Reperfusion Therapy, Cardiac

Basics

Description

  • Cardiac reperfusion therapy is required on patients that present with ST-segment elevation myocardial infarction (STEMI)
  • Early percutaneous coronary intervention (PCI), but not fibrinolytics may be considered in those with unstable angina (UA)/non–ST-segment elevation MI (NSTEMI)
  • Fibrinolytic therapy:
    • Reduces morbidity and mortality in STEMI in cases where PCI is not available in <120 min
    • The earlier fibrinolytics are started, the more myocardium is salvaged
    • Goal of fibrinolytic therapy is a door-to-needle time of 30 min if PCI is not planned or delayed >120 min
  • PCI:
    • Balloon inflation, stent placement, and thrombus removal are possible options in the cath lab and result in overstretching of vessel wall and partial disruption of intima, media, and adventitia, resulting in enlargement of lumen and outer diameter of diseased vessel and restoration of epicardial coronary arterial flow
    • Goal of primary PCI is a door-to-balloon time of 90 min from first medical contact for STEMI or <120 min if at a non-PCI center
    • Stent placement decreases early and late loss in luminal diameter seen with percutaneous transluminal coronary angioplasty (PTCA)
    • PCI provides greater coronary patency and thrombolysis in MI flow than do fibrinolytics and decreased mortality and morbidity
    • Lower risk of bleeding than with fibrinolytics
    • PCI can be both diagnostic as well as therapeutic
    • PCI should be strongly considered within first 48 hr after NSTEMI in discussion with a cardiologist
  • Glycoprotein IIb/IIIa inhibitors:
    • Antiplatelet agents that bind to platelet receptor glycoprotein IIb/IIIa and inhibit platelet aggregation
    • Reduce mortality and reinfarction rate in patients in whom PCI is planned; reasonable to administer at time of primary PCI
    • Not indicated for patients with STEMI, unless also undergoing PCI
  • Unfractionated heparin (UFH) and low–molecular-weight heparin (LMWH):
    • Adjuncts in treatment with aspirin, clopidogrel, fibrinolytics, glycoprotein IIb/IIIa inhibitors, and PCI
    • Anticoagulant therapy with either UFH or LMWH is indicated in patients with either STEMI (with PCI or fibrinolytics) or UA/NSTEMI
  • Clopidogrel or prasugrel should be added to standard therapy regardless of whether PCI or reperfusion therapy is planned
  • Statin therapy reduces clinical events in patients with stable coronary artery disease. This may also extend to patients experiencing an acute ischemic coronary event
  • Post arrest patients may have therapeutic hypothermia initiated in the ED prior to PCI or during PCI

Etiology

  • STEMI is caused by occlusion of an epicardial coronary artery, usually as a result of a thrombotic event
  • UA/NSTEMI is caused by a partial occlusion of coronary artery, also due to thrombus

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