillator placement) as well as by echo and cardiac MRI to determine how much heart muscle was salvaged by the treatment.

The investigators propose to test the effectiveness of a technique that uses a modified commercially available ultrasound system used for cardiac imaging, and a commercially available ultrasound contrast agent (microbubbles) to break up the blood clots that cause heart attacks. The ultrasound and microbubbles will be applied as soon as possible to patients presenting to the emergency department, after an EKG confirms that a heart attack is ongoing. Patients who provide emergent consent will be randomized to either conventional therapy for a heart attack, or conventional therapy and ultrasound with microbubbles. The ultrasound will be applied both before and after emergent heart catheterization, in order to break up the blood clots that are not only in the artery supplying the heart muscle, but also in the capillaries that are fed by this artery. Following the randomized treatment, patients will be followed for the development of any complications (recurrent heart attack, heart failure, or need for defibrillator placement) as well as by echo and cardiac MRI to determine how much heart muscle was salvaged by the treatment. A total of 250 patients will be enrolled and followed at two different sites. Randomization will be stratified at each study site. The initial site enrolling patients will be University of Sao Paulo Medical School. The other is Vrije Universiteit (VU) University Medical Center in Amsterdam.

Inclusion Criteria:

• Patients presenting to participating centers with chest pain and EKG evidence of an acute STEMI (two contiguous leads with >0.1 millivolt (mV) ST elevation or >0.1 ST depression in V2-V4) will be asked to participate. The inclusion criteria will be:

  1. Age ≥30 years.
  2. Eligible for emergent PCI/antithrombotic/antiplatelet therapy.
  3. Adequate apical and/or parasternal images by echocardiography.
  4. No contraindications or hypersensitivities to ultrasound contrast agents.

Exclusion Criteria:

1. Known or suspected hypersensitivity to ultrasound contrast agent used for the study.
2. Cardiogenic Shock
3. Life expectancy of less than two months or terminally ill.
4. Known severe cardiomyopathy.
5. Known bleeding diathesis or contraindication to glycoprotein 2b/3a inhibitors, anticoagulants, or aspirin
6. Known large right to left intracardiac shunts.