The 2013 STEMI Guideline: Data-driven Recommendations that Reduce Morbidity and Mortality

The 2012 ACCF/AHA Guideline for the Management of ST-Elevation Myocardial Infarction¹ is a major and comprehensive revision of the prior 2004 Guideline, incorporating both prior recent updates and the latest data on ST-segment elevation MI (STEMI). The guideline is the culmination of an extensive writing and review process involving two dozen writing group members, extensive collaboration with the 2011 ACCF/AHA/SCAI PCI writing group, and comprehensive review of over two dozen reviewers representing numerous major health care organizations. As noted in the guideline, STEMI comprises 25-40% of the 683,000 U.S. patients diagnosed with acute coronary syndrome (ACS) each year, and thus this guideline will apply to the management of several hundred thousand patients in the U.S. alone each year, in addition to the many other patients who are treated based on the recommendations of this guideline throughout North America and the world.

Primary percutaneous coronary intervention (PCI) remains the recommended method of reperfusion when it can be performed in a timely fashion by experienced operators. EMS transport directly to a PCI-capable hospital for primary PCI is the recommended triage strategy. The concept of “door-to-balloon time” or “door-to-needle time” is replaced with the concept of “first medical contact (FMC)-to-device time,” representing both the recognition that the key issue is triaging and treating the patient as soon as possible, not only “counting” when the patient enters an emergency room, and the fact that balloon dilation is often no longer the initial treatment in patients undergoing primary PCI. The systems goal of FMC-to-device time is 90 minutes or less. However, in cases in which patient transfer for PCI is the treatment strategy, the FMC-to-device system goal is now given as 120 minutes or less. The concept of door-in-door-out time is discussed in this guideline, and while a specific time frame is not set, it is emphasized that a door-in-door-out time of ≤30 minutes, which is associated with lower in-hospital mortality, is achieved in only 11% of patients. Factors to improve (shorten) treatment time for PCI-treated patients include use of prehospital ECG to diagnose STEMI, emergency physician activation of the PCI time, use of a central paging system to activate the PCI time, and the goal of the PCI team to arrive in the catheterization laboratory within 20 minutes of being paged.

When fibrinolytic therapy is used as the primary reperfusion strategy, the goal remains administration of such therapy within 30 minutes of hospital arrival. Importantly, while a great deal of research has been devoted to comparing primary PCI, facilitated PCI, and fibrinolytic strategies of patient management, the 2012 STEMI guideline again emphasizes that “the appropriate and timely use of some form of reperfusion therapy is likely more important than the choice of therapy.”

Guidelines for the performance of primary PCI were formulated in collaboration with the 2011 PCI Guideline writing group.² Primary PCI is indicated (class I) in patients with ischemic symptoms <12 hours, ischemic symptoms <12 hours and contraindications to fibrinolytic therapy (irrespective of the time delay from FMC), and patients with cardiogenic shock or acute severe heart failure (irrespective of the time delay from MI onset). Primary PCI is reasonable (class IIa) in patients with ongoing ischemia 12-24 hours after symptom onset. Based on the OAT trial, delayed PCI of a totally occluded infarct artery greater than 24 hours after STEMI should generally not be performed in most stable and asymptomatic patients. PCI of a noninfarct artery at the time of PCI in patients without hemodynamic compromise is now classified as “class III – harm” recommendation and should not be performed.

While the safety and potential benefits of drug-eluting stents (DES) in patients undergoing primary PCI are recognized, it is also emphasized that DES should not be implanted in patients with STEMI who are unable to tolerate or comply with a prolonged course of DAPT (class III – harm). The 2012 STEMI guideline now includes recommendations regarding not only clopidogrel but the newer P2Y12 inhibitors prasugrel (first addressed in a 2009 focused update³) and ticagrelor. A loading dose of one of these agents should be administered as early as possible or at the time of primary PCI. A 600 mg loading of clopidogrel is recommended when this agent is utilized in primary PCI, based on the more extensive, more reliable, and more rapid platelet inhibition achieved with this higher dose, as well as data from subgroup analysis of CURRENT-OASIS 7. Similar to what is stated in the 2011 PCI guidelines, there is the class IIa recommendation that it is reasonable to use 81 mg per day of aspirin in preference to higher maintenance doses after primary PCI.

“Rescue PCI” is given a class IIa recommendation and deemed “reasonable” in patients with evidence of failed reperfusion, or in those with reocclusion after fibrinolytic therapy.

The use of intra-aortic balloon pump (IABP) in patients with cardiogenic shock who do not quickly stabilize is given a class IIa recommendation (“can be useful”). Recognizing the availability of newer devices, these guidelines give the use of alternative LV assist devices for circulatory support in patients with refractory cardiogenic shock a class IIb recommendation (“may be considered”).

In patients who suffer out-of-hospital cardiac arrest caused by a STEMI-related arrhythmia, therapeutic hypothermia is recommended, as is immediate angiography and PCI when indicated.

The treatment of STEMI does not begin and end with primary PCI or fibrinolytic therapy. As with prior guidelines, the use of numerous pharmacotherapies that have been shown to decrease morbidity and mortality are discussed and emphasized, including beta-receptor blockers, ACEI inhibitors and ARBs, aldosterone antagonists, and statins. The initiation or continuation of high-intensity statins is recommended (class I) in all patients with STEMI and no contraindications to statin use. Posthospitalization care is similarly emphasized, including smoking cessation and cardiac rehabilitation.

In summary, this iteration of the STEMI guidelines provides a comprehensive yet concise and easily readable summary of the pre-, peri-, and post-hospital care of patients with STEMI, and provides the reader with clear and relevant guidelines that have been demonstrated to lead to decreased patient morbidity and mortality.